JPS636347A - Refrigeration cycle - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a refrigeration cycle used in a heat pump device, etc., and particularly relates to a refrigeration cycle in which capacity is controlled by adjusting the composition of refrigerant in accordance with the temperature on the load side. It is something.

[Conventional technology]

FIG. 5 is a refrigerant circuit diagram of a refrigeration cycle as described above and shown in US Pat. No. 2,938,362.

In Fig. 5, 1 is a compressor, 2a is a main condenser, 3 is a gas-liquid separator, 4 is a pressure reducing device, and 5 is an evaporator, which are connected in order in a ring to form the main refrigerant circuit. There is. 6
is a rectification device, and the rectification device 6 is formed integrally with an upper stacked column 6a and a lower receiver 6b. , a pipe 10a in which an electric heater 8 is provided, and a pipe 12 connecting the gas-liquid separator 3 and the pressure reducing device 4 at the bottom thereof.

The top of the stacked column 6a is connected to the gas-liquid separator 3 through a pipe 11 having a sub-condenser 2b. Note that the condenser 2 is composed of the main and sub-condensers 2a and 2b. The refrigeration cycle is filled with a mixed refrigerant, which is a non-azeotropic mixture having different boiling points, such as Freon 22 as a low boiling point refrigerant and R114 as a high boiling point refrigerant.

Next, the operation of this refrigeration cycle will be explained. As the compressor 1 operates, the high temperature and high pressure refrigerant gas discharged from the compressor 1 radiates heat in the main condenser 2a and heats the surroundings. As a result, the refrigerant gas is liquefied and guided to the gas-liquid separator 3, where the refrigerant liquid is led from the lower part of the gas-liquid separator 3 through the switching valve 9 to the pressure reducing device 4, where it becomes low pressure and low temperature and evaporates. Guided to vessel 5. In the evaporator 5, the refrigerant liquid is heated from the surroundings and gasified, and the refrigerant gas is sucked into the compressor 1, and the above-described operation is repeated. The above is the operation of the main refrigerant circuit.

This refrigeration cycle is filled with a mixture of non-azeotropic refrigerants with different boiling points, but due to the nature of boat fishing, when the concentration of the low boiling point refrigerant is high, the heating capacity in the main condenser 2a is large, and the high boiling point refrigerant When the concentration of is high, the heating capacity in the main condenser 2a is small. Utilizing this property, by adjusting the composition of the mixed refrigerant, the heating capacity can be varied and the capacity can be controlled. The rectifying device 6 is provided for capacity control and is operated by a switching valve 9 and an electric heater 8. That is, when a high boiling point refrigerant is required in the main refrigerant circuit when the capacity decreases, the switching valve 9 is switched from connecting the pipes 10a and 10b to connecting the pipes 12 and 10b. The refrigerant liquid rich in high boiling point refrigerant accumulated in the receiver 6b at the bottom of the device 6 is led to the pressure reducing device 4. As a result, the concentration of the high boiling point refrigerant in the main refrigerant circuit increases, and the heating capacity decreases. In this case, the refrigerant in the main refrigerant circuit becomes excessive by introducing the refrigerant from the receiver 6b into the main refrigerant circuit, but this excess refrigerant raises the liquid level of the gas-liquid separator 3,
It overflows from the gas-liquid separator 3 and is returned to the rectifier 6 through the pipe 7. The refrigerant returned to the rectifying device 6 is
It is rich in lower boiling point refrigerants than the refrigerants found in When the required amount of high boiling point refrigerant is introduced into the main refrigerant circuit, the switching valve 9 is returned to the state before switching, and the introduction of refrigerant from the receiver 6b to the main refrigerant circuit through the pipe 12 is stopped. In addition, when a low boiling point refrigerant is required in the main refrigerant circuit when the capacity increases, input is applied to the electric heater 8 to heat and evaporate the refrigerant liquid in the receiver 6b of the rectifier 6. . The evaporated refrigerant is relatively rich in low boiling point refrigerant and is stored in the loading device 6.
It is introduced into the sub-condenser 2b from the top of the upper laminated column 6a, where it is condensed and liquefied and flows into the gas-liquid separator 3.
It flows out from the bottom of. As a result, there is an excess of refrigerant in the main refrigerant circuit, but this excess refrigerant passes from the gas-liquid separator 3 through the pipe 7 to the laminated column 6 of the rectifier 6, as in the case described above.
a Return to the top. In the stacked tower 6a, a stacking action occurs between the refrigerant liquid returned from the top and descending, and the refrigerant gas evaporated and rising from the receiver 6b, and the rising refrigerant gas is rich in low boiling point refrigerant in the upper part. The descending refrigerant liquid is rich in high-boiling, cold liquid at the bottom. As a result, the high boiling point refrigerant accumulates in the receiver 6b of the rectifying device 6, and the low boiling point refrigerant is supplied to the main refrigerant circuit, so that the concentration of the low boiling point refrigerant becomes high (and the heating capacity increases.The required heating capacity When this happens, heating by the electric heater 8 is stopped.

[Problem that the invention seeks to solve]

Since the conventional refrigeration cycle is configured as described above, the sub-condenser must be installed above the gas-liquid separator, and if the condenser is installed away from the rectifier, the connection piping will be damaged. The number of parts is large and the length is long, which restricts the arrangement of parts and increases costs.Furthermore, if the electricity is turned off to the electric heater installed in the receiver of the rectifier, the rectifier, which is rich in high boiling point refrigerant, will When the pressure in the device decreases, refrigerant flows from the main refrigerant circuit into the rectification device, causing a shortage of refrigerant in the main refrigerant circuit, which requires the electric heater to be constantly energized, which results in wasted energy. there were.

This invention was made to solve the above-mentioned problems. It eliminates the sub-condenser, increases the degree of freedom in component arrangement, and reduces the number of pipes connecting the stacking device, compressor, and condenser. The purpose of the present invention is to provide a refrigeration cycle that can reduce costs by reducing the amount of water and shorten the length of piping, and can also save energy by eliminating wasted energy due to electric heaters.

[Means for solving problems]

The refrigeration cycle according to the present invention is provided with a heat exchanger in the lower part of the rectifier through which the high-pressure refrigerant condensed in the condenser flows, and piping between the upper part of the rectifier and the evaporator inlet side or outlet side of the main refrigerant circuit. These are connected by piping with on-off valves.

[Effect]

The refrigeration cycle in this invention heats the refrigerant liquid accumulated in the lower part of the rectifier by flowing high-pressure refrigerant condensed in the condenser of the main refrigerant circuit through a heat exchanger provided in the lower part of the rectifier. As a result, the conventional electric heater can be eliminated and the energy loss caused by it can be eliminated, and the upper part of the rectifier and the piping on the evaporator inlet side or outlet side of the main refrigerant circuit can be connected to piping with an on-off valve. Since the conventional sub-condenser is eliminated, the degree of freedom in piping can be increased, the number of piping can be reduced, and the length of the piping can also be shortened.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

In Fig. 1, 1 is a compressor, 2 is a condenser similar to a conventional main condenser, 3 is a gas-liquid separator, and 4 is a pressure reducing device (hereinafter referred to as the first
(referred to as a pressure reducing device), and 5 an evaporator, which are sequentially connected in an annular manner to form a main refrigerant circuit. One end of the pipe 7 having the second pressure reducing device 13 is connected to the gas-liquid separator 3, the other end of the pipe 7 is connected to the upper part of the stacking column 6a of the rectifier 6, and one end is connected to the receiver 6b of the rectifier 6. A third pressure reducing device 14 that can be opened and closed is provided to the connected piping 12.
The other end of the refrigerant refrigerant 2 is connected to the outlet side pipe 15 of the first pressure reducing device 4, thereby forming a parallel refrigerant circuit.

A heat exchanger 16 is provided in the receiver 6b of the rectifying device 6, and the heat exchanger 16 is connected to pipes 17 and 18 between the gas-liquid separator 3 and the first pressure reducing device 4 in the main refrigerant circuit at upper and lower ends. are connected to each other. In addition, an on-off valve 19 is provided in a pipe 20 whose one end is connected to the top of the stacked tower 6a, and the other end of the pipe 20 is merged with a portion of the pipe 12 closer to the main refrigerant circuit than the third pressure reducing device 14, and is connected to the first pressure reducing part. Connected to the device 4 outlet side.

The heat pump device of this embodiment is filled with a non-azeotropic mixture of low boiling point and high boiling point refrigerants similar to the conventional heat pump device.

Next, the operation of this heat pump device will be explained. As shown in FIG. 2, when the compressor 1 is operated, the high-temperature, high-pressure refrigerant gas discharged from the compressor 1 radiates heat in the condenser 2 and heats the surroundings. The refrigerant liquefied by this heating is led to the gas-liquid separator 3, and from the lower part of this, it is led to the heat exchanger 16 inserted into the receiver 6b via piping 17, and the led refrigerant liquid is led into the receiver 6b. Since the temperature is higher than that of the accumulated refrigerant liquid, this refrigerant liquid is heated and the refrigerant liquid flowing through the heat exchanger 16 is cooled, and this refrigerant liquid is passed through the piping 18.
The refrigerant is guided to the first pressure reducing device 4, where it becomes low pressure and low temperature, and is led to the evaporator 5, where the refrigerant is heated from the surroundings and gasified, and is sucked into the compressor 1, and the above-mentioned operation is repeated. In the above operation of the main refrigerant circuit, the second. The third pressure reducing device 13,14 and the on-off valve 19 are closed, the first pressure reducing device 4 is open, and the parallel refrigerant circuit in which the rectification device 6 is provided is separated from the main refrigerant circuit. This is an operation in which the concentration of high boiling point refrigerant in the main refrigerant circuit is low and the concentration of low boiling point refrigerant is high.

In the refrigeration cycle of this embodiment, as in the conventional one, the higher the concentration of the low boiling point refrigerant, the greater the heating capacity in the condenser.
When the concentration of high boiling point refrigerant is low, the heating capacity of the condenser is small.

Utilizing this property, the composition of the mixed refrigerant can be adjusted, the heating capacity can be made variable, and the capacity can be controlled. The rectifying device 6 for controlling the capacity is the second one. It is operated by a third pressure reducing device 13,14 and an on-off valve 19. In other words, if high boiling point refrigerant is required in the main refrigerant circuit when capacity decreases,
As shown in FIG. When the third pressure reducing device 13°14 is opened and the first pressure reducing device 4 is closed, the rectifying device 6
The refrigerant liquid enriched with high boiling point refrigerant accumulated in the lower part of the receiver 6b passes from the pipe 12 through the third pressure reducing device 14 to the evaporator 5.
will lead you to the entrance. In this case, the concentration of high boiling point refrigerant in the main refrigerant circuit becomes high, and the heating capacity becomes low. In this case, by introducing the refrigerant into the main refrigerant circuit from the receiver 6a, the refrigerant in the main refrigerant circuit becomes excessive, and the gas-liquid separator 3
The liquid level rises, the refrigerant liquid overflows, is introduced into the clean tower 6a of the rectifier 6 through the pipe 7, and is introduced into the lower production pipe 6d.
from there to the receiver 6b. The returned refrigerant is enriched with low boiling point refrigerants. When the required amount of high boiling point refrigerant is introduced into the main refrigerant circuit, the second. Third pressure reducing device 1
3, 14, close the on-off valve 19, stop introducing the refrigerant from the receiver 6b into the main refrigerant circuit, and open the first pressure reducing device 4.

In addition, if a low boiling point refrigerant is required in the main refrigerant circuit when the capacity is increased, the second pressure reducing device 13. The on-off valve 19 and the first pressure reducing device 4 are opened, and the third pressure reducing device 14 is closed. The refrigerant liquid in the receiver 6b is evaporated by heating by the heat exchanger 16 and introduced into the clean tower 6a. This refrigerant is relatively rich in low boiling point refrigerant, and is led from the top of the clean tower 6a through the on-off valve 19 to the main refrigerant circuit via a pipe 20. Therefore, the refrigerant in the main refrigerant circuit becomes excessive and is returned to the upper part of the clean tower 6a through the pipe 7 of the gas-liquid separator 3. In the clean tower 6a, a cleansing effect occurs between the refrigerant liquid returned from the top and descending, and the refrigerant gas evaporated and rising from the receiver 6b, and the rising refrigerant gas is rich in low boiling point refrigerant in the upper part. The descending refrigerant liquid is enriched with high boiling point refrigerant at the bottom. As a result, the high boiling point refrigerant accumulates in the receiver 6b, and the low boiling point refrigerant is supplied to the main refrigerant circuit, increasing the concentration of the low boiling point refrigerant and increasing the heating capacity.

Furthermore, as shown in FIG. 3rd: $i pressure device 1
By closing 3.14 and the on-off valve 19 and opening the first pressure reducing device 4, operation can again be performed in which the concentration of high boiling point refrigerant in the main refrigerant circuit is higher than that of low boiling point refrigerant.

In this invention, in the above embodiment, the piping 20 having the on-off valve 19 was connected to the outlet side piping 15 of the first pressure reducing device 4, but the piping having the on-off valve may be connected to the outlet side piping of the evaporator, etc. It is sufficient to connect it to an appropriate point in the main refrigerant circuit between the outlet of the device and the suction port of the compressor.

Further, in the present invention, the gas-liquid separation tank may be omitted, and the pipe 7 having the second pressure reducing device 13 may be connected to the pipe between the condenser 2 and the heat exchanger 16.

〔Effect of the invention〕

As explained above, according to the present invention, the high-pressure refrigerant condensed in the condenser of the main refrigerant circuit is caused to flow through the heat exchanger provided in the lower part of the rectifier, and the refrigerant liquid accumulated in the lower part of the rectifier is The conventional electric heater was eliminated, so
The energy loss caused by this can be eliminated and energy saving can be achieved.In addition, the upper part of the rectifier and the piping on the evaporator inlet side or outlet side of the main refrigerant circuit are connected by piping with an on-off valve, making it possible to Since the sub-condenser is eliminated, there is a greater degree of freedom in piping, the number of piping can be reduced, and the length of the piping can also be shortened, resulting in cost reduction.

[Brief explanation of the drawing]

FIG. 1 is a refrigerant circuit diagram showing a refrigeration cycle according to an embodiment of the present invention, FIGS. 2 to 4 are refrigerant circuit diagrams showing different operating states of the refrigeration cycle of FIG. 1, and FIG. 5 is a refrigerant circuit diagram of a conventional refrigeration cycle. It is a refrigerant circuit diagram showing a refrigeration cycle. 1 is a compressor, 2 is a condenser, 3 is a gas-liquid separator, 4 is a pressure reduction device, 5 is an evaporator, 6 is a rectification device, 6a is a clean tower, 6b is a receiver, ? , 12.15.1? . 18.20 is the piping, 13.14 is the second. a third pressure reducing device;
16 is a heat exchanger, 19 is an on-off valve. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (3)

[Claims] (1) A main refrigerant circuit in which a compressor, a condenser, a pressure reducing device, and an evaporator are sequentially connected in a ring, and a pressure reducing device in which the upper part is connected between the condenser and the pressure reducing device in the main refrigerant circuit and the lower part is in the main refrigerant circuit. In a refrigeration cycle which is equipped with a parallel refrigerant circuit having a rectification device connected to the inlet side or outlet side piping of the refrigerant, and is filled with a non-azeotropic mixed refrigerant of refrigerants having different boiling points, the refrigerant circuit in the lower part of the rectification device A heat exchanger is provided in which the high-pressure refrigerant condensed in the condenser flows, and the upper part of the rectifier is connected to the piping on the evaporator inlet side or outlet side of the main refrigerant circuit by piping having an on-off valve. refrigeration cycle. (2) The refrigeration cycle according to claim 1, wherein the parallel refrigerant circuit is provided with a pressure reducing device in at least one of the piping connected to the upper part of the rectification apparatus and the piping connected to the lower part of the rectification apparatus. (3) In the parallel circuit, a second pressure reduction device is installed in the piping that connects the upper part of the rectification device and the main refrigerant circuit via a gas-liquid separator provided between the condenser and the pressure reduction device. 2. The refrigeration cycle according to claim 1, wherein a third pressure reducing device is provided in the pipe connecting the lower part of the main refrigerant circuit to the pressure reducing device outlet side pipe of the main refrigerant circuit.