JP2018194200A - Refrigeration cycle device and liquid circulation device provided with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigerating cycle device of R32, which can suppress a decrease in operating efficiency and an abnormal increase in discharge temperature without increasing a refrigerant filling amount, and has excellent durability. SOLUTION: A pipe 252 through which a refrigerant flows is provided in a gas-liquid separation device 25, and the pipe 252 is provided below a first opening 252a and a first opening 252a. In a refrigerating cycle apparatus in which the refrigerant has the second opening 252b and the ratio of the opening area of the second opening 252b to the opening area of the first opening 252a is A, the refrigerant is refrigeration of R32. Assuming that the ratio of the opening area of the second opening 252b to the opening area of the first opening 252a in the refrigerating cycle device of R410A for the refrigerant corresponding to the cycle device is B, the relationship A> B is established. [Selection diagram] Fig. 2

Description

  The present invention relates to a refrigeration cycle apparatus using R32 having a low GWP (global warming potential) as a refrigerant and having a gas-liquid separator on the suction side of a compressor.

  In recent years, in refrigeration cycle devices such as air conditioners, refrigerants that use a small ozone depletion coefficient R410A as a substitute refrigerant for R22 have become mainstream, but refrigerant R410A has a large global warming potential (GWP). In the future, conversion to refrigerant R32, which has a relatively small GWP and can suppress global warming, is being carried out (see, for example, Patent Document 1).

JP 2014-169854 A

  By the way, also in the refrigeration cycle apparatus using the R32 refrigerant as described above, the amount of refrigerant charged in the refrigeration cycle apparatus should be as small as possible while maintaining the performance of the conventional apparatus from the viewpoints of the environment and safety. Is desirable.

  However, when the R32 refrigerant is applied to a conventional refrigeration cycle apparatus, for example, when a high heating capacity is output in an environment of a low outside air temperature such as −20 ° C., the discharge temperature rises abnormally due to the characteristics of the refrigerant R32. In addition, the durability of the refrigeration cycle apparatus is reduced.

  Therefore, in order to lower the discharge temperature, a method of raising the evaporation temperature to lower the refrigerant dryness at the outlet of the evaporator and lowering the suction refrigerant enthalpy of the compressor is generally performed. If the conventional gas-liquid separator for the refrigerant R410A is applied as it is to the refrigerant R32 refrigeration cycle apparatus having the gas-liquid separator on the suction side, the liquid refrigerant is less likely to return to the compressor from the gas-liquid separator. In a state where the refrigerant dryness at the outlet of the evaporator is lowered, it is difficult to suppress the increase in the discharge temperature.

  Therefore, it is necessary to further increase the evaporation temperature and store the liquid refrigerant in the gas-liquid separator to increase the return amount of the liquid refrigerant to the compressor, or to increase the refrigerant filling amount.

  However, when the liquid refrigerant is stored in the gas-liquid separator and the return amount of the liquid refrigerant to the compressor is increased, the heat absorption from the air is reduced, so the operating capacity and operating efficiency of the refrigeration cycle apparatus are significantly reduced. It had the problem of end.

  In addition, in response to increasing the amount of refrigerant filled, there is a problem that the amount of refrigerant increases significantly, and the operating efficiency decreases under conditions where the discharge temperature such as rated conditions can be operated in a normal range. .

  The present invention solves the above-described conventional problems, and can suppress a decrease in operating efficiency and an abnormal increase in discharge temperature without increasing the amount of refrigerant filled, and a refrigeration cycle apparatus having an R32 refrigerant having excellent durability. The purpose is to provide.

  In order to solve the conventional problems, a refrigeration cycle apparatus according to the present invention includes a refrigerant circuit formed by sequentially connecting a compressor, a heat source side heat exchanger, a pressure reducing device, a use side heat exchanger, and a gas-liquid separation device. In the gas-liquid separator, at least, a pipe through which a refrigerant flows is provided on the compressor side, and the pipe is provided below the first opening and the first opening. The refrigerant is R32 refrigeration cycle apparatus in which the ratio of the opening area of the second opening to the opening area of the first opening is A, and the refrigerant is R32 When the ratio of the opening area of the second opening to the opening area of the first opening in the refrigeration cycle apparatus of R410A is B, the relationship of A> B is established. .

  As a result, the gas-liquid separator of the refrigeration cycle apparatus having the refrigerant R32 has the second opening when the opening area of the second opening is larger than the gas-liquid separator of the refrigeration cycle apparatus having the refrigerant R410A. In addition, when the opening area of the first opening is small, the pressure difference between the tube outside and the tube inside of the second opening becomes large, so Even if the amount of liquid refrigerant is the same, the mass flow rate of the R32 liquid refrigerant that flows through the second opening and merges with the R32 gas refrigerant flowing from the first opening increases, so the refrigerant dryness at the evaporator outlet is greatly reduced. Even if not, the enthalpy of the refrigerant returning to the compressor is reduced, so even if the refrigerant discharge pressure of the refrigerant of the refrigerant refrigeration cycle apparatus R32 and the refrigerant R410A is the same, the discharge refrigerant temperature Less than or equal to Rukoto can.

  According to the present invention, it is possible to suppress a decrease in operating efficiency and an abnormal increase in discharge temperature without increasing the refrigerant filling amount, and it is possible to provide a refrigeration cycle apparatus in which the refrigerant having excellent durability is R32.

Schematic configuration diagram of a refrigeration cycle apparatus according to Embodiment 1 of the present invention. Schematic diagram of the same gas-liquid separator In the refrigeration cycle apparatus having the refrigerant R32 and the refrigerant R410A, the relationship between the intake refrigerant dryness of the compressor and the outside air temperature when the discharge temperature of the compressor and the condensing temperature on the high pressure side are the same. Illustration The figure which shows the relationship between the suction | inhalation refrigerant | coolant dryness of a compressor, and A / B at the time of changing the liquid level height in a gas-liquid separator in the refrigerating cycle apparatus of the R32 of the same refrigerant

  The first invention includes at least a refrigerant circuit formed by sequentially connecting a compressor, a heat source side heat exchanger, a decompression device, a use side heat exchanger, and a gas-liquid separator, and the gas-liquid separator includes A pipe through which refrigerant flows is provided on the compressor side, and the pipe has a first opening and a second opening provided below the first opening, In the refrigeration cycle apparatus with R32 as the refrigerant, where the ratio of the opening area of the second opening to the opening area of the first opening is A, the refrigerant corresponding to the refrigeration cycle apparatus with R32 as the refrigerant is in the refrigeration cycle apparatus with R410A as the refrigerant. When the ratio of the opening area of the second opening to the opening area of the first opening is B, the refrigeration cycle apparatus satisfies the relationship of A> B.

  As a result, the gas-liquid separator of the refrigeration cycle apparatus having the refrigerant R32 has the second opening when the opening area of the second opening is larger than the gas-liquid separator of the refrigeration cycle apparatus having the refrigerant R410A. In addition, when the opening area of the first opening is small, the pressure difference between the tube outside and the tube inside of the second opening becomes large, so Even if the amount of liquid refrigerant is the same, the mass flow rate of the R32 liquid refrigerant that flows through the second opening and merges with the R32 gas refrigerant flowing from the first opening increases, so the refrigerant dryness at the evaporator outlet is greatly reduced. Even if the refrigerant is discharged, the enthalpy of the refrigerant returning to the compressor is reduced. Therefore, even if the refrigerant discharged from the R32 refrigeration cycle apparatus and the refrigerant refrigeration cycle apparatus R410A have the same refrigerant discharge refrigerant pressure, Temperature equal or less It can be.

  Therefore, it is possible to suppress a decrease in operating efficiency and an abnormal increase in the discharge temperature without increasing the refrigerant filling amount of the refrigeration cycle, and it is possible to provide a refrigeration cycle apparatus in which the refrigerant having excellent durability is R32.

  According to a second aspect of the present invention, in the first aspect of the present invention, in the first aspect of the invention, the refrigerant in which the ratio of the opening area of the second opening to the opening area of the first opening is R32 is R32, and the refrigerant is R32 When the ratio of the opening area of the second opening to the opening area of the first opening in the refrigeration cycle apparatus of R410A corresponding to the refrigerant cycle apparatus of R410A is B, A is 1.9 times or more of B. It is characterized by this.

  Thereby, the storage amount (liquid level height) of the liquid refrigerant in the gas-liquid separation device of the refrigeration cycle device having the refrigerant R32 is equal to or less than the storage amount in the gas-liquid separation device of the refrigeration cycle device having the refrigerant R410A. However, by increasing the mass flow rate of the R32 liquid refrigerant flowing through the second opening, the dryness of the refrigerant sucked by the compressor (weight ratio occupied by the gas refrigerant out of all the refrigerant) can be reduced, and the refrigeration cycle of the refrigerant R410A The discharge temperature of the compressor is equal to or lower than that of the apparatus.

  Therefore, even in an environment with a low outside air temperature such as −20 ° C., a decrease in operation efficiency and an abnormal increase in discharge temperature can be suppressed without increasing the amount of refrigerant enclosed, and a refrigerant having excellent durability is a refrigeration of R32. A cycle device can be provided.

  The third invention is a liquid circulation device characterized in that the liquid heated by the utilization side heat exchanger of the first or second invention is circulated.

  As a result, when the liquid is hot water, it is possible to suppress a decrease in operating efficiency and an abnormal increase in discharge temperature without increasing the amount of refrigerant enclosed, and the hot water having R32 refrigeration cycle apparatus with excellent durability. A heating device or a hot water supply device can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a schematic configuration diagram of a refrigeration cycle apparatus according to a first embodiment of the present invention. In FIG. 1, a refrigeration cycle apparatus 1A includes a refrigerant circuit 2 that circulates refrigerant, a pump 31 that sends water to the user-side heat exchanger 22 that exchanges heat with the refrigerant in the user-side heat exchanger 22 of the refrigerant circuit 2, And a control device (not shown). Moreover, R32 which is low GWP is used for the refrigerant circulating through the refrigerant circuit 2. In addition, in the use side heat exchanger 22, when it is the structure which a refrigerant | coolant and air heat-exchange, it becomes an air blower, such as a fan, instead of the pump 31.

  The refrigerant circuit 2 is configured by connecting a compressor 21, a use side heat exchanger 22, an expansion valve (decompression device) 23, and a heat source side heat exchanger 24 in an annular shape by piping. In the refrigerant circuit 2 of the present embodiment, a gas-liquid separator (gas-liquid separator) 25 that performs gas-liquid separation is provided between the heat source side heat exchanger 24 and the compressor 21. The refrigerant circuit 2 is provided with a four-way valve 26 for switching between the heating operation and the defrosting operation.

  In the present embodiment, the refrigeration cycle device 1A functions as a heating device for a hot water circulation device that uses hot water generated by heating operation to heat, and the use-side heat exchanger 22 of the refrigerant circuit 2 includes a refrigerant. By exchanging heat between water and water, it functions as a heat exchanger that heats water.

  Specifically, for example, a heating terminal 32 such as a radiator or a floor heating panel and a hot water storage tank (not shown) are annularly connected to the hot water circuit 3 provided with the use side heat exchanger 22 and the pump 31 by piping. The hot water is circulated through the hot water circuit 3 so that hot water is supplied from the heating terminal 32 from the heating or hot water storage tank (not shown).

  Hereinafter, the operation of the refrigeration cycle apparatus 1A will be described with reference to FIG. In FIG. 1, the flow direction of the refrigerant during the heating operation is indicated by a solid arrow, and the flow direction of the refrigerant during the defrosting operation is indicated by a broken line. Hereinafter, the state change of the refrigerant in the heating operation and the defrosting operation will be described.

  In the heating operation, the discharged gas refrigerant that has been compressed by the compressor 21 and has become high temperature and high pressure flows into the use side heat exchanger 22 through the four-way valve 26, and here, from the hot water circuit 3 to the use side heat exchanger 22. The refrigerant dissipates heat into the flowing water, and the refrigerant condenses.

  The condensed and liquefied refrigerant is decompressed and expanded by the expansion valve 23 and then flows into the heat source side heat exchanger 24. The low-pressure two-phase refrigerant flowing into the heat source side heat exchanger 24 absorbs heat from the air blown by the fan 27 and evaporates. Thereafter, the low-pressure refrigerant flowing out of the heat source side heat exchanger 24 is again sucked into the compressor 21 via the four-way valve 26 and the gas-liquid separator 25.

  On the other hand, in the case of the defrosting operation, the discharged gas refrigerant that has been compressed by the compressor 21 and becomes high temperature and high pressure flows into the heat source side heat exchanger 24 through the four-way valve 26, and here, outside the heat source side heat exchanger. It dissipates heat to the frost attached to the surface and condensates.

  The condensed and liquefied refrigerant is decompressed and expanded by the expansion valve 23 and then flows into the use side heat exchanger 22. The low-pressure two-phase refrigerant flowing into the use side heat exchanger 22 absorbs heat from the water circulating in the hot water circuit 3 and evaporates. Thereafter, the low-pressure refrigerant flowing out from the use side heat exchanger 22 is again sucked into the compressor 21 via the four-way valve 26 and the gas-liquid separator 25.

  In the present embodiment, in order to prevent a large amount of liquid refrigerant from directly returning to the compressor 21 during the transient operation of the compressor 21 such as at the start-up or defrosting operation, the compression is performed. A gas-liquid separator 25 is provided on the suction side of the machine 21.

  FIG. 2 is a schematic diagram of the gas-liquid separator 25 provided in the refrigerant circuit 2. The container 250 is provided with two pipes, an inlet pipe 251 and an outlet pipe 252 that communicate the inside and outside of the container 250.

  Hereinafter, the behavior of the refrigerant inside the gas-liquid separator 25 will be described. First, during the heating operation, the refrigerant flowing out from the heat source side heat exchanger 24 flows into the container 250 of the gas-liquid separator 25 from the inlet pipe 251. If the flowing-in refrigerant is in a gas-liquid two-phase state, Separated into refrigerant and gas refrigerant.

  The separated gas refrigerant flows from the first opening 252 a of the outlet pipe 252 and returns to the compressor 21. On the other hand, the separated liquid refrigerant is stored in the container 250 of the gas-liquid separator 25, but when the liquid level rises to the second opening 252b, the water head pressure due to the liquid level height from the second opening 252b. And the pressure difference at the inlet / outlet of the second opening 252b caused by the pressure loss from the first opening 252a to the second opening 252b in the outlet pipe 252 flows into the outlet pipe 252 and together with the gas refrigerant, the compressor 21 Return to.

Further, the opening area of the first opening 252a and the opening area of the second opening 252b of the gas-liquid separator 25 of the refrigeration cycle apparatus 1A in which the refrigerant of the present invention is R32 are the second with respect to the opening area of the first opening 252a. When the ratio of the opening area of the opening 252b is A, and the ratio of the opening area of the second opening 252b to the opening area of the first opening 252a of the gas-liquid separator 25 when the refrigerant is R410A is B , A / B ratio is configured to be 1.9 times or more.

  FIG. 3 shows the present invention in which the refrigerant is R32 and the conventional technology in which the refrigerant is R410A under the same conditions that the condensation temperature on the high pressure side of the refrigerant circuit 2 is 56 ° C. and the discharge refrigerant temperature of the compressor 21 is 100 ° C. The relationship between the suction refrigerant dryness of the compressor 21 and the outside air temperature is described respectively.

  4 shows the relationship between the ratio A / B and the suction refrigerant dryness of the compressor 21 in the present invention in which the refrigerant is R32, where the liquid level in the gas-liquid separator 25 is as shown in FIG. In the case where the refrigerant is the same as that at point a of R410A, the case of 2/5 times and the case of 2 times are described respectively.

  First, from FIGS. 3 and 4, in the present invention in which the refrigerant is R32, when the ratio A / B is 1.9 times, and the liquid level in the gas-liquid separator 25 is the same, the refrigerant It can be seen that the same high-pressure condensing temperature and discharge refrigerant temperature of the compressor 21 can be realized as in the case of R410A.

  In the present invention in which the refrigerant is R32, when the ratio A / B is 2.2 times, the refrigerant is R410A even if the liquid level in the gas-liquid separator 25 is 2/5 times. It can be seen that the same high-pressure condensing temperature and discharge refrigerant temperature of the compressor 21 can be realized.

  In other words, in the present invention in which the refrigerant is R32, if the ratio A / B is 1.9 times or more, the refrigerant even if the liquid level in the gas-liquid separator 25 is less than the liquid level of the R410A refrigerant. Even in the present invention in which R32 is used as the refrigerant circulating in the circuit 2, it can be seen that the discharge refrigerant temperature of the compressor 21 is equal to or lower than that in the case where R410A is used as the refrigerant.

  This is because the storage amount (liquid level height) of the liquid refrigerant in the gas-liquid separation device 25 of the refrigerant circuit 2 with the refrigerant R32 is the storage amount (liquid level) in the gas-liquid separation device 25 of the refrigerant circuit 2 with the refrigerant R410A. The height of the R32 liquid refrigerant flowing through the second opening 252b increases even when the surface height is less than the surface height), so that the degree of dryness of the refrigerant sucked by the compressor 21 (weight ratio occupied by the gas refrigerant out of all the refrigerant) ) Becomes smaller and the discharge temperature of the compressor 21 is equal to or lower than that of the refrigerant circuit 2 of the refrigerant R410A.

  As described above, in the refrigerant circuit 2 of the refrigeration cycle apparatus 1A of the present invention, the refrigerant has the ratio A of the opening area of the second opening 252b to the opening area of the first opening 252a of the gas-liquid separator 25 of R32, When the ratio of the opening area of the second opening part 252b to the opening area of the first opening part 252a of the gas-liquid separator 25 of the refrigerant circuit 2 of the refrigerant circuit R410A is B, the ratio of A / B is 1.9 times or more. Then, even in an environment with a low outside air temperature such as −20 ° C., an operation in which an abnormal increase in the discharge temperature of the compressor 21 is suppressed can be performed.

  That is, without increasing the amount of refrigerant enclosed in the refrigerant circuit 2, it is possible to suppress a decrease in operating efficiency and an abnormal increase in the discharge temperature, and it is possible to provide the refrigeration cycle apparatus 1 </ b> A with R32 having excellent durability.

  Furthermore, even when R32 is used as the refrigerant circulating in the refrigerant circuit 2, the refrigerant expands only the second opening 252b of the outlet pipe of the existing gas-liquid separator 25 of R410A, or the first opening 252a. Since the ratio A / B can be doubled or more simply by reducing the opening area, there is no need to spend a great deal of man-hours and redesign.

Furthermore, since the refrigerant can share many components with the existing gas-liquid separator 25 of R410A, cost reduction can be realized.

Further, if the liquid level in the gas-liquid separator 25 is the same, the suction refrigerant dryness of the compressor 21 is the same, so the outer diameter of the container 250 of the gas-liquid separator 25 can be reduced. Thus, the amount of material used and the amount of refrigerant filled can be reduced. Therefore, an inexpensive and resource-saving refrigeration cycle apparatus can be obtained. Note that the fluid to be heated that is heated by the use-side heat exchanger 22 is not necessarily water but may be liquid.

  The present invention is particularly useful for a liquid circulation device that heats a liquid by a refrigeration cycle apparatus and uses the liquid for heating or hot water supply.

DESCRIPTION OF SYMBOLS 1A Refrigeration cycle apparatus 2 Refrigerant circuit 21 Compressor 22 Use side heat exchanger 23 Expansion valve (expansion means)
24 Heat source side heat exchanger 25 Gas-liquid separator (gas-liquid separator)
252 Outlet piping (piping)
252a first opening 252b second opening

Claims (3)

It includes at least a refrigerant circuit formed by sequentially connecting a compressor, a heat source side heat exchanger, a decompression device, a use side heat exchanger, and a gas-liquid separation device, and in the gas-liquid separation device, on the compressor side A pipe through which the refrigerant flows is provided, and the pipe has a first opening and a second opening provided below the first opening, and the opening of the first opening. In the refrigeration cycle apparatus in which the ratio of the opening area of the second opening to the area is A, the refrigerant of the first opening in the refrigeration cycle apparatus of R32, the refrigerant corresponding to the refrigeration cycle apparatus of R32 is the refrigerant of the refrigeration cycle apparatus of R410A. A refrigeration cycle apparatus characterized in that a relation of A> B is established, where B is a ratio of the opening area of the second opening to the opening area. In the refrigeration cycle apparatus in which the refrigerant is R32 in which the ratio of the opening area of the second opening to the opening area of the first opening is A, the refrigerant corresponding to the refrigeration cycle apparatus in which the refrigerant is R32 is the refrigeration cycle apparatus in which the refrigerant is R410A. 2. The refrigeration cycle according to claim 1, wherein A is 1.9 times or more of B, where B is a ratio of an opening area of the second opening to an opening area of the first opening. apparatus. A liquid circulation apparatus characterized in that the liquid heated by the use side heat exchanger according to claim 1 or 2 is circulated.

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