JP2646914B2 - Refrigeration equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a refrigeration system for controlling the capacity of a compressor by controlling the opening and closing of an intermediate bypass valve of a compressor by the pressure of refrigerant.

[0002]

2. Description of the Related Art FIG. 6 is a refrigerant circuit diagram of a conventional refrigeration system. In FIG. 6, reference numeral 1 denotes, for example, “Technical Manual for Mitsubishi Condensing Unit Scroll Compressor”
(Issued in January 1991), which is a displacement control compressor having a displacement control means of a bypass unloading method.
FIG. 8 shows a schematic sectional view of the structure. Reference numeral 5 denotes an intermediate pressure bypass valve for bypassing a part of the intermediate-pressure gaseous refrigerant in the middle of compression in the compression chamber 11 to a compression chamber inlet (not shown) via a bypass passage (not shown). 5
It opens and closes due to the pressure difference between the refrigerant pressure applied to the outside of the valve and the pressure applied to the inside of the valve. 9 is a fixed scroll, 10 is an orbiting scroll, 2 is a condenser, 3 is a throttle device, 4 is an evaporator, and these are refrigerant pipes 8-1, 8-2, 8-3, 8-4.
The refrigeration cycle is configured by connecting the refrigeration cycle. 6 is an electromagnetic valve connecting the refrigerant pipe 8-1 on the refrigerant discharge side of the displacement control compressor 1 and the intermediate bypass valve 5, and 7 is a refrigerant pipe 8-4 on the refrigerant suction side of the displacement control compressor 1 and an intermediate bypass valve. 5 is a low pressure solenoid valve.

Next, the operation will be described. In FIG. 6, the refrigerant is normally compressed by the displacement control compressor 1, becomes a high-temperature high-pressure gas refrigerant, and enters the condenser 2. After being condensed by releasing heat to a cooling fluid (for example, outside air) in the condenser 2, the refrigerant becomes a high-pressure liquid refrigerant, and is further gradually depressurized by the expansion device 3, and becomes a low-temperature, low-pressure gas-liquid mixed refrigerant at the expansion device outlet. To the evaporator 4. Then, the refrigerant evaporates by absorbing heat from a heat source fluid (for example, indoor air), becomes a low-temperature low-pressure gas refrigerant, and returns to the capacity control compressor 1. At this time,
By opening the high-pressure solenoid valve 6 and closing the low-pressure solenoid valve 7, high-pressure gas refrigerant is transmitted to the outside of the bypass valve 5, and FIG.
The intermediate pressure bypass valve 5 in FIG. 8 is pressed, and the refrigerant being compressed is compressed without bypassing. By repeating this, heat can be transferred from the heat source fluid to the cooling fluid.

Next, a description will be given of the time of capacity control. The refrigerant is compressed by the capacity control compressor 1 to become a high-temperature high-pressure gas refrigerant,
Enter the condenser 2. The refrigerant is a cooling fluid (for example, outside air)
By condensing by releasing heat to a high-pressure liquid refrigerant,
Further, the pressure is gradually reduced by the expansion device 3 to become a low-temperature low-pressure gas-liquid mixed refrigerant at the expansion device outlet, and then sent to the evaporator 4. Here, the refrigerant evaporates by absorbing heat from a heat source fluid (for example, indoor air), becomes a low-temperature low-pressure gas refrigerant, and returns to the displacement control compressor 1. At this time, by closing the high-pressure solenoid valve 6 and opening the low-pressure solenoid valve 7, the low-pressure gas refrigerant is transmitted to the outside of the intermediate pressure bypass valve 5 and is formed between the fixed scroll 9 and the orbiting scroll 10 in FIGS. The refrigerant in the compression chamber 11 is pushed open by the intermediate pressure gas refrigerant in the middle of compression of the intermediate pressure bypass valve 5 by the capacity control compressor 1, discharged to the outside of the compression chamber via a bypass (not shown), and discharged to the low pressure side. And is joined with the low-temperature low-pressure gas refrigerant returned from the evaporator 4, and is again sucked into the compression chamber low-pressure side of the displacement control compressor 1. As a result, only the remaining intermediate-pressure gas refrigerant that has not been bypassed is compressed and discharged by the displacement control compressor 1, so that the amount of refrigerant flowing through the refrigeration cycle decreases, and the heat capacity that transfers heat from the heat source fluid to the cooling fluid is reduced. Can be reduced.

[0005]

Since the conventional refrigeration system is configured as described above, two solenoid valves are necessarily required to transmit pressure to the intermediate pressure bypass valve during capacity control, and capacity control is required. There was a problem that it became complicated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has a simple capacity control in which the opening / closing control of an intermediate pressure bypass valve of a capacity control compressor can be performed by controlling one solenoid valve. The purpose is to obtain a simple refrigeration system.

[0007]

SUMMARY OF THE INVENTION A refrigerating apparatus according to the present invention exchanges heat with the suction side refrigerant of a displacement control compressor having an intermediate pressure bypass valve for bypassing a part of the intermediate pressure refrigerant during compression to a refrigerant suction side. Preferably, a heat exchanger is provided, and the refrigerant discharge side of the displacement control compressor and the intermediate bypass valve are connected via an electromagnetic valve and the heat exchanger. Further, a heat exchanger is provided so as to be able to exchange heat with the refrigerant on the inlet side of the evaporator, and the refrigerant discharge side of the displacement control compressor having the intermediate pressure bypass valve and the intermediate pressure bypass valve are connected to the solenoid valve and the heat exchanger. Are connected via a.

[0008]

When the solenoid valve provided on the refrigerant pipe connecting the refrigerant discharge side of the displacement control compressor to the intermediate pressure bypass valve is opened, the temperature of the displacement control compressor is increased via the solenoid valve. The high pressure of the high-pressure discharge refrigerant is applied to the intermediate pressure bypass valve, the valve is closed, and the refrigerant being compressed is compressed without being bypassed. When the solenoid valve is closed, the high-pressure and high-temperature discharge refrigerant is trapped between the solenoid valve and the intermediate pressure bypass valve. The trapped high-temperature and high-pressure discharge refrigerant is cooled by a heat exchanger provided between the solenoid valve and the intermediate pressure bypass valve to become a low-temperature low-pressure refrigerant, and the low pressure is applied to the outside of the intermediate pressure bypass valve. Since the pressure of the intermediate-pressure gas refrigerant during compression applied to the inside of the intermediate bypass valve is higher than the pressure applied to the outside of the intermediate bypass valve, the intermediate-pressure bypass valve is opened, and the refrigerant being compressed is returned to the refrigerant suction side. Capacity control is performed.

[0009]

【Example】

Embodiment 1 FIG. Hereinafter, a refrigeration apparatus according to an embodiment of the present invention shown in FIG. 1 will be described. In FIG. 1, the same reference numerals as those in FIG. 12
Is a heat exchanger disposed in the refrigerant pipe 8-4 so as to be able to exchange heat with the suction-side refrigerant of the displacement control compressor 1, and to the discharge-side refrigerant pipe 8-1 of the displacement control compressor 1 via the electromagnetic valve 13. Refrigerant piping 14
-1, 14-2, and the capacity control compressor 1
Is connected to the intermediate pressure bypass valve 5 by a refrigerant pipe 14-3, and a connection part A between the heat exchanger 12 and the refrigerant pipe 14-3 is larger than a connection part B with the refrigerant pipe 14-2. In a high position,
Further, the solenoid valve 13 and the refrigerant pipes 14-1 and 14-2 are arranged at the same height as the connection portion B or at a lower position.

Next, the operation will be described with reference to the Mollier diagrams shown in FIGS. In FIGS. 1 and 2, the refrigerant is normally compressed by the displacement control compressor 1 to become a high-temperature and high-pressure gas refrigerant 18 a and enters the condenser 2. The refrigerant that has entered the condenser 2 is condensed by releasing heat to a cooling fluid (for example, outside air) to become a high-pressure liquid refrigerant 19a, which is gradually depressurized by the expansion device 3, and is cooled by the low-temperature low-pressure gas-liquid at the outlet of the expansion device 3. After it becomes the mixed refrigerant 20a, it is sent to the evaporator 4. Then, the refrigerant evaporates by absorbing heat from a heat source fluid (for example, indoor air) and returns to the compressor 1 as a low-temperature low-pressure gas refrigerant 21a. At this time, a part of the high-temperature and high-pressure gas refrigerant 18a compressed by the displacement control compressor 1 by opening the electromagnetic valve 13 causes the electromagnetic valve 6, the heat exchanger 12, and the refrigerant pipes 14-1 and 14-
Propagate 2, 14-3. A part of the high-temperature and high-pressure gas refrigerant 18a exchanges heat with the suction-side refrigerant of the displacement control compressor 1.
2 moves from 18a to 22a in FIG. 2, but the solenoid valve 13 connecting the outlet side refrigerant pipe 8-1 of the capacity control compressor 1 and the heat exchanger 12 and the refrigerant pipes 14-1 and 14-2 exchange heat. Since it is provided at the same or lower position as the height of the connecting portion B of the vessel 12, the condensed high-pressure liquid refrigerant merges again with the high-temperature and high-pressure gas refrigerant 18a due to the difference in height to become a high-temperature and high-pressure gas refrigerant. As a result, the same pressure 22b as that of the high-temperature and high-pressure gas refrigerant 13a is transmitted to the pressure outside the intermediate pressure bypass valve 5 in FIGS. 7 and 8, and the intermediate pressure bypass valve 5 is held down by this pressure, and the refrigerant being compressed is bypassed. Instead, heat can be transferred from the heat source fluid to the cooling fluid as in the conventional embodiment.

Next, a description will be given of the time of the capacity control. Figure 1
In FIG. 3, the refrigerant is compressed by the displacement control compressor 1 to become a high-temperature high-pressure gas refrigerant 18 b and enters the condenser 2. The refrigerant is condensed by releasing heat to a cooling fluid (for example, outside air) to become a high-pressure liquid refrigerant 19b, and further decompressed gradually by the expansion device 3, and becomes a low-temperature low-pressure gas-liquid mixed refrigerant 20b at the outlet of the expansion device 3. After that, it is sent to the evaporator 4. Here, the refrigerant evaporates by absorbing heat from a heat source fluid (for example, room air), becomes a low-temperature low-pressure gas refrigerant 21b, and returns to the displacement control compressor 1. At this time, when the solenoid valve 13 is closed, a part of the high-temperature and high-pressure gas refrigerant 18b compressed by the displacement control compressor 1 becomes part of the intermediate pressure bypass valve 5, the solenoid valve 13, the heat exchanger 12, and the refrigerant pipe connecting the same. It is confined in a closed circuit by 14-2 and 14-3. This high-pressure high-temperature gas refrigerant 18b is supplied to the displacement control compressor 1
The heat is condensed by releasing heat from the heat exchanger 12 which exchanges heat with the inlet refrigerant of the compressor, and moves from 18b to 24a in FIG. 3, and the temperature and pressure are changed to the inlet refrigerant temperature 24c of the displacement control compressor 1 and the refrigerant temperature 24c. Becomes the saturation pressure 24b. As a result, the displacement control compressor 1 is disposed outside the intermediate pressure bypass valve 5 shown in FIGS.
The saturated pressure 24b at the inlet refrigerant temperature 24c is transmitted, and the refrigerant in the compression chamber 11 formed between the fixed scroll 9 and the orbiting scroll 10 is compressed by the capacity control compressor 1 while the intermediate pressure bypass valve 5 is compressed. Of the intermediate-pressure gas refrigerant, the refrigerant is discharged to the outside of the compression chamber via a bypass (not shown), returned to the low-pressure side, merges with the low-temperature low-pressure gas refrigerant returned from the evaporator 4, and is subjected to capacity control compression again. Inhaled by machine 1. As a result, only the remaining intermediate-pressure gas refrigerant that has not been bypassed is compressed by the capacity control compressor 1, so that the amount of refrigerant flowing through the refrigeration cycle decreases, and the capacity of heat transferred from the heat source fluid to the cooling fluid decreases. Then, capacity control is performed.

Embodiment 2 FIG. FIG. 4 shows a refrigeration apparatus according to another embodiment of the present invention. In FIG. 4, the same reference numerals as in FIG. 6 denote corresponding parts, and a description thereof will be omitted. Fifteen
Is a heat exchanger 11 connected to a refrigerant pipe 8-1 on the refrigerant discharge side of the displacement control compressor 1 via an electromagnetic valve 16 via refrigerant pipes 17-1 and 17-2. -1, 17-2
The refrigerant is discharged from the capacity control compressor 1 and the refrigerant on the inlet side of the evaporator 4 is disposed in the refrigerant pipe 8-3 on the inlet side so as to exchange heat. And heat exchanger 12 and refrigerant pipe
The connection part A with 17-3 is higher than the connection part B with the refrigerant pipe 17-2, and the solenoid valve 16 and the refrigerant pipes 17-1, 17-
Reference numeral 2 is provided at a position equal to or lower than the height of the connection portion B.

Next, the operation will be described with reference to the Mollier diagrams shown in FIGS. In FIG. 4 and FIG. 5, the refrigerant normally becomes the high-temperature high-pressure gas refrigerant 18 a compressed by the displacement control compressor 1 and enters the condenser 2. The refrigerant that has entered the condenser 2 is condensed by releasing heat to a cooling fluid (for example, outside air), becomes a high-pressure liquid refrigerant 19a, and is gradually depressurized by the expansion device 3, and is cooled by the low-temperature low-pressure gas-liquid at the outlet of the expansion device 3. After it becomes the mixed refrigerant 20a, it is sent to the evaporator 4. Then, the refrigerant evaporates by absorbing heat from a heat source fluid (for example, indoor air) and becomes a low-temperature low-pressure gas refrigerant 21a, and returns to the displacement control compressor 1. At this time, a part of the high-temperature and high-pressure gas refrigerant 18a compressed by the capacity control compressor 1 by opening the electromagnetic valve 16 is part of the electromagnetic valve 16, the heat exchanger 15, and the refrigerant pipes 17-1 and 17-1,
It travels on 17-2 and 17-3. A part of the high-temperature and high-pressure gas refrigerant 13a moves from 18a to 22a in FIG. 2 by the heat exchanger 12 which exchanges heat with the inlet refrigerant of the cooler 4, but the refrigerant pipe on the outlet side of the displacement control compressor 1 The solenoid valve 16 and the refrigerant pipes 17-1 and 17-2 for connecting the heat exchanger 15 to the heat exchanger 15
The high-pressure liquid refrigerant condensed with the high-temperature and high-pressure gas refrigerant 18a again due to the difference in height, and becomes a high-temperature and high-pressure gas refrigerant. 7 and 8, the same pressure 22b as that of the high-temperature and high-pressure gas refrigerant 18a is transmitted to the outside of the intermediate pressure bypass valve 5, and the intermediate pressure bypass valve 5 is pressed by this pressure. The heat can be transferred from the heat source fluid to the cooling fluid without being bypassed and compressed as in the conventional embodiment.

Next, a description will be given of the time of the capacity control. FIG.
In FIG. 5, the refrigerant is compressed by the displacement control compressor 1 to become a high-temperature high-pressure gas refrigerant 18b and enters the condenser 2. The refrigerant that has entered the condenser 2 is condensed by releasing heat to a cooling fluid (for example, outside air) to become a high-pressure liquid refrigerant 19b.
The pressure is gradually reduced at the outlet of the expansion device 3 to become the low-temperature low-pressure gas-liquid mixed refrigerant 20 b at the outlet of the expansion device 3, and then sent to the evaporator 4. Here, the refrigerant evaporates by absorbing heat from a heat source fluid (for example, room air), becomes a low-temperature low-pressure gas refrigerant 21b, and returns to the displacement control compressor 1. At this time, the high-pressure high-pressure gas refrigerant 18 compressed by the displacement control compressor 1 is closed by closing the high-pressure electromagnetic valve 16.
Part of b is intermediate pressure bypass valve 5, solenoid valve 16, heat exchanger
It is confined in a closed circuit by 15 and refrigerant pipes 17-2 and 17-3 connecting it. The high-pressure high-temperature gas refrigerant 18b is condensed by releasing heat from the heat exchanger 15 which exchanges heat with the refrigerant at the inlet of the cooler 4 and moves from 18b to 25a in FIG. Refrigerant temperature 25c and evaporation pressure 25
b. As a result, the evaporation pressure 25b is transmitted to the outside of the intermediate pressure bypass valve 5 shown in FIGS. 7 and 8, and the intermediate pressure bypass valve 5 is pushed open by the intermediate pressure gas refrigerant being compressed by the displacement control compressor 1. As a result, the refrigerant in the compression chamber 11 formed between the fixed scroll 9 and the orbiting scroll 10 is discharged out of the compression chamber via a bypass (not shown), returned to the low pressure side, and returned from the evaporator 4 to the low temperature and low pressure. It merges with the gas refrigerant and is sucked into the capacity control compressor 1 again. As a result, only the remaining intermediate-pressure gas refrigerant that has not been bypassed is compressed by the capacity control compressor 1, so that the amount of refrigerant flowing through the refrigeration cycle decreases, and the capacity of heat transferred from the heat source fluid to the cooling fluid decreases. Capacity control is performed.

Embodiment 3 FIG. In each of the first and second embodiments, the position of the connection portion A is higher than the position of the connection portion B, and the refrigerant pipe 14 connected to the connection portion B is provided.
-1, 14-2, 17-1, 17-2 and the solenoid valves 13, 16 are arranged at the same or lower position as the height of the connecting portion B. For example, the condensation capacity of the heat exchanger 12 (or 15) may be set to be smaller than the amount of refrigerant flowing into the heat exchanger 12 (or 15) via the solenoid valve 13 (or 16). In the same manner as in the first and second embodiments, if the solenoid valve 13 (or 16) is opened, the pressure applied to the intermediate pressure bypass valve 5 becomes substantially equal to the refrigerant pressure discharged from the displacement control compressor 1, and the intermediate pressure bypass valve 5 is opened. If the solenoid valve 13 (or 16) is closed, the solenoid valve 13 (or 1
The refrigerant confined between 6) and the intermediate pressure bypass valve 5 is cooled by the heat exchanger 12 (or 15), and the temperature and the pressure become lower than the pressure of the intermediate pressure gas refrigerant of the displacement control compressor 1. As a result, the intermediate pressure bypass valve 5 is opened, and the capacity control operation is performed.
The effect is obtained.

[0016]

As described above, according to the present invention, the refrigerant discharge side of the displacement control compressor is provided with one solenoid valve and the suction side refrigerant of the displacement control compressor or the inlet side refrigerant of the evaporator. Connected to the intermediate pressure bypass valve of the displacement control compressor via a heat exchanger that exchanges heat with the pressure control valve, so that pressure control to the intermediate pressure bypass valve can be performed by valve opening / closing control of the one solenoid valve, There are effects such as simple capacity control and a highly reliable refrigeration system.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram showing a refrigeration apparatus according to one embodiment of the present invention.

FIG. 2 is a Mollier diagram showing states of respective parts of a refrigeration cycle of the refrigeration apparatus shown in FIG.

FIG. 3 is a Mollier chart showing the state of each part of the refrigeration cycle during capacity control of the refrigeration apparatus shown in FIG.

FIG. 4 is a refrigerant circuit diagram showing a refrigeration apparatus according to another embodiment of the present invention.

5 is a Mollier diagram showing a state of each part of a refrigeration cycle of the refrigeration apparatus shown in FIG.

FIG. 6 is a refrigerant circuit diagram showing a conventional refrigeration apparatus.

FIG. 7 is a sectional view of the displacement control compressor shown in FIG. 6;

FIG. 8 is a sectional view of the displacement control compressor shown in FIG. 6;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Capacity control compressor 2 Condenser 3 Throttle device 4 Evaporator 5 Intermediate pressure bypass valve 12 Heat exchanger 13 Solenoid valve 14-1, 14-2, 14-3 Refrigerant piping

Claims (2)

(57) [Claims] 1. A displacement control compressor having an intermediate pressure bypass valve that is opened / closed by the pressure of the refrigerant and bypasses a part of the intermediate pressure refrigerant during compression to a refrigerant suction side,
In a device provided with a refrigeration cycle in which a condenser, a throttle device, and an evaporator are sequentially connected by a refrigerant pipe, a refrigerant discharge side portion of the displacement control compressor includes an electromagnetic valve, and the displacement control compressor. A refrigeration unit connected to the intermediate pressure bypass valve via a heat exchanger that exchanges heat with the suction side refrigerant. 2. A capacity control compressor having an intermediate pressure bypass valve which is controlled to open and close by a pressure of the refrigerant and bypasses a part of the intermediate pressure refrigerant during compression to a refrigerant suction side.
In a device provided with a refrigeration cycle in which a condenser, a throttle device, and an evaporator are sequentially connected by a refrigerant pipe, a refrigerant discharge side of the displacement control compressor is provided with an electromagnetic valve, and an inlet of the evaporator. A refrigeration apparatus characterized by being connected to the intermediate pressure bypass valve via a heat exchanger that exchanges heat with the side refrigerant.