JP2000018735A - Refrigerating machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a heat exchanger itself compact, and enable the improvement of COP, using a nonazeotropic mixed refrigerant. SOLUTION: In a refrigerating machine equipped with a closed circulation passage for a nonazeotropic mixed refrigerant including a compressor, a first heat exchanger for condensation, a liquid receiver, an economizer, a first expansion valve, and a second heat exchanger for evaporation, a liquid subcooler 15 being a vertical one path counterflow type heat exchanger, which lets a refrigerant at high pressure having flown out of an economizer flow in and lets it flow from under to above, and lets it flow out toward the first expansion valve from under, and besides lets it flow in the refrigerant at low pressure having flown out of a second heat exchanger 17 and lets it flow from under to above and turns it into gas form toward the suction part of the compressor and lets it flow out, is provided in a body with the second heat exchanger, and this is a vertical one path counterflow type where the second heat exchanger 17 lets the refrigerant having flown in via the first expansion valve flow from under to above, and besides lets cooled water flow from above to under, and it lets the refrigerant containing unevaporated components flow out toward the liquid subcooler 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigeration system using a non-azeotropic refrigerant mixture.

[0002]

2. Description of the Related Art In recent years, the ozone layer surrounding the earth has been protected,
In order to prevent global warming, the use of a refrigerant widely used in the past, for example, R22, has been internationally banned, and the development of a substitute refrigerant has been urgently required. For example, refrigerant R4
07C and R410A are one of the refrigerants that are currently attracting attention. However, as compared with the refrigerant R22, in the case of the refrigerant instead of this, only a low coefficient of performance (COP: evaporating capacity / power) can be obtained even when used alone, so that a non-azeotropic mixed refrigerant composed of a plurality of refrigerants is used. Various proposals have been made to improve the coefficient of performance by using the method (eg,
No. 102254).

[0003]

For example, Japanese Patent Application Laid-Open No. Hei.
In the case of the invention described in Japanese Patent Publication No. 102254, although not specified in the publication, it is assumed that an aluminum plate-fin type heat exchanger is used for the condenser and the evaporator.
However, this type of heat exchanger has a problem that it is expensive in addition to being easily corroded. In addition, other devices have a problem that a sufficient COP cannot be achieved unless the heat exchanger is made very large.
SUMMARY OF THE INVENTION The present invention has been made in order to eliminate such a conventional problem, and has provided a refrigeration apparatus that uses a non-azeotropic mixed refrigerant to make a heat exchanger itself compact and that can improve COP. It is something to offer.

[0004]

In order to solve the above-mentioned problems, a first invention comprises at least a compressor, a first heat exchanger for condensation, a liquid receiver, a first expansion valve, and a second heat exchanger for evaporation. In the refrigerating apparatus provided with a closed non-azeotropic mixed refrigerant circulation channel including: a high-pressure refrigerant before reaching the first expansion valve is caused to flow and flow from top to bottom; And a low-pressure refrigerant flowing out of the second heat exchanger flows in from the second heat exchanger, flows upward from the bottom, and flows out in a gaseous state toward the suction portion of the compressor. A vertical type in which a liquid subcooler, which is a heat exchanger, is provided, and the second heat exchanger causes the refrigerant to flow from the bottom through the first expansion valve, while the water to be cooled flows from the top to the bottom. 1-pass counter-flow type and liquid supercooled refrigerant containing non-evaporated component And the liquid subcooler and the second heat exchanger are disposed on both sides of a plate group consisting of a plurality of plates forming a fluid flow path of the plate heat exchanger. A structure in which one of the end plates made of a pressure-resistant member is omitted, and the side surfaces having both end plates omitted are brought into contact with each other, and the liquid supercooler is opposed to the contacted side surfaces. A first end plate made of a pressure-resistant member provided with a high-pressure refrigerant outflow port and a low-pressure refrigerant outflow port, and a refrigerant outflow port and a cooled water outflow port of the second heat exchanger that face the contacted side surface. The liquid subcooler and the plate group of the second heat exchanger are sandwiched by a second end face plate made of a pressure-resistant member provided,
The liquid subcooler and the second heat exchanger were integrally formed.

[0005] Further, a second invention provides at least a compressor,
1st heat exchanger for condensation, liquid receiver, 1st expansion valve, 2nd for evaporation
In a refrigeration apparatus having a closed non-azeotropic mixed refrigerant circulation path including a heat exchanger, a high-pressure refrigerant before reaching the first expansion valve is caused to flow and flow from top to bottom, and A vertical one-pass for allowing the low-pressure refrigerant flowing out of the second heat exchanger to flow in from the second heat exchanger to flow upward from the bottom while flowing toward the expansion valve, and flowing out in a gaseous state toward the suction part of the compressor; While providing a liquid subcooler which is a counter-flow type heat exchanger, the second heat exchanger allows the refrigerant flowing through the first expansion valve to flow upward from below,
A vertical one-pass counterflow type in which the water to be cooled flows from top to bottom, and a refrigerant containing an unevaporated component flows out toward the liquid subcooler, and a refrigerant outlet of the second heat exchanger And a refrigerant gas space portion having an upper portion communicating with the refrigerant outlet and a lower portion having a lower portion communicating with the low pressure refrigerant inlet. A first gas-liquid separator, a suction refrigerant flow path for communicating the refrigerant gas space with a suction part of the compressor, and a combined refrigerant flow path for communicating the low-pressure refrigerant outlet with the suction refrigerant flow path. And a refrigerant from the low-pressure refrigerant outlet into a refrigerant gas interposed at a junction between the suction refrigerant flow path and the merged refrigerant flow path and flowing from the refrigerant gas space toward the suction part of the compressor. Suction means for sucking gas and accompanying it is provided.

Further, in a third invention, in addition to the structure of the second invention, the first gas-liquid separator is arranged above the liquid subcooler.

According to a fourth aspect of the present invention, in addition to the structure of the first aspect, the compressor is a semi-hermetic type housed in the same casing as a motor as a drive unit thereof, and the liquid subcooler and A second gas-liquid separator having a lower portion serving as a refrigerant liquid storage portion and an upper portion serving as a refrigerant gas space portion is provided between the compressor and the compressor, and communicates the low-pressure refrigerant outlet with the refrigerant gas space portion. A first refrigerant flow path, a second refrigerant flow path for directly connecting the refrigerant liquid reservoir to the suction part of the compressor, and a refrigerant flowing from the refrigerant gas space through a motor in the casing to the suction part. It was formed by providing a suction refrigerant channel for guiding gas.

According to a fifth aspect of the present invention, in addition to the configuration of the above-mentioned inventions, the first heat exchanger allows the refrigerant flowing from the compressor to flow from top to bottom while cooling water flows from bottom to top. It is a vertical one-pass counterflow type to be disposed and arranged above the liquid receiver.

[0009]

Next, an embodiment of the present invention will be described with reference to the drawings. 1 to 3 show a refrigeration apparatus according to a first embodiment of the present invention, in which a non-azeotropic mixed refrigerant composed of a plurality of refrigerants is supplied to a compressor 11, a first heat exchanger 12 for condensation, a liquid receiver 13, an economizer. 14. A closed circulation flow path I is formed to pass through the liquid subcooler 15, the first expansion valve 16, and the second heat exchanger 17 for evaporation, and then return to the compressor 11 through the liquid subcooler 15 again. It is. In addition, it branches off from the portion of the circulation flow path I between the economizer 14 and the liquid subcooler 15, passes through the second expansion valve 18, and is separated from the portion of the circulation flow path I in the economizer 14 separately and thermally. This economizer 1 can be exchanged
4, an intermediate flow path II is provided to reach a gas compression space in the compressor 11.

The compressor 11 is, for example, a single stage or a low stage,
Any of a two-stage compressor in which a high-stage compressor body is arranged in series may be used, and examples thereof include a screw type, a reciprocating type, and a turbo type. In the case of a two-stage compressor, the intermediate passage II is located between the suction port of the low-stage compressor body and the discharge port of the high-stage compressor body, and does not communicate with any of these suction ports and discharge ports. It reaches the part of the circulation channel I.

The first heat exchanger 12 is of a well-known vertical one-pass counterflow type plate type. In the first heat exchanger 12, the refrigerant from the compressor 11 flows through the refrigerant inlet 21 provided at the upper part, flows from top to bottom, and flows out from the refrigerant outlet 22 provided at the lower part, while the cooling water Flows through the cooling water inlet 23 provided at the lower part, flows upward from the bottom, flows out from the cooling water outlet 24 provided at the upper part, and heat exchange is performed between the refrigerant and the cooling water. .

The liquid receiver 13 is of a horizontal type and is disposed below the first heat exchanger 12. Thus, the refrigerant liquid condensed in the first heat exchanger 12 immediately flows down to the liquid receiver 13 without staying in the first heat exchanger 12. When the refrigerant liquid accumulates in the lower part of the first heat exchanger 12, not only the heat transfer area decreases, the condensing pressure increases, but also the gas flowing down to the vicinity of the stagnant liquid is transformed into a component ratio of a low boiling point. And the liquefaction temperature decreases. On the other hand, from below
As the cooling water rises in the resident liquid and is heated during this time,
The temperature rises, and the temperature difference between the cooling water and the stagnant liquid approaches, making it difficult to exchange heat. Further, in the first heat exchanger 12, the temperature of the cooling water that exchanges heat with the refrigerant increases from the lower part to the upper part. Therefore, in the first heat exchanger 12, the upper part is harder to condense, and the condensing performance decreases. Will be caused. However, in the refrigeration apparatus according to the first embodiment, by disposing the liquid receiver 13 below the first heat exchanger 12, the condensed refrigerant immediately flows out of the first heat exchanger 12. Therefore, the above-described problem does not occur, and good heat exchange is performed.

The economizer 14 expands the high-pressure refrigerant liquid by the second expansion valve 18 and exchanges heat between the refrigerant liquid whose temperature has dropped and the high-pressure refrigerant liquid from the receiver 13, thereby removing the high-pressure refrigerant liquid. Cooling is performed. The refrigerant gas evaporated by heat exchange in the economizer 14 from the second expansion valve 18 is sucked into a gas compression space portion in the compressor 11, that is, an intermediate pressure portion. The liquid subcooler 15 is basically a plate type of a vertical one-pass counterflow type, and is formed integrally with the second heat exchanger 17 as described later. In the liquid subcooler 15, the high-pressure refrigerant in the liquid state, which has passed through the economizer 14, flows in from the upper high-pressure refrigerant inlet 25, flows downward from above, and flows out from the lower high-pressure refrigerant outlet 26. The low-pressure refrigerant containing the unevaporated component from the second heat exchanger 17 flows from the low-pressure refrigerant inlet 27 at the lower part and flows upward from below, and exchanges heat with the high-pressure refrigerant from the economizer 14 to exchange heat at the upper part. The refrigerant is discharged in a gaseous state from the low-pressure refrigerant outlet 28 toward the suction part S of the compressor 11.

The second heat exchanger 17 is basically a vertical one-pass counterflow type plate type. Then, the high-pressure refrigerant in the liquid state is expanded by the first expansion valve 16, and the refrigerant whose pressure and temperature have dropped is converted into the second heat exchanger 17 in the liquid state.
The coolant flows from the lower coolant inlet 35 into the upper coolant outlet 35 and flows out from the upper coolant outlet 36 in a state containing the un-evaporated components.
7, flows downward from above, and is cooled down by heat exchange with the refrigerant to flow out from the cooled water outlet 38 at the lower part.

FIG. 1 shows the flow of the refrigerant, and does not show the positional relationship, dimensions, shape, etc., of the components constituting the refrigeration system. 15 and the second heat exchanger 17 are separately shown. However, in this refrigerating apparatus, FIG.
As shown in FIG. 3, the liquid subcooler 15 and the second heat exchanger 17 are integrally formed. Hereinafter, this will be described in more detail.
4 to 6 show a conventionally known vertical one-pass counterflow type plate heat exchanger H, which is the same as the first heat exchanger 12. The heat exchanger H includes a plurality of plates 31 each having a fluid flow path therein, which are brought into contact with each other to form a plate group.
2 and 33, and the end plate 3
The plate group is sandwiched between 2 and 33.

On the other hand, in the case of this refrigerating apparatus, as shown in FIGS. One of the end plates made of the pressure-resistant member is omitted, and the two plate groups are brought into contact with each other. And the high pressure refrigerant outflow inlet 2 of the liquid subcooler 15
6, 25, and a first end plate 41 made of a pressure-resistant member provided with low-pressure refrigerant outflow ports 28, 27, and refrigerant outflow ports 36, 35 and cooling water outflow ports 38, 38 of the second heat exchanger 17.
The liquid subcooler 15 and the second heat exchanger 17 are sandwiched by a second end face plate 42 made of a pressure-resistant member provided with 37, and the liquid subcooler 15 and the second heat exchanger 17 are separated. It is formed as a one-plate heat exchanger in appearance.

With this configuration, the second heat exchanger 17 contains the refrigerant in the liquid state as much as possible, that is, the quality (the weight ratio of the gas in the refrigerant) becomes as small as possible so that the refrigerant and the refrigerant are cooled. The heat exchange with water is performed, and the heat exchange is performed more efficiently than the heat exchange between the gaseous refrigerant and the water to be cooled. In addition, the liquid supercooler 15 subcools the high-pressure refrigerant by utilizing the heat of vaporization of the low-pressure refrigerant in the liquid state from the second heat exchanger 17.
The temperature of the refrigerant after decompression flowing into the refrigerant 7 decreases according to the temperature reduction phenomenon peculiar to the non-azeotropic mixed refrigerant, so that the heat exchange efficiency is improved and the COP is also improved.

By the way, the end plate of the above-mentioned plate type heat exchanger is designed so that each plate is not broken by internal pressure.
It is a pressure-resistant member that protects them from the side, and in reality, the ratio of space and weight occupied in the heat exchanger is considerably large. In the present refrigeration apparatus, the liquid subcooler 15 and the second heat exchanger 17 are integrally formed, and originally two compact end plates that are interposed between the two units are compactly assembled. As a result, the space occupied by the entire device can be reduced and the weight can be reduced.

In FIGS. 1 to 3, solid arrows indicate the flow of the refrigerant and dashed-dotted arrows indicate the flow of the cooling water or the water to be cooled. Also, as described above, the first heat exchanger 12
And the liquid subcooler 15 is the same vertical type 1 as the second heat exchanger 17.
When the second heat exchanger 17 shown in FIG. 6 is applied to the first heat exchanger 12 in the plate type of the counter flow type, the solid arrow indicates the flow of the cooling water, and the dashed line indicates the flow of the refrigerant. Similarly, when applied to the liquid subcooler 15, the solid arrow indicates the flow of the low-pressure refrigerant, and the dashed-dotted arrow indicates the flow of the high-pressure refrigerant.

FIG. 7 shows a refrigeration apparatus according to a second embodiment of the present invention. Parts common to those of the refrigeration apparatus according to the first embodiment shown in FIGS. Omitted. In this refrigeration system, the refrigerant outlet 36 of the second heat exchanger 17 and the low-pressure refrigerant inlet 27 of the liquid subcooler 15
, A refrigerant gas space 51 having an upper part communicating with the refrigerant outlet 36 and a lower part having a low pressure refrigerant inlet 27.
A first gas-liquid separator 53 is provided as a refrigerant liquid reservoir 52 communicating with the refrigerant gas, and separates the refrigerant liquid and the refrigerant gas here. Further, a suction refrigerant flow passage 54 for connecting the refrigerant gas space 51 to the suction portion S of the compressor 11,
A merging refrigerant flow path 55 for communicating the low-pressure refrigerant outflow port 28 with the suction refrigerant flow path 54, and a merging portion between the suction refrigerant flow path 54 and the merging refrigerant flow path 55, are provided from the refrigerant gas space 51 to the compressor 11. An ejector 56 is provided which causes the refrigerant gas flowing toward the suction portion S to suck the refrigerant gas from the low-pressure refrigerant outlet 28 and accompany the refrigerant gas. Note that the first gas-liquid separator 53 is arranged above the liquid subcooler 15.

Further, the heat exchange efficiency in the liquid subcooler 15 is improved by such a configuration. That is, when the refrigerant is directly sent from the second heat exchanger 17 to the liquid subcooler 15, a large amount of gaseous refrigerant having low heat exchange efficiency is included, while the heat exchange efficiency utilizing latent heat during evaporation is reduced. Less refrigerant in good liquid state. However, in the case of the refrigeration apparatus according to the third embodiment, the first gas-liquid separator 5
3 is provided, where the refrigerant liquid and the refrigerant gas are separated and, for heat exchange, rather hindered refrigerant gas is directly sent to the compressor 11 and only the refrigerant liquid is led to the liquid subcooler 15. Thus, a desired state is created for the heat exchange in the liquid subcooler 15.

FIG. 8 shows a refrigerating apparatus according to a third embodiment of the present invention, and the same reference numerals are given to parts common to the refrigerating apparatuses according to the above-described embodiments, and description thereof will be omitted. In this refrigerating apparatus, the compressor 11 is of a semi-hermetic type housed in the same casing C as the motor M as a driving part thereof, and the compressor 11 is provided between the liquid subcooler 15 and the compressor 11.
The lower part is a refrigerant liquid reservoir 61 and the upper part is a refrigerant gas space 62.
A first refrigerant flow path 64 that communicates the low-pressure refrigerant outlet 28 and the refrigerant gas space 62 with the second gas-liquid separator 63 and the refrigerant liquid reservoir 61 is drawn into the compressor 11 by suction. A second refrigerant flow path 65 that directly communicates with the section S, and a suction refrigerant flow path 66 that guides the refrigerant gas from the refrigerant gas space section 62 through the motor M in the casing C to the suction section S. is there. Further, a first temperature sensor 67 is provided on the primary side of the refrigerant inlet 35, and a second temperature sensor 68 is provided on the suction refrigerant flow path 66 so as to detect the refrigerant temperature. The opening degree of the first expansion valve 16 is controlled so that the difference between the temperatures detected by the temperature sensor 67 and the second temperature sensor 68 becomes constant.

In the refrigerating apparatus using the non-azeotropic mixed refrigerant, as described above, the temperature difference between the refrigerant on the primary side of the refrigerant inlet 35 of the second heat exchanger 17 and the refrigerant in the suction refrigerant passage 66 of the compressor 11. The opening degree of the first expansion valve 16 is controlled so as to be constant, and the temperature difference is usually set to the temperature slip plus α, and this α becomes the degree of superheat. In order to realize a high efficiency operation of the refrigeration system, it is desirable to make this α as small as possible. However, since the second gas-liquid separator 63 and the second refrigerant flow path 65 are not provided, the refrigerant flows from the low-pressure refrigerant outlet 28 to the refrigerant. Is directly led to the suction portion S, the smaller the α is, the greater the amount of liquid mist scattered in the suction refrigerant flow path 66. As a result, even if the refrigerant temperature is detected by the second temperature sensor 68 on the primary side, the detected temperature is not limited to the refrigerant gas temperature, but may be the refrigerant liquid temperature. A problem arises in that the opening degree control of No. 16 becomes unstable.

In the case of the refrigerating apparatus according to the third embodiment, the refrigerant gas and the refrigerant gas are separated by the second gas-liquid separator 63 so that the second temperature sensor 68 detects only the temperature of the refrigerant gas. This prevents the above-described problem from occurring. Further, when the refrigerant in the refrigerant liquid reservoir 61 passes through the portion of the motor M, the motor M is excessively cooled, and as a result, the efficiency of the compressor 11 is reduced. For this reason, in this refrigeration system, the refrigerant liquid in the refrigerant liquid reservoir 61 is directly guided to the suction part S without passing through the motor M by the second refrigerant flow path 65, and only the refrigerant gas in the refrigerant gas space 62 is supplied to the motor M. The motor M is cooled by passing through the portion. In addition to preventing the motor M from being excessively cooled, the suction of the refrigerant liquid into the suction portion S is promoted by the pressure drop of the refrigerant gas due to the pressure loss when the refrigerant gas passes through the motor M.

The refrigerant mixture in each of the above embodiments includes a mixture of two or more refrigerants, as well as a mixture of three or more refrigerants. In each of the above embodiments, the first heat exchanger 12 and the second heat exchanger 17 use water as the fluid to be exchanged with the mixed refrigerant, but the present invention is not limited to this. In the second embodiment of the present invention, an ejector is shown as a suction unit. However, the present invention is not limited to this. For example, a suction pump may be provided instead of the ejector.

[0026]

As is apparent from the above description, according to the first invention, at least the compressor, the first heat exchanger for condensation,
In a refrigeration system including a closed non-azeotropic refrigerant mixture circulation path including a liquid receiver, a first expansion valve, and a second heat exchanger for evaporation, a high-pressure refrigerant before reaching the first expansion valve flows thereinto. And flows out from the upper part to the lower part and flows out from the lower part toward the first expansion valve, while the low-pressure refrigerant flowing out from the second heat exchanger flows and flows from the lower part to the upper part and sucks the compressor. A liquid subcooler, which is a vertical one-pass counter-flow type heat exchanger that flows out in a gas state toward the part,
The second heat exchanger is a vertical one-pass counterflow type in which refrigerant flows from bottom to top through the first expansion valve, while water to be cooled flows from top to bottom, and contains unevaporated components. The refrigerant is allowed to flow toward the liquid subcooler, and each of the liquid subcooler and the second heat exchanger is formed of a plate group including a plurality of plates forming a fluid flow path of a plate heat exchanger. A structure in which one end plate of the end plates made of pressure-resistant members on both sides to be sandwiched is omitted, and the side surfaces with both end plates omitted are brought into contact with each other, facing the contacted side surfaces, A first pressure-resistant member provided with a high-pressure refrigerant outlet and a low-pressure refrigerant outlet of the liquid subcooler;
The end face plate and the side surface in contact with the end face plate;
The liquid subcooler and the respective plate groups of the second heat exchanger are sandwiched by a second end plate made of a pressure-resistant member provided with a refrigerant outflow port and a cooled water outflow port of the heat exchanger, and the liquid subcooling is performed. The heat exchanger and the second heat exchanger are integrally formed. For this reason, in the refrigerating apparatus using the non-azeotropic mixed refrigerant, the heat exchange efficiency and the evaporating performance in the second heat exchanger for evaporation are improved, and the coefficient of performance (COP) can be improved. There is an effect that the space can be reduced and the weight can be reduced.

According to the second invention, for a closed non-azeotropic mixed refrigerant including at least a compressor, a first heat exchanger for condensation, a liquid receiver, a first expansion valve, and a second heat exchanger for evaporation. In the refrigerating apparatus having the circulation flow path of the above, the high-pressure refrigerant before reaching the first expansion valve is caused to flow in, flow from top to bottom, and flow out from the lower part toward the first expansion valve, and A liquid subcooler, which is a vertical one-pass counter-flow type heat exchanger that causes the low-pressure refrigerant flowing out of the heat exchanger to flow in, flow upward from the bottom, and flow out in a gas state toward the suction portion of the compressor. And the second heat exchanger is provided with the first heat exchanger.
A vertical one-pass counter-flow type in which the refrigerant flowing through the expansion valve flows from bottom to top while the water to be cooled flows from top to bottom, and the refrigerant containing unevaporated components is directed to the liquid subcooler. A refrigerant gas space interposed in the refrigerant flow path between the refrigerant outlet of the second heat exchanger and the low-pressure refrigerant inlet of the liquid subcooler, and having an upper part communicating with the refrigerant outlet. A first gas-liquid separator having a lower portion and a lower portion serving as a refrigerant liquid reservoir communicating with the low-pressure refrigerant inflow port; a suction refrigerant flow path communicating the refrigerant gas space with a suction portion of the compressor; A merging refrigerant flow path that communicates the low-pressure refrigerant outlet with the refrigerant flow path, a merging part between the suction refrigerant flow path and the merging refrigerant flow path, and from the refrigerant gas space to the suction part of the compressor. The refrigerant gas flowing from the low-pressure refrigerant outlet into the refrigerant gas flowing toward Is allowed, there is a structure in which the ejector to associated. For this reason, pressure loss is reduced,
As in the first invention, the heat exchange efficiency and the evaporation performance are improved, and the coefficient of performance (COP) can be improved.

According to the third invention, in addition to the structure of the second invention, the first gas-liquid separator is arranged above the liquid subcooler. From this, there is an effect that the effect of the second invention is further promoted.

Further, according to the fourth aspect of the invention, the compressor is a semi-hermetic type housed in the same casing as a motor as a driving unit thereof, and the compressor is provided between the liquid subcooler and the compressor. A first refrigerant flow path interposing a second gas-liquid separator in which a lower portion is a refrigerant liquid storage portion and an upper portion is a refrigerant gas space portion, and communicates the low-pressure refrigerant outlet with the refrigerant gas space portion; A second refrigerant flow path that directly communicates the refrigerant liquid reservoir with a suction part of the compressor; and a suction refrigerant flow path that guides refrigerant gas from the refrigerant gas space through a motor in the casing to the suction part. Are formed. Therefore, in the case of a refrigeration system using a semi-hermetic compressor, the first
An effect that the effect of the invention is further promoted is exhibited.

Further, according to the fifth invention, the first heat exchanger allows the refrigerant flowing from the compressor to flow from top to bottom while the cooling water flows from bottom to top. It is of a type and arranged above the liquid receiver. For this reason, in addition to the effect by each said invention, there exists an effect that the heat exchange efficiency in the 1st heat exchanger for condensation is maintained in a favorable state, and the condensation performance improves.

[Brief description of the drawings]

FIG. 1 is a refrigerant system diagram of a refrigeration apparatus according to a first embodiment of the present invention.

FIG. 2 is a front view schematically showing a liquid subcooler and a second heat exchanger of the refrigeration apparatus shown in FIG.

FIG. 3 is a perspective view schematically showing a part of a liquid subcooler and a second heat exchanger shown in FIG. 2;

FIG. 4 is a front view of a conventionally known vertical one-pass counterflow type plate heat exchanger.

FIG. 5 is a left side view of the heat exchanger shown in FIG.

FIG. 6 is an exploded perspective view of the heat exchanger shown in FIG.

FIG. 7 is a refrigerant system diagram of a refrigeration apparatus according to a second embodiment of the present invention.

FIG. 8 is a refrigerant system diagram of a refrigeration apparatus according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Compressor 12 1st heat exchanger 13 Liquid receiver 14 Economizer 15 Liquid supercooler 16 1st expansion valve 17 2nd heat exchanger 18 2nd expansion valve 21 Refrigerant inlet 22 Refrigerant outlet 23 Cooling water inlet 24 Cooling Water outlet 25 High-pressure refrigerant inlet 26 High-pressure refrigerant outlet 27 Low-pressure refrigerant inlet 28 Low-pressure refrigerant outlet 31 Plate 32,33 End plate 34 Bolt / nut 35 Refrigerant inlet 36 Refrigerant outlet 37 Cooled water inlet 38 Cooled water flow Outlet 41 First end face plate 42 Second end face plate 51 Refrigerant gas space part 52 Refrigerant liquid reservoir part 53 First gas-liquid separator 54 Suction refrigerant flow path 55 Merging refrigerant flow path 56 Ejector 61 Refrigerant liquid storage part 62 Refrigerant gas space 63 Second gas-liquid separator 64 First refrigerant flow path 65 Second refrigerant flow path 66 Suction refrigerant flow path 67 First temperature sensor 68 Second temperature sensor I Circulation flow path II Subcooling flow path S Suction section

Claims (5)

[Claims] 1. A closed circulation path for a non-azeotropic mixed refrigerant including at least a compressor, a first heat exchanger for condensation, a receiver, a first expansion valve, and a second heat exchanger for evaporation. In the refrigerating apparatus, the high-pressure refrigerant before reaching the first expansion valve is flowed in from the top to the bottom, and is discharged from the lower part toward the first expansion valve, while the low-pressure refrigerant flowing from the second heat exchanger is discharged. A liquid subcooler, which is a vertical one-pass counter-flow type heat exchanger that allows a refrigerant to flow in from the bottom to flow upward from the bottom and to flow out in a gas state toward the suction portion of the compressor, and A vertical one-pass counterflow type in which the heat exchanger flows the refrigerant flowing through the first expansion valve from bottom to top while flowing the water to be cooled from top to bottom, and contains a non-evaporated component. To the liquid subcooler, and the liquid subcooler and For each of the second heat exchangers, one of the end plates made of pressure-resistant members on both sides sandwiching a plate group consisting of a plurality of plates forming a fluid flow path of the plate heat exchanger is omitted. In addition to the structure, the two sides without the end plates abut each other,
A first end plate made of a pressure-resistant member provided with a high-pressure refrigerant outflow port and a low-pressure refrigerant outflow port of the liquid subcooler, facing the contacted side surface, and facing the contacted side surface, and The liquid subcooler and each plate group of the second heat exchanger are sandwiched by a second end face plate made of a pressure-resistant member provided with a refrigerant outflow port and a cooled water outflow port of the second heat exchanger, A refrigeration apparatus wherein the liquid subcooler and the second heat exchanger are integrally formed. 2. A closed circulation path for a non-azeotropic mixed refrigerant including at least a compressor, a first heat exchanger for condensation, a liquid receiver, a first expansion valve, and a second heat exchanger for evaporation. In the refrigerating apparatus, the high-pressure refrigerant before reaching the first expansion valve is flowed in from the top to the bottom, and is discharged from the lower part toward the first expansion valve, while the low-pressure refrigerant flowing from the second heat exchanger is discharged. A liquid subcooler, which is a vertical one-pass counter-flow type heat exchanger that allows a refrigerant to flow in from the bottom to flow upward from the bottom and to flow out in a gas state toward the suction portion of the compressor, and A vertical one-pass counterflow type in which the heat exchanger flows the refrigerant flowing through the first expansion valve from bottom to top while flowing the water to be cooled from top to bottom, and contains a non-evaporated component. To the liquid subcooler, and the second heat exchanger A refrigerant gas space portion that is interposed in the refrigerant flow path between the refrigerant outlet and the low-pressure refrigerant inlet of the liquid subcooler and has an upper portion communicating with the refrigerant outlet, and a lower portion communicating with the low-pressure refrigerant inlet. A first gas-liquid separator serving as a liquid reservoir, a suction refrigerant flow path for connecting the refrigerant gas space to a suction part of the compressor, and a confluence for connecting the low-pressure refrigerant outlet to the suction refrigerant flow path A refrigerant flow path, interposed at the junction of the suction refrigerant flow path and the merged refrigerant flow path, into the refrigerant gas flowing from the refrigerant gas space toward the suction part of the compressor, the low-pressure refrigerant outlet A refrigerating apparatus provided with suction means for sucking and accompanying refrigerant gas from the refrigerator. 3. The refrigeration apparatus according to claim 2, wherein the first gas-liquid separator is disposed above the liquid subcooler. 4. A compressor according to claim 1, wherein said compressor is a semi-hermetic type housed in the same casing as a motor which is a driving unit thereof, and a lower portion of said compressor is provided between said liquid supercooler and said compressor. A second gas-liquid separator having an upper portion serving as a refrigerant gas space portion is provided, and a first refrigerant flow path that communicates the low-pressure refrigerant outlet with the refrigerant gas space portion, and the refrigerant liquid reservoir portion is formed as described above. A second refrigerant flow path directly communicating with the suction part of the compressor, and a suction refrigerant flow path for guiding the refrigerant gas from the refrigerant gas space through the motor in the casing to the suction part. The refrigeration apparatus according to claim 1, wherein: 5. The vertical one-pass counterflow type in which the first heat exchanger causes the refrigerant flowing from the compressor to flow from top to bottom, and the cooling water to flow from bottom to top. The refrigeration apparatus according to any one of claims 1 to 4, wherein the refrigeration apparatus is disposed above the vessel.