JP2000146326A - Vapor compressing refrigerating machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vapor compressing refrigerating machine employing water as refrigerant. SOLUTION: A vapor compressing refrigerating machine is provided with a multi-stage compressor 11 for compressing refrigerant R sequentially, a condenser 4 for cooling the refrigerant R, sent from the multi-stage compressor 11, by secondary fluid X, an expansion valve 7 for expanding the refrigerant R, sent from the condenser 4, through adiabatic expansion, an evaporator 8, for cooling another secondary fluid Y by the refrigerant R sent from the expansion valve 7 and sending the refrigerant R to the multi-stage compressor 11, and heat exchangers 17, 18 for cooling the refrigerant R, compressed sequentially by the multi-stage compressor 11, by the secondary fluid X. The heat of the refrigerant R is transferred to the secondary fluid X during respective stages compression processes of the multi-stage compressor 11 to restrain the rise of discharging temperature of the refrigerant R for the multi-stage compressor 11 and improve the performance coefficient of the refrigerating machine employing water as the refrigerant R.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a vapor compression refrigerator.

[0002]

2. Description of the Related Art Refrigerators are quite matured research and development fields, and the basic theory has been established. However, in order to further improve the performance, research on various equipment and refrigeration cycles is continuously performed. ing.

FIG. 8 shows an example of a refrigerator (vapor compression refrigerator) operating in a vapor compression cycle. This vapor compression refrigerator uses a rotating force transmitted from a motor 1 via a speed reducer 2 to a refrigerant. A single-stage compressor 3 for compressing and discharging R;
The condenser 4 cools the refrigerant R sent from the single-stage compressor 3 via the pipe 5 by the secondary fluid X flowing through the secondary flow path 4a, and from the condenser 4 via the pipe 6 The expansion valve 7 for adiabatically expanding the supplied refrigerant R and the secondary fluid Y flowing through the secondary flow path 8a take cold energy from the refrigerant R supplied from the expansion valve 7 through the pipe 9. To evaporate and the refrigerant R
And an evaporator 8 that feeds the oil to the single-stage compressor 3 via a pipe 10.

That is, the refrigerant R, which has absorbed heat from the secondary fluid Y in the evaporator 8 and has become dry saturated vapor, is supplied to the single-stage compressor 3.
Then, the refrigerant R which is isentropically compressed into superheated vapor is released into the secondary fluid X in the condenser 4 to become a saturated liquid.

Further, the refrigerant R which has become a saturated liquid is supplied to the expansion valve 7.
When the air passes through the evaporator 8, it is decompressed and isenthalpy-expanded to become wet saturated steam, enters the evaporator 8, absorbs heat from the secondary fluid Y, and becomes dry saturated steam.

Generally, water is used for the secondary fluid X of the condenser 4, and the secondary fluid X heated by obtaining heat released from the refrigerant R in the condenser 4 is supplied to a cooling tower or the like. After being cooled by the heat exchange means, it is again supplied to the secondary flow path 4a.

Water is often used also for the secondary fluid Y of the evaporator 8, but when the object to be cooled is 0 ° C. or less, in order to prevent freezing, water mixed with antifreeze, Fluid with a freezing temperature of 0 ° C or less such as ethylene glycol
Used for the next fluid Y.

[0008] The secondary fluid Y cooled by absorbing heat in the refrigerant R in the evaporator 8 is heated by a heat exchange means such as a cooling pipe, and then sent to the secondary flow path 8a again. .

FIG. 9 is a pressure enthalpy diagram (Ph diagram) of the above-mentioned vapor compression refrigerator.
, B3 denotes an outlet of the single-stage compressor 3, A7 denotes an inlet of the expansion valve 7, and B7 denotes an outlet of the expansion valve 7.

The amount of heat q8 absorbed by the refrigerant R in the evaporator 8 per kg, the amount of heat q4 released by the refrigerant R in the condenser 4 per kg, and the compression work w in the single-stage compressor 3 are:
The enthalpy (thermodynamic state quantity) of the refrigerant R is represented as follows.

[0011]

[Equation 1] q4 = h1-h2

[0012]

## EQU2 ## q8 = h4-h3 = h4-h2

[0013]

W = h2-h1 h1: enthalpy of refrigerant R as superheated vapor h2: enthalpy of refrigerant R as saturated liquid h3: enthalpy of refrigerant R as wet saturated vapor h4: dry enthalpy of refrigerant R Enthalpy of refrigerant R

The capacity of a vapor compression refrigerator is often evaluated by the following coefficient of performance ε.

[0015]

Ε = (h4−h3) / (h2−h1)

That is, the capacity of the vapor compression refrigerator is determined by how many times the heat from the secondary fluid Y of the evaporator 8 can be removed from the work by the single-stage compressor 3.

When the refrigerant R is cooled (supercooled) to a temperature not higher than the saturation temperature in the condenser 4, the pressure and enthalpy of the refrigerant R change along a path shown by a two-dot chain line in FIG.
As a result, it is well known that the amount of absorbed heat q8 (refrigeration capacity) of the evaporator 8 is increased and the coefficient of performance ε is improved.

As the refrigerant R of the above-mentioned vapor compression refrigerator, it is generally desirable to use a refrigerant satisfying the following conditions. 1) It is chemically stable and does not decompose or deteriorate. 2) No chemical reaction with constituent materials of the refrigerator. 3) There is no danger of burning or explosion. 4) Harmless to humans and animals. 5) Leak detection is easy. 6) It does not exhibit a phase change at high pressure and low pressure more than necessary. 7) Low specific heat and high thermal conductivity. 8) Does not contribute to global warming and does not destroy the ozone layer.

[0019]

However, the ammonia and freon-based refrigerants (R12, R22, R123, R1) used as the refrigerant R in the conventional vapor compression refrigerators.
34a, and mixtures thereof), and hydrocarbon-based refrigerants (such as propane, isobutane, methane, and mixtures thereof) do not satisfy all of the aforementioned conditions.

That is, although ammonia has excellent thermodynamic properties, it is highly toxic and, in addition, corrodes a copper material having good thermal conductivity.

The freon-based refrigerant is chemically stable and has no danger of combustion or explosion. However, in recent years, its use has been regulated in order to suppress global warming and ozone layer depletion.

Hydrocarbon-based refrigerants have a characteristic of easily burning and exploding, and require strict management.

The present invention has been made in view of the above circumstances, and has as its object to provide a vapor compression refrigerator using water as a refrigerant which is chemically stable and does not affect the global environment.

[0024]

In order to achieve this object, in a vapor compression refrigerator according to the first aspect of the present invention, a multi-stage compressor for sequentially compressing refrigerant, and a refrigerant supplied from the multi-stage compressor. A condenser that cools the refrigerant with a secondary fluid, an expansion valve that adiabatically expands the refrigerant sent from the condenser, a multistage cooling of the secondary fluid with the refrigerant sent from the expansion valve, and multi-stage cooling. An evaporator for feeding the compressor and a heat exchanger for cooling the refrigerant sequentially compressed by the multistage compressor with a secondary fluid are provided, and water is used as the refrigerant.

According to a second aspect of the present invention, there is provided a vapor compression refrigerator comprising a multi-stage compressor for sequentially compressing refrigerant, and a condenser for cooling the refrigerant supplied from the multi-stage compressor by a secondary fluid. An expansion valve for adiabatically expanding a refrigerant supplied from the condenser, an evaporator for cooling a secondary fluid by the refrigerant supplied from the expansion valve, and supplying the refrigerant to a multi-stage compressor; And a refrigerant tank for bringing the refrigerant supplied from the compressor into the expansion valve into contact with the refrigerant sequentially compressed by the multi-stage compressor, and uses water as the refrigerant.

Further, in the vapor compression refrigerator according to a third aspect of the present invention, a multi-stage compressor for sequentially compressing the refrigerant, and a condenser for cooling the refrigerant sent from the multi-stage compressor with a secondary fluid. An expansion valve for adiabatically expanding a refrigerant supplied from the condenser, an evaporator for cooling a secondary fluid by the refrigerant supplied from the expansion valve and supplying the refrigerant to a multi-stage compressor, A heat exchanger that cools the refrigerant sequentially compressed by the compressor with the secondary fluid, and a refrigerant tank that makes contact with the refrigerant fed from the condenser to the expansion valve and the refrigerant sequentially compressed by the multi-stage compressor, Water is used as the refrigerant.

Further, in the vapor compression refrigerator according to a fourth aspect of the present invention, a single-stage compressor for compressing the refrigerant, and a condensate for cooling the refrigerant sent from the single-stage compressor with a secondary fluid. A condenser, an expansion valve for adiabatically expanding the refrigerant supplied from the condenser, and an evaporator for cooling the secondary fluid by the refrigerant supplied from the expansion valve and supplying the refrigerant to the single-stage compressor. And a cooler for cooling the refrigerant compression process portion of the single-stage compressor with a secondary fluid, and uses water as the refrigerant.

In the vapor compression refrigerator according to the first aspect of the present invention, the heat of the refrigerant sequentially compressed by the multi-stage compressor is
The refrigerant is transmitted to the secondary fluid by the heat exchanger, thereby suppressing an increase in the discharge temperature of the refrigerant of the multi-stage compressor, thereby improving the coefficient of performance of the refrigerator.

In the vapor compression refrigerator according to the second aspect of the present invention, the refrigerant sequentially compressed by the multistage compressor is brought into contact with the refrigerant supplied from the condenser to the expansion valve by the refrigerant tank. In addition, an increase in the discharge temperature of the refrigerant of the multi-stage compressor is suppressed, and the coefficient of performance of the refrigerator is improved.

Further, in the vapor compression refrigerator according to the third aspect of the present invention, the heat of the refrigerant sequentially compressed by the multi-stage compressor is transmitted to the secondary fluid by the heat exchanger, and the heat is transferred to the secondary fluid by the multi-stage compressor. The refrigerant that is sequentially compressed is brought into contact with the refrigerant supplied from the condenser to the expansion valve by the refrigerant tank, thereby suppressing an increase in the refrigerant discharge temperature of the multi-stage compressor, and improving the coefficient of performance of the refrigerator.

Further, in the vapor compression refrigerator according to claim 4 of the present invention, the heat of the cooling process part of the single-stage compressor is transmitted to the secondary fluid by the cooler, and the heat of the single-stage compressor is reduced. A rise in the refrigerant discharge temperature is suppressed, and the coefficient of performance of the refrigerator is improved.

[0032]

Embodiments of the present invention will be described below with reference to the drawings.

In FIGS. 1 to 7, the same reference numerals as in FIGS. 8 and 9 denote the same parts.

FIG. 1 shows a first embodiment of a vapor compression refrigerator according to the present invention.
Compressor 11 that sequentially compresses and discharges the refrigerant R by the rotational force transmitted from the speed reducer 2 through the secondary flow path 4a
That cools the refrigerant R sent from the multi-stage compressor 11 via the pipe 12 by the secondary fluid X flowing through the condenser 4
And an expansion valve 7 for adiabatically expanding the refrigerant R supplied from the condenser 4 through the pipe 6 and a pipe 9 from the expansion valve 7 by the secondary fluid Y flowing through the secondary flow path 8a. An evaporator 8 which takes cold energy from the refrigerant R sent through the evaporator 8 to evaporate the refrigerant R and supplies the refrigerant R to the multi-stage compressor 11 via the pipe 13
And water is used as the refrigerant R.

The multi-stage compressor 11 includes three compression parts (a casing in which a scroll and a diffuser are formed, an impeller mounted in the casing, etc.)
5 and 16, the first stage compression process portion 14 and the second stage
A heat exchanger 17 having secondary flow paths 17a, 18a is provided in the flow path of the refrigerant R between the stage compression process portion 15 and the second stage compression process portion 15 and the third stage compression process portion 16. , 18 are provided.

The secondary passages 17a, 1 of the heat exchangers 17, 18
The inlet of 8a communicates with the pipe 4b for supplying the secondary fluid X to the secondary flow path 4a of the condenser 4 via the pipes 17b and 18b, and the outlets of the secondary flow paths 17a and 18a are: Line 17
The secondary fluid X is connected to a conduit 4c for discharging the secondary fluid X from the secondary flow path 4a of the condenser 4 through the pipes c and 18c.

FIG. 2 is a pressure enthalpy diagram (Ph diagram) of the above-mentioned vapor compression refrigerator, wherein A14 is an inlet of the first stage compression process portion 14, and B14 is an outlet of the first stage compression process portion 14. (The inlet of the heat exchanger 17), A15 is the inlet of the second stage compression process part 15 (the outlet of the heat exchanger 17), B15 is the outlet of the second stage compression process part 15 (the inlet of the heat exchanger 18), A16 Is the inlet of the third stage compression stage 16 (the outlet of the heat exchanger 18);
B16 is the outlet of the third stage compression section 16; A7 is the expansion valve 7
, B7 represents the outlet of the expansion valve 7.

In the above-described vapor compression refrigerator, the refrigerant R discharged from the first stage compression stage portion 14 of the multistage compressor 11
Is cooled by the secondary fluid X flowing through the secondary flow path 17a of the heat exchanger 17, and the refrigerant R discharged from the second stage compression process portion 15 flows through the secondary flow path 18a of the heat exchanger 18. Since the cooling is performed by the secondary fluid X, an increase in the discharge temperature of the refrigerant R of the multi-stage compressor 11 is suppressed.

Therefore, the outlet B of the third stage compression process section 16
The enthalpy at 16 can be reduced as compared with the case where the cooling of the refrigerant R shown by the two-dot chain line in FIG. 2 is not performed.

Thus, the specific volume of ammonia is 100
Even if water having twice or more times is used as the refrigerant R, it is possible to improve the coefficient of performance ε for evaluating the performance of the vapor compression refrigerator.

Further, since water that is chemically stable and non-toxic is used as the refrigerant R, the refrigerant R does not contribute to global warming and ozone layer destruction. Even if the refrigerant R leaks, it burns and explodes. There is no danger of being safe.

FIG. 3 shows a second embodiment of the vapor compression refrigerator according to the present invention. In this vapor compression refrigerator, pipes 17b and 18b and pipes 17c and 18c in FIG. At the inlets of the secondary flow paths 17a, 18a of the heat exchangers 17, 18, independent pipe lines 17d, 18d for supplying the secondary fluid X to the secondary flow paths 17a, 18a are connected. The outlets of the passages 17a, 18a are connected to the secondary passages 17a, 18a.
a separate line 17 for discharging secondary fluid X from a
e, 18e are connected.

Also in the above-mentioned vapor compression refrigerator, the refrigerant R discharged from the compression process parts 14 and 15 of the multi-stage compressor 11 is transferred to the secondary passages 17 a and 18 a of the heat exchangers 17 and 18.
Is cooled by the secondary fluid X flowing therethrough, so that the same operational effects as those of the vapor compression refrigerator shown in FIG. 1 can be obtained.

FIG. 4 shows a third embodiment of the vapor compression refrigerator according to the present invention.
Compressor 19 for sequentially compressing and discharging the refrigerant R by the rotational force transmitted from the speed reducer 2 through the reducer 2, the condenser 4, the expansion valve 7, the evaporator 8, and a refrigerant tank 20 having an airtight structure. Water is used for R.

The multi-stage compressor 19 includes two compression process parts 2
A conduit 23 communicating with an outlet of the evaporator 8 is connected to an inlet of the first stage compression process part 21,
The outlet of the second stage compression section 22 is connected to a line 24 communicating with the inlet of the condenser 4.

The outlet of the first stage compression section 21 and the inlet of the second stage compression section 22 are connected to the refrigerant tank 20 via lines 25 and 26.

Further, the outlet of the condenser 4 and the inlet of the expansion valve 7 are connected to the refrigerant tank 20 via lines 27 and 28, and the outlet of the expansion valve 7 is evaporated via the line 9. Table 8
Connected to the entrance.

FIG. 5 is a pressure enthalpy diagram (Ph diagram) of the above-mentioned vapor compression refrigerator, where A21 is an inlet of the first stage compression process portion 21, and B21 is an outlet of the first stage compression process portion 21. , A22 is the inlet of the second stage compression process part 22, and B22 is the second stage.
The outlet of the stage compression process part 22, C 27 is the refrigerant tank 2 of the line 27.
0 (connection end of the pipe 28 to the refrigerant tank 20), A
Reference numeral 7 denotes an inlet of the expansion valve 7, and B7 denotes an outlet of the expansion valve 7.

In the above-described vapor compression refrigerator, the refrigerant tank 20
, The refrigerant R (superheated steam) supplied from the first stage compression process portion 21 to the second stage compression process portion 22 of the multi-stage compressor 19 and the refrigerant R (supplied from the condenser 4 to the expansion valve 7) Since the heat exchange is performed with the saturated liquid), the rise in the discharge temperature of the refrigerant R of the multi-stage compressor 19 is suppressed.

Therefore, the outlet B of the second stage compression process part 22
22 enthalpies can be reduced.

Thus, even when water is used as the refrigerant R, the coefficient of performance ε for evaluating the performance of the vapor compression refrigerator can be improved.

Further, since water that is chemically stable and non-toxic is used as the refrigerant R, the refrigerant R does not contribute to global warming or ozone layer destruction. Even if the refrigerant R leaks, it burns and explodes. There is no danger of being safe.

FIG. 6 shows a fourth embodiment of the vapor compression refrigerator according to the present invention.
Single-stage compressor 3, a condenser 4, an expansion valve 7, which compresses and discharges the refrigerant R by the rotational force transmitted from the
A cooling jacket 29 surrounding the evaporator 8 and the cooling process part of the single-stage compressor 3 is provided, and water is used as the refrigerant R.

At the inlet of the cooling jacket 29, a pipe 4
The pipe 29b communicating with the pipe 4c is connected to a pipe 29b communicating with the pipe 4c.
Is connected.

In the above-described vapor compression refrigerator, the pipeline 4b,
Since the secondary fluid X flowing into the cooling jacket 29 via the pipe 29b and flowing out from the cooling jacket 29 via the pipes 29c and 4c cools the compression process part of the single-stage compressor 3, the single-stage compressor 3 is cooled. The rise in the discharge temperature of the refrigerant R is suppressed.

Therefore, the enthalpy at the outlet of the single-stage compressor 3 can be reduced.

Thus, even when water is used as the refrigerant R, the coefficient of performance ε for evaluating the performance of the vapor compression refrigerator can be improved.

Further, in the single-stage compressor 3, since the refrigerant R is compressed at an isothermal temperature, the enthalpy difference between the inlet and the outlet of the compressor becomes smaller than the entropy compression, and the motor for driving the single-stage compressor 3 1 can be reduced.

Further, since water that is chemically stable and non-toxic is used as the refrigerant R, the refrigerant R does not contribute to global warming or ozone layer destruction. There is no danger of being safe.

FIG. 7 shows a fifth embodiment of the vapor compression refrigerator according to the present invention. In this vapor compression refrigerator, a cooling jacket 29 is used instead of the pipes 29b and 29c in FIG. An independent conduit 29 d for supplying the secondary fluid X to the cooling jacket 29 is connected to the inlet of the cooling jacket 29, and the cooling jacket 29 is connected to the outlet of the cooling jacket 29.
An independent pipe line 29e for discharging the secondary fluid X from is connected.

In the above-described vapor compression refrigerator, the secondary fluid X flowing into the cooling jacket 29 via the pipe 29d and flowing out from the cooling jacket 29 via the pipe 29d is used to compress the single-stage compressor 3 by the secondary fluid X. Since the process part is cooled, the same operation and effect as those of the vapor compression refrigerator shown in FIG. 6 can be obtained.

The steam compression refrigerator of the present invention is not limited to the above-described embodiment. For example, the steam compression refrigerator shown in FIG. A compressor may be added to cool the refrigerant sequentially compressed by the multi-stage compressor with the secondary fluid. Of course, other changes may be made without departing from the spirit of the present invention.

[0063]

As described above, according to the vapor compression refrigerator of the present invention, the following various excellent effects can be obtained.

(1) In the vapor compression refrigerator according to the first aspect of the present invention, the heat of the refrigerant sequentially compressed by the multi-stage compressor is transmitted to the secondary fluid by the heat exchanger, so that the multi-stage compressor is provided. Therefore, even if water is used as the refrigerant, the coefficient of performance of the refrigerator can be improved.

(2) In the vapor compression refrigerator according to the second aspect of the present invention, the refrigerant sequentially compressed by the multistage compressor is brought into contact with the refrigerant supplied from the condenser to the expansion valve by the refrigerant tank. Thus, the rise in the discharge temperature of the refrigerant of the multi-stage compressor is suppressed, so that even if water is used as the refrigerant, the coefficient of performance of the refrigerator can be improved.

(3) In the vapor compression refrigerator according to the third aspect of the present invention, the heat of the refrigerant sequentially compressed by the multi-stage compressor is transmitted to the secondary fluid by the heat exchanger, and the multi-stage compressor is also provided. The refrigerant that is sequentially compressed by the refrigerant tank is brought into contact with the refrigerant that is sent from the condenser to the expansion valve by the refrigerant tank, thereby suppressing an increase in the discharge temperature of the refrigerant of the multi-stage compressor. It is possible to improve the coefficient of performance of the refrigerator.

(4) In the vapor compression refrigerator according to the fourth aspect of the present invention, the heat of the cooling process portion of the single-stage compressor is
Since it is transmitted to the secondary fluid by the cooler and suppresses a rise in the discharge temperature of the refrigerant of the single-stage compressor, even if water is used as the refrigerant,
It is possible to improve the coefficient of performance of the refrigerator,
The load on the prime mover that drives the single-stage compressor can be reduced.

(5) Further, in any of the vapor compression refrigerators according to the first to fourth aspects of the present invention, since chemically stable and non-toxic water is used as the refrigerant, the refrigerant can be used for global warming. It is safe from accidents and ozone depletion, and has no danger of combustion or explosion even if refrigerant leaks.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a first example of an embodiment of a vapor compression refrigerator of the present invention.

FIG. 2 is a pressure enthalpy diagram of the vapor compression refrigerator shown in FIG.

FIG. 3 is a conceptual diagram showing a second example of the embodiment of the vapor compression refrigerator of the present invention.

FIG. 4 is a conceptual diagram showing a third example of the embodiment of the vapor compression refrigerator of the present invention.

FIG. 5 is a pressure enthalpy diagram of the vapor compression refrigerator shown in FIG.

FIG. 6 is a conceptual diagram showing a fourth example of the embodiment of the vapor compression refrigerator of the present invention.

FIG. 7 is a conceptual diagram showing a fifth example of the embodiment of the vapor compression refrigerator of the present invention.

FIG. 8 is a conceptual diagram showing an example of a conventional vapor compression refrigerator.

FIG. 9 is a pressure enthalpy diagram of the vapor compression refrigerator shown in FIG.

[Explanation of symbols]

 Reference Signs List 3 single-stage compressor 4 condenser 7 expansion valve 8 evaporator 11 multi-stage compressor 17 heat exchanger 18 heat exchanger 19 multi-stage compressor 20 refrigerant tank 29 cooling jacket (cooler) R refrigerant X secondary fluid Y secondary fluid

Claims (4)

[Claims] 1. A multi-stage compressor for sequentially compressing a refrigerant, a condenser for cooling the refrigerant sent from the multi-stage compressor by a secondary fluid, and an expansion for adiabatically expanding the refrigerant sent from the condenser. A valve, an evaporator that cools the secondary fluid with the refrigerant supplied from the expansion valve and supplies the refrigerant to the multi-stage compressor,
A heat exchanger for cooling a refrigerant sequentially compressed by the multi-stage compressor with a secondary fluid, wherein water is used as the refrigerant. 2. A multi-stage compressor for sequentially compressing a refrigerant, a condenser for cooling the refrigerant sent from the multi-stage compressor with a secondary fluid, and an expansion for adiabatically expanding the refrigerant sent from the condenser. A valve, an evaporator that cools the secondary fluid with the refrigerant supplied from the expansion valve and supplies the refrigerant to the multi-stage compressor,
A refrigerant tank that makes contact with the refrigerant fed from the condenser to the expansion valve and the refrigerant sequentially compressed by the multi-stage compressor,
A vapor compression refrigerator characterized by using water as a refrigerant. 3. A multi-stage compressor for sequentially compressing the refrigerant, a condenser for cooling the refrigerant sent from the multi-stage compressor with a secondary fluid, and an expansion for adiabatically expanding the refrigerant sent from the condenser. A valve, an evaporator that cools the secondary fluid with the refrigerant supplied from the expansion valve and supplies the refrigerant to the multi-stage compressor,
A heat exchanger for cooling the refrigerant sequentially compressed by the multistage compressor with a secondary fluid, and a refrigerant tank for bringing the refrigerant supplied from the condenser to the expansion valve into contact with the refrigerant sequentially compressed by the multistage compressor. A vapor compression refrigerator comprising: water as a refrigerant. 4. A single-stage compressor for compressing a refrigerant, a condenser for cooling the refrigerant sent from the single-stage compressor with a secondary fluid, and adiabatically expanding the refrigerant sent from the condenser. An expansion valve, an evaporator for cooling the secondary fluid by the refrigerant supplied from the expansion valve and supplying the refrigerant to the single-stage compressor, and cooling the refrigerant compression process portion of the single-stage compressor by the secondary fluid A vapor compression refrigerator comprising: a water cooler; and a water cooler.