TWI568984B - Gas - liquid heat exchange type refrigeration device - Google Patents

Description

Gas-liquid heat exchange type freezing device

The present invention relates to a gas-liquid heat exchange type refrigerating apparatus, which comprises: a refrigerant that has condensed in a condenser and a refrigerant that has evaporated in an evaporator, and heat exchange with each other in a gas-liquid heat exchanger, so that the respective refrigerants are respectively Supercooling and overheating to increase the refrigeration capacity.

Generally, the refrigeration system is a closed-circuit refrigerant circulation circuit in which a compressor, a condenser, an expansion valve, and an evaporator are connected in series according to a refrigerant pipe, and a high-pressure gas refrigerant compressed by a compressor is used. The condenser releases heat and liquefies, becomes a high-pressure liquid refrigerant, and then expands (equal expansion) according to the expansion valve to decompress the liquid refrigerant, and then evaporates the low-pressure liquid refrigerant after the boiling point is lowered in the evaporator, according to the freezer The internal portion captures the latent heat of vaporization required for evaporation to cool the interior of the freezer.

As a method of improving the refrigeration capacity or coefficient of achievement (COP) of such a refrigeration system, there is known a method in which a gas-liquid heat exchanger is provided between an evaporator of an refrigerant circulation circuit and an expansion valve, and The refrigerant condensed by the condenser and the refrigerant evaporated in the evaporator are heat exchanged in the gas-liquid heat exchanger, and the refrigerants are supercooled and superheated.

Further, Patent Document 1 proposes a device for a refrigerating and air-conditioning apparatus equipped with a gas-liquid heat exchanger, which is a gas-liquid heat exchange between a condenser and a gas-liquid heat exchanger of a refrigerant circulation circuit. An expansion valve is respectively disposed between the evaporator and the evaporator, and the opening degree of the expansion valve is controlled based on the temperature of the refrigerant at the outlet of the condenser and the temperature of the refrigerant at the inlet of the compressor, according to the dryness of the refrigerant to be maintained at the outlet of the evaporator. The target value is used to achieve efficient operation, and the problem of scattering of dew condensation water caused by evaporation of the evaporator (less refrigerant) is eliminated.

[Prior patent documents]

(Patent Literature)

Patent Document 1: Japanese Laid-Open Patent Publication No. 2009-162388

However, in the case where the refrigerating and air-conditioning apparatus proposed in Patent Document 1 is operated in an environment in which the number of revolutions of the compressor such as a refrigerating vehicle greatly fluctuates, the heat exchange performance of the gas-liquid heat exchanger is also accompanied by compression. The number of revolutions of the machine changes greatly. For example, if the number of revolutions of the compressor is lowered, the amount of refrigerant circulation is reduced, and the amount of heat exchange in the gas-liquid heat exchanger is insufficient to cause a cooling failure. Conversely, if the number of revolutions of the compressor is increased, the amount of refrigerant circulating is increased. When the amount of heat exchange is too large, the temperature at which the refrigerant discharge at the outlet of the compressor rises is insufficient, and problems such as deterioration of the refrigerator oil occur.

The present invention has been made in view of the above problems, and an object of the invention is to provide a gas-liquid heat exchange type refrigerating apparatus capable of suppressing fluctuations in refrigeration capacity caused by fluctuations in the number of revolutions of a compressor and suppressing discharge at a compressor outlet. The temperature rises to prevent deterioration of the refrigerating machine oil.

In order to achieve the above object, the gas-liquid heat exchange type refrigerating apparatus of claim 1 is based on a refrigerant line, and at least a compressor, a condenser, a heat exchange control valve, a gas-liquid heat exchanger, an expansion valve, and an evaporator. a refrigerant circulation circuit that is connected in series to form a closed circuit, and a refrigerant that has been condensed in the condenser and decompressed according to the heat exchange control valve and a refrigerant that has evaporated in the evaporator, in the gas-liquid The heat exchanger performs heat exchange to supercool or superheat each of the refrigerants, and the gas-liquid heat exchange type refrigerating apparatus is characterized in that discharge is provided between the compressor and the condenser in the refrigerant circulation circuit. a temperature sensor, and between the heat exchange control valve and the gas-liquid heat exchanger, a pressure sensor is provided, and a control means is provided, the control means being based on the detection according to the discharge temperature sensor Controlling the heat exchange at the outlet of the compressor at the outlet of the compressor and the pressure of the refrigerant at the outlet of the heat exchange control valve as detected by the aforementioned pressure sensor The opening of the valve is controlled to control the flow rate of the refrigerant passing through the aforementioned heat exchange control valve and flowing through the gas-liquid heat exchanger.

The invention according to claim 2, wherein the control means reduces the opening degree of the heat exchange control valve if the number of revolutions of the compressor decreases. When the number of revolutions of the compressor is increased, the opening degree of the heat exchange control valve is increased.

The invention according to claim 3, wherein the control means is the refrigerant at the outlet of the compressor detected by the discharge temperature sensor. When the temperature exceeds the set value, the opening degree of the heat exchange control valve is reduced to a value that maintains the refrigerant in a gas-liquid mixed state, and the refrigerant is depressurized by the heat exchange control valve and passes through the gas-liquid The refrigerant after the heat exchanger.

According to the inventions of the first and second aspects of the invention, if the number of revolutions of the compressor is lowered, the opening degree of the heat exchange control valve is reduced, so that the flow rate of the refrigerant flowing through the gas-liquid heat exchanger is increased, and the heat exchange is performed. The amount is increased, and according to the increase in the amount of heat exchange, the decrease in the amount of heat exchange in the gas-liquid heat exchanger caused by the decrease in the amount of refrigerant circulation due to the decrease in the number of revolutions is compensated, so that the amount of heat exchange can be suppressed. Insufficient cooling failure caused by insufficient.

In addition, when the number of rotations of the compressor increases, the opening degree of the heat exchange control valve is increased, so that the flow rate of the refrigerant flowing through the gas-liquid heat exchanger is lowered, and the amount of heat exchange is reduced, and the amount of heat exchange is reduced. The increase in the amount of heat exchange in the gas-liquid heat exchanger caused by the increase in the amount of circulation due to the increase in the number of revolutions is compensated, so that the refrigerant at the outlet of the compressor due to the excessive amount of heat exchange can be suppressed. The rise in the temperature of the spit.

According to the invention of claim 3, if the temperature of the refrigerant at the outlet of the compressor exceeds a set value, the opening degree of the heat exchange control valve 3 is greatly reduced to be decompressed by the heat exchange control valve. Since the refrigerant that has passed through the gas-liquid heat exchanger is maintained in a gas-liquid mixed state, the temperature difference between the refrigerant passing through the gas-liquid heat exchanger and the gas state from the evaporator is reduced in the form of a gas-liquid two-phase flow, and thus the temperature difference is small. The amount of heat exchange between the two refrigerants in the gas-liquid heat exchanger is suppressed to be low. Therefore, the degree of superheat of the refrigerant at the inlet of the compressor is suppressed to be low, and the rise of the discharge temperature of the refrigerant at the outlet of the compressor can be suppressed, and deterioration of the refrigerating machine oil can be prevented.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Fig. 1 is a refrigerant circuit diagram of a gas-liquid heat exchange type refrigerating apparatus according to the present invention. In the illustrated gas-liquid heat exchange type refrigerating apparatus, a compressor 1, a condenser 2, a heat exchange control valve 3, and a gas-liquid heat exchange The expansion valve 5, the expansion valve 5, and the evaporator 6 are connected in series according to the refrigerant lines L1, L2, L3, L4, and L5 to constitute a closed refrigerant circulation circuit. Here, the heat exchange control valve 3 is disposed on the refrigerant line L2 for connecting the condenser 2 and the gas-liquid heat exchanger 4; the expansion valve 5 is disposed in the refrigerant line L3 The refrigerant line L3 is used to connect the gas-liquid heat exchanger 4 and the evaporator 6. Further, the heat exchange control valve 3 is constituted by an electronic control valve that controls the opening degree in a stepless manner.

Further, in the gas-liquid heat exchange type refrigerating apparatus of the present invention, the discharge temperature sensor 7 is provided on the refrigerant line L1 for connecting the compressor 1 and the condenser 2, and the pressure sensor 8 is provided in the refrigerant. Between the heat exchange control valve 3 of the line L2 and the gas-liquid heat exchanger 4, the evaporation temperature sensor 9 is disposed on the refrigerant line L4 for connecting the evaporator 6 and the gas-liquid heat exchanger 4, these The discharge temperature sensor 7, the pressure sensor 8, and the evaporating temperature sensor 9 are electrically connected to the control means, that is, the controller 10. Further, the heat exchange control valve 3 constituted by the electronically controlled valve is electrically connected to the controller 10, and the heat exchange control valve 3 controls its opening degree in accordance with a control signal from the controller 10 as will be described later.

Next, the operation of the gas-liquid heat exchange type refrigerating apparatus of the present invention will be described below using the Mollier diagram (P-i diagram, P-h diagram) shown in Fig. 2 .

When the compressor 1 is rotationally driven according to an engine (not shown) as a drive source, the gaseous refrigerant in the state (pressures P ₁ and 焓i ₁ ) shown at a in FIG. 2 is compressed by the compressor 1 . The high-temperature high-pressure gas refrigerant (compression stroke) in the state (pressures P ₂ and 焓i ₂ ) shown in the figure b of FIG. ₂ is introduced into the condenser 2 through the refrigerant line L1. In addition, the compression power W (converted into heat) of the compressor 1 at this time is represented by (i _{2 -} i ₁ ).

In the condenser 2, the high-temperature and high-pressure gaseous refrigerant releases the heat of condensation Q ₂ to the outside air, and changes from the state at b in Fig. 2 to the state at c (phase change) to liquefy (condensation stroke). The high-pressure liquid refrigerant in the state (pressure P ₂ , 焓i ₃ ) shown at c in Fig. ₂ . Further, the amount of heat generation (condensation heat) Q ₂ at this time is represented by (i _{2 -} i ₃ ).

Then, as described above, the high-pressure liquid refrigerant liquefied in the condenser 2 changes state in the second diagram, for example, via a path (condition) indicated by B. That is, liquefied in the condenser 2 in the high-pressure liquid refrigerant through the refrigerant line L2 control valve reaches the heat exchanger 3, the control valve 3 based on the exchange of heat, is reduced to a pressure P ₃ up to adiabatic expansion (like The enthalpy expansion (expansion stroke) is in the state shown in d of Fig. 2 (pressures P ₃ and 焓i ₃ ), and a part of the refrigerant is vaporized.

As described above, a part of the vaporized refrigerant is introduced into the gas-liquid heat exchanger 4 through the refrigerant line L2, and the gas-liquid heat exchanger 4 is vaporized in the evaporator 6 and vaporized as will be described later. Since the gaseous refrigerant is introduced through the refrigerant line L4, the refrigerant (a part of the vaporized refrigerant) introduced from the refrigerant line L2 to the gas-liquid heat exchanger 4 is evaporated from the evaporator 6 The low-temperature gaseous refrigerant introduced into the refrigerant line L4 is heat-exchanged, thereby being supercooled, and becomes a liquid refrigerant in the state (pressure P ₃ , 焓i ₄ ) shown in e of FIG. 2 . Further, the supercooling heat ΔQ ₂ in this case is represented by (i _{3 -} i ₄ ).

Then, as described above, the refrigerant that has been supercooled in the gas-liquid heat exchanger 4 is subjected to adiabatic expansion (equal expansion) (expansion stroke) according to the pressure reduction by the expansion valve 5, and the state is changed to the second state. The state shown in f (pressures P ₁ , 焓i ₄ ) is such that a part of the refrigerant is vaporized and the boiling point is lowered according to the pressure reduction. As described above, the refrigerant that has been depressurized according to the expansion valve 5 and whose boiling point has been lowered is introduced into the evaporator 6 from the refrigerant line L3, and during the flow of the evaporator 6, the refrigerant takes the heat of vaporization Q ₁ from the surroundings. On the other hand, the evaporation changes from the state shown at the point f to the state shown at g (pressure P ₁ , 焓i ₅ ) to vaporize (evaporation stroke). The heat of vaporization Q ₁ at this time is represented by (i ₅ -i ₄ ), but as described above, the refrigerant before being decompressed by the expansion valve 5 is supercooled ΔQ ₂ in the gas-liquid heat exchanger 4 (= i ₃ -i _4), so that the heat of evaporation will increase this amount subcooling heat ΔQ _2, then the refrigeration capacity also increases corresponding to the amount ΔQ _2.

Thereafter, the low-pressure gaseous refrigerant evaporated in the evaporator 6 is used to introduce the refrigerant gas line L2 into the gas-liquid heat during the flow from the refrigerant line L4 to the gas-liquid heat exchanger 4 as described above. The high-pressure refrigerant in the exchanger 4 is supercooled, so that the temperature of the low-pressure gas refrigerant rises, and when it is sucked into the compressor 1, the state shown at g in Fig. 2 changes to the state shown at a. (Pressures P ₁ , 焓i ₁ ), and only the heat ΔQ ₁ shown in the figure is superheated. Then, the superheated gaseous refrigerant is again compressed by the compressor 1, and thereafter, the refrigerant repeats the same state change as described above.

Further, in the gas-liquid heat exchange type refrigerating apparatus of the present invention, the above-described refrigerating cycle is repeated, and the required refrigerating operation is performed by absorbing heat according to evaporation of the low-temperature liquid refrigerant in the evaporator 6, and the compressor is operated from the compressor. The temperature of the gaseous refrigerant to be discharged is detected based on the discharge temperature sensor 7, and the discharged gaseous refrigerant is condensed by the condenser 2, and then decompressed according to the heat exchange control valve 3. The pressure of the decompressed refrigerant is detected based on the pressure sensor 8, and these detected values are transmitted to the controller 10. Then, the controller 10 controls the refrigerant pressure at the outlet of the control valve 3 based on the temperature of the refrigerant at the outlet of the compressor 1 detected by the discharge temperature sensor 7 and the heat exchange detected by the pressure sensor 8. To control the opening degree of the heat exchange control valve 3.

Specifically, when the number of revolutions of the compressor 1 is lowered, the opening degree of the heat exchange control valve 3 is reduced, and conversely, when the number of revolutions of the compressor 1 is increased, the opening degree of the heat exchange control valve 3 is increased. Further, when the temperature of the refrigerant at the outlet of the compressor 1 detected by the discharge temperature sensor 7 exceeds the set value, the opening degree of the heat exchange control valve 3 is reduced to maintain the refrigerant in the gas-liquid In the state of the mixed state, the refrigerant is a refrigerant that has been depressurized by the heat exchange control valve 3 and passed through the gas-liquid heat exchanger 4 (see FIG. 4).

When the gas-liquid heat exchange type refrigerating apparatus of the present invention is mounted on a refrigerating vehicle, for example, the number of rotations of the compressor 1 driven by the engine varies depending on the traveling state of the refrigerating vehicle.

For example, if the number of rotations of the compressor 1 is lowered, the circulation amount of the refrigerant in the refrigeration cycle is reduced, and thus the refrigeration capacity is lowered. In this case, as described above, since the controller 10 reduces the opening degree of the heat exchange control valve 3. Therefore, the flow rate of the refrigerant flowing through the gas-liquid heat exchanger 4 rises, and the amount of heat exchange increases, and according to the increase in the amount of heat exchange, the gas-liquid heat exchanger 4 is caused by the decrease in the amount of refrigerant circulation due to the decrease in the number of revolutions. The reduction in the amount of heat exchange in the middle is compensated, so that the cooling failure due to insufficient heat exchange amount can be suppressed.

Here, the state of the high-pressure liquid refrigerant liquefied in the condenser 2 changes from the heat exchange control valve 3 to the expansion valve 5 through the gas-liquid heat exchanger 4, for example, B and C in FIG. D process to represent. When the operation is performed in the state indicated by the B process, the pressure of the high-pressure liquid refrigerant is reduced from P ₂ to P ₃ according to the heat exchange control valve 3, and if the number of revolutions of the compressor 1 is decreased, The degree of reduction in the number of revolutions reduces the opening degree of the heat exchange control valve 3, and as shown in the processes of C and D in Fig. 2, the pressure of the high-pressure liquid refrigerant is decompressed to P ₃ ', P ₃ ” (P ₃ >P ₃ '>P ₃ "), to increase the flow rate of the refrigerant flowing through the gas-liquid heat exchanger 4, the heat exchange amount can be increased as shown in the drawing, so that the aforementioned heat exchange amount shortage can be suppressed. Poor cooling.

Fig. 3 shows the relationship between the flow velocity (m/s) of the refrigerant in the gas-liquid heat exchanger 4 and the heat transfer performance KA (W/K). From the graph, the heat transfer performance (heat exchange amount) will follow. As the flow rate of the refrigerant increases, it increases.

Here, the process A in FIG. 2 shows a process (condition) in which the refrigerant is supercooled in the gas-liquid heat exchanger 4 without using the heat exchange control valve 3 and then expanded according to the expansion valve 5 Through the process A, the state of the refrigerant is changed as a standard, and the flow rate of the refrigerant when the refrigerant is changed in the state by the processes B, C, and D, and the heat exchange in the gas-liquid heat exchanger 4 are obtained by simulation. The amount and performance improvement rate were obtained, and the results shown in Table 1 were obtained.

As is clear from the results of Table 1, when the number of revolutions of the compressor 1 is lowered, if the opening degree of the heat exchange control valve 3 is reduced, the flow velocity of the refrigerant is increased, and the amount of heat exchange in the gas-liquid heat exchanger 4 is increased. As a result, the performance is improved and the refrigeration capacity can be improved.

On the other hand, if the number of revolutions of the compressor 1 is increased to increase the circulation amount of the refrigerant, the discharge temperature of the refrigerant at the outlet of the compressor 1 rises due to excessive exchange of heat in the gas-liquid heat exchanger 4, and freezing occurs. Since the engine oil is deteriorated, etc., as described above, the controller 10 performs control so that the opening degree of the heat exchange control valve 3 is increased.

For example, in the case where the operation is performed in the state shown in the D process of FIG. 2, the pressure of the high-pressure liquid refrigerant is decompressed from P ₂ to P ₃ ” according to the heat exchange control valve 3, and the compressor 1 is When the number of revolutions is increased, the opening degree of the heat exchange control valve 3 is increased in accordance with the degree of increase in the number of revolutions, and as shown in the processes of C and B in Fig. 2, the pressure of the high-pressure liquid refrigerant is reduced to only P. ₃ ', P ₃ (P ₃ '<P ₃ '<P ₃ ), to reduce the flow rate of the refrigerant flowing through the gas-liquid heat exchanger 4, the amount of heat exchange can be reduced as shown, and thus heat exchange When the amount of excess refrigerant is increased, the discharge temperature of the refrigerant at the outlet of the compressor 1 is suppressed, and deterioration of the refrigerating machine oil can be prevented.

As is clear from the results of Table 1, when the number of revolutions of the compressor 1 is increased, if the opening degree of the heat exchange control valve 3 is increased, the flow rate of the refrigerant is lowered, and the amount of heat exchange in the gas-liquid heat exchanger 4 is reduced. As a result, the performance is degraded and the freezing ability is lowered.

Further, in the gas-liquid heat exchange type refrigerating apparatus of the present invention, if the temperature of the refrigerant at the outlet of the compressor 1 detected by the discharge temperature sensor 7 exceeds the set value, the controller 10 will The opening degree of the heat exchange control valve 3 is reduced to a value at which the refrigerant is maintained in a gas-liquid mixed state, and the refrigerant is depressurized by the heat exchange control valve 3 and passed through the gas-liquid heat exchanger 4 Refrigerant.

For example, the state of the high-pressure liquid refrigerant liquefied in the condenser 2 changes from the heat exchange control valve 3 to the expansion valve 5 through the gas-liquid heat exchanger 4, for example, B, C, and D in FIG. process denoted, if the opening degree of the control valve 3 is reduced in accordance with the heat exchange to be liquefied in the condenser 2 in the high-pressure liquid refrigerant, greatly reduced the pressure from P ₂ to P ₃ ', P ₃ ", may be The refrigerant that has been decompressed by the heat exchange control valve 3 and passed through the gas-liquid heat exchanger 4 is maintained in a gas-liquid mixed state, that is, in a state indicated by the B process. The pressure of the high-pressure liquid refrigerant is reduced from P ₂ to P ₃ according to the heat exchange control valve 3, and if the number of revolutions of the compressor 1 is decreased, the heat exchange control valve 3 is made according to the degree of decrease in the number of revolutions The opening degree is reduced, and as shown in the C and D processes of FIG. 2, the pressure of the high-pressure liquid refrigerant is reduced to P ₃ ', P ₃ ′ (P ₃ ′ < P3 ′ < P ₃ ), so that the utilization is utilized. The refrigerant that has been decompressed by the heat exchange control valve 3 and passed through the gas-liquid heat exchanger 4 is maintained in a gas-liquid mixed state.

As described above, the refrigerant that has been depressurized by the heat exchange control valve 3 and passed through the gas-liquid heat exchanger 4 passes through the gas-liquid heat exchanger 4 in the form of a gas-liquid two-phase flow while maintaining the gas-liquid mixed state. The temperature difference between the refrigerant and the gaseous refrigerant introduced into the gas-liquid heat exchanger 4 from the evaporator 6 via the refrigerant line L4 is small, and the amount of heat exchange between the two refrigerants in the gas-liquid heat exchanger 4 can be suppressed. Therefore, the degree of superheat of the refrigerant at the inlet of the compressor 1 is suppressed, and the rise in the discharge temperature of the refrigerant at the outlet of the compressor 1 is suppressed, and deterioration of the refrigerating machine oil can be prevented.

Here, the process A in FIG. 4 shows a process in which the refrigerant is supercooled in the gas-liquid heat exchanger 4 without using the heat exchange control valve 3, and then expands according to the expansion valve 5, and the process proceeds. A, based on the simulation, the refrigerant flow rate when the refrigerant changes state in each of the processes B, C, and D, the amount of heat exchange in the gas-liquid heat exchanger 4, and The performance improvement rate is obtained, and the results shown in Table 2 are obtained.

As is clear from the results of Table 2, when the temperature of the refrigerant at the outlet of the compressor 1 detected by the discharge temperature sensor 7 exceeds the set value, the opening degree of the heat exchange control valve 3 is greatly reduced, and the refrigerant is cooled. The flow rate is increased. On the other hand, the refrigerant passing through the gas-liquid two-phase flow in the form of a gas-liquid two-phase flow and the gas introduced into the gas-liquid heat exchanger 4 from the evaporator 6 via the refrigerant line L4. The temperature difference between the refrigerants is reduced, and as a result, the amount of heat exchange between the two refrigerants in the gas-liquid heat exchanger 4 can be suppressed, and the refrigeration ability is lowered.

As described above, according to the present invention, the following effects can be obtained. In other words, it is possible to suppress variations in the refrigeration capacity caused by fluctuations in the number of revolutions of the compressor 1, and it is possible to suppress an increase in the discharge temperature at the outlet of the compressor 1, and to prevent deterioration of the refrigerator oil.

1. . . compressor

2. . . Condenser

3. . . Heat exchange control valve

4. . . Gas liquid heat exchanger

5. . . Expansion valve

6. . . Evaporator

7. . . Spit temperature sensor

8. . . Pressure sensor

9. . . Evaporation temperature sensor

10. . . Controller (control means)

L1～L5. . . Refrigerant line

Fig. 1 is a refrigerant circuit diagram of the gas-liquid heat exchange type refrigerating apparatus of the present invention.

Fig. 2 is a Mollier diagram showing changes in the state of the refrigerant in the case where the degree of opening of the heat exchange control valve is controlled in accordance with the fluctuation in the number of revolutions of the compressor in the gas-liquid heat exchange type refrigerating apparatus of the present invention.

Fig. 3 is a graph showing the relationship between the flow rate of the condensate refrigerant and the heat transfer performance in the gas-liquid heat exchanger.

Fig. 4 is a view showing a change in the state of the refrigerant after the opening degree of the heat exchange control valve is controlled when the discharge temperature of the refrigerant at the outlet of the compressor exceeds the set value in the gas-liquid heat exchange type refrigerating apparatus of the present invention. Morrill map.

1. . . compressor

2. . . Condenser

3. . . Heat exchange control valve

4. . . Gas liquid heat exchanger

5. . . Expansion valve

6. . . Evaporator

7. . . Spit temperature sensor

8. . . Pressure sensor

9. . . Evaporation temperature sensor

10. . . Controller (control means)

L1～L5. . . Refrigerant line

Claims (3)

A gas-liquid heat exchange type refrigerating device is configured to connect at least a compressor, a condenser, a heat exchange control valve, a gas-liquid heat exchanger, an expansion valve and an evaporator in series according to a refrigerant pipe to form a closed circuit refrigerant cycle a circuit for causing a refrigerant that has been condensed in the condenser and decompressed according to the heat exchange control valve and a refrigerant that has evaporated in the evaporator to exchange heat in the gas-liquid heat exchanger to cause the Each of the refrigerants is supercooled or superheated, and the gas-liquid heat exchange type refrigerating apparatus is characterized in that a discharge temperature sensor is provided between the compressor and the condenser in the refrigerant circulation circuit, and the heat exchange control is performed. Between the valve and the gas-liquid heat exchanger, a pressure sensor is disposed, and a control means is provided, the control means is based on the temperature and basis of the refrigerant at the outlet of the compressor detected according to the discharge temperature sensor The refrigerant pressure detected at the outlet of the heat exchange control valve detected by the pressure sensor to control the opening degree of the heat exchange control valve to control the heat exchange through the foregoing The control valve and the refrigerant flow rate through the liquid heat exchanger. The gas-liquid heat exchange type refrigerating apparatus according to claim 1, wherein the control means reduces the opening degree of the heat exchange control valve when the number of revolutions of the compressor decreases, and the number of revolutions of the compressor When increased, the opening degree of the aforementioned heat exchange control valve is increased. The gas-liquid heat exchange type refrigerating apparatus according to claim 1, wherein the control means is detected by the discharge temperature sensor When the temperature of the refrigerant at the outlet of the compressor exceeds a set value, the opening degree of the heat exchange control valve is reduced to a value that maintains the refrigerant in a gas-liquid mixed state, and the refrigerant is controlled by the heat exchange. The refrigerant is depressurized by the valve and passed through the gas-liquid heat exchanger.