[Technical Field]
[0001] The present invention relates to a storage type hot water supplying system.
[Background Art]
[0002] Hot water supplying systems are known e.g. from documents
US 2014/0291411 A1,
EP 1 780 476 A1,
JP 2013 036648 A and
JP S61 29649 A. A storage type hot water supplying system according to the preamble of claim 1 is
known from the patent
US20014/0291411A1. Furthermore, a known storage type hot water supplying system includes a heat pump
configured to heat a heating medium, a heat exchanger configured to exchange heat
between the heated heating medium and water, and a hot water storage tank configured
to store the heated hot water (for example, see PTL 1).
[0003] In the system disclosed in PTL 1, the rotational speed of a first pump (13) is adjusted
so that the temperature of a heating medium flowing out of a first heat exchanger
(11) of the heat pump becomes equal to a first temperature higher than a heat storage
temperature set in advance. The rotational speed of a second pump (22) is adjusted
so that the temperature of hot water flowing out of a second heat exchanger (16) becomes
equal to the abovementioned heat storage temperature.
[Citation List]
[Patent Literature]
[0004] [PTL 1] Japanese Unexamined Patent Application Publication No.
2013-36648
[Summary of Invention]
[Technical Problem]
[0005] The heat exchange capacity of the heat exchanger configured to exchange heat between
the heating medium and the water decreases over time. This is due to the deposition
of scale, for example. The conventional system described above has the following problem.
When the heat exchange capacity of the second heat exchanger (16) decreases over time,
the temperature of the hot water flowing out of the second heat exchanger (16) decreases
if the circulation flow rate of the water remains constant. In order to maintain the
temperature of the hot water flowing out of the second heat exchanger (16), the rotational
speed of the second pump (22) is reduced, and the circulation flow rate of the water
decreases. When the circulation flow rate of the water decreases, the temperature
of the heating medium returning from the second heat exchanger (16) to the first heat
exchanger (11) of the heat pump rises. The rise in the temperature of the heating
medium flowing into the first heat exchanger (11) of the heat pump degrades energy
efficiency, for example, decreases the coefficient of performance.
[0006] The present invention has been made in order to solve the abovementioned problem,
and an object thereof is to provide a storage type hot water supplying system capable
of reducing the degradation in energy efficiency even when the heat exchange capacity
of the heat exchanger decreases over time.
[Solution to Problem]
[0007] A storage type hot water supplying system according to the present invention includes:
heating means for heating a heating medium; a heat exchanger configured to exchange
heat between the heating medium and water; a hot water storage tank configured to
store hot water heated in the heat exchanger; a first pump configured to circulate
the heating medium in a first circuit connecting the heat exchanger and the heating
means to each other; a second pump configured to circulate water in a second circuit
connecting the heat exchanger and the hot water storage tank to each other; and control
means for controlling the first pump and the second pump. In a heat accumulating operation
for accumulating hot water in the hot water storage tank, the first pump is controlled
so that a temperature of the heating medium heated by the heating means becomes equal
to a target temperature, and the second pump is controlled so that a water temperature
difference that is a difference between a temperature of the hot water heated in the
heat exchanger and a temperature of the water before being heated in the heat exchanger
becomes equal to a heating medium temperature difference that is a difference between
the temperature of the heating medium heated by the heating means and a temperature
of the heating medium before being heated by the heating means.
[Advantageous Effects of Invention]
[0008] According to the storage type hot water supplying system of the present invention,
the degradation in the energy efficiency can be reduced even when the heat exchange
capacity of the heat exchanger decreases over time.
[Brief Description of Drawings]
[0009]
Fig. 1 illustrates a storage type hot water supplying system of a first embodiment.
Fig. 2 illustrates a storage type hot water supplying system of a second embodiment.
[Description of Embodiments]
[0010] Embodiments are described below with reference to the drawings. Common elements in
the drawings are denoted by the same symbols, and overlapping descriptions are simplified
or omitted.
First embodiment
[0011] Fig. 1 illustrates a storage type hot water supplying system of a first embodiment.
As illustrated in Fig. 1, a storage type hot water supplying system 1 of this embodiment
includes a tank unit 2, a heat pump device 3, a control device 50, and a remote controller
60. The tank unit 2 includes a hot water storage tank 8. The heat pump device 3 is
an example of heating means for heating a heating medium. The control device 50 is
an example of control means for controlling the operation of the storage type hot
water supplying system 1. The remote controller 60 is an example of a user interface.
The remote controller 60 can receive user operation such as a command for operation
and the change of set values.
[0012] The tank unit 2 and the heat pump device 3 are connected to each other via a conduit
14, a conduit 15, and electric wiring (not shown). The tank unit 2 may be placed indoors
or may be placed outdoors. The heat pump device 3 may be placed outdoors. The remote
controller 60 may be installed in a room.
[0013] In this embodiment, the control device 50 is installed in the tank unit 2. Various
kinds of actuators such as a valve, a pump, and a compressor and various kinds of
sensors included in the storage type hot water supplying system 1 are electrically
connected to the control device 50. The remote controller 60 is connected to the control
device 50 through wired or wireless connection such that bi-directional data communication
is possible. Although not shown, the remote controller 60 may include a display configured
to display information such as the state of the storage type hot water supplying system
1, an operation unit such as a button to be operated by a user, and a voice output
device configured to provide voice guide.
[0014] The heat pump device 3 includes a refrigerant circuit. The refrigerant circuit includes
a compressor 31, a heat exchanger 33, a decompression device 34, an evaporator 36,
and a refrigerant pipe 35 annularly connecting those elements to each other. The heat
exchanger 33 exchanges heat between a high-pressure and high-temperature refrigerant
compressed by the compressor 31 and a liquid heating medium. The heating medium may
be water or may be brine other than water such as calcium chloride solution, ethylene
glycol solution, and alcohol. The decompression device 34 expands and decompress the
high-pressure refrigerant that has passed through the heat exchanger 33. The decompression
device 34 may be an expansion valve capable of changing the opening degree thereof.
The evaporator 36 evaporates the low-pressure refrigerant that has passed through
the decompression device 34. The fluid of which heat is exchanged with the refrigerant
in the evaporator 36 may be air, ground water, waste water, or solar water, for example.
The heat pump device 3 may include a fan or a pump (not shown) configured to send
the fluid to the evaporator 36.
[0015] The heat pump device 3 may be able to change the heating power [kW]. The heating
power is a quantity of heat provided to the heating medium by the heat pump device
3 per unit of time. The control device 50 may change the heating power of the heat
pump device 3 by changing the capacity of the compressor 31. The control device 50
may change the capacity of the compressor 31 by changing the rotational speed of the
compressor 31. The control device 50 may change the rotational speed of the compressor
31 by inverter control, for example.
[0016] The hot water storage tank 8 stores hot water heated by the heat pump device 3. The
hot water storage tank 8 is covered by a heat insulating material (not shown). Thermal
stratification in which the temperature of the upper layer is high and the temperature
of the lower layer is low can be formed in the hot water storage tank 8 due to the
density difference in water depending on the temperature. An inlet 8a provided in
the lower portion of the hot water storage tank 8 is connected to a water supply pipe
9. Water supplied from a water source such as water supply is decompressed to a predetermined
pressure by a decompression valve 37, and flows into the hot water storage tank 8
from the inlet 8a through the water supply pipe 9.
[0017] An outlet 8e provided in the upper portion of the hot water storage tank 8 is connected
to a hot water supply pipe 21. The hot water stored in the hot water storage tank
8 flows from the outlet 8e, and is supplied to the outside of the storage type hot
water supplying system 1 through the hot water supply pipe 21. The hot water storage
tank 8 is maintained in a full state by causing the same amount of water as the hot
water that has flowed out to the hot water supply pipe 21 to flow into the hot water
storage tank 8 from the water supply pipe 9.
[0018] A plurality of tank temperature sensors 42 and 43 are mounted on the hot water storage
tank 8 in positions at different heights. The volume of the hot water and the heat
storage amount in the hot water storage tank 8 can be detected by detecting the temperature
distribution in the hot water storage tank 8 in the vertical direction by the tank
temperature sensors 42 and 43. The control device 50 may control the start and stop
of heat accumulating operation that is the operation of accumulating hot water in
the hot water storage tank 8 on the basis of the volume of the hot water or the heat
storage amount in the hot water storage tank 8. In the configuration in Fig. 1, two
tank temperature sensors 42 and 43 are installed on the hot water storage tank 8,
but three or more tank temperature sensors may be installed on the hot water storage
tank 8.
[0019] The tank unit 2 further includes a conduit 10, a first pump 11, a second pump 12,
a conduit 13a, a conduit 13b, a conduit 16, a three-way valve 17, and a heat exchanger
38. The three-way valve 17 is flow-passage switching means including an a port, a
b port, and a c port. The heat exchanger 38 exchanges heat between the heating medium
heated in the heat pump device 3 and the water.
[0020] The conduit 10 connects an outlet 8b provided in the lower portion of the hot water
storage tank 8 and an inlet for water of the heat exchanger 38 to each other. The
second pump 12 is connected to the conduit 10 at a place midway through the conduit
10. The conduit 13a connects an outlet for water of the heat exchanger 38 and the
a port of the three-way valve 17 to each other. The conduit 13b connects the c port
of the three-way valve 17 and an inlet 8d formed in the upper portion of the hot water
storage tank 8 to each other. The conduit 16 connects the b port of the three-way
valve 17 and an inlet 8c formed in the lower portion of the hot water storage tank
8 to each other. In Fig. 1, the inlet 8c is located at a position lower than the outlet
8b. The present invention is not limited to such configuration, and the inlet 8c may
be located at a position at the same height as the outlet 8b, or the inlet 8c may
be located at a position higher than the outlet 8b.
[0021] The conduit 14 connects an outlet for the heating medium of the heat exchanger 38
of the tank unit 2 and an inlet for the heating medium of the heat exchanger 33 of
the heat pump device 3 to each other. The first pump 11 is connected to the conduit
14 at a place midway through the conduit 14. The conduit 15 connects an outlet for
the heating medium of the heat exchanger 33 of the heat pump device 3 and an inlet
for the heating medium of the heat exchanger 38 of the tank unit 2 to each other.
[0022] The following is performed in the heat accumulating operation. The three-way valve
17 is put in a state in which the a port is in communication with the c port, and
the b port is shut off. The heat pump device 3, the first pump 11, and the second
pump 12 are operated. The heating medium heated in the heat exchanger 33 of the heat
pump device 3 flows into the heat exchanger 38 through the conduit 15. The water taken
from the outlet 8b of the hot water storage tank 8 flows into the heat exchanger 38
through the conduit 10. In the heat exchanger 38, the heating medium heats the water.
That is, the heating medium is cooled by the water. The heating medium cooled in the
heat exchanger 38 returns to the heat exchanger 33 through the conduit 14. The hot
water heated in the heat exchanger 38 flows into the hot water storage tank 8 from
the inlet 8d through the conduit 13a, the three-way valve 17, and the conduit 13b.
Hot water is accumulated in the hot water storage tank 8 from the top to the bottom
by circulating the heating medium and the water as above.
[0023] In this embodiment, a first circuit connecting the heat exchanger 38 and the heat
pump device 3 to each other is formed by the conduit 14 and the conduit 15. A second
circuit connecting the heat exchanger 38 and the hot water storage tank 8 to each
other is formed by the conduit 10, the conduit 13a, the three-way valve 17, and the
conduit 13b.
[0024] The control device 50 can change the flow rate of the heating medium flowing in the
first circuit by controlling the capacity of the first pump 11. The rotational speed
of the first pump 11 may be variable. The first pump 11 may include a pulse width
modulation control type DC motor that can change the rotational speed by a speed command
voltage from the control device 50.
[0025] The control device 50 can change the flow rate of the water flowing in the second
circuit by controlling the capacity of the second pump 12. The rotational speed of
the second pump 12 may be variable. The second pump 12 may include a pulse width modulation
control type DC motor that can change the rotational speed by a speed command voltage
from the control device 50.
[0026] A first temperature sensor 4 is installed in the conduit 15. The first temperature
sensor 4 detects the temperature of the heating medium that has been heated by the
heat pump device 3, that is, the temperature of the heating medium flowing out of
the heat exchanger 33. The temperature of the heat medium flowing into the heat exchanger
38 can be detected by the first temperature sensor 4. A second temperature sensor
5 is installed in the conduit 14. The second temperature sensor 5 detects the temperature
of the heating medium before being heated by the heat pump device 3, that is, the
temperature of the heating medium flowing into the heat exchanger 33. The temperature
of the heating medium flowing out of the heat exchanger 38 can be detected by the
second temperature sensor 5. In the configuration in Fig. 1, the first temperature
sensor 4 and the second temperature sensor 5 are in the heat pump device 3, but the
first temperature sensor 4 and the second temperature sensor 5 may be arranged in
the tank unit 2.
[0027] A third temperature sensor 6 is installed in the conduit 13a. The third temperature
sensor 6 detects the temperature of the hot water flowing out of the heat exchanger
38, that is, the temperature of the hot water that has been heated in the heat exchanger
38. A fourth temperature sensor 7 is installed in the conduit 10. The fourth temperature
sensor 7 detects the temperature of the water flowing into the heat exchanger 38,
that is, the temperature of the water before being heated in the heat exchanger 38.
[0028] The user can set a first hot water supply temperature TH and a second hot water supply
temperature TL for the storage type hot water supplying system 1. The second hot water
supply temperature TL is a temperature lower than the first hot water supply temperature
TH. The remote controller 60 may be capable of receiving the user operation for setting
the first hot water supply temperature TH and the second hot water supply temperature
TL. The remote controller 60 may transmit information of set values of the first hot
water supply temperature TH and the second hot water supply temperature TL that are
input into the remote controller 60 by the user to the control device 50. For example,
the first hot water supply temperature TH may be set as 60°C and the second hot water
supply temperature TL may be set as 50°C.
[0029] The control device 50 may set a target temperature Tp1 of the heating medium that
has been heated by the heat pump device 3, that is, the heating medium flowing into
the heat exchanger 38 in the heat accumulating operation on the basis of the first
hot water supply temperature TH. The target temperature Tp1 is set to be a temperature
higher than the first hot water supply temperature TH. The control device 50 may set
a value obtained by adding an assumed value α of a terminal temperature difference
of the heat exchanger 38 in the heat accumulating operation to the first hot water
supply temperature TH as the target temperature Tp1. The terminal temperature difference
is a difference between the temperature of the heating medium flowing into the heat
exchanger 38 and the temperature of the hot water flowing out of the heat exchanger
38. For example, when it is assumed that the assumed value α of the terminal temperature
difference of the heat exchanger 38 is 10°C and the first hot water supply temperature
TH is 60°C, the target temperature Tp1 may set as 70°C. In this way, the following
is obtained. In the heat accumulating operation, the temperature of the hot water
flowing out of the heat exchanger 38 becomes equal to the first hot water supply temperature
TH. The hot water of which temperature is equal to the first hot water supply temperature
TH is accumulated in the hot water storage tank 8. The hot water of which temperature
is equal to the first hot water supply temperature TH set by the user can be supplied
from the hot water storage tank 8 to the outside through the hot water supply pipe
21.
[0030] The temperature in the hot water storage tank 8 decreases by supplying hot water
to the hot water supply pipe 21 from the hot water storage tank 8 and dissipating
heat from the hot water storage tank 8 to the surroundings. When the hot water storage
temperature detected by the tank temperature sensor 42 or the tank temperature sensor
43 becomes equal to or below the second hot water supply temperature TL, the control
device 50 may start the heat accumulating operation with the detection as a trigger.
[0031] In the heat accumulating operation, the control device 50 adjusts the capacity of
the first pump 11 so that a temperature Tout1 of the heating medium that has been
heated by the heat pump device 3, that is, the temperature Tout1 detected by the first
temperature sensor 4 becomes equal to the target temperature Tp1. When the capacity
of the first pump 11 is reduced, the flow rate of the heating medium flowing in the
first circuit decreases, and the temperature Tout1 increases. When the capacity of
the first pump 11 is increased, the flow rate of the heating medium flowing in the
first circuit increases, and the temperature Tout1 decreases. The control device 50
may adjust the capacity of the first pump 11 on the basis of the deviation between
the target temperature Tp1 and the temperature Tout1. With use of the deviation, the
control device 50 may adjust the capacity of the first pump 11 on the basis of proportional
control, integral control, differential control, or the combination of two or three
of the above.
[0032] In the heat accumulating operation, the difference between the temperature Tout1
of the heating medium that has been heated by the heat pump device 3 and a temperature
Tin1 of the heating medium before being heated by the heat pump device 3 is herein
referred to as a heating medium temperature difference ΔT1. That is, the difference
is defined as the following expression.
[0033] In the heat accumulating operation, the difference between a temperature Tout2 of
the hot water that has been heated in the heat exchanger 38 and a temperature Tin2
of the water before being heated in the heat exchanger 38 is herein referred to as
a water temperature difference ΔT2. That is, the difference is defined as the following
expression.
[0034] The control device 50 can obtain the value of the heating medium temperature difference
ΔT1 on the basis of the temperatures detected by the first temperature sensor 4 and
the second temperature sensor 5. The control device 50 can obtain the value of the
water temperature difference ΔT2 on the basis of the temperatures detected by the
third temperature sensor 6 and the fourth temperature sensor 7.
[0035] When the capacity of the second pump 12 is reduced, the following result is obtained.
The flow rate of the water flowing in the second circuit decreases, the temperature
Tout2 increases, and the water temperature difference ΔT2 increases. The heat exchange
amount in the heat exchanger 38 decreases, and hence the temperature Tin1 of the heating
medium flowing out of the heat exchanger 38 increases, and the heating medium temperature
difference ΔT1 decreases.
[0036] When the capacity of the second pump 12 is increased, the following result is obtained.
The flow rate of the water flowing in the second circuit increases, the temperature
Tout2 decreases, and the water temperature difference ΔT2 decreases. The heat exchange
amount in the heat exchanger 38 increases, and hence the temperature Tin1 of the heating
medium flowing out of the heat exchanger 38 decreases, and the heating medium temperature
difference ΔT1 increases.
[0037] In the heat accumulating operation, the control device 50 adjusts the capacity of
the second pump 12 so that the water temperature difference ΔT2 becomes equal to the
heating medium temperature difference ΔT1. That is, the second pump 12 is controlled
so that the following expression is satisfied.
[0038] When the water temperature difference ΔT2 tends to be smaller than the heating medium
temperature difference ΔT1, the water temperature difference ΔT2 can be approximated
to the heating medium temperature difference ΔT1 by being increased by reducing the
capacity of the second pump 12. Meanwhile, when the water temperature difference ΔT2
tends to be larger than the heating medium temperature difference ΔT1, the water temperature
difference ΔT2 can be approximated to the heating medium temperature difference ΔT1
by being reduced by increasing the capacity of the second pump 12. The control device
50 may adjust the capacity of the second pump 12 on the basis of the deviation between
the heating medium temperature difference ΔT1 and the water temperature difference
ΔT2. With use of the deviation, the control device 50 may adjust the capacity of the
second pump 12 on the basis of proportional control, integral control, differential
control, or the combination of two or three of the above.
[0039] The heat exchange capacity of the heat exchanger 38 decreases over time. This is
due to the deposition of scale, for example. Scale is thought to be mineral components
contained in water such as calcium ion and magnesium ion that have deposited and adhered
as carbonate crystals.
[0040] As the heat exchange capacity of the heat exchanger 38 decreases over time, the terminal
temperature difference of the heat exchanger 38 increases over time. In the description
below, the initial terminal temperature difference of the heat exchanger 38 is referred
to as α, and the increase over time is referred to as β. The increase β of the terminal
temperature difference of the heat exchanger 38 over time may increase at a rate of
about 1°C/year depending on the quality of the water.
[0041] As described above, in the heat accumulating operation, the first pump 11 is controlled
so that the temperature Tout1 of the heating medium flowing into the heat exchanger
38 becomes equal to the target temperature Tp1. As a result, the following expression
is satisfied.
[0042] The hot water storage temperature of the hot water storage tank 8 immediately after
the heat accumulating operation can be assumed to be equal to the temperature Tout2
of the hot water that has been heated in the heat exchanger 38. Thus, in the description
below, the hot water storage temperature of the hot water storage tank 8 immediately
after the heat accumulating operation is referred to as the hot water storage temperature
Tout2.
[0043] The temperature Tout2 of the hot water that has been heated in the heat exchanger
38, that is, the hot water storage temperature Tout2 is a value obtained by subtracting
the terminal temperature difference of the heat exchanger 38 from the temperature
Tout1 of the heating medium flowing into the heat exchanger 38, that is, the target
temperature Tp1. The initial terminal temperature difference of the heat exchanger
38 is α. In this case, the hot water storage temperature Tout2 can be calculated by
the following expression.
[0044] The terminal temperature difference of the heat exchanger 38 when the heat exchange
capacity of the heat exchanger 38 has decreased over time is (α + β). In this case,
the hot water storage temperature Tout2 can be calculated by the following expression.
[0045] As above, in this embodiment, as the heat exchange capacity of the heat exchanger
38 decreases over time, the hot water storage temperature Tout2 decreases by the increase
β of the terminal temperature difference of the heat exchanger 38 over time from the
initial temperature.
[0046] When the temperature Tout2 decreases by β, the water temperature difference ΔT2 decreases
by β in accordance with the expression (2) described above. When the water temperature
difference ΔT2 decreases, the heat exchange amount in the heat exchanger 38 decreases,
and hence the temperature Tin1 of the heating medium flowing out of the heat exchanger
38 increases. Even when the temperature Tin1 increases, the temperature Tout1 is maintained
at a value equal to the target temperature Tp1 in accordance with the expression (4)
described above. As a result, the heating medium temperature difference ΔT1 decreases
in accordance with the expression (1) described above. In accordance with the expression
(3) described above, ΔT2=ΔT1 is satisfied. Thus, the heating medium temperature difference
ΔT1 also decreases by β. As a result, in this embodiment, the temperature Tin1 of
the heating medium before being heated by the heat pump device 3 increases by β from
the state before the heat exchange capacity of the heat exchanger 38 decreases over
time.
(Comparative example)
[0047] In a control method of a comparative example, the following is performed. A target
hot water storage temperature Tp is set to a constant value. For example, Tp=TH may
be satisfied. In the heat accumulating operation, the capacity of the second pump
12 is adjusted so that the temperature Tout2 of the hot water flowing out of the heat
exchanger 38 becomes equal to the target hot water storage temperature Tp. When the
terminal temperature difference of the heat exchanger 38 increases from α to (α +
β) over time, the flow rate of the water flowing in the second circuit needs to be
reduced in order to maintain the temperature Tout2 of the hot water flowing out of
the heat exchanger 38 at the target hot water storage temperature Tp. Thus, the capacity
of the second pump 12 is reduced. In order to maintain the temperature Tout2 at the
target hot water storage temperature Tp in the comparative example, the flow rate
of the water flowing in the second circuit needs to be lower than that in this embodiment.
Therefore, in the comparative example, the heat exchange amount in the heat exchanger
38 becomes even more lower than this embodiment, and the temperature Tin1 of the heating
medium flowing out of the heat exchanger 38, that is, the temperature Tin1 of the
heating medium before being heated by the heat pump device 3 rises even more than
that in this embodiment. In the comparative example, the increase in the temperature
Tin1 from the state before the heat exchange capacity of the heat exchanger 38 has
decreased over time is larger than β.
[0048] The energy efficiency, for example, the coefficient of performance of the heat pump
device 3 becomes lower as the temperature Tin1 of the heating medium before being
heated by the heat pump device 3 becomes higher. In this embodiment, the increase
in the temperature Tin1 as the heat exchange performance of the heat exchanger 38
decreases over time can be smaller than that in the comparative example. As a result,
in this embodiment, the decrease in the energy efficiency, for example, the decrease
in the coefficient of performance of the heat pump device 3 when the heat exchange
performance of the heat exchanger 38 decreases over time can be smaller than that
of the comparative example.
[0049] In this embodiment, the temperature Tout2 of the hot water flowing out of the heat
exchanger 38 in the heat accumulating operation decreases in accordance with the decrease
in the heat exchange performance of the heat exchanger 38 over time. In this embodiment,
it is desired that the second pump 12 be controlled so that the water temperature
difference ΔT2 becomes equal to the heating medium temperature difference ΔT1 even
when the temperature Tout2 of the hot water flowing out of the heat exchanger 38 in
the heat accumulating operation does not reach the set value of the first hot water
supply temperature TH. In this manner, the decrease in the energy efficiency of the
heat pump device 3 can be reduced more reliably even when the heat exchange performance
of the heat exchanger 38 decreases over time.
[0050] When the temperature of the heating medium heated in the heat pump device 3 becomes
higher, the energy efficiency of the heat pump device 3 becomes lower. In this embodiment,
it is desired that the target temperature Tp1 of the heating medium heated by the
heat pump device 3 not be changed even when the temperature Tout2 of the hot water
flowing out of the heat exchanger 38 in the heat accumulating operation does not reach
the set value of the first hot water supply temperature TH. In this manner, the decrease
in the energy efficiency of the heat pump device 3 can be reduced more reliably even
when the heat exchange performance of the heat exchanger 38 decreases over time.
[0051] In this embodiment, it is desired that the target temperature Tp1 of the heating
medium heated by the heat pump device 3 be increased when the temperature Tout2 of
the hot water flowing out of the heat exchanger 38 in the heat accumulating operation
does not reach the set value of the second hot water supply temperature TL. In this
manner, the temperature of the hot water stored in the hot water storage tank 8 is
prevented from becoming lower than the set value of the second hot water supply temperature
TL. As a result, the hot water of which temperature is the second hot water supply
temperature TL set by the user can be reliably supplied from the hot water storage
tank 8.
[0052] The control device 50 may limit the upper limit of the target temperature Tp1 of
the heating medium heated by the heat pump device 3 in the heat accumulating operation.
For example, the control device 50 may set the upper limit so that the target temperature
Tp1 does not exceed 90°C. When the target temperature Tp1 is set too high, the life
of the heat pump device 3 can be affected. Bad influence on the life the heat pump
device 3 can be reliably prevented by limiting the upper limit of the target temperature
Tp1.
[0053] The control device 50 may limit the lower limit of the flow rate of the water flowing
in the second circuit in the heat accumulating operation. For example, the control
device 50 may set a lower limit for the capacity of the second pump 12 so that the
flow rate of the water flowing in the second circuit does not fall below 1 L/min.
When the flow rate of the water flowing in the second circuit in the heat accumulating
operation is too low, the heating power can become insufficient. The heating power
can be reliably prevented from becoming insufficient by limiting the lower limit of
the flow rate of the water flowing in the second circuit.
[0054] When the heat exchange performance of the heat exchanger 38 excessively decreases
over time, the temperature Tout2 of the hot water flowing out of the heat exchanger
38 sometimes does not reach a reference value even when the target temperature Tp1
is increased to the upper limit and the flow rate of the water flowing in the second
circuit is reduced to the lower limit in the heat accumulating operation. In such
a case, the control device 50 may notify the user of an abnormality. At this time,
the abnormality may be displayed on the display of the remote controller 60, or an
audio guide indicating the abnormality may be output from the remote controller 60.
The user can be prompted to repair or exchange the heat exchanger 38 by notifying
the user of the abnormality. The reference value described above may be equal to the
set value of the second hot water supply temperature TL.
[0055] When the heat accumulating operation is started, the control device 50 may activate
the second pump 12 after the heat pump device 3 and the first pump 11 are activated.
The value of the heating medium temperature difference ΔT1 can be unstable immediately
after the activation of the heat pump device 3 and the first pump 11. When the second
pump 12 is controlled so that the water temperature difference ΔT2 becomes equal to
the heating medium temperature difference ΔT1 while the value of the heating medium
temperature difference ΔT1 is unstable, hunting is likely to occur. The control stability
of the second pump 12 can be enhanced by starting the operation of the second pump
12 after a certain amount of time has passed after the heat pump device 3 and the
first pump 11 have been activated and after the value of the heating medium temperature
difference ΔT1 has been stabilized. Although it depends on the lengths of the conduits
14 and 15, it can take one or more minutes for the heating medium to circulate in
the first circuit for one or more cycles and for the heating medium temperature difference
ΔT1 to be stabilized. Thus, the operation of the second pump 12 may be started after
one minute has passed after the operation of the first pump 11 has started.
Second embodiment
[0056] Next, a second embodiment is described with reference to Fig. 2. Differences from
the abovementioned embodiment 1 are mainly described, and description of the same
parts or corresponding parts is simplified or omitted.
[0057] A storage type hot water supplying system 1 of the second embodiment illustrated
in Fig. 2 includes a first flow rate sensor 18 and a second flow rate sensor 19. The
first flow rate sensor 18 is installed in the conduit 15. The first flow rate sensor
18 detects the volumetric flow rate of the heating medium flowing in the first circuit.
The first flow rate sensor 18 may be installed in the conduit 14 instead of the conduit
15. The second flow rate sensor 19 is installed in the conduit 10. The second flow
rate sensor 19 detects the volumetric flow rate of the water flowing in the second
circuit. The second flow rate sensor 19 may be installed in the conduit 13a or the
conduit 13b instead of the conduit 10.
[0058] In the heat accumulating operation, the control device 50 may adjust the capacity
of the second pump 12 so that the volumetric flow rate of the water detected by the
second flow rate sensor 19 becomes equal to the volumetric flow rate of the heating
medium detected by the first flow rate sensor 18. In a case where water is used as
the heating medium of the first circuit, when the volumetric flow rate of the water
flowing in the second circuit becomes equal to the volumetric flow rate of the water
that is the heating medium flowing in the first circuit, the water temperature difference
ΔT2 accordingly becomes equal to the heating medium temperature difference ΔT1. As
a result, an effect similar to that in the first embodiment can be obtained by the
configuration as described above.
[0059] In the heat accumulating operation, the control device 50 may adjust the capacity
of the second pump 12 so that the heat capacity flow rate of the water flowing in
the second circuit becomes equal to the heat capacity flow rate of the heating medium
flowing in the first circuit. The control device 50 may calculate a heat capacity
flow rate Cph × ph × Vh [kW/K] of the heating medium by multiplying prestored values
of a specific heat Cph [kJ/kgK] of the heating medium and a density ph [kg/m
3] of the heating medium by a volumetric flow rate Vh [m
3/second] of the heating medium detected by the first flow rate sensor 18. The control
device 50 may calculate a heat capacity flow rate Cpw × ρw × Vw [kW/K] of the water
by multiplying prestored values of a specific heat Cpw [kJ/kgK] of the water and a
density pw [kg/m
3] of the water by a volumetric flow rate Vw [m
3/second] of the water detected by the second flow rate sensor 19. When the heat capacity
flow rate of the water flowing in the second circuit becomes equal to the heat capacity
flow rate of the heating medium flowing in the first circuit, the water temperature
difference ΔT2 accordingly becomes equal to the heating medium temperature difference
ΔT1. As a result, an effect similar to that in the first embodiment can be obtained
by the configuration as described above. The method described above can be applied
to a case in which the heating medium of the first circuit is not water.
[0060] According to the second embodiment, an effect similar to that in the first embodiment
can be obtained even without using the information detected by the second temperature
sensor 5, the third temperature sensor 6, and the fourth temperature sensor 7. The
storage type hot water supplying system 1 of the second embodiment does not necessarily
need to include the second temperature sensor 5, the third temperature sensor 6, and
the fourth temperature sensor 7.
[0061] The functions of the control device 50 included in the storage type hot water supplying
system 1 of the first embodiment and the second embodiment may be implemented by a
processing circuit. In the examples illustrated in Fig. 1 and Fig. 2, the processing
circuit of the control device 50 includes at least one processor 51 and at least one
memory 52. When the processing circuit includes at least one processor 51 and at least
one memory 52, the functions of the control device 50 may be implemented by software,
firmware, or a combination of software and firmware. At least one of the software
and the firmware may be described as a program. At least one of the software and the
firmware may be stored in at least one memory 52. At least one processor 51 may implement
the functions of the control device 50 by reading and executing a program stored in
at least one memory 52. At least one memory 52 may include a nonvolatile semiconductor
memory or a volatile semiconductor memory, or a magnetic disk.
[0062] The processing circuit of the control device 50 may include at least one dedicated
hardware. When the processing circuit includes at least one dedicated hardware, the
processing circuit may be, for example, a single circuit, a composite circuit, a programmed
processor, a parallel-programmed processor, an ASIC (Application Specific Integrated
Circuit), an FPGA (Field-Programmable Gate Array), or a combination of the above.
Each of the functions of the units of the control device 50 may be implemented by
the processing circuit. The functions of the units of the control device 50 may be
collectively implemented by the processing circuit. A part of the functions of the
control device 50 may be implemented by dedicated hardware, and other parts of the
functions of the control device 50 may be implemented by software or firmware. The
processing circuit may implement the functions of the control device 50 by hardware,
software, firmware, or a combination of the above.
[0063] The present invention is not limited to a configuration in which the operation of
the storage type hot water supplying system 1 is controlled by a single control device.
The present invention may employ a configuration in which the operation of the storage
type hot water supplying system 1 is controlled by a plurality of control devices
in cooperation with each other.
[Reference Signs List]
[0064]
1 storage type hot water supplying system
2 tank unit
3 heat pump device
4 first temperature sensor
5 second temperature sensor
6 third temperature sensor
7 fourth temperature sensor
8 hot water storage tank
8a inlet
8b outlet
8c, 8d inlet
8e outlet
9 water supply pipe
10 conduit
11 first pump
12 second pump
13a, 13b, 14, 15, 16 conduit
17 three-way valve
18 first flow rate sensor
19 second flow rate sensor
21 hot water supply pipe
31 compressor
33 heat exchanger
34 decompression device
35 refrigerant pipe
36 evaporator
37 decompression valve
38 heat exchanger
42, 43 tank temperature sensor
50 control device
51 processor
52 memory
60 remote controller
1. A storage type hot water supplying system (1), comprising:
heating means (3) for heating a heating medium;
a heat exchanger (38) configured to exchange heat between the heating medium and water;
(38); a hot water storage tank (8) configured to store hot water heated in the heat
exchanger
a first circuit (14, 15) connecting the heat exchanger (38) and the heating means
(3) to each other;
a first pump (11) configured to circulate the heating medium in the first circuit
(14, 15);
a second circuit (10, 13a, 13b, 17) connecting the heat exchanger (38) and the hot
water storage tank (8) to each other;
a second pump (12) configured to circulate water in the second circuit (10, 13a, 13b,
17); and
control means (50) for controlling the first pump (11) and the second pump (12),
characterized in that the control means (50) is configured such that, in a heat accumulating operation
for accumulating hot water in the hot water storage tank (8), the first pump (11)
is controlled so that a temperature of the heating medium heated by the heating means
(3) and flowing out of the heating means (3) becomes equal to a target temperature,
and the second pump (12) is controlled so that a water temperature difference that
is a difference between a temperature of the hot water heated in the heat exchanger
(38) and flowing out of the heat exchanger (38) and a temperature of the water before
being heated in the heat exchanger (38) and flowing into the heat exchanger (38) becomes
equal to a heating medium temperature difference that is a difference between the
temperature of the heating medium heated by the heating means (3) and flowing out
of the heating means (3) and a temperature of the heating medium before being heated
by the heating means (3) and flowing into the heating means (3).
2. The storage type hot water supplying system (1) according to claim 1, further comprising
means (60) for receiving a user operation for setting a first hot water supply temperature
and a second hot water supply temperature lower than the first hot water supply temperature,
wherein:
the target temperature is a temperature higher than a set value of the first hot water
supply temperature; and
the control means (50) is configured to control the second pump (12) in the heat accumulating
operation so that the water temperature difference becomes equal to the heating medium
temperature difference even when the temperature of the hot water heated in the heat
exchanger (38) does not reach the set value of the first hot water supply temperature.
3. The storage type hot water supplying system (1) according to claim 2, wherein the
control means (50) is configured such that the target temperature is not changed even
when the temperature of the hot water heated in the heat exchanger (38) does not reach
the set value of the first hot water supply temperature in the heat accumulating operation.
4. The storage type hot water supplying system (1) according to claim 2 or 3, wherein
the control means (50) is configured to increase the target temperature when the temperature
of the hot water heated in the heat exchanger (38) does not reach a set value of the
second hot water supply temperature in the heat accumulating operation.
5. The storage type hot water supplying system (1) according to any one of claims 1 to
4, further comprising:
means (18) for detecting a flow rate of the heating medium flowing in the first circuit
(14, 15); and
means (19) for detecting a flow rate of the water flowing in the second circuit (10,
13a, 13b, 17),
wherein the control means (50) is configured to control the second pump (12) in the
heat accumulating operation so that a volumetric flow rate or a heat capacity flow
rate of the water flowing in the second circuit (10, 13a, 13b, 17) becomes equal to
a volumetric flow rate or a heat capacity flow rate of the heating medium flowing
in the first circuit (14, 15).
6. The storage type hot water supplying system (1) according to any one of claims 1 to
5, wherein the control means (50) is configured to limit an upper limit of the target
temperature in the heat accumulating operation.
7. The storage type hot water supplying system (1) according to any one of claims 1 to
6, wherein, the control means (50) is configured to control the first and second pumps
(11, 12) such that when the heat accumulating operation is started, the second pump
(12) is activated after the first pump (11) is activated.
8. The storage type hot water supplying system (1) according to any one of claims 1 to
7, wherein the control means (50) is configured to limit a lower limit of a flow rate
of the water flowing in the second circuit (10, 13a, 13b, 17) in the heat accumulating
operation.
9. The storage type hot water supplying system (1) according to any one of claims 1 to
8, further comprising means (60) for notifying a user of an abnormality when the temperature
of the hot water heated in the heat exchanger (38) does not reach a reference value
in the heat accumulating operation.
1. Warmwasserzufuhrsystem (1) mit Speicherfunktion, umfassend:
eine Heizeinrichtung (3) zum Erwärmen eines Heizmediums;
einen Wärmetauscher (38), der dafür ausgelegt ist, Wärme zwischen dem Heizmedium und
Wasser auszutauschen;
einen Warmwasserspeichertank (8), der dafür ausgelegt ist, warmes Wasser zu speichern,
das in dem Wärmetauscher (38) erwärmt worden ist;
einen ersten Kreis (14; 15), der den Wärmetauscher (38) und die Heizeinrichtung (3)
miteinander verbindet;
eine erste Pumpe (11), die dafür ausgelegt ist, das Heizmedium im ersten Kreis (14,
15) umzuwälzen;
einen zweiten Kreis (10, 13a, 13b, 17), der den Wärmetauscher (38) und den Warmwasserspeichertank
(8) miteinander verbindet;
eine zweite Pumpe (12), die dafür ausgelegt ist, Wasser im zweiten Kreis (10, 13a,
13b, 17) umzuwälzen; und
eine Steuereinrichtung (50) zum Steuern der ersten Pumpe (11) und der zweiten Pumpe
(12),
dadurch gekennzeichnet, dass die Steuereinrichtung (50) so konfiguriert ist, dass in einer Wärmespeicherungsoperation
zum Speichern von warmem Wasser im Warmwasserspeichertank (8) die erste Pumpe (11)
so gesteuert wird, dass eine Temperatur des Heizmediums, das von der Heizeinrichtung
(3) erwärmt worden ist und aus der Heizeinrichtung (3) strömt, einer Zieltemperatur
gleich wird, und die zweite Pumpe (12) so gesteuert wird, dass eine Wassertemperaturdifferenz,
das heißt eine Differenz zwischen einer Temperatur des warmen Wassers, das im Wärmetauscher
(3, 8) erwärmt worden ist und aus dem Wärmetauscher (38) strömt, und einer Temperatur
des Wassers, bevor es im Wärmetauscher (38) erwärmt wird und in den Wärmetauscher
(38) strömt, einer Heizmediumtemperaturdifferenz gleich wird, das heißt einer Differenz
zwischen der Temperatur des Heizmediums, das von der Heizeinrichtung (3) erwärmt worden
ist und aus der Heizeinrichtung (3) strömt, und einer Temperatur des Heizmediums,
bevor es von der Heizeinrichtung (3) erwärmt wird und in die Heizeinrichtung (3) strömt.
2. Warmwasserzufuhrsystem (1) mit Speicherfunktion nach Anspruch 1, ferner eine Einrichtung
(60) zum Empfangen einer Betätigung durch einen Benutzer zum Einstellen einer ersten
Warmwasserzuleitungstemperatur und einer zweiten Warmwasserzuleitungstemperatur, die
niedriger ist als die erste Warmwasserzuleitungstemperatur, umfassend, wobei:
die Zieltemperatur eine Temperatur ist, die höher ist als ein eingestellter Wert der
ersten Warmwasserzuleitungstemperatur; und
die Steuereinrichtung (50) dafür ausgelegt ist, die zweite Pumpe (12) in der Wärmespeicherungsoperation
so zu steuern, dass die Wassertemperaturdifferenz der Heizmediumtemperaturdifferenz
gleich wird, auch wenn die Temperatur des warmen Wassers, das im Wärmetauscher (38)
erwärmt wird, den eingestellten Wert für die erste Warmwasserzuleitungstemperatur
nicht erreicht.
3. Warmwasserzufuhrsystem (1) mit Speicherfunktion nach Anspruch 2, wobei die Steuereinrichtung
(50) so konfiguriert ist, dass die eingestellte Temperatur nicht geändert wird, auch
wenn die Temperatur des warmen Wassers, das im Wärmetauscher (38) erwärmt wird, den
eingestellten Wert für die erste Warmwasserzuleitungstemperatur in der Wärmespeicherungsoperation
nicht erreicht.
4. Warmwasserzufuhrsystem (1) mit Speicherfunktion nach Anspruch 2 oder 3, wobei die
Steuereinrichtung (50) so konfiguriert ist, dass die Zieltemperatur erhöht wird, wenn
die Temperatur des warmen Wassers, das im Wärmetauscher (38) erwärmt wird, einen eingestellten
Wert für die zweite Warmwasserzuleitungstemperatur in der Wärmespeicherungsoperation
nicht erreicht.
5. Warmwasserzufuhrsystem (1) mit Speicherfunktion nach einem der Ansprüche 1 bis 4,
ferner umfassend:
eine Einrichtung (18) zum Erfassen eines Durchsatzes des Heizmediums, das im ersten
Kreis (14, 15) fließt, und
eine Einrichtung (19) zum Erfassen eines Durchsatzes des Wassers, das im zweiten Kreis
(10, 13a, 13b, 17) fließt,
wobei die Steuereinrichtung (50) dafür ausgelegt ist, die zweite Pumpe (12) in der
Wärmespeicherungsoperation so zu steuern, dass ein volumetrischer Durchsatz oder Wärmekapazitätsdurchsatz
des Wassers, das im zweiten Kreis (10, 13a, 13b, 17) strömt, einem volumetrischen
Durchsatz oder einem Wärmekapazitätsdurchsatz des Heizmediums, das im ersten Kreis
(14, 15) strömt, gleich wird.
6. Warmwasserzufuhrsystem (1) mit Speicherfunktion nach einem der Ansprüche 1 bis 5,
wobei die Steuereinrichtung (50) dafür ausgelegt ist, in der Wärmespeicherungsoperation
eine Obergrenze für die Zieltemperatur zu begrenzen.
7. Warmwasserzufuhrsystem (1) mit Speicherfunktion nach einem der Ansprüche 1 bis 6,
wobei die Steuereinrichtung (50) dafür ausgelegt ist, die erste und die zweite Pumpe
(11, 12) so zu steuern, dass zu Beginn der Wärmespeicherungsoperation die zweite Pumpe
(12) aktiviert wird, nachdem die erste Pumpe (11) aktiviert worden ist.
8. Warmwasserzufuhrsystem (1) mit Speicherfunktion nach einem der Ansprüche 1 bis 7,
wobei die Steuereinrichtung (50) dafür ausgelegt ist, in der Wärmespeicherungsoperation
eine Untergrenze für einen Durchsatz des Wassers, das im zweiten Kreis (10, 13a, 13b,
17) strömt, zu begrenzen.
9. Warmwasserzufuhrsystem (1) mit Speicherfunktion nach Anspruch 1 oder 8, ferner eine
Einrichtung (60) umfassend zum Mitteilen einer Anomalie an einen Benutzer, wenn die
Temperatur des warmen Wassers, das im Wärmetauscher (38) erwärmt wird, in der Wärmespeicherungsoperation
einen Bezugswert nicht erreicht.
1. Système d'alimentation en eau chaude du type à stockage (1), comprenant :
un moyen de chauffage (3) pour chauffer un milieu de chauffage ;
un échangeur thermique (38) qui est configuré pour échanger de la chaleur entre le
milieu de chauffage et l'eau ;
un réservoir de stockage d'eau chaude (8) qui est configuré pour stocker l'eau chaude
qui est chauffée à l'intérieur de l'échangeur thermique (38) ;
un premier circuit (14, 15) qui connecte l'échangeur thermique (38) et le moyen de
chauffage (3) l'un à l'autre ;
une première pompe (11) qui est configurée pour faire circuler le milieu de chauffage
à l'intérieur du premier circuit (14, 15) ;
un second circuit (10, 13a, 13b, 17) qui connecte l'échangeur thermique (38) et le
réservoir de stockage d'eau chaude (8) l'un à l'autre ;
une seconde pompe (12) qui est configurée pour faire circuler l'eau à l'intérieur
du second circuit (10, 13a, 13b, 17) ; et
un moyen de commande (50) pour commander la première pompe (11) et la seconde pompe
(12),
caractérisé en ce que le moyen de commande (50) est configuré de telle sorte que, lors d'une opération
d'accumulation de chaleur pour accumuler de l'eau chaude à l'intérieur du réservoir
de stockage d'eau chaude (8), la première pompe (11) soit commandée de telle sorte
qu'une température du milieu de chauffage qui est chauffé par le moyen de chauffage
(3) et qui s'écoule en sortie du moyen de chauffage (3) devienne égale à une température
cible, et de telle sorte que la seconde pompe (12) soit commandée de telle sorte qu'une
différence de température de l'eau qui est une différence entre une température de
l'eau chaude qui est chauffée à l'intérieur de l'échangeur thermique (38) et qui s'écoule
en sortie de l'échangeur thermique (38) et une température de l'eau avant qu'elle
ne soit chauffée à l'intérieur de l'échangeur thermique (38) et avant qu'elle ne s'écoule
à l'intérieur de l'échangeur thermique (38) devienne égale à une différence de température
du milieu de chauffage qui est une différence entre la température du milieu de chauffage
qui est chauffé par le moyen de chauffage (3) et qui s'écoule en sortie du moyen de
chauffage (3) et une température du milieu de chauffage avant qu'il ne soit chauffé
par le moyen de chauffage (3) et avant qu'il ne s'écoule à l'intérieur du moyen de
chauffage (3).
2. Système d'alimentation en eau chaude du type à stockage (1) selon la revendication
1, comprenant en outre un moyen (60) pour recevoir une opération d'utilisateur pour
régler une première température d'alimentation en eau chaude et une seconde température
d'alimentation en eau chaude qui est plus faible que la première température d'alimentation
en eau chaude, dans lequel :
la température cible est une température qui est plus élevée qu'une valeur de réglage
de la première température d'alimentation en eau chaude ; et
le moyen de commande (50) est configuré pour commander la seconde pompe (12) lors
de l'opération d'accumulation de chaleur de telle sorte que la différence de température
de l'eau devienne égale à la différence de température du milieu de chauffage même
lorsque la température de l'eau chaude qui est chauffée à l'intérieur de l'échangeur
thermique (38) n'atteint pas la valeur de réglage de la première température d'alimentation
en eau chaude.
3. Système d'alimentation en eau chaude du type à stockage (1) selon la revendication
2, dans lequel le moyen de commande (50) est configuré de telle sorte que la température
cible ne soit pas modifiée même lorsque la température de l'eau chaude qui est chauffée
à l'intérieur de l'échangeur thermique (38) n'atteint pas la valeur de réglage de
la première température d'alimentation en eau chaude lors de l'opération d'accumulation
de chaleur.
4. Système d'alimentation en eau chaude du type à stockage (1) selon la revendication
2 ou 3, dans lequel le moyen de commande (50) est configuré pour augmenter la température
cible lorsque la température de l'eau chaude qui est chauffée à l'intérieur de l'échangeur
thermique (38) n'atteint pas une valeur de réglage de la seconde température d'alimentation
en eau chaude lors de l'opération d'accumulation de chaleur.
5. Système d'alimentation en eau chaude du type à stockage (1) selon l'une quelconque
des revendications 1 à 4, comprenant en outre :
un moyen (18) pour détecter un débit d'écoulement du milieu de chauffage qui s'écoule
à l'intérieur du premier circuit (14, 15) ; et
un moyen (19) pour détecter un débit d'écoulement de l'eau qui s'écoule à l'intérieur
du second circuit (10, 13a, 13b, 17),
dans lequel le moyen de commande (50) est configuré pour commander la seconde pompe
(12) lors de l'opération d'accumulation de chaleur de telle sorte qu'un débit d'écoulement
volumétrique ou qu'un débit d'écoulement en termes de capacité thermique de l'eau
qui s'écoule à l'intérieur du seconde circuit (10, 13a, 13b, 17) devienne égal à un
débit d'écoulement volumétrique ou à un débit d'écoulement en termes de capacité thermique
du milieu de chauffage qui s'écoule à l'intérieur du premier circuit (14, 15).
6. Système d'alimentation en eau chaude du type à stockage (1) selon l'une quelconque
des revendications 1 à 5, dans lequel le moyen de commande (50) est configuré pour
limiter une limite supérieure de la température cible lors de l'opération d'accumulation
de chaleur.
7. Système d'alimentation en eau chaude du type à stockage (1) selon l'une quelconque
des revendications 1 à 6, dans lequel le moyen de commande (50) est configuré pour
commander les première et seconde pompes (11, 12) de telle sorte que, lorsque l'opération
d'accumulation de chaleur est démarrée, la seconde pompe (12) soit activée après que
la première pompe (11) est activée.
8. Système d'alimentation en eau chaude du type à stockage (1) selon l'une quelconque
des revendications 1 à 7, dans lequel le moyen de commande (50) est configuré pour
limiter une limite inférieure d'un débit d'écoulement de l'eau qui s'écoule à l'intérieur
du second circuit (10, 13a, 13b, 17) lors de l'opération d'accumulation de chaleur.
9. Système d'alimentation en eau chaude du type à stockage (1) selon l'une quelconque
des revendications 1 à 8, comprenant en outre un moyen (60) pour notifier à un utilisateur
une anomalie lorsque la température de l'eau chaude qui est chauffée à l'intérieur
de l'échangeur thermique (38) n'atteint pas une valeur de référence lors de l'opération
d'accumulation de chaleur.