[0001] This invention relates to thermodynamic power generation.
[0002] Conventional thermodynamic power plants for converting thermal energy into mechanical
energy and/or electrical energy do not normally fully utilise the intrinsic heat energy
contained in the fuel or other medium or source, such as for example a solar energy
converter, from which the thermal energy is derived. It is accordingly an object of
the present invention to avoid or at least to minimize the above disadvantage.
[0003] According to one aspect of the invention a method of operating a closed cycle power
plant includes the steps of heating a working fluid to an operating temperature; utilizing
a flow of heated working fluid to drive a thermodynamic prime mover and thereby to
drive associated plant; utilizing low grade waste heat and/or low grade reject heat
and/or low grade random heat losses from the prime mover and/or associated plant and/or
other associated apparatus to heat a recovery fluid; and introducing heated recovery
fluid into heated working fluid flowing to the prime mover in a position upstream
of the prime mover.
[0004] The arrangement according to the invention facilitates the recuperation of low grade
heat losses and/or low grade waste heat and/or reject heat from the system and the
transfer of such heat back into the working cycle to improve the utilization of the
heat energy available in fuel or any other source or medium used for heating the working
fluid.
[0005] The recovery fluid may be utilized to cool the prime mover and/or associated plant
and/or other associated apparatus, whereby the recovery fluid absorbs low grade heat
from the system. Such absorbed low grade heat may be introduced into the heated working
fluid when the heated recovery fluid is introduced into the heated working fluid.
[0006] The recovery fluid may comprise a fluid which is physically and/or chemically different
from, but compatible with the working fluid. Thus, a mixture of two or more fluids
of different chemical composition may be used.
[0007] The recovery fluid may be derived or extracted wholly or partially from the working
fluid.
[0008] The recovery fluid may comprise a permanent gas or a condensable gas or vapour and
may be utilized in any suitable state or condition.
[0009] The recovery fluid may comprise the same fluid chemically as the working fluid. Thus,
a first portion of the working fluid may be heated to the operating temperature to
drive the prime mover; and a second portion of the working fluid may be heated by
the low grade waste heat and/or low grade reject heat and/or random heat losses.
[0010] The working fluid may comprise any suitable medium, such as freon or sulphur hexafluoride
or methanol and/or water, and may be utilized in any suitable chemical and/or physical
form or composition.
[0011] The heated working fluid may be at a higher temperature and pressure than the heated
recovery fluid and a flow of the heated working fluid may be utilized to aspirate
the heated recovery fluid into the heated working fluid.
[0012] At least part of the condensable gaseous and/or vaporous fluid passing from the prime
mover (and which will hereinafter simply be referred to as "condensable fluid") may
be condensed by compression produced by kinetic motion imparted to such condensable
fluid. The compressive condensation may or may not be effected in conjunction with
cooling of the condensable fluid.
[0013] Kinetic motion may be imparted to the condensable fluid passing from the prime mover
by drawing off at elevated pressure upstream of the prime mover part of the heated
working fluid and causing a flow of such drawn-off portion of the working fluid to
impart kinetic motion to such condensable fluid passing from the prime mover.
[0014] Additionally or alternatively, cooled recovery fluid may be introduced into the condensable
fluid passing from the prime mover, thereby to simultaneously cool and increase the
kinetic motion of condensable fluid passing from the prime mover.
[0015] At least part of the condensed fluid may be utilized to cool the prime mover.
[0016] In the process of cooling the prime mover, the condensed fluid will become heated
in a recuperative preheating stage and such pre-heated condensed fluid may comprise
working fluid which may be heated to the higher operating temperature for driving
the prime mover.
[0017] Alternatively or additionally, at least part of the condensed fluid may be cooled
by expansive evaporation.
[0018] Vacuum conditions for expansive evaporation may be created by a flow of heated working
fluid or a part thereof.
[0019] At least part of the condensable fluid and/or the cooled condensed fluid may constitute
or comprise the recovery fluid for recuperating low grade heat losses and/or reject
and/or waste heat and returning such recuperated heat to the system by introducing
the heated recovery fluid into the working fluid upstream of the prime mover.
[0020] It is also possible for part of the condensable fluid and/or the cooled condensed
fluid to constitute or comprise recovery fluid for recuperating very low grade heat
losses and/or reject and/or waste heat and returning such recuperated heat to the
system by introducing the resultant heated recovery fluid into the fluid system in
the cooling stage or at any other suitable point.
[0021] The prime mover and associated plant may comprise a turbo-electric unit.
[0022] A thermodynamic turbine may drive electric generating means, such as an alternator
adapted to feed into a load.
[0023] The load may comprise an electric motor and/or an electric and/or other energy accumulator
and/or any suitable power conversion means.
[0024] The recovery fluid may be utilized to cool the electric generator and/or the electric
motor and/or the load and/or other apparatus or parts in which thermal losses occur,
and/or in which waste or reject heat is available, whereby the recovery fluid absorbs
at least part of the heat losses and/or the reject and/or waste heat before the recovery
fluid is introduced into the heated working fluid upstream of the prime mover and/or
into the fluid system at any other suitable point, such as in the cooling stage.
[0025] The heated recovery fluid may advantageously be compressed prior to the introduction
into the heated working fluid. The heat generated by mechanical work performed during
compression may also be recuperated by the recovery fluid.
[0026] The working fluid may be heated to the operating temperature by any suitable heating
means, such as fuel burning means and/or electrical and/or nuclear heating means and/or
solar energy absorber means. Solar and/or nuclear heating may advantageously be utilized
in the system.
[0027] Heating of the working fluid to the operating temperature may be effected by controlled
external combustion means whereby atmospheric pollution may be minimized.
[0028] The operating speed and/or the power output of the prime mover may be controlled
by regulating the magnitude of the load applied to the prime mover and/or by regulating
the heat input to the working fluid and/or by introducing condensed fluid into heated
gaseous or vaporous working fluid upstream of the prime mover.
[0029] Part of the condensable fluid passing from the prime mover and/or at least part of
the condensed fluid may be introduced into the heated working fluid in a position
upstream of the prime mover, thereby to control the operating temperature and/or flow
conditions and/or power output of the prime mover.
[0030] In a preferred embodiment, a load applied to electric generating means driven by
the prime mover is regulated to control the operating speed of the prime mover. Excess
power may be absorbed in an energy storage system.
[0031] The operating speed and the power output of the prime mover may be controlled to
substantially constant values. The combustion rate of fuel burning heating means may
thus be maintained substantially constant over extended periods whereby optimal operation
of the power plant may be achieved.
[0032] The load applied to electrical generating means driven by the prime mover and/or
the heat input to the working fluid may be regulated in accordance with the speed
and/or electrical output of the generating means.
[0033] According to another aspect of the invention a closed cycle power plant includes
heating means; a thermodynamic prime mover; a cooling chamber in and/or round the
prime mover; electric generating means drivingly coupled to the prime mover; a cooling
chamber in and/or round the generating means; condenser means; cooling means; a first
fluid line or circuit extending from an outlet from the cooling chamber of the prime
mover through the heating means and communicating with a high pressure inlet into
the prime mover; a second fluid line or circuit extending from a low pressure outlet
from the prime mover through the condenser means and communicating with an inlet into
the cooling chamber of the prime mover; a third fluid line or circuit branching off
from the second fluid line or circuit downstream of the condenser means and communicating
with the cooling means; and a fourth fluid line or circuit extending from the cooling
means to the cooling chamber of the generating means and from there to the first fluid
line or circuit in a position between the heating means and the prime mover; and means
operative to introduce fluid from the fourth fluid line or circuit into the first
fluid line or circuit.
[0034] Aspirator means may be provided to aspirate fluid from the fourth fluid line or circuit
into the first fluid line or circuit.
[0035] A return line or circuit branching off from the second fluid line or circuit upstream
of the condenser means may communicate with the first fluid line or circuit between
the heating means and the prime mover, to permit condensable fluid passing from the
prime mover to be introduced directly into the first fluid line or circuit upstream
of the prime mover.
[0036] A branch fluid line or circuit may communicate with the second fluid line or circuit
in a position between the condenser means and the cooling chamber of the prime mover
and may be adapted to communicate with the return line to permit condensed fluid to
be introduced directly into the first fluid line ahead of the prime mover.
[0037] A further aspirator may be provided in the first fluid line or circuit between the
heating means and the prime mover, the further aspirator being operative under the
influence of fluid flow along the first fluid line or circuit to aspirate condensable
fluid and/or condensed fluid into the first fluid line or circuit from the return
line or circuit..
[0038] The thermodynamic prime mover may comprise a thermodynamic turbine.
[0039] The electric generating means may comprise an A.C. alternator.
[0040] The alternator may have a variable excitation system or a constant excitation system,
such as derived from a permanent magnetic field.
[0041] The electric generating means may include tubular conductors in its magnetic windings,
the tubular conductors comprising or forming part of the cooling chamber of the generating
means and being connected in fluid circuit with the fourth fluid line or circuit.
The tubular conductors may constitute one or more internal cooling compartments.
[0042] A compressor may be connected in the fourth fluid line or circuit between the generating
means and the aspirator.
[0043] At least part of the cooling chamber of the generating means which is connected in
the fourth fluid line or circuit, may comprise a cooling compartment which is located
about the generating means and which communicates with the low pressure side of the
compressor, whereby the compressor is adapted to create a low pressure atmosphere
about the generating means.
[0044] The cooling compartment located about the generating means may constitute an external
cooling compartment which may be in communication with the internal cooling compartment/s
constituted by the tubular conductors.
[0045] The aspirator may comprise a tubular body connected in the first fluid line or circuit;
and an inlet into the tubular body communicating with the fourth fluid line or circuit,
fluid flow along the first fluid line or circuit through the tubular body being operative
to aspirate fluid from the fourth fluid line or circuit into the first fluid line
or circuit through the inlet.
[0046] The cooling means may comprise expansive evaporation cooling means.
[0047] An aspirator in the first fluid line or circuit may be operative under the infuence
of fluid flow along the first fluid line or circuit to withdraw fluid from the expansive
evaporation cooling means, thereby to create low pressure conditions in the cooling
means.
[0048] Alternatively or additionally, the expansive evaporation cooling means may be connected
to the low pressure side of the compressor, whereby the compressor is adapted to create
low pressure conditions to a greater or lesser degree in the cooling means.
[0049] A single or multi-stage cooling means may be provided.
[0050] The condenser means may comprise dynamic compressive condenser means.
[0051] The compressive condenser means may be operative to condense condensable gaseous
and/or vaporous fluid passing from the prime mover (i.e. "condensable exhaust fluid")
by compression produced by kinetic motion imparted to the condensable fluid.
[0052] The compressive condenser means may comprise a tubular body; a first inlet communicating
with the low pressure outlet from the prime mover via portion of the second fluid
line; and a second inlet communicating via a fifth fluid line with the first fluid
line in a position between the heating means and the prime mover, fluid flow through
the second inlet being operative to aspirate condensable fluid passing from the prime
mover through the first inlet into the tubular body and to compress such condensable
fluid by converting its directional kinetic motion into a pressurised condition.
[0053] The tubular body may include a third inlet communicating with the cooling means,
cooled fluid introduced under pressure through the third inlet being operative to
cool and further to compress by kinetic motion the condensable fluid passing from
the prime mover.
[0054] Condensed fluid passing via the second fluid line from the condenser to the cooling
chamber of the prime mover, is heated in the cooling chamber which acts as a pre
-heating stage for fluid passing from the cooling chamber of the prime mover to the
heating means along the first fluid line.
[0055] The heating means may comprise fuel burning means. The heating means may include
a main heating stage in which working fluid flowing along the first fluid line is
subjected to heating by the combustion of fuel.
[0056] The heating means may also include a pre-heating stage in which working fluid flowing
along the first fluid line is subjected to heating by hot waste gases of combustion.
[0057] The heating means may also include superheating means.
[0058] Alternatively or additionally to fuel burning means, the heating means may comprise
electric and/or solar and/or nuclear heating means.
[0059] The prime mover and the electric generating means may comprise a turbo-electric unit
operating at constant or variable power output.
[0060] The power plant may include a load which is electrically connected to the output
of the electric generating means.
[0061] The load may comprise one or more components and may include and/or constitute an
energy storage system.
[0062] The load may comprise an electric motor and/or energy accumulator means and/or power
conversion means.
[0063] The energy accumulator means may comprise a chemical energy accumulator, such as
an electric storage battery connected to the rectified output of the electric generating
means, and/or a heat energy accumulator, such as a mass of glauber salts or other
suitable fusible material provided with an electric heater connected to the output
of the electric generating means.
[0064] Control means may be provided for regulating the operating speed and/or the power
output of the loaded prime mover. The operating speed and/or power output of the loaded
prime mover may be regulated to substantially constant values.
[0065] The control means may be adapted to vary the heat input to working fluid flowing
along the first fluid line. Where fuel burning heating means is used, the heat input
to the working fluid may be varied by varying the fuel supply to the heating means.
The heat input may be varied in accordance with the output of the electric generating
means and/or energy accumulator means. Variation of the heat input may involve a certain
reaction time delay in the control of the operating speed of the prime mover.
[0066] Alternatively or additionally, the control means may be adapted to regulate rapidly
the operating speed of the prime mover by varying the load on the prime mover. The
load on the prime mover may be varied by varying the load connected to the electric
generating means. The load on the generating means may be varied in accordance with
the output of the generating means.
[0067] The load applied to the prime mover may thus form part of the prime mover speed control
system.
[0068] The total load applied directly or indirectly to the prime mover may comprise a plurality
of load components which may be combined and/or varied in any suitable manner to establish
a required controlled operating condition in order to achieve optimal utilization
of the prime mover and/or associated plant and/or apparatus.
[0069] Thus, a combination of load components, which individually may be of constant or
variable magnitude, may be suitably controlled to present a substantially constant
load to the prime mover. The prime mover may run at substantially constant rotational
speed and simultaneously at substantially constant power output despite variations
in individual load components. Accordingly, the fuel consumption and therefore the
combustion rate of fuel burning heating means may be maintained at a substantally
constant value corresponding to optimal utilization of heat energy available in fuel
as well as of the power plant and the connected load components as a complete system.
[0070] The power plant may further include a sixth fluid line or circuit extending from
the cooling means to a cooling system for the electric load and/or for control means
associated with the electrical generating means and/or the load, the sixth fluid circuit
or line extending from such cooling system to any suitable point in the fluid system
for the reintroduction into the system of heat recuperated by recovery fluid flowing
in the sixth fluid circuit or line in the cooling system.
[0071] Normally, the heat recuperated by the sixth fluid line or circuit will be of a very
low grade with the result that the heated recovery fluid is likely to include a liquid
component. It is therefore preferable for the sixth fluid line or circuit to return
to the cooling means.
[0072] It will be appreciated that with the arrangement according to the invention, a maximum
recuperation of heat losses and/or of reject heat and/or waste
[0073] heat may be effected and the recuperated heat returned to the system to obtain maximum
utilisation of the intrinsic heat energy available in fuel or other medium or source
from which thermal energy is derived.
[0074] The invention also includes within its scope an electrical machine including tubular
electric conductors adapted to be connected to a cooling fluid circuit.
[0075] The cooling fluid circuit may form part of a thermo-dynamic fluid circuit of a power
plant.
[0076] For a clear understanding of the invention, preferred embodiments will now be described
purely by way of example with reference to the accompanying drawings in which:-
Figure 1 is a diagrammatic circuit diagram of a constant power output, closed cycle,
thermodynamic turbo-electric power plant according to the invention.
Figure 2 is a sectional view of an aspirator in the fluid circuit of the power plant
of figure 1.
Figure 3 is a diagrammatic sectional view of the dynamic compressive condenser means
of the power plant of figure 1.
Figure 4 is a diagrammatic sectional representation of an A.C. alternator with tubular
stator windings, of the power plant of figure 1.
Figure 5 is a diagrammatic representation of the stator windings of the alternator
of figure 4.
Figure 6 is a diagrammatic circuit diagram of a variable power output, closed cycle,
thermodynamic, turbo-electric power plant according to the invention.
[0077] Referring first to figures 1 to 5, the power plant comprises heating means A; thermodynamic
turbine B which is located in a cooling chamber; electric alternator C which is located
in an external cooling compartment, is provided with an internal cooling compartment
and is drivingly coupled to turbine B; compresser D which is also drivingly coupled
to turbine B; compressive condenser means E; expansive evaporation cooling means F;
and a load G for the alternator C.
[0078] The power plant also includes a plurality of fluid lines or circuits for conveying
working fluid and heat recovery fluid as will be described in greater detail below.
[0079] First fluid line 1 comprising portions la, Ib, 1c and ld, extends from outlet 2 from
the cooling chamber of turbine B, through pump 33, through heating means A, through
moisture trapping vessel 50, through aspirators 13 and 17, and communicates with a
high pressure inlet 3 into turbine B. A second fluid line 4 comprising portions 4a,
4b and 4c, extends from low pressure outlet 5 from prime mover B through combining
vessel 51, through condenser E and communicates with inlet 6 into the cooling chamber
of turbine B. Third fluid line 7 branches off from second fluid line 4 downstream
of condenser E at 8 and communicates with cooling means F through a reservoir 9 for
working fluid, such as freon. Fourth fluid line 10 comprising portions 10a, 10b ...lOh,
extends from the bottom of the chamber 52 of cooling means F, through pump 32, through
the tubular stator windings 12 and the external cooling compartment 11 of alternator
C (figures 4 and 5), through evaporator vessel 53, liquid trap 54, compressor D, the
upper region 52a of the chamber 52 of cooling means F, and through aspirator 13 (figure
2) to first fluid line 1. Aspirator 13 is located in a position between heating means
A and turbine B and is operative to aspirate fluid from the fourth fluid line 10 into
the first fluid line 1.
[0080] Heating means A comprises annular boiler chamber 26 in which liquid working fluid
can be heated by fuel burner 27. Heating means A further includes in its flue a heat
exchanger tube 59 which is connected in first fluid line 1 and acts as a preheating
stage for liquid in boiler 26. Preheated liquid flowing from preheater tube 59 enters
boiler chamber 26 tangentially towards its lower end at 60, the tangential entry into
boiler chamber 26 serving to enhance circulation and heating of the working fluid
in boiler chamber 26.
[0081] Heating means A further includes superheating heat exchanger tube 28 which communicates
with the upper end of boiler chamber 26 at diametrically opposite zones 6la, 61b.
Tube 28 acts as a superheater and conveys heated working fluid in gaseous form from
the upper end of boiler chamber 26 and down the bore of annular boiler chamber 26,
thereby to cause superheating of the working fluid by heat from fuel burner 27. It
will be appreciated that preheater 59, boiler chamber 26 and superheater 28 forms
part of the first fluid circuit 1.
[0082] As illustrated diagrammatically in figure 4, the stator windings 12 of alternator
C comprise hollow electrical conductors of tubular configuration which constitute
an internal cooling compartment or compartments within the alternator C, such cooling
compartment being in communication with the external cooling compartment 11 surrounding
alternator C. Both the internal and external cooling compartments are connected in
circuit with the fourth fluid line 10 between portions 10c and lOd.
[0083] Where the stator windings 12 of alternator C comprise star connected, 3-phase windings,
the fourth fluid line 10 may be connected at lOx to the interconnected star-point
of the tubular windings as shown in figure 5, outer ends 12a of the windings opening
directly into the interior of the external cooling compartment 11 which has an outlet
lla communicating with the fourth fluid line at 10y.
[0084] The external cooling compartment 11 of alternator C communicates with the evaporator
vessel 53 which communicates with an intermediate pressure side of compresser D which,
in turn, is located in the fourth fluid line 10 between alternator C and aspirator
13, so that during operation a low pressure atmosphere is created in the upper region
53a of evaporator vessel 53 to evaporate heated cooling fluid passing from alternator
C and to draw the resultant vapour through compressor D and through the upper region
52a of the chamber 52 of evaporator cooling means F which is in free communication
with the suction inlet 15 of aspirator 13.
[0085] As shown in figure 2, aspirator 13 comprises tubular body 14 which is connected in
the first fluid line portion ld. Tubular body 14 is provided with a constriction 14a
intermediate its ends and a constricted high pressure inlet 14b. High pressure fluid
flowing along the first fluid line 1 passes through tubular body 14 at accelerated
velocity. Aspirator 13 is also provided with a suction inlet 15 which is connected
to the fourth fluid line portion 10h. A flow of high pressure working fluid through
tubular body 14- aspirates recovery fluid which is at lower pressure, from the fourth
fluid line 10 into the first fluid line 1 and into the working fluid flowing along
the first fluid line 1. Dynamic compressive condenser E is operative to condense condensable
gaseous and/or vaporous fluid passing from the low pressure outlet 5 of turbine B
and through combining vessel 51 along second fluid line 4, by compression produced
by kinetic motion imparted to the condensable fluid and by accompanying cooling.
[0086] The condenser E used in the plant of figure 1 is shown in full lines in figure 3.
The additional parts shown in chain dotted lines may be added for the plant of figure
6.
[0087] As shown in figure 3, condensor E comprises a tubular body 20 which is adapted to
be connected in the second fluid line 4 and which includes a constricted zone 20a
intermediate its ends. Body 20 is provided with a first axially directed inlet nozzle
21a adapted to communicate with the combining vessel 51 in line with the low pressure
outlet 5 from turbine B and has an outlet 21b adapted to communicate with branch point
8. Condensor E also includes second axially directed inlet 22 located within first
inlet nozzle 21a and adapted to communicate via a fifth- fluid line 23 with the first
fluid line 1 at 24 through liquid trap 50 in a position between the heating means
A and aspirators 13, 17. Condenser E further includes a third inlet 25 into the zone
around the first inlet 21a upstream of the constricted zone 20a of body 20. Third
inlet 25 is adapted to communicate with the lower portion 52b of the chamber 52 of
cooling stage F via portions 10a and 10a of the fourth fluid line 10 and connecting
fluid line 62a.
[0088] High pressure fluid flow into body 20 through second inlet 22 aspirates condensable
fluid passing from the low pressure outlet 5 of turbine B, through the combining vessel
50 and into tubular body 20 through its first inlet end 2la. Accelerated kinetic motion
is imparted to the condensable fluid in constricted zone 20a of body 20 and the directional
kinetic motion of the condensable fluid is converted into a pressurised condition
in the enlarged zone 20b beyond constricted zone 20a, thereby to compress and condense
the condensable fluid.
[0089] Cooled fluid from cooling means F is introduced under pressure by pump 32 along the
portions 10a, 10a of the fourth fluid line 10 and along connecting line 62a into the
body 20 in the zone around first inlet 21a through the third inlet 25, thereby to
cool and further to compress by kinetic motion the condensable fluid passing from
the outlet 5 of turbine B.
[0090] As shown in figure 3, tubular body 20 is provided with an outlet 67 in the constricted
zone 20a and with an enclosure 68 around the constricted zone 20a and outlet 67. Liquid
passing through constricted zone 20a, particularly during starting up of the plant,
can drain through outlet 67 into enclosure 68 and from there through outlet 69 which
is provided with a flap-type non-return valve 70 adapted to permit the outflow of
liquid from enclosure 68 but does not permit an inflow of fluid into enclosure 68.
[0091] In operation of the power plant, a first portion of condensed fluid which passes
from condenser E, constitutes a working fluid which flows from branch point 8 along
the second fluid line portion 4c into the cooling chamber of turbine B which acts
as a preheating stage which imparts heat to the working fluid during the process of
the latter acting to cool the turbine B.
[0092] In order to maintain a predetermined liquid level in boiler 26, preheated working
fluid is pumped by speed controlled pump 33 from the cooling chamber of turbine -B
along the first fluid line portions la and lb to the pre-heating stage 59 of heating
means A which is connected in the first fluid line 1 and in which the working fluid
is heated further in the flue of the heating means A by means of hot waste gases of
combustion from fuel burner 27. Thereafter the working fluid is heated to a required
operating temperature by fuel burner 27 in boiler 26 and superheater 28 which is also
connected in the first fluid line l. The working fluid is heated to its operating
temperature by the combustion in burner 27 of any suitable fuel supplied to it from
fuel reservoir 29.
[0093] The heated working fluid flows from superheater 28 along the first fluid line portion
lc, through moisture trapping vessel 50 and through aspirators 13 and 17 into turbine
B through its high pressure inlet 3 to rotatably drive the turbine in conventional
manner.
[0094] Condensable fluid in gaseous and/or vaporous form flows from turbine B through its
low pressure outlet 5, through combining vessel 51 and along the second fluid line
portion 4b to compressive condenser E where it is condensed to restart the operating
cycle for driving turbine B.
[0095] Combining vessel 51 is connected by return line 55 through control valve 56 to the
suction inlet of a further aspirator 17 which is similar to aspirator 13 and which
is connected in parallel with aspirator 13 in the first fluid line portion ld in a
position between moisture trapping vessel 50 and turbine B. Low pressure conditions
are created in combining vessel 51 by further aspirator 17 which is operative under
the influence of high pressure fluid flowing along the first fluid line 1 to aspirate
part of the condensable exhaust fluid passing from turbine B through low pressure
outlet 5, from combining vessel 51, along fluid return line 55, through control valve
56 and directly back into the first fluid line 1 for return to turbine B.
[0096] Branch line 57 connects the portion 4c of second fluid line 4 through control valve
58 to the interior of combining vessel 51. The low pressure conditions created in
combining vessel 51 causes small quantities of condensed liquid to be drawn from second
fluid line portion 4c into combining vessel 51 from where it is aspirated together
with part of the condensable turbine exhaust fluid along return line 55 by aspirator
17 and into high temperature, superheated working fluid flowing to turbine B along
fluid line 1. The condensed liquid evaporates in first fluid line 1 and increases
the fluid volume flow into turbine B even if the temperature of the working fluid
is reduced slightly. The rate of flow of condensed fluid into combining vessel 51
may be controlled by means of valve 58 and the rate of aspiration of condensable turbine
exhaust fluid and/or condensed fluid from condenser E into fluid line 1 through aspirator
17 may be controlled by means of valve 56.
[0097] Turbine B is mechanically coupled to compressor D and alternator C so that upon rotation
of turbine B, it rotatably drives compressor D and alternator C.
[0098] A second portion of condensed fluid which passes from condenser E, constitutes a
cooling or recovery fluid and flows from branch point 8, to fluid reservoir 9 and
from there along third fluid line 7 into the lower region 52b of the chamber 52 of
cooling means F.
[0099] A flow of high pressure working fluid along the first fluid line 1 through aspirator
13, causes aspiration of fluid along fourth fluid line portion 10h from the upper
region 52a of the chamber 52 of cooling means F, thereby to create low pressure conditions
in chamber 52 and cause evaporative cooling of the fluid.
[0100] Part of the cooled fluid flows under pressure of pump 32 from the lower region of
cooling means F, along fourth fluid line portions 10a, 10b and along connecting line
62a, to the inlet 25 of condenser E for the cooling and compressive condensation of
condensable exhaust fluid passing from turbine B , as described above.
[0101] Another part of the cooled fluid flows along the fourth fluid line portions 10a,
10b and lOc, through the hollow stator windings 12 and the external cooling compartment
11 of alternator C, through evaporator vessel 53, along fourth fluid line portion
10e, through liquid separator 54, along fourth fluid line portion 10f to compressor
D and from there passes freely through the upper region 52a of cooling means F, along
fourth fluid line portion 10h to aspirator 13.
[0102] During the process of cooling alternator C, the recovery fluid absorbs low grade
heat losses developed in the alternator and the recovered heat content causes evaporation
of recovery fluid in evaporator vessel 53.
[0103] Low pressure conditions are created in the upper region 53a of evaporator vessel
53 by suction along fourth fluid line portions 10e, 10f, lOg and 10h from the. aspirator
13 which is connected in circuit with cooling means E and compressor D. This suction
causes aspiration into the first working fluid line 1, of vapour which is produced
in the upper region 53a of evaporator vessel 53 by the heat content of recovery fluid
contained in the lower region 53a of evaporator vessel 53. The recovery fluid also
absorbs low grade heat generated by mechanical work performed during compression in
compressor D. The low grade heat absorbed by the recovery fluid is introduced into
the heated working fluid flowing along the first fluid line 1 by the introduction
of the recovery fluid into the first fluid line 1 through aspirator 13.
[0104] Other low grade waste heat and/or low grade reject heat and/or random heat losses
in the power plant or associated apparatus may be recuperated by recovery fluid and
introduced with the recovery fluid from fourth fluid line 10 through aspirator 13
into heated working fluid flowing along the first fluid line 1 as described above.
[0105] Thus, low grade heat loss in the bearings of turbine B and/or compressor D and/or
alternator C may be recovered by providing heat exchanger 63 having a coil 63a which
is connected in a closed oil circulating circuit 64. Heated oil from bearing housings
37 is pumped by pump 65 along fluid line portions 64a, 64b of the oil circuit 64,
through heat exchanger coil 63a, where the oil is cooled by cool recovery fluid. The
cooled oil then flows along fluid line portion 64c to header tank 66 and from there
through oil filter 71, along fluid line portions 64d and back to bearing housings
37. Cool recovery fluid for cooling the oil in heat exchanger 63 flows from point
46 in the fourth fluid line 10, along portion 47a of a sixth fluid line 47 which will
be described below, along branch line portion 72a and through heat exchanger 63 where
the recovery fluid absorbs low grade heat. Heated recovery fluid flows along branch
line portion 72b into the lower region 53a of evaporator vessel 53 which is connected
in fourth fluid line 10.
[0106] Heated recovery fluid from heat exchanger 63 entering evaporator vessel 53 adds recovered
heat to recovery fluid in evaporator vessel 53. Heated recovery fluid which is now
in vaporous form, is passed from evaporator vessel 53 along fourth fluid line portion
10e, through non-return valve 73, through liquid separator 54, through compressor
D and freely through the upper region 52a of chamber 52 of cooling means F and along
fourth fluid line portion 10h for introduction into the first fluid line through aspirator
13.
[0107] As shown in figure 1, alternator C is electrically connected through rectifier 39
to load G which comprises D.C. motor 40 and storage battery 41 which are connected
in series with each other. The series arrangement of motor 40 and battery 41 are connected
through gate means 42 to motor torque control means 43.
[0108] Speed control means 44 is provided for regulating the electrical output of alternator
C by controlled variation of the magnitude of the electrical load imposed on alternator
C, thereby to regulate rapidly to a constant value the running speed of the turbo-electric
unit. The electrical load imposed on the alternator C may be varied by varying the
input power to battery 41 which is also connected to motor 40. It will be appreciated
that the load G forms part of the turbine speed control system.
[0109] Additionally or alternatively, the speed of the turbo-electric unit may be regulated
with a certain reaction time delay by arranging for control means 44 also to regulate
the operation of fuel control valve 45 of heating means A in accordance with the state
of charge of storage battery 41, thereby to regulate the supply of fuel from reservoir
29 to burner 27 and thus the heat input to the working fluid in heating means A by
burner 27.
[0110] Turbine B may thus be controlled to run at substantially constant rotational speed
and simultaneously at substantially constant power output despite variations in the
load on the storage battery 41. The fuel consumption and therefore the combustion
rate of fuel can thus be maintained at a substantially constant value corresponding
to an optimal utilization of the power plant and the connected storage load as a complete
system.
[0111] Low grade waste heat and/or low grade reject heat and/or random heat losses from
rectifier 39, motor 40, battery 41, gate means 42, motor torque control means 43 and
speed control means 44 may be recuperated and reintroduced into the system by passing
recovery fluid from the fourth fluid line 10 at point 46 in fluid line portion lOc,
along a sixth fluid circuit 47 and through the cooling units 39a, 40a, 41a, 42a, 43a
and 44a respectively for these components which constitute a cooling system H. Normally,
the heat recuperated in the cooling system H is of a very low grade with the result
that the heated recovery fluid is likely to include a liquid component. In order to
avoid or minimize erosion by liquid in the cooling system of alternator C and in compressor
D, the heated recovery fluid from cooling system H is returned along sixth fluid line
portion 47b into the upper region 53a of the evaporator 53 where separation of vaporous
and liquid components of the recovery fluid takes place. The vaporous component is
then extracted along fourth fluid line portion 10e for introduction through liquid
separator 54, compressor D, the upper region of the chamber 52 of cooling means F,
along fourth fluid line portion 10h and through aspirator 13 into the first fluid
line 1. The liquid component discharged into evaporator vessel 53 is subjected to
an overall heat extraction effect under reduced pressure conditions.
[0112] Many variations in detail of the power plant of figure 1 is possible without departing
from the scope of the appended claims. Thus, under certain circumstances compressor
D may be omitted, or may be replaced by an expander or by additional aspirator units
similar to items 13 and 17.
[0113] A fuel pre-heater 74 may be provided in heating means A in the fuel supply line 75
from fuel reservoir 29 to fuel burner 27. As a safety feature, a normally open, electrically
operable, emergency fuel shut-off valve 76a may be provided in fuel supply line 75.
[0114] For rapid starting of the power plant, an outer annular boiler chamber 77 with an
electric immersion heating element 78, may be provided round boiler chamber 26 of
heating means A. A normally open starting switch 79 in an electric supply circuit
to immersion heating element 78 is closed to energise heating element 78 and cause
evaporation in chamber
' 77 of liquid introduced from evaporator vessel 53 along fluid line 88. Closure of
starting switch 79 also starts pump 32 in fourth fluid line 10 to fill at least partially
the evaporator vessel 53, start-up boiler chamber 77 and also main boiler chamber
26 along fluid line portion 62a, through condenser E, along fluid line portion 4c,
through the cooling chamber of turbine B and along fluid line. portions la and lb.
Closure of starting switch 79 also causes ignition of fuel burner 27 to heat working
fluid in main boiler chamber 26.
[0115] A build up of vapour pressure in start-up boiler chamber 77 when the liquid therein
is heated by heating element 78, causes closure of non-return valve 89 in the bottom
of boiler chamber 77 and of non-return valve 73 in fourth fluid line portion 10e,
thereby to supply vapour under pressure along fluid line 80, through liquid separator
54 and along fourth fluid line portion 10f to compressor D which acts as an expander,
thereby to rotate compressor D. Rotation of compressor D causes rotation of turbine
B to draw heated working fluid for driving turbine B, from heating means A along first
fluid line portions lc and ld and into the high pressure input 3 of turbine B.
[0116] Moisture trapping vessel 50 in first fluid line 1 also serves as an emergency pressure
equalising chamber, as well as an emergency condensing chamber in the event of a loss
of full load. During emergency run-away conditions, fuel shut-off valve 76a closes
the fuel supply; normally closed valve 76b opens to cool the superheated working fluid
with cooling liquid from cooling means F flowing along fourth fluid line portions
10a, 10a and branch line portions 62a, 62b; and normally closed valve 76c opens to
discharge the emergency condensate and cooling liquid. The high and low pressure sides
of turbine B are accordingly equalised and the residual heat is dispensed in the cooling
system. Under normal operating conditions the collected moisture level cannot rise
above the opening in vessel 50 at point 24 which communicates with the fifth fluid
line 23.
[0117] As described above, combining vessel 51 may be utilised in conjunction with valve
58 in branch line 57 to adjust the turbine operating temperature and flow conditions,
by introducing small quantities of liquid through aspirator 17 into first fluid line
1 to adjust the degree of superheat or dryness of the working gas or vapour. This
also provides means for improving the efficiency of energy conversion by introducing
flash vapour droplets into the superheated fluid in first fluid line 1 via the aspirator
17 to increase the volume flow through the turbine. Another way of looking at this
procedure is that it represents a method of adding low grade heat at the highest possible
temperature, namely at superheat temperature and not at boiling temperature.
[0118] Heater exchanger 63 in the oil circulation circuit 64 may comprise a counter flow
heat exchanger. This heat exchanger has the advantage that it completely isolates
the oil from the recovery fluid to avoid oil contamination of the latter.
[0119] The header tank 66 in the oil circulation circuit 64 accumulates a small reserve
of oil so that short term failure of oil pump 65 can be tolerated without damage to
the bearings.
[0120] Evaporator vessel 53 also acts as a liquid trap and provides low grade heat recovery
via fourth fluid line portions 10e and 10f and compressor D, the vapour thereby doing
positive work on the way to the main evaporator constituted by chamber 52 of cooling
means F.
[0121] During normal operation valve 82 is opened slightly to recover heat along fluid line
80 from outer boiler chamber 77 which then serves as a shielding jacket round heating
means A.
[0122] Fuel control valve 45 of fuel burner 27 may be fitted with a small servo-motor 83
to allow automatic adjustment of control valve 45 under the influence of speed control
means 44 of alternator C.
[0123] Pump 33 in first fluid line 10 may also be provided with a servo-motor control 84
which is operated under the influence of fluid level senser 84a in boiler 26.
[0124] Control valve 85 in fourth fluid line portion 10b may likewise be controlled by a
servo-motor 86 to control the liquid level in outer start-up boiler chamber 77 and
in evaporator vessel 53 as dictated by float valve 87. The liquid level in evaporator
vessel 53 and in boiler chamber 77 may be controlled by the opening and closing of
control valve 85 which regulates the flow of cool condensed fluid along fourth fluid
line portions 10b, 10c and 10d to evaporator vessel 53 and along equalising fluid
line 88 to boiler chamber 77.
[0125] Liquid separator 54 may be arranged for accumulated liquid therein to be bled off
continuously through small orifice 87 into evaporator cooling means F. Should the
level of liquid in evaporator vessel 53 rise unduly and liquid overflow into liquid
separator 54, the normally closed magnetic valve 87a will open fully, thereby rapidly
to drain the separator 54 through valve 87a into cooling means F.
[0126] Equalising fluid line 34 may be connected across the suction inlets to aspirators
13 and 17.
[0127] Referring now to figure 6, the variable power output plant illustrated in this figure
is in many respects similar to the constant power output plant of figure 1 and like
parts are indicated by like reference numerals in figures 1 and 6.
[0128] The plant of figure 6 provides a system for utilising a dual component working fluid.
This may have certain advantages. For example, the problem of chemical dissociation
of the freons at elevated temepratures may be overcome or at least minimized by utilising
a fluid component of relatively high density which is suitable for use at high temeperatures,
which is combined or mixed with a more volatile fluid component of less density and
a lower evaporation temperature. It may also be advantageous to separate partially
or wholly the liquid phase components after condensation. For this purpose, the separating
compressive condenser means El of figure 6 may be used.
[0129] The condenser means El of figure 6 is identical to the condenser means E of figure
1 as illustrated in full lines in figure 3 with the addition of the parts shown in
chain dotted lines which may replace working fluid reservoir of figure 1. The additional
parts comprise a pair of axially extending spiral shaped deflection plates 114 in
the enlarged zone 20b to impart a rotational movement to condensed fluid emerging
from constricted zone 20a of body 20. The rotational speed of the condensed fluid
is increased by the introduction of high pressure vapour or gas through tube 115 into
annular chamber 116 round body 20. A series of circumferentially spaced apertures
117 are provided through the wall of body 20 within chamber 116 and are disposed as
nearly as possible tangentially with respect to the wall of body 20 so that generally
tangentially directed high pressure jets of vapour or gas are injected into the enlarged
zone 20b of body 20.
[0130] The rotation of the condensed fluid separates centrifically the two constituent components
(which differ in specific gravity) into a less dense, more volatile component and
a more dense, less volatile component. The more volatile component passes from body
20 through central outlet duct 21c which communicates via third fluid line 7 with
the lower region 112b of the first stage compartment 112 of two stage expansive evaporation
cooling means Fl. The more dense, less volatile component passes from body 20 through
the outer annular zone 21d of outlet 21b, which is located round central outlet duct
21c. Annular outlet zone 2ld communicates via second fluid line portion 4c with inlet
6 into the cooling chamber of turbine B. The more dense, less volatile component of
the working fluid passes through the cooling chamber of turbine B, through the cooling
chamber outlet 2 and is pumped along first fluid line 1 to heating means Al by pump
33.
[0131] Part of the more dense, less volatile component of the working fluid is also contained
in the second stage compartment 113 of cooling means Fl and is circulated through
fourth fluid line 10 and any other heat recovery circuits such as 120 and 121, as
recovery fluid.
[0132] Instead of being fuel burning means, the heating means Al of figure 6 comprise electric
boiler 90 which acts as a preheating stage and electric superheater 91 adapted to
heat the more dense, less volatile component of the working fluid flowing along the
first fluid circuit 1 to a required operating temperature and pressure.
[0133] Vessel 107 serves as a liquid trap in first fluid circuit 1 and also as an emergency
condensor during overspeed conditions during which normally closed electromagnetic
valve 108a opens to release pressurised cooling liquid from fourth fluid line 10 along
release line 109 into vessel 107. Simultaneously, normally closed electromagnetic
valve 108b opens to allow condensate to drain along drainage line 110 through vessel
111 in the second fluid line 4, and along second fluid line portion 4b to condenser
means El.
[0134] The upper region 112a of the first stage compartment 112 of cooling means Fl communicates
with the suction inlet 17a into aspirator 17 which is connected in first fluid line
1 so that low pressure conditions are created in the upper region 112a of first stage
cooling compartment 112 under the influence of a flow of high pressure working fluid
through aspirator 17 along first fluid line 1. The more volatile, low density component
of the working fluid in the lower region 112b of first stage cooling compartment 112
is evaporated in the low pressure atmosphere in the upper region 112a and the vapour
is aspirated by aspirator 17 into the high pressure working fluid flowing along first
fluid line 1 to turbine B.
[0135] The fourth fluid line 10 extends from the lower region 113b of the second stage compartment
of cooling means Fl, through pump 32 to the external cooling compartment 11 and tubular
stator windings 12 (figures 4 and 5) of alternator C, through the upper region 113a
of second stage cooling compartment 113, through compressor D and through aspirator
13 to the first fluid line 1. Low pressure conditions are created in the upper region
113a of second stage cooling compartment 113 under the influence of a flow of high
pressure working fluid through aspirator 13 along first fluid line 1.
[0136] The less volatile, high density component of the working fluid and remnants of the
more volatile, low density component which are contained in the lower region 113 of
the second stage compartment 113 of cooling means Fl are evaporated in the low pressure
atmosphere in the upper region 113a and are aspirated by aspirator 13 into the high
pressure working fluid flowing along fluid line 1 to turbine B.
[0137] The remaining evaporatively cooled fluid in the lower region 113b of second stage
cooling compartment 113 is circulated by pump 32 as heat recovery fluid to all the
components of the system where cooling is required and is returned to the second stage
compartment 113. The warm recovery fluid returning to second stage compartment 113
contains low grade waste heat and/or low grade reject heat and/or low grade reject
heat and/or random loss heat.
[0138] The first stage compartment 112 of the cooling means Fl includes a heat exchanger
fluid circuit 92 for the introduction of very low grade heat into the system from
an external source, by circulating low temperature heated fluid through fluid circuit
92.
[0139] Under the action of low grade heat flux introduced through heat exchanger 92, the
more volatile, low density component of the working fluid is caused to vaporise by
virtue of the low pressure conditions prevailing in the first stage compartment, thereby
releasing the more volatile component of the condensate. The less volatile, more dense
component of the working fluid returns to second stage compartment 113 since all the
cooling return lines (i.e. the heat recovery return lines) communicate with second
stage compartment 113. The interiors of the first and second stage compartments 112
and 113 are in communication with each other via aperture 114 in the lower region
of the partition between the two compartments. This allows a liquid interchange to
a limited extent, whereby the liquid levels in the two compartments may equalise to
some extent.
[0140] Oil chamber/s 37 is/are connected by oil line 64, through oil circulating pump 65,
heat exchanger 63, header tank 54 to form a closed oil circuit. Fourth fluid line
10 supplying pressurised cooling fluid at point 94 is connected to the heat exchanger
vessel. Vaporised fluid is extracted at point 38 for return to second stage cooling
compartment 113 along fluid line portion 72b. The electric loads Gl which are connected
to alternator C by leads 95 comprise electric boiler 90 and electric superheater 91
of heating means Al and also battery 41 and electric heater 96 of thermal accumulator
97. Battery 41 is connected to alternator C through rectifier 39.
[0141] Thermal accumulator 97 further comprises a fluid tight casing 98 within which is
contained a mass 99 of glauber salts, fused eutectic materials or any other suitable
material which has the characteristic of being able to store and release heat in a
manner which may be controllable by variation of pressure applied to the material.
A conduit 100 with a control valve 101 is provided for introducing into and releasing
from the interior of casing 98 a fluid under pressure in order to control the accumulation
and release of heat by the mass 99 of glauber salts or the like.
[0142] Thermal accumulator 97 further includes a heat exchanger fluid circuit 102 which
is located in the mass 99 of glauber salts or the like and is connected in the first
fluid line 1 between the hot outlet 2 from the cooling chamber of turbine B and the
heating means Al.
[0143] During operation of the power plant of figure 6, electric output from alternator
C is utilized to controllably energize electric boiler 90 and/or superheater 91 of
heating means Al through semi-conductor control elements 104 and 105 respectively,
and also to charge battery 41 through controlled rectifier 39. Electric output from
alternator C is also controllably applied to energize electric heater 96 of thermal
accumulator 97 through semi-conductor control elements 106, thereby to heat the mass
99 of glauber salts or the like.
[0144] By means of control valve 101, the fluid pressure on the mass 99 of glauber salts
can be regulated as required to control the accumulation by the mass 99 of heat supplied
to it by electric heater 96 and the release of accumulated heat by the mass 99 to
working fluid flowing in the first fluid circuit 1 as it passes through the heat exchanger
fluid circuit 102 of thermal accumulator 97. The working fluid which flows along the
first fluid line 1 and which has been preheated in the cooling chamber of turbine
B, can thus be preheated further in thermal accumulator 97 in a controlled manner
according to requirements, on the way to heating means Al where it is heated further
to a required operating temperature.
[0145] The power plant of figure 6 is not controlled for constant power output from the
turbine B or the plant as a whole. The rotational speed of the turbo-alternator is
regulated to a constant value by controlled power absorption in storage battery 41
and/or in thermal accumulator 97.
[0146] An electric power output from the plant can be obtained along lead 103 connected
to battery 41.
[0147] The power plant of figure 6 is largely self sufficient in regard to its energy requirements
and whatever extraneous energy it requires to maintain the operational cycle may be
supplied as low grade heat energy via the heat exchanger fluid circuit 92 in the first
stage compartment 112 of cooling means Fl.
[0148] Many variations in detail are possible without departing from the spirit of the invention.
[0149] The invention includes within its scope dynamic compressive condenser means including
a tubular body provided with a constricted zone intermediate its ends; a first inlet
for condensable fluid located in the interior of the body in the proximity of the
constricted zone; and a second inlet located within the first inlet, fluid flow into
the first inlet through the second inlet being operative to aspirate condensable fluid
into the tubular body through the first inlet and impart kinetic motion to the condensable
fluid in the constricted zone, the kinetic motion being converted into a pressure
condition in an enlarged zone in the body beyond the constricted zone.
[0150] The first inlet into the tubular body may comprise an axially directed inlet nozzle.
[0151] The second inlet into the tubular body may also comprise an axially directed inlet
nozzle located within the first nozzle.
[0152] The tubular body may include a third inlet for cool fluid into the zone about the
first inlet, a flow of cool fluid into the body through the third inlet being operative
to cause cooling and further compression by kinetic motion of condensable fluid within
the body.
[0153] The body may include an outlet for liquid. The outlet may be located in the constricted
zone.
[0154] An enclosure may be provided around the outlet. The enclosure may include an outlet
and a non-return valve operative to permit an outflow of fluid from the enclosure
but prevent an inflow of fluid into the enclosure.
[0155] The invention also includes within its scope fluid heating means including an upright
cylindrical boiler chamber adapted to be heated; and a tangential fluid inlet into
the boiler chamber in a lower region thereof.
1. A method of operating a closed cycle power plant including the steps of heating
a working fluid to an operating temperature; and utilizing a flow of heated working
fluid to drive a thermodynamic prime mover and thereby to drive associated plant;
characterised in that low grade waste heat and/or low grade reject heat and/or low
grade random heat losses from the prime mover and/or associated plant and/or other
associated apparatus is utilized to heat a recovery fluid; and heated recovery fluid
is introduced into heated working fluid flowing to the prime mover in a position upstream
of the prime mover.
2. A method as claimed in claim 1, characterised in that the recovery fluid comprises
a fluid which is physically and/or chemically different from but compatible with the
working fluid.
3. A method as claimed in claim 1, characterised in that the recovery fluid is derived
or extracted wholly or partially from the working fluid.
4. A method as claimed in any one of the preceding claims, characterised in that the
heated working fluid is at a higher temperature and pressure than the heated recovery
fluid and a flow of the heated working fluid is utilized to aspirate the heated recovery
fluid into the heated working fluid.
5. A method as claimed in any one of the preceding claims, characterised in that at
least part of the condensable fluid passing from the prime mover is condensed by compression
produced by kinetic motion imparted to the condensable fluid.
6. A method as claimed in claim 5, characterised in that part of the condensable fluid
passing from the prime mover and/or at least part of the condensed fluid is introduced
into the heated working fluid in a position upstream of the prime mover.
7. A method as claimed in claims 5 or 6, characterised in that at least part of the
condensed fluid is utilized to cool the prime mover.
8. A method as claimed in claims 5 to 7, characterised in that at least part of the
condensed fluid is cooled by expansive evaporation.
9. A method as claimed in any one of the preceding claims, characterised in that at
least part of condensable fluid passing from the prime mover and/or at least part
of cooled condensed fluid constitutes or comprises recovery fluid for recuperating
low grade waste heat and/or low grade reject heat and/or low grade random heat losses.
10. A method as claimed in any one of the preceding claims, characterised in that
the operating speed and/or the power output of the prime mover is controlled by regulating
the magnitude of a load applied to the prime mover and/or by regulating the heat input
to the working fluid and/or by introducing condensed fluid into heated gaseous or
vaporous working fluid upstream of the prime mover.
11. A method as claimed in claim 10, characterised in that the operating speed and
the power output of the prime mover is controlled to substantially constant values,
the prime mover and associated plant comprising a turbo-electric unit including electric
generating means adapted to feed into a load, the load applied,to the electric generating
means and/or the heat input to the working fluid being adapted to be regulated in
accordance with the speed and/or electrical output of the generating means.
12. A closed cycle power plant characterised by heating means; a thermodynamic prime
mover; a cooling chamber in and/or round the prime mover; electric generating means
drivingly coupled to the prime mover; a cooling chamber in and/or round the generating
means; condenser means; cooling means; a first fluid line or circuit extending from
an outlet from the cooling chamber of the prime mover through the heating means and
communicating with a high pressure inlet into the prime mover; a second fluid line
or circuit extending from a low pressure outlet from the prime mover through the condenser
means and communicating with an inlet into the cooling chamber of the prime mover;
a third fluid line or circuit branching off from the second fluid line or circuit
downstream of the condenser means and communicating with the cooling means; and a
fourth fluid line or circuit extending from the cooling means to the cooling chamber
of the generating means and from there to the first fluid line or circuit in a position
between the heating means and the prime mover; and means operative to introduce fluid
from the fourth fluid line or circuit into the first fluid line or circuit.
13. A power plant as claimed in claim 12, characterised in that aspirator means is
provided to aspirate fluid from the fourth fluid line or circuit into the first fluid
line or circuit.
14. A power plant as claimed in claim 12 or 13 characterised by a branch line or circuit
which communicates with the second fluid line or circuit in a position between the
condenser means and the cooling chamber of the prime mover and is adapted to communicate
directly or indirectly with the return line to permit condensed fluid to be introduced
into the first fluid line ahead of the prime mover.
15. A power plant as claimed in any one of claims 12 to 14, characterised in that
the cooling means comprises expansive evaporation cooling means.
16. A power plant as claimed in any one of claims 12 to 15, characterised in that
the condenser means comprises dynamic compressive condenser means.
17. A power plant as claimed in claim 16, characterised in that the compressive condenser
means comprises a tubular body; a first inlet into the body communicating with the
low pressure outlet from the prime mover via portion of the second fluid line; a second
inlet into the body communicating via a fifth fluid line with the first fluid line
in a position between the heating means and the prime mover, fluid flow through the
second inlet being operative to aspirate condensable fluid passing from the prime
mover through the first inlet into the tubular body and to compress such condensable
fluid by converting its directional kinetic motion into a pressurised condition; and
a third inlet into the body communicating with the cooling means, cooled fluid introduced
under pressure through the third inlet being operative to cool and further to compress
by kinetic motion the condensable fluid passing from the prime mover.
18. A power plant as claimed in claim 17, characterised in that the tubular body includes
means operative centrifically to separate condensed fluid comprising at least two
components of different density and volatility into its components; and at least two
outlets, the one outlet being connected to the second fluid line or circuit and operative
to pass a more dense and less volatile component along the second fluid line to the
inlet into the cooling chamber of the prime mover and the other outlet being connected
to the third fluid line and operative to pass a less dense and more volatile component
along the third fluid line to the cooling means.
19. A power plant as claimed in any one of claims 12 to 18, including a load which
is electrically connected to the output of the electric generating means, characterised
in that the load includes and/or constitutes an energy storage or accummulator system.
20. A power plant as claimed in any one of claims 12 to 18, including a load connected
to the output of the electric generating means, characterised in that the load comprises
an electric motor and/or energy accummulator means and/or power conversion means.
21. A power plant as claimed in any one of claims 12 to 20, characterised by control
means operative to regulate the operating speed and/or the power output of the prime
mover.
22. A power plant as claimed in claim 21, wherein the control means is adapted to
vary the heat input to working fluid flowing along the first fluid line.
23. A power plant as claimed in claim 21 characterised in that the control means is
adapted to vary a load on the prime mover in accordance with the output of the generating
means.
24. An electrical machine characterised by tubular electric conductors adapted to
be connected to a cooling fluid circuit.
25. Dynamic compressive condenser means, characterised by a tubular body provided
with a constricted zone intermediate its ends; a first inlet for condensable fluid
located in the interior of the body in the proximity of the constricted zone; a second
inlet located within the first inlet, fluid flow into the first inlet through the
second inlet being operative to aspirate condensable fluid into the tubular body through
the first inlet and impart kinetic motion to the condensable fluid in the constricted
zone, the kinetic motion being converted into a pressure condition in an enlarged
zone in the body beyond the constricted zone.
26. Condenser means as claimed in claim 25 characterised in that the tubular body
includes means operative to separate condensed fluid comprising two components of
different densities into its components; an outlet from the body for the less dense
component; and a further outlet for the more dense component.