BACKGROUND OF THE INVENTION
Field of the invention
[0001] The present invention relates to a refrigeration cycle apparatus, and particularly
to a refrigeration cycle apparatus suitable for reusing existing pipes in which solid
foreign matters and liquid impurities remain. A refrigeration cycle apparatus of the
kind referred to in the preamble portion of patent claim 1 is known from
JP 2005 315435 A.
Description of related art
[0002] As a refrigeration cycle apparatus forming a refrigeration cycle by connecting a
compressor, a heat source unit side heat exchanger, an expansion device, and a using
side heat exchanger by means of a liquid refrigerant pipe and a gas refrigerant pipe,
there is known an air conditioner, for example.
[0003] In the air conditioner, in order to address environmental problems, there is an increasing
need to exchange a conventional air conditioner using a CFC-based refrigerant, an
HCFC-based refrigerant or the like as a refrigerant (hereinafter referred to as an
old machine) into a new air conditioner using an HFC-based refrigerant with no solubility
with a mineral oil or the like and a refrigerating machine oil for the HFC-based refrigerant
(hereinafter referred to as a new 81-66033EP/CM/cs machine). At the time of exchanging
these machines, existing refrigerant pipes having connected an indoor unit and an
outdoor unit of the old machine are reused.
[0004] However, the reused connection pipes may retain residual contaminants (liquid impurities)
enclosed within the old machine such as a refrigerating machine oil (an mineral oil,
alkylbenzene or the like), an oxidation degraded reactant of the refrigerating machine
oil and a chlorine compound, which are insoluble or poor soluble components with respect
to the HFC-based refrigerant used in the new machine.
[0005] Further, when remarkable abrasion occurs in a sliding part of a refrigerant compressor
mounted on the old machine, a large quantity of solid foreign matters originating
from the abrasion powders are generated, discharged outside the refrigerating compressor
together with a gas refrigerant and a refrigerating machine oil, and remain in the
connection pipes to be reused.
[0006] If the existing pipes are reused without any countermeasure against these impurities
and solid foreign matters, there is possibility that the reliability of the air conditioner
remarkably decreases due to degradation of the refrigerating machine oil in the new
machine caused by the impurities, acceleration of the abrasion of the sliding part
of the refrigerant compressor caused by mixing of the solid foreign matters into the
refrigerant compressor mounted on the new machine, or the like.
[0007] In connection with the degradation of the refrigerating machine oil in the new machine
among the above factors,
JP-2003-42603 A discloses a working method of setting the concentration of the impurities remaining
in the connection pipes with respect to the refrigerating machine oil in the new machine
to be equal to or smaller than an acceptable value by enclosing the same refrigerating
machine oil as that in the new machine within the pipes at the time of vacuuming,
for example. Moreover,
JP-2000-9368 A discloses to perform cleaning operation of collecting the impurities remaining in
the connection pipes when reusing the connection pipes, for example.
[0008] Moreover, in connection with the abrasion of the sliding part of the refrigerant
compressor in the new machine due to the solid foreign matters, it is known to install
a strainer or the like between a heat source side unit of the new machine and the
connection pipes so that a large quantity of solid foreign matters do not flow into
the refrigerant compressor.
JP-2002-224513 A discloses one example of the strainer used herein, for example.
[0009] GB 2411712 A discloses a refrigeration cycle apparatus, forming a refrigeration cycle by connecting
a compressor, a heat source unit side heat exchanger, an expansion device, and a using
side heat exchanger by means of a liquid refrigerant pipe and a gas refrigerant pipe.
BRIEF SUMMARY OF THE INVENTION
[0010] However, the above prior art does not pay attention to reusing the existing pipes
effectively.
[0011] That is, the period of renewal construction may become long due to addition of refrigerating
machine oil enclosing work, cleaning operation work or the like for setting the concentration
of impurities to be equal to or smaller than an acceptable value, for example.
[0012] Accordingly, a problem to be solved of the present invention is to provide a refrigeration
cycle apparatus which can efficiently reuse existing pipes.
[0013] This object is accomplished with a refrigeration cycle apparatus as claimed in claim
1.
[0014] Dependent claims are directed on features of preferred embodiments of the invention.
[0015] Since the liquid impurity such as mineral oil is almost insoluble with respect to
the liquid refrigerant, it is separated from the liquid refrigerant, and since the
liquid impurity has a lower specific gravity than the liquid refrigerant, it moves
upwards. Accordingly, by providing a filter for capturing the liquid impurity at the
upper stage side in the liquid refrigerant stored in the receiver, the liquid impurity
can be effectively captured. Further, since the space of each of the openings of the
refrigerant pipes is defined by the lower stage side filter, the solid foreign matter
is captured by the filter soon after discharged from the refrigerant pipes.
[0016] In addition, according to this configuration, since the flow rate of the liquid refrigerant
at the place where the upper stage side filter is provided is relatively slow, it
is possible to prevent the liquid impurity once captured from flowing out again together
with the flow of the refrigerant.
[0017] According to the present invention, it is possible to provide a refrigeration cycle
apparatus enabling the existing pipes to be effectively reused.
[0018] Other objects, features and advantages of the invention will become apparent from
the following description of an embodiment of the invention taken in conjunction with
the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0019]
Fig. 1 is a view showing a system diagram of a refrigeration cycle of an air conditioner
of the present invention;
Fig. 2 is a cycle system diagram showing another embodiment according to the present
invention;
Fig. 3 is a graph showing mineral oil separation characteristics under a coexistence
condition of an HFC-based refrigerant, refrigerating machine oil for HFC, and mineral
oil;
Fig. 4 is a view showing a longitudinal cross-section of a receiver and a filter device
installed in the receiver; and
Fig. 5 is a view showing a cross-section of a solid matter capturing strainer.
DETAILED DESCRIPTION OF THE INVENTION
[0020] Hereinafter, an embodiment of the refrigeration cycle apparatus to which the present
invention is applied will be described with reference to Figs 1 to 5. Although the
following description will be made using an air conditioner as one example, the present
invention is not only limited to this but also applicable to a refrigeration cycle
apparatus which forms a refrigeration cycle and reuses existing pipes. Moreover, in
the embodiment, a multi-type air conditioner in which a plurality of indoor units
are connected to one outdoor unit is described as an example, the present invention
is not limited to this but also applicable to an air conditioner with one to one connection.
In the following description, the same functional parts are denoted by the same reference
numerals to eliminate duplicated descriptions.
[0021] Fig. 1 is a view showing a cycle system diagram of the air conditioner of the present
embodiment. As illustrated in the figure, the air conditioner is composed by an outdoor
unit 30, indoor units 40a and 40b, a liquid refrigerant pipe 7 and a gas refrigerant
pipe 12 which connect these, and the like.
[0022] The outdoor unit 30 is provided with a compressor 1, a four-way valve 2, a heat source
unit side heat exchanger 3, an outdoor expansion valve 4, a receiver 5, an accumulator
15 and the like, and constructed by connecting those with a refrigerant pipe. At connection
ports to the liquid refrigerant pipe 7 and the gas refrigerant pipe 12, gate valves
6 and 13 are provided, and a solid matter capturing strainer 14a is provided in the
refrigerant pipe on a suction side of the compressor 1. Moreover, the respective indoor
units 40a and 40b are provided with indoor expansion valves 9a and 9b, using side
heat exchangers 10a and 10b, and the like, and constructed by connecting those with
the refrigerant pipes.
[0023] Fig. 2 is a view showing a modified embodiment of the air conditioner of the present
embodiment. The difference between Fig. 1 and Fig. 2 is only the position on which
the strainer 14 is arranged. In other words, the solid matter capturing strainer 14a
is provided on the suction side of the compressor 1 in the outdoor unit 30 in Fig.
1, however, alternatively, a solid matter capturing strainer 14b may be provided in
the gas refrigerant pipe 12 as shown in Fig. 2.
[0024] In such an air conditioner, when renewing the outdoor unit 30 and the indoor units
40a and 40b, reusing the liquid refrigerant pipe 7 and the gas refrigerant pipe 12
is performed. However, if these existing pipes are simply reused, there is possibility
that the reliability of the air conditioner is significantly degraded due to degradation
of refrigerating machine oil in a new machine caused by liquid impurities (mineral
oil enclosed in an old machine, refrigerating machine oil such as alkylbenzene, an
oxidation degraded reactant in the refrigerating machine oil, a chlorine based compound,
and the like) remaining in the pipes, and acceleration of abrasion of a sliding part
of the refrigerant compressor caused by foreign matters mixing into the refrigerant
compressor mounted on the new machine.
[0025] Hereinafter, a method for recovering solid foreign matters and impurities remaining
in the existing pipes, however not part of the claimed invention, will be described.
Hereinafter, the description is made by using mineral oil as one example of the impurities.
[0026] When an air conditioning device using CFC or HCFC becomes life-expired, it is replaced.
First, the CFC or HCFC refrigerant is recovered, and the outdoor unit 30 and the indoor
units 40a and 40b are replaced with those illustrated in Fig. 1. The liquid connection
pipe 7 and the gas connection pipe 12 of the old machine are reused. Since the HFC
is charged in the outdoor unit 30 in advance, the indoor units 40a and 40b, the liquid
connection pipe 7 and the gas connection pipe 12 are vacuumed in a connecting state
while closing the gate valves 6 and 13, and then additional charging of the HFC and
opening of the gate valves 6 and 13 are performed.
[0027] As basic operation of the air conditioner, in case of the cooling operation, a high
temperature and high pressure gas refrigerant compressed by the compressor 1 is discharged
from the compressor 1, passes through the four-way valve 2, flows into the heat source
unit side heat exchanger 3, and exchanges heat there to be condensed into liquid.
The condensed liquid refrigerant passes through the outdoor expansion valve 4, which
is a first expansion device and fully opened, an excess refrigerant is accumulated
in the receiver 5, and a remaining refrigerant passes through the gate valve 6 and
is sent to the indoor units 40a and 40b.
[0028] The sent liquid refrigerant flows into the indoor expansion valves 9a and 9b, which
are second expansion devices, is decompressed there to be at a low pressure so as
to be in a low pressure two phase state, and exchanges heat with a using side medium,
such as air, to be evaporated into gas in the using side heat exchangers 10a and 10b.
After that, the gas refrigerant returns to the compressor 1 through the solid matter
capturing strainer 14b, the gate valve 13 and the four-way valve 2 in the case of
Fig. 2, through the gate valve 13, the four-way valve 2, and through the solid matter
capturing strainer 14a in the case of Fig. 1.
[0029] In case of the heating operation, the high temperature and high pressure gas refrigerant
compressed by the compressor 1 is discharged from the compressor 1 together with the
refrigerating machine oil for HFC, flows into the using side heat exchangers 10a and
10b through the four-way valve 2 and the gate valve 13 (and the solid matter capturing
strainer 14b in the case of Fig. 2), exchanges heat there with the using side medium
such as air and is condensed into liquid. The condensed liquid refrigerant is flown
into the gate valve 6 and the receiver 5, decompressed to be at a low pressure by
the outdoor expansion valve 4, exchanges heat with a heat source unit side medium
such as air and water in the heat source unit side heat exchanger 3, and is evaporated
into gas. The gas refrigerant returns to the compressor 1 through the four-way valve
(and the solid matter capturing strainer 14a in the case of Fig. 1).
[0030] Fig. 3 is a view illustrating the separation characteristics of the mineral oil when
the mineral oil which is an insoluble component with respect to the HFC-based refrigerant
is mixed into the HFC-based refrigerant and the refrigerating machine oil for HFC
at the ratio of about 10 % (= mineral oil quantity / (quantity of refrigerating machine
oil for HFC + mineral oil quantity)). The horizontal axis indicates the solubility
of refrigerant with respect to the refrigerating machine oil (refrigerating machine
oil for HFC + mineral oil quantity), 0% indicates the case of consisting only of the
refrigerating machine oil (refrigerating machine oil for HFC + mineral oil), and 100%
indicated the case of consisting only of the refrigerant. The vertical axis indicates
temperature.
[0031] As illustrated in this figure, the mineral oil is hardly dissolved in the HFC-based
refrigerant while it is dissolved in the refrigerating machine oil for HFC. In addition,
the mineral oil do not separate in the compressor in which a large quantity of refrigerating
machine oil for HFC exists, but separates in the liquid connection pipe 7 and the
receiver 5 in which a large quantity of liquid refrigerant exists.
[0032] Subsequently, the filter device which is a characteristic part of the present invention
and installed in the receiver 5 will be described with reference to Fig. 4. The filter
device is composed by different filters 53 and 54 and the like, which are configured
in a two stage of upper and lower sides in the receiver 5. The filter 53 is provided
in the upper stage in the receiver 5 and made of a fibrous material with a relatively
large mesh number, and the material of the fiber is composed of at least one of polyester
and polypropylene.
[0033] The liquid refrigerant and the refrigerating machine oil for HFC dissolved in the
liquid refrigerant are the liquid with remarkably low viscosity. On the contrary,
the mineral oil is the liquid with remarkably higher viscosity as compared to those
of the liquid refrigerant and the refrigerating machine oil for HFC dissolved in the
liquid refrigerant. Therefore, while the liquid refrigerant and the refrigerating
machine oil for HFC dissolved in the liquid refrigerant pass through the filter 53,
the mineral oil is trapped between the fibers of the filter 53 with the large mesh
number, and after that, it is captured by a capillary phenomenon in the fibers.
[0034] Therefore, by arranging the filter 53 in the receiver 5, the mineral oil discharged
together with the refrigerating machine oil for HFC from the inside of the compressor
1 separates in the receiver 5, and it is possible to capture only the separated mineral
oil by the filter 53.
[0035] In the case that the compressor 1 is of a high-pressure chamber type in which the
pressure of the refrigerating machine oil accumulating part in the compressor 1 is
high, or that an oil separator is arranged at the discharge part of the compressor
1, the temperature of the refrigerating machine oil accumulated in the compressor
1 and the oil separator becomes high. On the other hand, the temperature of the receiver
5 becomes lower than that temperature. In addition, since the degradation of the refrigerating
machine oil is accelerated as the temperature thereof increases, and further the degradation
of the refrigerating machine oil for HFC is accelerated as the mixing amount of mineral
oil (degraded oil) remaining in the existing pipes is larger, by capturing the mineral
oil with the receiver 5 of which temperature is lower than that in the compressor
1 or the oil separator, it is possible to prevent the refrigerating machine oil for
HFC from being degraded.
[0036] Moreover, in order to capture the mineral oil in the filter 53, it is necessary for
the filter 53 to be brought into contact with the mineral oil. Therefore, when starting
and stopping the compressor 1, the refrigerant is recovered in the receiver 5 by performing
operation while setting the expansion device on the downstream side of the receiver
5 (which is the indoor expansion valves 9a and 9b in the case of cooling operation,
or the outdoor expansion valve 4 in the case of heating operation) in a fully closed
state or a slightly opened state close to the fully closed state.
[0037] This enables the filter 53 to be brought into contact with the mixed liquid of the
HFC-based refrigerant, the refrigerating machine oil for HFC and the mineral oil,
and thus only the mineral oil separates in the receiver 5 so that only the mineral
oil can be captured.
[0038] Further, the captured amount of the mineral oil by the filter 53 decreases as the
flow rate with respect to the filter 53 becomes higher. This is because the mineral
oil once captured by the filter 53 is extruded outside the filter 53 by fluid force
of the refrigerant. In addition, since the flowing-in speed of the mixed liquid becomes
higher as it is close to pipe tip end parts of refrigerant introducing and delivering
pipes 51 and 52 for introducing the mixed liquid of the HFC-based refrigerant, the
refrigerating machine oil for HFC and the mineral oil into the receiver 5, the mixed
liquid of the HFC-based refrigerant, the refrigerating machine oil for HFC and the
mineral oil introduced in the receiver 5 is delivered from the receiver 5 after passing
through the filter 53 by directing the pipe tip end parts downwards. This enables
the mineral oil introduced in the receiver 5 to be prevented from being delivered
without passing through the filter 53.
[0039] By the above mentioned configuration, it is possible to suppress the time of renewing
construction work without requiring such a work that the refrigerating machine oil
provided by a drum can container from the maker of the refrigerating machine oil is
charged while using a special hose taking care of prevention of mixing of a contaminant
when setting the density of the impurities to be equal to or below an allowable value,
as in the case of a conventional art. Moreover, it is possible to suppress such a
problem that when a multi-air-conditioner for a building with long pipes is renewed,
a new machine becomes large in volume by charging a large quantity of refrigerating
machine oil corresponding to a large quantity of impurities remaining in the connection
pipes into the new machine so that the new machine cannot be installed as in the case
of a conventional method of preliminarily charging refrigerating machine oil to be
added into the new machine oil.
[0040] Moreover, when reusing the connection pipes, it is unnecessary to perform cleaning
operation for recovering the impurities remaining in the connection pipes, and thus
the working time of the renewing construction work can be suppressed, resulting in
effectively reusing of the existing pipes.
[0041] Further, the filter 54 arranged in the lower stage than the filter 53 is provided
near the pipe tip end parts of the refrigerant introducing and delivering pipes 51
and 52 in the receiver 5. In other words, the spaces 62 at the tip end portions of
the refrigerant introducing and delivering pipes 51 and 52 are defined by the filter
54. The filter 54 is made of a fibrous material of which size is greater than that
of the filter 53, and has a mesh number enabling solid matters of several µm to be
removed. That is, the material is fibrous in which fibers are more densely superposed,
gaps between fibers are smaller, and the density is larger than those of the filter
53, and is composed of at least one of polyester, polypropylene, and SUS, as a characteristic
of the fiber.
[0042] As the filter 53 for capturing the mineral oil, it is desirable to set a different
density from that of the filter 54 in order to make the gaps between the fibers of
the filter 53 large possibly, and to set the amount of the mineral oil which can be
captured to be large possibly, since the mineral oil is captured inside the fibers
by means of the capillary phenomena. In addition, in order not to deliver the solid
foreign matters introduced from the refrigerant introducing and delivering pipes 51
and 52 from the inside of the receiver 5, the filter 54 is arranged to surround the
vicinity of the pipe tip end parts of the refrigerant introducing and delivering pipes
51 and 52.
[0043] Here, a strainer for capturing foreign matters or the prior art can capture solid
foreign matters of which particle size is equal to or greater than 20 µm. However,
as a result of measuring the particle size distribution of the solid foreign matters
generated by the abrasion of the sliding part of the refrigerant compressor and recovered
from the actual machine, it has been found that the number of the solid foreign matters
having a particle diameter equal to or greater than 20 µm is half or more of the total
number of the solid foreign matters, and thus in case of the strainer which can capture
solid foreign matters of which particle diameter is equal to or greater than 20 µm,
solid foreign matters of which particle diameter is equal to or smaller than 20 µm
will flow into the refrigerant compressor.
[0044] Moreover, in the document of "
Lubrication", volume 17, No. 11 (1972), pages 741 to 746, the minimum gap in a slide bearing also used in a refrigerant compressor is 1 to
20 µm, and the document "Tribology and Environment" K.K. Shinjusha, page 53, Fig.
2.2.3.7(b) describes that the abrasion of a sliding part is accelerated mostly under
a condition in which the particle size of a solid foreign matter is equal to the minimum
gap of a bearing.
[0045] In this respect, according to the present embodiment, the solid foreign matters discharged
from the refrigerant introducing and delivering pipes 51 and 52 are attached on a
surface of the filter 54 on a side of the refrigerant introducing and delivering pipes
51 and 52 by the above mentioned configuration. As a result thereof, it is possible
to prevent the solid foreign matters from mixing into the compressor mounted on the
new machine to accelerate the abrasion of the sliding part of the compressor, so that
the reliability of the air conditioner can be prevented from being degraded.
[0046] In addition, in order to prevent the filter 54 from being clogged by the solid foreign
matters, it is desirable to sufficiently ensure the area of the filter 54 on the side
of the refrigerant introducing and delivering pipes 51 and 52.
[0047] Next, an installing method of the filter 53 for removing the refrigerant insoluble
components in the upper stage and the filter 54 for removing the solid foreign matters
in the lower stage, which are accommodated in the receiver, will be described.
[0048] At the time of manufacturing, after sandwiching the filters 53 and 54 between punching
metals 55 and 56, caps 58 and 59 and a body 60 are welded together. At that time,
the temperature of the inner wall surface of the body 60 exceeds the maximum operation
temperature of the filters 53 and 54. Accordingly, if the filters 53 and 54 are constructed
so as to be in contact with the inner wall surface of the body 60, the filters 53
and 54 will be melted by the heat, and will not be able to capture the refrigerant
insoluble components. Further, this causes the passage of the liquid refrigerant introduced
in the receiver 5 and the refrigerating machine oil for HFC dissolved in the liquid
refrigerant to be blocked in the receiver 5, so that those can not be delivered from
the inside of the receiver 5, and the equipment stops due to overshooting of the discharge
temperature of the compressor 1, or the abrasion of the sliding part occurs due to
lack of the refrigerating machine oil in the compressor 1.
[0049] Therefore, in the present embodiment, a predetermined gap Δd is provided between
the body 60 and the filters 53 and 54 so that the temperatures of the filters 53 and
54 is equal to or smaller than the maximum operation temperature, to prevent the temperature
of the inner wall surface of the body 60 from being transmitted to the filters.
[0050] As illustrated in Fig. 5, the solid matter capturing strainers 14a and 14b have the
structure in which an introducing cap 71 having an opening in its center is connected
on one bottom side, and a cylindrical screen 70 having a screen arranged therein for
capturing solid foreign matters is encapsulated in a pressure-resistant container
74 on the other bottom side. The connection of the introducing cap 71 and the screen
70 prevents the solid foreign matters from flowing into and out from a connection
part of the introducing cap 71 and the screen 70 by entire welding in the circumferential
direction.
[0051] Further, the connection between the inner surface of the pressure-resistant container
74 and the introducing cap 71 also prevents the flowing-in and flowing-out of the
solid foreign matters by entire caulking in the circumferential direction or by entire
welding in the circumferential direction.
[0052] The flow of the refrigerant, the refrigerating machine oil and the solid foreign
matters in the solid matter capturing strainer 14a and 14b flows as shown in the solid
line arrows when the refrigerant, the refrigerating machine oil and the solid foreign
matters firstly flow into the strainers from the side of the pipe 72. The refrigerant
and the refrigerating machine oil pass through the openings of the screen and flow
out from the side of the pipe 73. Since the solid matters having a particle size equal
to or greater than that of the openings of the screen 70 cannot pass through the screen
70, those are captured by the inner surface of the screen 70.
[0053] Moreover, the flow of the refrigerant, the refrigerating machine oil, and the solid
foreign matters in case of performing the reverse cycle operation such as a cooling
and heating combined machine is illustrated shown in the dotted line arrows.
[0054] As illustrated in Fig. 2, when the solid matter capturing strainer 14b is arranged
between the gas connection pipe 12 and the gas gate valve 13, there is the possibility
that the solid foreign matters captured by the inner surface of the screen 70 are
flown outside the solid matter capturing strainer 14b by the fluid forces of the refrigerant
and the refrigerating machine oil. However, it is possible to prevent the solid foreign
matters from flowing into the refrigerant compressor 1 by enclosing those in the liquid
refrigerant pipe 7 and the gas refrigerant pipe 12 by the solid matter capturing strainer
14b and the filter 54 arranged in the receiver.
[0055] The material of the screen 70 used for the solid matter capturing strainer 14a and
14b is desirably made from SUS, which is a material which captures solid foreign matters
having a particle size equal to or greater than several µm, does not degrades the
refrigerant and the refrigerating machine oil to be used, as well as the screen 70
itself.
[0056] Moreover, according to the document "
Tribology and Environment" K.K. Shinjusha, page 53, Fig. 2.2.3.7(c), as the amount of foreign matters to be supplied to the sliding
part of a bearing increases, the amount of abrasion increases. In view of this fact,
the acceptable value of the mixing amount of the solid foreign matters is set as a
specification of the refrigerant compressor 1, and if the mixing amount of the solid
foreign matters is equal to or smaller than the acceptable value, there is no problem
even if a part of the solid foreign matters remaining in the liquid refrigerant pipe
7 and the gas refrigerant pipe 12, passes through the screen 70 and flows into the
refrigerant compressor 1.
[0057] That is, although the screen 70 used for the solid matter capturing strainer 14a
and 14b captures solid foreign matters having a particle size equal to or greater
than several µm, there is no problem if the capturing rate is equal to or smaller
than 100%.
[0058] Moreover, in order to withstand the fluid forces from the refrigerator and the refrigerating
machine oil, the inner periphery and the outer periphery of the screen 70 may be reinforced
by a high-strength member such as punching metal
[0059] At that time, if the solid matter capturing strainer 14a is arranged on the suction
side of the compressor 1 as illustrated in Fig. 1, the solid foreign matters remaining
in the liquid refrigerant pipe 7 and the gas refrigerant pipe 12, which are solid
foreign matters in the refrigeration cycle, and abrasion powder generated due to the
aging degradation of the compressor 1 are all gathered in the solid matter capturing
strainer 14a. Therefore, it is important to ensure the area of the screen 70 of the
solid matter capturing strainer 14a sufficiently, so as not to clog the solid matter
capturing strainer 14a by the solid foreign matters.
[0060] As illustrated in Fig. 2, if the solid matter capturing strainer 14b is arranged
between the gas connection pipe 12 and the gas gate valve 13, only the solid foreign
matters remaining in the liquid refrigerant pipe 7 and the gas refrigerant pipe 12
flow into the solid matter capturing strainer 14b during the cooling operation. On
the contrary, during the heating operation, only abrasion powder generated due to
the aging degradation of the compressor 1 flows into the solid matter capturing strainer
14b. By this fact, the amount of the solid foreign matters flowing into the solid
matter capturing strainer 14b is smaller than the solid matter capturing strainer
14a, and the area of the screen 70 of the solid matter capturing strainer 14b can
be set smaller, which enables downsizing.
[0061] It should be further understood by those skilled in the art that although the foregoing
description has been made on embodiments of the invention, the invention is not limited
thereto and various changes and modifications may be made without departing from the
invention and the scope of the appended claims.
1. A refrigeration cycle apparatus, forming a refrigeration cycle by connecting a compressor
(1), a heat source unit side heat exchanger (3), an expansion device, and a using
side heat exchanger by means of a liquid refrigerant pipe (7) and a gas refrigerant
pipe (12), wherein the liquid refrigerant pipe (7) is provided with a container (5),
in the container (5), respective openings (63, 64) of an upstream side pipe (51) and
a downstream side pipe (52) of the liquid refrigerant are provided, characterized in that
the gas refrigerant pipe (12) is provided with a strainer (14) and
in the container in the liquid refrigerant pipe
two filters (53, 54) are provided which are configured in two stages of upper and
lower sides of the container, the filter (54) arranged in the lower stage defining
spaces (62) at the respective openings (63, 64) of the upstream side pipe (51) and
the downstream side pipe (52) and capturing different target objects, respectively,
discharged from the refrigerant pipe (7), and
the filter (53) provided in the upper stage for capturing mineral oil is made of a
fibrous material of a mesh number enabling HFC refrigerating machine oil to pass through
and the mineral oil to be captured, the filter (54) provided in the lower side for
capturing solid foreign matters is made of a fibrous material of a mesh number enabling
HFC refrigerating machine oil to pass through and solid foreign matters of several
µm or more to be captured.
2. The refrigeration cycle apparatus according to claim 1, characterized in that the expansion device comprises a first expansion device (4) and a second expansion
device (9a, 9b), and the container is a receiver (5) provided between the first expansion
device (4) and the second expansion device (9a, 9b) to store the liquid refrigerant.
3. The refrigeration cycle apparatus according to claim 2, characterized in that the two filters (53, 54) are provided in the receiver with a predetermined gap from
an inner wall surface of the receiver (5).
4. The refrigeration cycle apparatus according to claim 3, characterized in that the filter (54) for capturing the solid foreign matters and the filter (53) for capturing
the mineral oil are formed from a fibrous material made of polyester, and the filter
(54) for capturing the solid foreign matters is formed to have a density larger than
that of the filter (53) for capturing the mineral oil.
5. The refrigeration cycle apparatus according to any one of claims 1 to 4, characterized in that the strainer (14) is provided between the using side heat exchangers (10a, 10b) and
the compressor (1), and a screen of the strainer (14) is formed from SUS enabling
solid matters of several µm or more to be captured.
6. The refrigeration cycle apparatus according to claim 2, characterized in that one of the first expansion device (4) and the second expansion device (9a, 9b) on
the downstream side of the receiver (5) is fully closed, or at a slightly opened angle
when at least one of starting and stopping the compressor.
7. The refrigeration cycle apparatus according to claim 2, further comprising a four-way
valve (2).
1. Kältekreislaufvorrichtung, die einen Kältekreislauf durch Anschließen eines Verdichters
(1), einen wärmequelleneinheitsseitigen Wärmetauscher (3), eine Ausdehnungsvorrichtung
und einen nutzungsseitigen Wärmeaustauscher mittels einer Flüssigkältemittelrohrleitung
(7) und einer Gaskältemittelrohrleitung (12) ausbildet, wobei die Flüssigkältemittelrohrleitung
(7) mit einem Behälter (5) versehen ist,
wobei im Behälter (5) jeweilige Öffnungen (63, 64) einer stromaufwärtsseitigen Rohrleitung
(51) und einer stromabwärtsseitigen Rohrleitung (52) des flüssigen Kältemittels vorgesehen
sind,
dadurch gekennzeichnet, dass die Gaskältemittelrohrleitung (12) mit einem Filter (14) vorgesehen ist und im Behälter
in der Flüssigkeitskältemittelrohrleitung zwei Filter (53, 54) vorgesehen sind, die
in zwei Stufen von oberen und unteren Seiten des Behälters ausgebildet sind, wobei
der Filter (54) in den die untere Stufe definierenden Räume (62) an den jeweiligen
Öffnungen (63, 64) der stromaufwärtsseitigen Rohrleitung (51) und der stromabwärtsseitigen
Rohrleitung (52) angeordnet ist und unterschiedliche Zielobjekte einfängt, die jeweils
von der Kältemittelrohrleitung (7) abgegeben werden, und
wobei der Filter (53), der in der oberen Stufe zum Einfangen von Mineralöl vorgesehen
ist, aus einem faserigen Material mit einer Mesh-Zahl hergestellt ist, welches es
dem HFC-Kältemaschinenöl ermöglicht, hindurch zu strömen, und welches das Mineralöl
einfängt, wobei der Filter (54) in der unteren Seite zum Einfangen fester Fremdstoffe
aus einem faserigen Material mit einer Mesh-Zahl hergestellt ist, welches es dem HFC-Kältemaschinenöl
ermöglicht, hindurch zu strömen, und welches feste Fremdstoffe von mehreren µm oder
mehr einfängt.
2. Kältekreislaufvorrichtung gemäß Anspruch 1, dadurch gekennzeichnet, dass die Ausdehnungsvorrichtung eine erste Ausdehnungsvorrichtung (4) und eine zweite
Ausdehnungsvorrichtung (9a, 9b) umfasst und der Behälter ein Empfänger (5) ist, der
zwischen der ersten Ausdehnungsvorrichtung (4) und der zweiten Ausdehnungsvorrichtung
(9a, 9b) vorgesehen ist, um das flüssige Kältemittel zu speichern.
3. Kältekreislaufvorrichtung nach Anspruch 2, dadurch gekennzeichnet, dass die zwei Filter (53, 54) im Empfänger mit einem vorbestimmten Spalt von einer inneren
Wandfläche des Empfängers (5) vorgesehen sind.
4. Kältekreislaufvorrichtung nach Anspruch 3, dadurch gekennzeichnet, dass der Filter (54) zum Einfangen der festen Fremdstoffe und der Filter (53) zum Einfangen
des Mineralöls aus einem faserigen Material aus Polyester ausgebildet sind und der
Filter (54) zum Einfangen der festen Fremdstoffe so ausgebildet ist, dass er eine
Dichte aufweist, die größer ist als jene des Filters (53) zum Einfangen des Mineralöls.
5. Kältekreislaufvorrichtung nach einem der Ansprüche 1 bis 4, dadurch gekennzeichnet, dass der Filter (14) zwischen den nutzungsseitigen Wärmetauschern (10a, 10b) und dem Verdichter
(1) vorgesehen ist, und ein Sieb des Filters (14) aus SUS ausgebildet ist, wodurch
Feststoffe von mehreren µm oder mehr eingefangen werden können.
6. Kältekreislaufgerät nach Anspruch 2, dadurch gekennzeichnet, dass eines von der ersten Ausdehnungsvorrichtung (4) und der zweiten Ausdehnungsvorrichtung
(9a, 9b) auf der stromabwärtigen Seite des Empfängers (5) vollständig geschlossen
ist oder sich in einem leicht geöffneten Winkel befindet, wenn der Verdichter entweder
gestartet oder gestoppt wird.
7. Die Kältekreislaufvorrichtung nach Anspruch 2, ferner umfassend ein Vierwegeventil
(2).
1. Appareil à cycle de réfrigération, formant un cycle de réfrigération en connectant
un compresseur (1), un échangeur de chaleur situé du côté de l'unité de source de
chaleur (3), un dispositif d'expansion, et un échangeur de chaleur situé du côté utilisation
au moyen d'un tuyau de réfrigérant liquide (7) et d'un tuyau de réfrigérant gazeux
(12),
le tuyau de réfrigérant liquide (7) étant pourvu d'un réservoir (5),
sachant que, dans le réservoir (5), des ouvertures respectives (63,64) d'un tuyau
situé côté amont (51) et d'un tuyau situé côté aval (52) de réfrigérant liquide sont
prévues,
caractérisé en ce que le tuyau de réfrigérant gazeux (12) est pourvu d'une passoire (14) et que, dans le
réservoir du tuyau de réfrigérant liquide, il est prévu deux filtres (53,54) qui sont
réalisés dans deux niveaux des côtés supérieur et inférieur du réservoir, le filtre
(54) disposé dans le niveau inférieur définissant des espaces (62) aux ouvertures
respectives (63,64) du tuyau situé du côté amont (51) et du tuyau situé côté aval
(52) et capturant différents objets cibles déchargés respectivement par le tuyau de
réfrigérant (7), et
le filtre (53) prévu dans le niveau supérieur pour capturer de l'huile minérale est
composé d'un matériau fibreux ayant un nombre de mailles permettant à de l'huile de
machine réfrigérante HFC de traverser et à l'huile minérale d'être capturée, le filtre
(54) prévu au niveau inférieur pour capturer des matières étrangères solides est composé
d'un matériau fibreux ayant un nombre de mailles permettant à de l'huile de machine
réfrigérante HFC de traverser et à des matières étrangères solides de plusieurs µm
ou plus d'être capturées.
2. Appareil à cycle de réfrigération selon la revendication 1, caractérisé en ce que le dispositif d'expansion comprend un premier dispositif d'expansion (4) et un second
dispositif d'expansion (9a, 9b), et que le réservoir est un récepteur (5) prévu entre
le premier dispositif d'expansion (4) et le second dispositif d'expansion (9a, 9b)
pour stocker le réfrigérant liquide.
3. Appareil à cycle de réfrigération selon la revendication 2, caractérisé en ce que les deux filtres (53,54) sont prévus dans le récepteur avec un intervalle prédéterminé
par rapport à une surface de paroi interne du récepteur (5).
4. Appareil à cycle de réfrigération selon la revendication 3, caractérisé en ce que le filtre (54) destiné à capturer les matières étrangères solides et le filtre (53)
destiné à capturer l'huile minérale sont composés d'un matériau fibreux constitué
de polyester, et que le filtre (54) destiné à capturer les matières étrangères solides
est réalisé de manière à avoir une densité supérieure à celle du filtre (53) destiné
à capturer l'huile minérale.
5. Appareil à cycle de réfrigération selon l'une quelconque des revendications 1 à 4,
caractérisé en ce que la passoire (14) est prévue entre les échangeurs de chaleur situés du côté utilisation
(10a, 10b) et le compresseur (1), et qu'un écran de la passoire (14) est composé de
SUS permettant à des matières solides de plusieurs µm ou plus d'être capturées.
6. Appareil à cycle de réfrigération selon la revendication 2, caractérisé en que l'un
parmi le premier dispositif d'expansion (4) et le second dispositif d'expansion (9a,9b)
situé du côté aval du récepteur (5) est entièrement fermé, décrit un angle légèrement
ouvert lors d'au moins une opération de démarrage et d'arrêt du compresseur.
7. Appareil à cycle de réfrigération selon la revendication 2, comprenant en outre une
vanne à quatre distributions (2).