JPH01196458A - Separation type freezer - Google Patents

Abstract

PURPOSE:To prevent the freezing ability of the freezer from lowering by providing a bypass pipe which leads a part of a coolant from a high-pressure liquid pipe to the suction side of a compressor when the temperature or pressure of a high-pressure coolant exceeds a predetermined value and making the diameter of each of unit pipelines connected to the high-pressure liquid pipe smaller than that of a coolant pipe. CONSTITUTION:During a space cooling (cooling) operation, since no liquid receiving apparatus is provided in a high-pressure liquid pipe 15, the over-cooling degree is suppressed. A high- pressure liquid coolant which has left a power source side heat exchange 2 flows along a unit pipeline 9. During this operation the high-pressure liquid coolant becomes like a flash gas and reaches a pressure reducing apparatus 7, and the diameter of the unit pipeline 9 is reduced and hence the quantity of the coolant occupying the unit pipeline 9 is reduced. Even if the unit pipelines 9 and 10 are long, the quantity of circulating coolant does not become a sort of shortage, and hence there is no need to fill the coolant at the time of supplying the coolant in the spot pipelines. Further, when due to a sort of the shortage of the coolant, the temperature of the discharged coolant in the compressor 1 rises up and becomes a set value of 100 deg.C or higher, a switching valve 13 and an auxiliary valve 18 are opened by a signal from a detector 12, and a part of a high-pressure liquid coolant is introduced into a low-pressure vessel 3, and hence the rise of the temperature of the discharged coolant is suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to a separate air conditioner, a separate air conditioner/heater, and a separate cooler ( related to separate type refrigeration equipment (for food cooling), etc.

(b) Conventional technology In separate refrigeration systems, the length of the inter-unit piping that connects the heat source side unit and the user side unit varies greatly, for example from 7 m to 50 m, depending on the installation location of both units. Even if the amount of refrigerant to be filled into the refrigerant circuit is selected according to the intermediate length of 30 m, it will not work when the pipe is short (7 m).
) and the difference in pipe length (approximately 20 m) that occurs when using long pipes (50 m) is too large, so the amount of refrigerant charged is too large when using short pipes, and too little when using long pipes, resulting in a significant decrease in refrigeration capacity. It had the disadvantage of being

For this reason, high-pressure liquid pipes are provided with liquid receivers to store excess refrigerant, and when refrigerant is insufficient, refrigerant is replenished during on-site piping. (For example, see Utility Model Publication No. 55-21016.) (c) Problems to be Solved by the Invention When a liquid receiver is provided as described above, a large capacity liquid receiver is required to store a large amount of surplus refrigerant. There were problems in that the manufacturing cost was high and the heat source side unit was large. In addition, there is a risk that the refilling work of replenishing refrigerant at the time of on-site piping may be accidentally forgotten, and filling the refrigerant with an appropriate amount is a troublesome work and has been avoided.

An object of the present invention is to provide a separate type refrigeration system that solves the above problems.

(d) Means for Solving the Problems In order to achieve the above objects, the present invention connects a compressor, a heat source side heat exchanger, and a low-pressure container that separates the refrigerant sucked into the compressor into gas and liquid through a refrigerant pipe. A separate type refrigeration system, or a compressor, in which a heat source side unit with a heat exchanger and a user side unit having a user side heat exchanger and a pressure reducer that reduces the pressure of the refrigerant flowing into the user side heat exchanger are connected by a pair of inter-unit piping. A heat source side unit that connects a four-way valve, a heat source side heat exchanger, a pressure reducer for heating, and a low pressure container that separates the refrigerant sucked into the compressor into gas and liquid by a refrigerant pipe, a user side heat exchanger, and a cooling side unit. In a heat pump-type separate refrigeration system in which a user unit with a pressure reducer is connected to a user unit by a pair of inter-unit piping, if the temperature or pressure of high-pressure refrigerant in the heat source unit exceeds a set value, the refrigerant is discharged from the high-pressure liquid pipe. A bypass pipe is provided to guide a part of the refrigerant to the suction side of the compressor, and the pipe diameter of the inter-unit pipe connected to the high-pressure liquid pipe is made smaller than the pipe diameter of the refrigerant pipe.

Further, there is a user side in which a compressor, a user side heat exchanger, a pressure reducer that reduces the pressure of the refrigerant flowing into the user side heat exchanger, and a low pressure container that separates the refrigerant sucked into the compressor into gas and liquid are connected by a refrigerant pipe. A separate refrigeration system in which a unit and a heat source side unit having a heat source side heat exchanger are connected by a pair of inter-unit piping, or a compressor, a four-way valve, a user side heat exchanger, a cooling pressure reducer, and the compressor. A heat pump type in which the user side unit is connected to a low-pressure container that separates the refrigerant sucked into gas and liquid through a refrigerant pipe, and the heat source side unit has a heat exchanger on the heat source side and a pressure reducer for heating, and is connected through a pair of inter-unit piping. In the separate type refrigeration system, a bypass pipe is provided in the user-side unit to guide a part of the refrigerant from the high-pressure liquid pipe to the suction side of the compressor when the temperature or pressure of the high-pressure refrigerant exceeds a set value, and
The pipe diameter of the inter-unit pipe connected to the high-pressure liquid pipe is made smaller than the pipe diameter of the refrigerant pipe.

The bypass pipe preferably has an on-off valve that opens when the temperature of the refrigerant discharged from the compressor exceeds a set value, and the refrigerant outlet end of the bypass pipe is preferably connected to the refrigerant inlet pipe of the low-pressure container.

Furthermore, the diameter of the high-pressure liquid pipe is the same as that of the inter-unit piping connected to this liquid pipe, and an auxiliary pressure reducer is interposed in the high-pressure liquid pipe, and an auxiliary on-off valve is installed in parallel with this auxiliary pressure reducer. Preferably, the auxiliary on-off valve is opened when the temperature of the refrigerant discharged from the compressor exceeds a set value.

(f) Effect In the separate type refrigeration system configured as described above, the refrigerant filling amount is set so that approximately 173 refrigerant accumulates in the low-pressure container when the length of the pipe between units is 7 m, and the liquid receiver is small. Either use one with a large capacity or eliminate it. Therefore, during cooling or heating, the high-pressure liquid refrigerant becomes a bit of flash gas as it flows through the inter-unit piping and reaches the pressure reducer. The amount of high-pressure liquid refrigerant occupied by the
Even if it is m, the amount of circulating refrigerant does not seem to be insufficient,
There is no need to fill the refrigerant at the time of on-site piping, but it is inevitable that the refrigerant temperature discharged from the compressor will rise abnormally due to this refrigerant shortage, and this discharge refrigerant temperature will exceed the set value of 100.
When the temperature exceeds °C, the on-off valve of the bypass pipe opens and a portion of the high-pressure liquid refrigerant is sucked into the compressor, suppressing a rise in the temperature of the discharged refrigerant.

(F) Embodiment Figure 1 is a refrigerant circuit diagram of a separate refrigeration system showing the first embodiment of the present invention. A heat source side unit (5) is connected to a low pressure container (3) for separating the refrigerant into gas and liquid through a refrigerant pipe (4).
) and a user-side unit (8) having a user-side heat exchanger (6) and a pressure reducer (7) such as a capillary tube that reduces the pressure of the refrigerant flowing into the user-side heat exchanger, and a pair of inter-unit piping ( 9
) (1o) to form a cooling cycle.

(11) is a bypass pipe installed in the heat source side unit (5), which includes an on-off valve (13) and a capillary tube ( 14) is interposed, and this bypass pipe 1
The refrigerant outlet end of 1) is connected to the refrigerant inlet pipe (16) of the low pressure container (3) so that a part of the refrigerant from the high pressure liquid pipe (15) is not directly sucked into the compressor (1). .

(17) is an auxiliary pressure reducer such as a capillary tube interposed in the high-pressure liquid pipe (15), and (18) is connected in parallel with this auxiliary pressure reducer. This is an auxiliary on-off valve that opens with a signal from 12).

Moreover, the pipe diameter of the inter-unit pipe <9) connected to the high-pressure liquid pipe (15>) should be changed to the pipe diameter of the refrigerant pipe 4) (for example, 9.52~
15.88ffll) smaller (e.g. 6.35m
m) is set.

In the separation type refrigeration system configured as described above, the refrigerant charging amount is set so that about 173 refrigerant accumulates in the low pressure container (3) when the inter-unit piping (9) (10) is short, about 7 m long. Therefore, when the piping is short, the temperature of the refrigerant discharged from the compressor (1) does not rise above 100°C, so the on-off valve (13) and the auxiliary on-off valve (18) remain closed, and the compressor (1) - Heat source side heat exchanger (2) - Auxiliary pressure reducer (
17) - Inter-unit piping (9) - Pressure divider (7) - Utilization side heat exchanger (6) - Inter-unit piping (10) - Low pressure vessel (
3) - Cooling operation in which the refrigerant circulates sequentially through the compressor (1), the heat source side heat exchanger (2) acts as a condenser, and the user side heat exchanger (6) acts as an evaporator. It is done.

During such cooling operation, the degree of supercooling is suppressed because the high-pressure liquid pipe (15) is not provided with a liquid receiver, and the high-pressure liquid refrigerant that exits the heat source side heat exchanger (2) is transferred to the inter-unit pipe. (9
), it becomes a bit of flash gas and reaches the pressure reducer (7), and since the pipe diameter of this inter-unit piping (9) has become smaller, the refrigerant occupied in this inter-unit piping (9) The amount of piping between units (
9) Even if (10) is a long pipe with a length of about 50 m, the amount of circulating refrigerant will not be so insufficient, and there is no need to fill the refrigerant at the time of on-site piping. However, due to this refrigerant shortage, it is unavoidable that the temperature of the discharged refrigerant from the compressor 1) rises abnormally, and this discharged refrigerant temperature reaches the set value 1o.

When the temperature exceeds ℃, a signal from the detector (12) turns on the on-off valve (1).
3) and the auxiliary on-off valve (18) opens and a portion of the high-pressure liquid refrigerant is guided to the low-pressure container (3), suppressing the rise in discharge refrigerant temperature and reducing the resistance value of the auxiliary pressure reducer (17). The difference in piping resistance between units between long piping and short piping becomes smaller.

Furthermore, if the inter-unit piping (9) is a long piping, this inter-unit piping (9) with a small pipe diameter will act as a refrigerant pressure reducer, but when the piping is short, the inter-unit piping (9)
The pressure reducer (7) does not function very well as a refrigerant pressure reducer.
) is necessary.

Also, the high pressure liquid pipe (15) in the heat source side unit (5) and the high pressure liquid pipe (19> in the usage side unit (8)) are set to have the same pipe diameter (for example, 6.3511111) as the inter-unit pipe (9). If the amount occupied by the high-pressure liquid refrigerant in terms of pipe diameter is further reduced, even if the inter-unit piping <9) (10) is a long pipe with a length of about 50 m, the shortage of circulating refrigerant can be further alleviated.

In addition, the on-off valve (13) and the auxiliary on-off valve (18) are connected to the compressor (
It may be possible to open and close by detecting the discharge refrigerant pressure in 1) or the refrigerant pressure in the high-pressure liquid pipe (15), but since the inter-unit piping (9) and (10) are long piping, the amount of circulating refrigerant is insufficient. If the temperature becomes slightly low, the temperature of the refrigerant discharged from the compressor (1) will quickly rise, so it is preferable to detect the temperature of the refrigerant discharged from the compressor (1) as described above in the first embodiment.

FIG. 2 is a refrigerant circuit diagram of a heat pump type separate refrigeration system showing a second embodiment of the present invention. What differs from the first embodiment is that in the heat source side unit (20), four directions for switching between cooling and heating channels are provided. An anti-icing coil (23) integrally provided at the bottom of the valve (21), the liquid receiver (22), and the heat source side heat exchanger (2).
), the heating pressure reducer (24), (25), and the cooling check valve (26) are connected with the refrigerant pipe (4) as shown in the figure, and the cooling pressure reducer (27) is connected in the user side unit (27). (2
8) and a heating reversal valve (29) are connected in parallel as shown in the figure, and the same parts as in the first embodiment are given the same reference numerals and their explanation will be omitted.

To explain the refrigerant circuit operation, the inter-unit piping (9) (1
0) with a short piping length of about 7 m, by setting the four-way valve (21) to the solid line state during cooling operation, the compressor 1) - four-way valve (21) - heat source side heat exchanger ( 2)-
Cooling check valve (26) - Anti-icing coil 23) - Liquid receiver (22) - Auxiliary pressure reducer (17) - Inter-unit piping (9)
) - Cooling pressure reducer (28) - User side heat exchanger (6> - Inter-unit piping (10) - Four-way valve (21) - Low pressure vessel (3)
) - The refrigerant circulates sequentially with the compressor (1), and the heat source side heat exchanger (2) and anti-icing coil (23) act as a condenser,
The user-side heat exchangers (6) each act as an evaporator to cool the room.

On the other hand, during heating operation, by switching the four-way valve (21) to the broken line state, the Stop valve (29) - Inter-unit piping (9) - Auxiliary pressure reducer (1)
7) - Supercooling coil (23) from the bottom of the liquid receiver (22)
- Heating pressure reducer (25) - Heat source side heat exchanger (2) - Four-way valve 21) - Low pressure vessel (3) - Compressor ( 1), the refrigerant is sequentially circulated through the user-side heat exchanger (6) and the ice-forming coil (
23) acts as a condenser, and the heat source side heat exchanger (2) acts as an evaporator, thereby heating the room.

During such heating operation, the lower part of the heat source side heat exchanger (2) is heated by the anti-icing coil (23), so this heat exchanger (
2) The lower part of the liquid receiver (22) will not freeze.
When the liquid refrigerant no longer accumulates inside, the heating pressure reducer (
The liquid refrigerant flowing through 25) becomes gas refrigerant and passes through this pressure reducer (
25), almost no refrigerant flows through the heating pressure reducer (
The degree of pressure reduction is adjusted such that the refrigerant is depressurized only by step 24). Moreover, since this liquid receiver (22) is of a small capacity, the degree of supercooling is suppressed during cooling operation as well as during heating operation, and the anti-icing coil 23) is used during cooling operation. , during heating operation, the heating check valve (2
The high-pressure liquid refrigerant using each of 9) becomes a bit of flash gas as it flows through the inter-unit piping (9), and the pipe diameter of this inter-unit piping (9) is small. 9) The amount of refrigerant occupied by the unit is reduced, and even if the pipes (9) and (10) between the units are long pipes with a length of about 50 m, the amount of circulating refrigerant will not be so short, and the refrigerant can be transferred to the pipes at the site. There is no need to charge the refrigerant, but it is inevitable that the refrigerant temperature discharged from the compressor (1) will rise abnormally due to this refrigerant shortage. The on-off valve (13) and the auxiliary on-off valve (18) are opened by the signal from 12), and part of the high-pressure liquid refrigerant is guided to the low-pressure container 3), and the resistance value of the auxiliary pressure reducer (17) is reduced. Since the degree of supercooling increases by this amount, the rise in discharge refrigerant temperature is suppressed.

In addition, if the inter-unit piping (9) is a long leg pipe, this inter-unit piping (9) with a small pipe diameter will act as a refrigerant pressure reducer, but when the pipe is short, the inter-unit piping (9)
The cooling pressure reducer (28) and the heating pressure reducer (24) and (25) are necessary because the refrigerant does not function much as a refrigerant pressure reducer.

Also, it is preferable to provide an auxiliary pressure reducer (17) and an auxiliary on-off valve (18), and the diameter of the high-pressure liquid pipes (15) and (19) should be set to the diameter of the inter-unit pipe (9) (for example, 6.35 mm). ), and that it is preferable to use the detector (12) to detect the refrigerant temperature discharged from the compressor (1) are the same as in the first embodiment.

FIG. 3 is a refrigerant circuit diagram of a separate refrigeration system showing a third embodiment of the present invention, which differs from the first embodiment in the heat source side unit (
30) has only the heat source side heat exchanger 2) built in, and the user side unit (31) has the user side heat exchanger (6) and pressure reducer (7) built-in.
In addition, there is a compressor (1), a low pressure vessel (3) and a bypass pipe (1).
1), etc., and the same parts as in the first embodiment are denoted by the same reference numerals and the explanation thereof will be omitted.

To explain the refrigerant circuit operation, the inter-unit piping (9) (1
When the compressor (1
) - Inter-unit piping (10) - Heat source side heat exchanger (2) -
Inter-unit piping (9) - Auxiliary pressure reducer 17) - Pressure reducer (
7) - Utilization side heat exchanger (6) - Low pressure container (3) - Compressor (1) The refrigerant is circulated in order, and the heat source side heat exchanger (2) serves as a condenser, and the utilization side heat exchanger (6) ) acts as an evaporator in a cooling operation.

During such cooling operation, the degree of supercooling is suppressed because the high-pressure liquid pipe (15) is not provided with a liquid receiver, and the high-pressure liquid refrigerant that exits the heat source side heat exchanger (2) is transferred to the inter-unit pipe. (9
), it becomes a bit of flash gas and reaches the auxiliary pressure reducer (17), and this inter-unit piping (9
) is smaller, so this inter-unit piping (
9) The amount of refrigerant occupied by the unit is reduced, and even if the pipes (9) and (10) between the units are long pipes with a length of about 50 m, the amount of circulating refrigerant will not be so short, and the refrigerant can be transferred to the pipes at the site. There is no need to charge the refrigerant, but due to this refrigerant shortage, it is inevitable that the discharge refrigerant temperature of the compressor (1) will rise abnormally, and this discharge refrigerant temperature will exceed the set value of 100°C.
When the temperature exceeds the limit, a signal from the detector (12) is sent to the on-off valve (13).
〉 and the auxiliary on-off valve (18) open and a part of the high-pressure liquid refrigerant is guided to the low-pressure container (3), and the degree of supercooling increases by the amount that the resistance value of the auxiliary pressure reducer <17) decreases, so the discharge refrigerant temperature decreases. The increase in

In addition, if the inter-unit piping (9) is a long leg pipe, this inter-unit piping (9) with a small pipe diameter will act as a refrigerant pressure reducer, but when the pipe is short, the inter-unit piping (9)
The pressure reducer (7) does not function very well as a refrigerant pressure reducer.
) is necessary.

Also, it is preferable to provide an auxiliary pressure reducer (17) and an auxiliary on-off valve (18), and the diameters of the high-pressure liquid pipes (15) and (19) should be adjusted to the diameter of the inter-unit piping (9) (for example, 6.35ml).
), it is preferable to use the same pipe diameter as the detector (12).
As in the first embodiment, it is preferable to detect the temperature of the refrigerant discharged from the compressor (1).

FIG. 4 is a refrigerant circuit diagram of a heat pump type separate refrigeration system showing a fourth embodiment of the present invention. What differs from the third embodiment is that the user side unit (32) has a four-way valve for switching between cooling and heating channels. 2
1), a cooling pressure reducer (28), and a heating check valve (29) are installed as shown in the figure, and a heating pressure reducer (24) and a cooling check valve 26) are installed in the heat source side unit (33). Components that are the same as those in the third embodiment are designated by the same reference numerals, and a description thereof will be omitted.

To explain the refrigerant circuit operation, the inter-unit piping (9) (1
0) with a short piping length of about 7 m, by setting the four-way valve (21) to the solid line state during cooling operation, the piping between the compressor (1), the four-way valve (21), and the unit ( 10
) - Heat source side heat exchanger (21) - Cooling reverse valve (26) -
Inter-unit piping (9) - Auxiliary pressure reducer (17) - Cooling pressure reducer (28> - User side heat exchanger (6) - Four-way valve (21)
- Low pressure container (3) - Compressor (1), the refrigerant circulates in order, the heat source side heat exchanger (2) acts as a condenser, the user side heat exchanger (6) acts as an evaporator, and the indoor is cooled.

On the other hand, during heating operation, by switching the four-way valve (21) to the broken line state, compressor (1) - four-way valve (21) - user side heat exchanger (6> - heating check valve (29) - auxiliary Pressure reducer (17) - Inter-unit piping (9) - Heating pressure reducer (25)
) - Heat source side heat exchanger (2) - Inter-unit piping (10) -
The refrigerant circulates in sequence through the four-way valve (21) - low pressure container (3) - compressor (1), with the user side heat exchanger (6) acting as a condenser and the heat source side heat exchanger (2) acting as an evaporator. Each acts to heat the room.

During such cooling/heating operation, the degree of supercooling is suppressed because the high-pressure liquid pipes (15) and (19) are not provided with liquid receivers. The high-pressure liquid refrigerant that has exited the respective units (17) becomes a bit of flash gas as it flows through the inter-unit piping (9), and the pipe diameter of this inter-unit piping (9) is small. The amount of refrigerant occupied in the pipe (9) is reduced, and even if the inter-unit pipe (9) Do) is a long pipe with a length of about 50 m, the amount of circulating refrigerant will not be so short, and the refrigerant can be transferred to the local pipe. However, due to this refrigerant shortage, it is inevitable that the discharge refrigerant temperature of the compressor (1) will rise abnormally, and if the discharge refrigerant temperature exceeds the set value of 100"C, the detector (12)
) The on-off valve (13) and the auxiliary on-off valve (18)
opens and a portion of the high-pressure liquid refrigerant is guided to the low-pressure container (3), and the degree of supercooling increases by the amount that the resistance value of the auxiliary pressure reducer (17) is reduced, thereby suppressing a rise in the temperature of the discharged refrigerant.

Furthermore, if the inter-unit piping (9) is a long piping, this inter-unit piping (9) with a small pipe diameter will act as a refrigerant pressure reducer, but when the piping is short, the inter-unit piping (9)
The cooling pressure reducer (28) and the heating pressure reducer (24) are necessary because the refrigerant does not function much as a refrigerant pressure reducer.

Also, it is preferable to provide an auxiliary pressure reducer (17) and an auxiliary on-off valve (18), and the diameter of the high-pressure liquid pipe (15>(19)) should be set to the diameter of the inter-unit pipe (9) (for example, 6.35nll). )
As in the first embodiment, it is preferable that the tube diameter is the same as that of the first embodiment, and that it is preferable that the temperature of the refrigerant discharged from the compressor (1) be detected by the detector (12).

(G) Effects of the Invention Since the present invention is configured as described above, it produces the following effects.

■In the separate refrigeration system of Claims 1, 2.3, or 4, when the temperature or pressure of the high-pressure refrigerant in the heat source side unit or the user side unit exceeds a set value, a part of the refrigerant from the high-pressure liquid pipe is removed. In addition to providing a bypass pipe that leads to the suction side of the compressor, the pipe diameter of the inter-unit pipe connected to the high-pressure liquid pipe is made smaller than the pipe diameter of other refrigerant pipes, so that the high-pressure liquid occupied in the inter-unit pipe is The amount of refrigerant decreases, and even if the piping between units is long, for example, 50 m, the amount of circulating refrigerant does not become insufficient, and there is no need to refill the refrigerant at the time of on-site piping. When the temperature or pressure of the refrigerant increases, a portion of the high-pressure liquid refrigerant is sucked into the compressor from the high-pressure liquid pipe via the bypass pipe, so it is possible to prevent the temperature of the refrigerant discharged from the compressor from increasing abnormally.

Furthermore, since it is equipped with a low-pressure container that separates the refrigerant sucked into the compressor into gas and liquid, and a pressure reducer that reduces the pressure of the refrigerant flowing into the user-side heat exchanger or heat source-side heat exchanger, the piping between the units can be as short as, for example, 7 m. In the case of piping, excess refrigerant accumulates in a low-pressure container, and the pressure of the refrigerant that cannot be reduced so much in the piping between units can be sufficiently reduced in pressure with a pressure reducer, allowing air conditioning (cooling) and heating operations to be performed with an appropriate amount of circulating refrigerant and degree of refrigerant pressure reduction. be able to.

■ In the separated refrigeration system of claim 5, when the amount of circulating refrigerant becomes insufficient because the piping between the units is long, the temperature of the refrigerant discharged from the compressor quickly rises. Since the temperature of the discharged refrigerant is detected and the on-off valve of the bypass pipe is opened and closed, it is possible to reliably prevent the temperature of the compressor from rising abnormally.

- In the separation type refrigeration system of claim 6, a part of the high-pressure liquid refrigerant is guided from the bypass pipe to the low-pressure container and separated into gas and liquid, and then sucked into the compressor, thereby preventing the compressor from compressing the liquid. It can be prevented.

■In the separate refrigeration system of claim 7, the amount of high-pressure liquid refrigerant occupied in the inter-unit piping and the high-pressure liquid pipe is reduced, so it is possible to further alleviate the shortage of circulating refrigerant due to long piping. .

■In the separate type refrigeration system of claim 8, the auxiliary pressure reducer acts when the inter-unit piping is short and does not act when it is long, so the difference in resistance between the inter-unit piping between short piping and long piping is reduced. Cooling/heating operation can be performed with a substantially appropriate amount of circulating refrigerant in both pipes and long pipes.

(2) In the separate refrigeration system of the ninth aspect, the auxiliary pressure reducer is controlled by the compressor discharge refrigerant temperature, which changes depending on the length of the inter-unit piping, so that the effect (2) can be further enhanced.

[Brief explanation of the drawing]

FIG. 1 is a refrigerant circuit diagram of a separate type refrigeration system showing a first embodiment of the present invention, FIG. 2 is a refrigerant circuit diagram of a heat pump type separate type refrigeration system showing a second embodiment of the present invention, and FIG. 4 is a refrigerant circuit diagram of a separate refrigeration system showing a third embodiment of the present invention.
The figure is a refrigerant circuit diagram of a heat pump type separation type refrigeration apparatus showing a fourth embodiment of the present invention. (1)...Compressor, (2)...Heat source side heat exchanger,
(3)...Low pressure container, (4)...Refrigerant pipe, (
5) (20) (30) (33)...Heat source side unit,
(6)...user-side heat exchanger, (7)...pressure reducer,
(8) (27) (31) (32)... User side unit, (9) (10)... Inter-unit piping, (1
1)...Bypass pipe, (13)...On-off valve, (
15)...High pressure liquid pipe, (16)...Refrigerant inlet pipe of low pressure container, (17)...Auxiliary pressure reducer, (18)...
- Auxiliary on-off valve, (24) (25)... Heating pressure reducer, (28)... Cooling pressure reducer.

Claims (1)

[Scope of Claims] 1. A heat source side unit in which a compressor, a heat source side heat exchanger, and a low-pressure container that separates the refrigerant sucked into the compressor into gas and liquid are connected by a refrigerant pipe, and a user side heat exchanger and this In a separate refrigeration system in which a user unit is connected to a user unit that has a pressure reducer that reduces the pressure of the refrigerant flowing into the user heat exchanger through a pair of inter-unit piping, the temperature or pressure of the high-pressure refrigerant in the heat source unit is set to the installed value. In this case, a bypass pipe is installed to guide part of the refrigerant from the high-pressure liquid pipe to the suction side of the compressor, and the pipe diameter of the inter-unit pipe connected to the high-pressure liquid pipe is made smaller than the pipe diameter of the refrigerant pipe. Separate type refrigeration equipment characterized by the following. 2. A heat source side unit in which a compressor, a four-way valve, a heat source side heat exchanger, a heating pressure reducer, and a low pressure container that separates the refrigerant sucked into the compressor into gas and liquid are connected by refrigerant pipes, and a user side heat exchanger. In a heat pump type separate type refrigeration system in which a user unit with a cooling pressure reducer and a cooling pressure reducer are connected by a pair of inter-unit piping, when the temperature or pressure of high-pressure refrigerant in the heat source side unit exceeds a set value, the high-pressure liquid pipe A bypass pipe is provided to guide a part of the refrigerant from the compressor to the suction side of the compressor, and the pipe diameter of the inter-unit pipe connected to the high-pressure liquid pipe is made smaller than the pipe diameter of the refrigerant pipe. Separate heat pump type refrigeration equipment. 3. A user side in which a compressor, a user-side heat exchanger, a pressure reducer that reduces the pressure of the refrigerant flowing into the user-side heat exchanger, and a low-pressure container that separates the refrigerant sucked into the compressor into gas and liquid are connected by refrigerant pipes. In a separate refrigeration system in which a unit and a heat source side unit having a heat source side heat exchanger are connected by a pair of inter-unit piping, if the temperature or pressure of high pressure refrigerant in the user side unit exceeds a set value, the high pressure liquid pipe will A separation characterized in that a bypass pipe is provided to guide a part of the refrigerant to the suction side of the compressor, and the pipe diameter of the inter-unit pipe connected to the high-pressure liquid pipe is smaller than the pipe diameter of the refrigerant pipe. mold refrigeration equipment. 4. A user-side unit in which a compressor, a four-way valve, a user-side heat exchanger, a cooling pressure reducer, and a low-pressure container that separates the refrigerant sucked into the compressor into gas and liquid are connected by refrigerant pipes, and a heat source-side heat exchanger. In a heat pump type separate type refrigeration system in which a heat source side unit having a heating pressure reducer and a heat source side unit are connected by a pair of inter-unit piping, if the temperature or pressure of high pressure refrigerant in the user side unit exceeds a set value, the high pressure liquid pipe A bypass pipe is provided to guide a part of the refrigerant from the compressor to the suction side of the compressor, and the pipe diameter of the inter-unit pipe connected to the high-pressure liquid pipe is made smaller than the pipe diameter of the refrigerant pipe. Separate heat pump type refrigeration equipment. 5. Claims 1, 2, and 3, wherein the bypass pipe is a pipe with an on-off valve that opens when the temperature of the refrigerant discharged from the compressor exceeds a set value.
Or the separate type refrigeration device according to 4. 6. A separate refrigeration system according to claim 1, wherein the refrigerant outlet end of the bypass pipe is connected to the refrigerant inlet pipe of the low pressure container. 7. The separation type refrigeration system according to claim 1, 2, 3, or 4, wherein the diameter of the high-pressure liquid pipe is the same as that of the inter-unit piping connected to the liquid pipe. 8. The separate refrigeration system according to claim 1, 2, 3, or 4, wherein an auxiliary pressure reducer is interposed in the high-pressure liquid pipe and an auxiliary on-off valve is provided in parallel with the auxiliary pressure reducer. 9. The separate refrigeration system according to claim 8, wherein the auxiliary on-off valve is a valve that opens when the temperature of the refrigerant discharged from the compressor exceeds a set value.