JP2007127411A - Refrigerating cycle device using non-azeotropic mixture refrigerant - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigerating cycle device using a non-azeotropic mixture refrigerant, involving a less number of connection points with a composition separation circuit and embodied in a simple refrigerant circuit constitution. <P>SOLUTION: The refrigerating cycle device is equipped with a heat source unit 62 consisting of a refrigerating cycle, a composition separating unit 63 consisting of the composition separation circuit having a refrigerant rectifier 11, a first cooler 13, and a second cooler 12, and a first and a second piping to connect the heat source unit 62 with the composition separating unit 63, wherein the first piping is connected through the second cooler 12 to the piping laid around the lower part of the refrigerant rectifier 11, the discharge part of a compressor 1, and a refrigerant passage four-way valve 2, while the second piping is connected through the first cooler 13 to the piping laid around the lower part of the refrigerant rectifier 11, the refrigerant passage four-way valve 2, and the suction part of the compressor 1, and further third piping is provided connected through the second cooler 12 to the piping leading from the lower part of the refrigerant rectifier 11 of the second piping to the first cooler 13 and the outlet piping of the first cooler 13 of the second piping. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a refrigeration cycle that uses a non-azeotropic refrigerant mixture as a refrigerant, and in particular, relates to a refrigeration cycle apparatus capable of changing the refrigerant composition circulating in the refrigeration cycle and improving performance and performing hot water supply.

Conventionally, a refrigerant composition changing means for changing the composition of the refrigerant circulating in the refrigeration cycle in order to control the capacity of an air conditioner equipped with a compressor whose rotation speed cannot be changed and to reduce the high pressure at the time of high-temperature hot water discharge by a heat pump type hot water heater An on-board refrigeration cycle apparatus has been proposed.
Here, an example disclosed in Japanese Patent Laid-Open No. 10-267436 is known as an example of controlling the capacity by changing the composition of the non-azeotropic refrigerant mixture circulating in the refrigeration cycle. The conventional refrigeration cycle aims to obtain a wide range of capacity control with high efficiency without using an inverter that changes the rotation speed of the compressor. The compressor, the heat source side heat exchanger, the decompressor, and the utilization A refrigeration cycle equipped with a side heat exchanger, a non-azeotropic refrigerant mixture consisting of a low-boiling refrigerant and a high-boiling refrigerant, a refrigerant rectifier that produces a refrigerant rich in low-boiling components, and a refrigerant rectifier. A first refrigerant reservoir that stores the refrigerant and a second refrigerant reservoir that stores a refrigerant rich in high-boiling components, and the amount of liquid refrigerant in the first refrigerant reservoir and the second refrigerant reservoir By adjusting the value, the composition circulating in the refrigeration cycle can be continuously changed, and the ability according to the load can be always exhibited.

  A conventional refrigeration air conditioner will be described with reference to FIG. In FIG. 8, 60 is an outdoor unit, which includes a compressor 1, a four-way valve 2, a heat source side heat exchanger 3, and an accumulator 6 as a second refrigerant reservoir. Reference numeral 61 denotes an indoor unit, which includes an expansion valve 4 and a use side heat exchanger 5 which are first decompression devices. The outdoor unit 60 and the indoor unit 61 are connected by two pipes to form a refrigeration cycle. This refrigeration cycle is filled with a non-azeotropic refrigerant mixture comprising a high-boiling component and a low-boiling component. The heat source side heat exchanger 3 operates as an evaporator during heating operation, and operates as a condenser during cooling operation. The use side heat exchanger 5 operates as a condenser during the heating operation, and operates as an evaporator during the cooling operation.

  Next, refrigerant composition changing means for continuously changing the composition of the non-azeotropic refrigerant mixture circulating in the refrigeration cycle in the outdoor unit 60 will be described. Reference numeral 11 denotes a refrigerant rectifier, and the outlet of the compressor 1 and the lower part of the refrigerant rectifier 11 are connected by a pipe through an electromagnetic valve 21. A cooler 12 for exchanging heat with the pipe is provided. Further, the lower part of the refrigerant rectifier 11 and the accumulator 6 are connected by piping through a capillary tube 24 and an electromagnetic valve 22. A cooler 13 and a refrigerant reservoir 14 as a first refrigerant reservoir are annularly connected to the upper part of the refrigerant rectifier 11, and a part of the refrigerant sucked into the compressor 1 is electromagnetic. It is configured to be able to flow in through the valve 23. The refrigerant rectifier 11, the refrigerant reservoir 14, the cooler 12, the cooler 13, the electromagnetic valves 21, 22, 23, the capillaries 24, and their connection pipes are housed in the outdoor unit 60.

  In this configuration, for example, during the heating operation, surplus refrigerant in the refrigeration cycle is stored in the accumulator 6. The refrigerant in the accumulator 6 is separated into a liquid refrigerant rich in high-boiling components and a vapor refrigerant rich in low-boiling components. For this reason, when a liquid refrigerant is stored in the accumulator 6, the low boiling point component of the refrigerant composition circulating in the cycle increases as compared with the filling composition.

  On the other hand, in order to increase the high-boiling component of the refrigerant composition circulating in the refrigeration cycle, a part of the high-temperature and high-pressure vapor refrigerant discharged from the compressor 1 is caused to flow into the cooler 12 via the electromagnetic valve 21, The high-temperature refrigerant vapor is cooled by the low-temperature and low-pressure compressor suction refrigerant in the cooler 12 and is cooled to a saturated vapor or a gas-liquid two-phase state. The high-pressure gas-liquid two-phase refrigerant exiting the cooler 12 flows into the lower part of the refrigerant rectifier 11, and among these, the refrigerant vapor rises in the refrigerant rectifier 11. In the upper part of the refrigerant rectifier 11, the raised refrigerant vapor flows into the cooler 13, is cooled by the low-temperature compressor suction refrigerant that has flowed in through the electromagnetic valve 23, and is condensed and liquefied. This liquid refrigerant flows into the refrigerant reservoir 14 and is stored. From the inside of the refrigerant reservoir 14, the liquid refrigerant flows from the upper part of the refrigerant rectifier 11 as the reflux liquid of the refrigerant rectifier 11. That is, in the refrigerant rectifier 11, the rising vapor refrigerant and the falling liquid refrigerant make gas-liquid contact, heat and mass transfer are performed, and the vapor refrigerant rising in the refrigerant rectifier 11 gradually Low-boiling components increase, and liquid refrigerant rich in low-boiling components is stored in the refrigerant reservoir 14.

As the liquid refrigerant stored in the refrigerant reservoir 14 increases, the liquid refrigerant in the accumulator 6 decreases, and the liquid refrigerant rich in high-boiling components stored in the accumulator 6 is released into the cycle, resulting in a low boiling point. The liquid refrigerant rich in the components is stored in the refrigerant reservoir 14. As a result, the refrigerant composition circulating in the refrigeration cycle can be enriched with high-boiling components.
For example, in a refrigeration cycle filled with a refrigerant (R407C) in which R32 is 23%, R125 is 25%, and R134a is mixed at a weight ratio of 52%, the composition of R32 is controlled in the range of 45% to 5%, The capacity can be controlled in the range of 130% to 70% when the capacity at the filling composition (composition of R32 is 23%) is 100.

  As described above, in the conventional invention, the refrigeration cycle is adjusted by adjusting the amount of liquid refrigerant rich in low boiling point components stored in the refrigerant reservoir 14 and the amount of liquid refrigerant rich in high boiling point components stored in the accumulator 6. Since the refrigerant composition circulating in the interior can be changed, the refrigerant composition can be changed over a wide range at a lower cost than in the case of controlling the rotational speed by an inverter.

  In the conventional refrigeration cycle apparatus, since the low-pressure gas refrigerant of the refrigeration cycle is used as a cooling source for cooling the refrigerant supplied to the refrigerant rectifier 11 and a cooling source for cooling the outlet steam of the refrigerant rectifier 11, the refrigeration cycle And the refrigerant rectifier 11 have a large number of connection points (in FIG. 8, the number of connection points between the refrigeration cycle and the refrigerant composition changing means is six points a to f). There was a problem that became complicated.

  The present invention has been made to solve the above-described problems, and can reduce the number of connection points between the refrigeration cycle and the composition separation circuit with a simple refrigerant configuration, improve workability, and separate the composition into an existing refrigeration cycle apparatus. To provide a refrigeration cycle apparatus that uses a non-azeotropic refrigerant mixture that can easily connect a circuit, can flow an appropriate refrigerant flow rate in each flow path, and can improve reliability and performance. With the goal.

A refrigeration cycle apparatus using a non-azeotropic refrigerant mixture according to the present invention comprises a compressor, a refrigerant flow path switching means, a use side heat exchanger, a first pressure reducing device, and a heat source side heat exchanger connected in an annular shape, and has a low boiling point. A heat source unit comprising a refrigeration cycle that circulates a non-azeotropic refrigerant mixture comprising a refrigerant and a high-boiling refrigerant; a first cooler and a refrigerant reservoir are connected in an annular shape to the upper part; a second cooler is connected to the lower part; Composition separation means for separating the composition of the non-azeotropic refrigerant mixture is provided, and the non-azeotropic refrigerant mixture flowing out from the lower portion of the composition separation means is used as a cooling source for the first cooler and the second cooler. A composition separation unit comprising the composition separation circuit, a lower portion of the composition separation means, and a pipe between the discharge section of the compressor and the refrigerant flow switching means are connected via the second cooler. The first piping and the composition separation A second pipe connected via a first cooler to a lower part of the stage, and a pipe between the refrigerant flow switching means and the suction portion of the compressor; and the composition separating means of the second pipe A pipe between a lower part and the first cooler, and a third pipe connected to the outlet side pipe of the first cooler of the second pipe via the second cooler, The heat source unit and the composition separation unit are connected at two locations of the first pipe and the second pipe,
Based on the change in the composition of the non-azeotropic refrigerant mixture, a part of the non-azeotropic refrigerant mixture discharged from the compressor of the heat source unit through the first pipe is introduced into the composition separation unit, The composition separation unit changes the composition of the non-azeotropic refrigerant mixture, a part of the non-azeotropic refrigerant mixture having the changed composition flows through the first cooler through the second pipe, and the other part The third pipe flows through the second cooler, then joins the second pipe, and is supplied to the heat source unit through the second pipe.

  In addition, a second pressure reducing device is provided in a pipe between the second cooler and the lower part of the composition separating unit, and a pipe between the lower part of the composition separating unit and the connection part with the third pipe is provided in the second pipe. 3 A decompressor is provided.

  In addition, a second pressure reducing device is provided in a pipe between the second cooler and the lower part of the composition separating unit, a connection part between the lower part of the composition separating unit and the third pipe, the first cooler, A third pressure reducing device is provided in the pipe between the second pipe, and a fourth pressure reducing device is provided in the pipe between the connection portion between the second pipe and the third pipe and the second cooler.

  Also, a second pressure reducing device is provided in a pipe between the second cooler and the lower part of the composition separating means, and a third pressure reducing device is provided in a pipe between the lower part of the composition separating means and the first cooler. It is a thing.

  In addition, a first on-off valve is provided in a pipe between the refrigeration cycle of the first pipe and the second cooler inlet, and between the first cooler outlet of the second pipe and the refrigeration cycle. The pipe is provided with a second on-off valve.

  Further, the heat source unit housing the refrigeration cycle and the composition separation unit housing the composition separation circuit are installed separately.

According to this invention, the compressor, the refrigerant flow switching means, the use side heat exchanger, the first pressure reducing device, and the heat source side heat exchanger are connected in an annular shape, and are non-azeotropic consisting of a low boiling point refrigerant and a high boiling point refrigerant. A heat source unit composed of a refrigeration cycle for circulating the mixed refrigerant, and a first cooler and a refrigerant reservoir connected in an annular shape at the upper part and a second cooler connected at the lower part to separate the composition of the non-azeotropic refrigerant mixture A composition separation unit comprising a composition separation circuit having composition separation means and using the non-azeotropic refrigerant mixture flowing out from the lower portion of the composition separation means as a cooling source for the first cooler and the second cooler The first pipe connected via the second cooler to the pipe between the lower part of the composition separation means, the discharge part of the compressor and the refrigerant flow switching means, and the composition separation means And the refrigerant flow path switching means A second pipe connected to the pipe between the suction portion of the compressor via the first cooler, and a pipe between the lower part of the composition separating means of the second pipe and the first cooler. And a third pipe connected to the outlet side pipe of the first cooler of the second pipe via the second cooler, and the heat source unit and the composition separation unit are The non-azeotropic mixing discharged from the compressor of the heat source unit by the first pipe based on the change in composition of the non-azeotropic refrigerant mixture, connected at two locations of one pipe and the second pipe A part of the refrigerant is introduced into the composition separation unit, the composition of the non-azeotropic refrigerant mixture is changed by the composition separation unit, and the part of the non-azeotropic refrigerant mixture having the changed composition is changed by the second pipe. It flows through the first cooler and the other part is due to the third pipe. Since it flows through the second cooler, and then merges with the second pipe and is supplied to the heat source unit via the second pipe, the flow rate of the refrigerant flowing through the first cooler and the second cooler It can be optimized, and compared with the case where the refrigerant sucked from the compressor is used as the cooling source of the first cooler, the number of connection points between the refrigeration cycle and the composition separation circuit can be reduced, and workability is improved. The cost can be reduced.
In addition, the refrigeration cycle and the composition separation unit can be installed separately and the composition separation circuit can be connected to an existing refrigeration cycle apparatus with a simple modification.

  In addition, a second pressure reducing device is provided in a pipe between the second cooler and the lower part of the composition separating unit, and a pipe between the lower part of the composition separating unit and the connection part with the third pipe is provided in the second pipe. Since the three decompression devices are provided, the intermediate pressure of the refrigerant rectifier and the flow rate of the refrigerant vapor rising inside the refrigerant rectifier can be appropriately controlled.

  In addition, a second pressure reducing device is provided in a pipe between the second cooler and the lower part of the composition separating unit, a connection part between the lower part of the composition separating unit and the third pipe, the first cooler, Since the third pressure reducing device is provided in the pipe between the second pipe and the fourth pressure reducing device is provided in the pipe between the connection portion of the second pipe and the third pipe and the second cooler, each flow path It is possible to flow an appropriate refrigerant flow rate.

  Also, a second pressure reducing device is provided in a pipe between the second cooler and the lower part of the composition separating means, and a third pressure reducing device is provided in a pipe between the lower part of the composition separating means and the first cooler. Therefore, there is an effect that the intermediate pressure of the refrigerant rectifier and the flow rate of the refrigerant vapor rising inside can be appropriately controlled.

  In addition, a first on-off valve is provided in a pipe between the refrigeration cycle of the first pipe and the second cooler inlet, and between the first cooler outlet of the second pipe and the refrigeration cycle. Since the second open / close valve is provided in the pipe, the refrigerant composition circulating in the refrigeration cycle can be changed by a simple valve opening / closing operation.

  In addition, since the heat source unit housing the refrigeration cycle and the composition separation unit housing the composition separation circuit are installed separately, it is possible to connect the composition separation circuit with a simple modification of an existing refrigeration cycle apparatus. It is possible to suppress high pressure and improve performance.

Embodiment 1 FIG.
Hereinafter, a refrigeration cycle apparatus showing Embodiment 1 of the present invention will be described.
FIG. 1 is a configuration diagram showing a refrigeration cycle apparatus according to the present embodiment.
First, the configuration of the refrigeration cycle apparatus of the present invention will be described. In the figure, 62 is a heat source unit that stores a refrigeration cycle, 63 is a composition separation unit that houses a composition separation circuit, and these are connected by two pipes that are first and second pipes, and circulate in the refrigerant circuit. The refrigeration cycle in which the refrigerant composition to be changed can be changed is formed. The refrigeration cycle is filled with, for example, a three-component non-azeotropic refrigerant R407C (R32: R125: R134a = 23: 25: 52 wt%) composed of a high boiling point component (R134a) and a low boiling point component (R32 + R125). .

The refrigeration cycle includes a compressor 1, a four-way valve 2, a heat source side heat exchanger 3, an expansion valve 4 that is a first pressure reducing device, a use side heat exchanger 5, and an accumulator 6, which are housed in a heat source unit 62. ing.
The composition separation circuit includes a refrigerant rectifier 11 as a composition separation means, a refrigerant reservoir 14 for storing refrigerant, a first cooler 13, a second cooler 12, a capillary tube 31 as a second decompression device, a first 3 includes a capillary 33 as a pressure reducing device, a capillary 32 as a fourth pressure reducing device, and electromagnetic valves 21 and 22 as first and second on-off valves. A first cooler 13 is disposed above the refrigerant rectifier 11. And the refrigerant reservoir 14 are connected in a ring shape. These are housed in the composition separation unit 63.

  Further, the refrigerant rectifier 11 is filled with a filler for increasing the gas-liquid contact area. The compressor 1 outlet and the lower part of the refrigerant rectifier 11 are connected to each other by a first pipe via an electromagnetic valve 21 that is a first on-off valve. A second cooler 12 and a capillary tube 31 for cooling the discharge gas with the refrigerant liquid flowing out from the refrigerant rectifier 11 are provided. The liquid refrigerant flowing out from the lower part of the refrigerant rectifier 11 branches into two pipes, that is, the second pipe and the third pipe, while the second pipe includes the capillary tube 33, the first cooler 13, and the electromagnetic It flows into the inlet of the accumulator 6 through the flow path formed by the valve 22. On the other hand, the third pipe passes through the flow path including the capillary tube 32 and the second cooler 12, joins between the first cooler 13 and the electromagnetic valve 22, and flows into the inlet of the accumulator 6.

  Next, the operation of the present embodiment configured as described above will be described. In the present embodiment, the refrigeration cycle apparatus is an air-cooled hot water supply chiller that uses a water heat exchanger for the heat source side heat exchanger 3 and an air heat exchanger for the use side heat exchanger 5, and circulates in the refrigeration cycle. A method of changing the composition of the low boiling point component to suppress the high pressure rise during hot water supply will be described. In this case, the use-side heat exchanger 5 operates as an evaporator during a hot water supply operation (hot water supply operation) and operates as a condenser during a chiller operation (cold water supply operation). The heat source side heat exchanger 3 operates as a condenser during the hot water supply operation, and operates as an evaporator during the chiller operation.

  First, the case of hot water supply (hot water supply) operation will be described. In the hot water supply operation, the four-way valve 2 is connected as shown by a solid line, the compressor outlet and the inlet of the heat source side heat exchanger 3 are connected, and the inlet of the accumulator 6 and the outlet of the use side heat exchanger 5 are connected. The parts are connected to each other. The high-temperature and high-pressure vapor refrigerant discharged from the compressor 1 is condensed and liquefied by a heat source side heat exchanger 3 that operates as a condenser via a four-way valve 2 to be a medium-temperature and high-pressure liquid refrigerant, and is depressurized by an expansion valve 4. It becomes a low-pressure gas-liquid two-phase refrigerant and flows into the use side heat exchanger 5 operating as an evaporator. This refrigerant evaporates in the use side heat exchanger 5 and returns to the compressor 1 again through the four-way valve 2 and the accumulator 6. At this time, the cold water that is the medium to be heated flowing into the heat source side heat exchanger 3 is heated by the condensation latent heat of the refrigerant to become hot water, and is supplied to a hot water storage tank or the like. In addition, air that is a medium to be cooled flowing into the use side heat exchanger 5 is cooled by the latent heat of vaporization of the refrigerant, and then released to the outside air.

Next, the operation when changing the refrigerant composition circulating in the refrigeration cycle during the hot water supply operation will be described.
In the hot water supply operation described above, when increasing the high boiling point component of the refrigerant composition circulating in the refrigeration cycle, the electromagnetic valves 21 and 22 are opened. At this time, part of the high-temperature and high-pressure vapor refrigerant that has left the compressor 1 flows into the second cooler 12 through the electromagnetic valve 21. This high-temperature refrigerant vapor is cooled by a part of the low-temperature and low-pressure liquid refrigerant that flows out from the lower part of the refrigerant rectifier 11 in the second cooler 12 and is decompressed by the capillary 32, and is saturated or in a gas-liquid two-phase state. Until cooled. The high-pressure gas-liquid two-phase refrigerant that has exited the second cooler 12 is depressurized to an intermediate pressure by the capillary tube 31 and then flows into the lower part of the refrigerant rectifier 11. Among these, the refrigerant vapor passes through the refrigerant rectifier 11. To rise.

  Here, the specifications of the capillaries 31 and 32 are determined so that the intermediate pressure of the refrigerant rectifier 11 and the flow rate of the rising refrigerant vapor are appropriate. In the upper part of the refrigerant rectifier 11, the rising refrigerant vapor flows into the first cooler 13, flows out from the lower part of the refrigerant rectifier 11, and is cooled by another part of the liquid refrigerant decompressed by the capillary tube 33. Condensed liquid. The condensed and liquefied refrigerant flows into the refrigerant reservoir 14 and is stored. In the refrigerant reservoir 14, the liquid refrigerant that has flowed in is gradually accumulated, and when the refrigerant reservoir 14 becomes full, the overflowed liquid refrigerant flows from the upper part of the refrigerant rectifier 11 as the circulating liquid of the refrigerant rectifier 11. To do. In this state, in the refrigerant rectifier 11, the rising vapor refrigerant and the descending liquid refrigerant make gas-liquid contact, and heat and mass transfer are performed. The low-boiling component gradually increases in the vapor refrigerant rising, and the liquid refrigerant stored in the refrigerant reservoir 14 gradually becomes rich in low-boiling components. The flow rate of the liquid refrigerant flowing out from the lower part of the refrigerant rectifier 11 is the sum of the liquid refrigerant descending in the refrigerant rectifier 11 and the liquid refrigerant in the gas-liquid two-phase refrigerant flowing into the refrigerant rectifier 11. Flow rate. As described above, the liquid refrigerant rich in low-boiling components is stored in the refrigerant reservoir 14, and the refrigerant composition circulating in the refrigeration cycle can be rich in high-boiling components.

  Here, the target value and control method of the refrigerant composition circulating in the refrigeration cycle will be described with reference to FIGS. FIG. 2 shows the relationship between the composition of the low boiling point component (R32 + R125) and the high pressure when a desired hot water supply temperature (for example, 70 ° C.) is obtained in R407C. In FIG. 2, a shows the relationship between the composition of the low boiling point component and the high pressure, and a shows the use limit of the high pressure of the compressor. A is a high pressure corresponding to 48 wt% of the low boiling point component, B is a change in the high pressure when the composition of the low boiling point is lowered, and C is a high pressure change (use of the high pressure of the compressor). The composition (21 wt%) of the low boiling point component in the case of (limit) or less is shown.

  From FIG. 2, the low boiling point component (48 wt%) in the standard composition of R407C has a high hot pressure for obtaining a desired hot water supply temperature that exceeds the use limit value of the compressor. It shows that driving cannot be realized. However, by utilizing the fact that R407C is a non-azeotropic refrigerant mixture, the desired hot water supply temperature can be obtained within the use limit of the compressor by reducing the composition of the low boiling point component from 48 wt% to 21 wt%. Therefore, the target value of the refrigerant composition capable of suppressing the high pressure to be below the use limit value of the compressor and obtaining a predetermined hot water supply temperature is 21 wt% or less.

  Furthermore, the control method to the target value of a refrigerant composition is demonstrated using FIG. FIG. 3 shows the composition change of the low-boiling components circulating in the refrigeration cycle with respect to the elapsed time (composition change operation time) after the electromagnetic valves 21 and 22 are opened. FIG. 3 shows that the electromagnetic valves 21 and 22 need to be opened for To time (for example, 1 hour) or more in order to set the refrigerant composition circulating in the refrigeration cycle to the target value. That is, by setting the opening time of the solenoid valves 21 and 22 to a predetermined time or more, it is possible to control the refrigerant composition to the target value.

  Next, when the circulation composition in the refrigeration cycle is changed from a state where the high boiling point component is increased to a state where the low boiling point component is increased, the electromagnetic valve 21 is closed and the electromagnetic valve 22 is opened. In this state, no refrigerant is supplied to the refrigerant rectifier 11, and the intermediate-pressure liquid refrigerant rich in low-boiling components stored in the refrigerant reservoir 14 flows from the upper part to the lower part of the refrigerant rectifier 11. Partly flows into the accumulator 6 through a flow path comprising the capillary tube 32, the second cooler 12, and the electromagnetic valve 22, and the other part from the capillary tube 33, the first cooler 13, and the electromagnetic valve 22. It flows into the accumulator 6 through the flow path. In this way, the liquid refrigerant rich in low boiling point components is discharged from the refrigerant reservoir 14 into the refrigeration cycle. On the other hand, the opening degree of the expansion valve 4 is controlled so that the degree of refrigerant supercooling at the outlet of the heat source side heat exchanger 3 is appropriate (for example, 10 ° C.), and excess refrigerant in the refrigeration cycle is stored in the accumulator 6. It is stored in. The refrigerant in the accumulator 6 is separated into a liquid refrigerant rich in high-boiling components and a vapor refrigerant rich in low-boiling components. Among these, the vapor refrigerant is mainly sucked into the compressor 1. Therefore, the refrigerant composition circulating in the refrigeration cycle can be made rich in low-boiling components.

  Next, the operation at the time of chiller (cold water supply) operation will be described. In the case of chiller operation, the four-way valve 2 is connected as indicated by a dotted line, and the compressor 1 outlet and the use side heat exchanger 5 are connected, and the accumulator 6 inlet and the heat source side heat exchanger 3 are connected. During the chiller operation, the high-temperature and high-pressure vapor refrigerant compressed by the compressor 1 is condensed and liquefied by the use-side heat exchanger 5 operating as a condenser via the four-way valve 2, depressurized by the expansion valve 4, and low-pressure gas-liquid It becomes a two-phase refrigerant and flows into the heat source side heat exchanger 3 that operates as an evaporator. This refrigerant evaporates in the heat source side heat exchanger 3 and returns to the compressor 1 again through the four-way valve 2 and the accumulator 6. The opening degree of the expansion valve 4 is controlled so that the refrigerant supercooling degree at the outlet of the use side heat exchanger 5 is appropriate (for example, 10 ° C.), and excess refrigerant in the refrigeration cycle is stored in the accumulator 6. Stored. The procedure for changing the circulation composition in the refrigeration cycle at the time of the chiller operation is the same as that at the time of the hot water supply operation described above, and is omitted.

  As described above, according to the present invention, by using the liquid refrigerant flowing out from the refrigerant rectifier 11 as a cooling source for the first cooler 13 and the second cooler 12, the refrigeration cycle apparatus and the composition separation circuit are used. Compared to the case where the number of connection points is two and the intake refrigerant of the compressor 1 of the conventional example is used as a cooling source, the number of connection points (six points in FIG. 8) can be reduced, and the workability in device manufacture is improved, resulting in lower costs. can do. In addition, since there are two connection locations, the heat source unit and the composition separation unit can be installed separately, and cheese (T-type) piping is provided at the compressor discharge portion and the suction portion of the refrigeration cycle apparatus. The composition separation circuit can be connected to an existing refrigeration cycle apparatus with a simple modification, and high-pressure suppression and performance improvement of the refrigeration cycle apparatus can be easily realized.

  Further, the liquid refrigerant flowing out from the lower part of the refrigerant rectifier 11 is branched into two flow paths, and capillaries suitable for the respective flow paths are installed. is there. Moreover, since the solenoid valve is provided in the connection pipe between the refrigeration cycle and the composition separation circuit, the refrigerant composition circulating in the refrigeration cycle can be changed by a simple valve opening / closing operation.

  Furthermore, in the present embodiment, an example of using R407C composed of R32, R125, and R134a has been shown, but the same applies to the case of using the R32 / 134a system excluding R125 having a high global warming potential. The effect can be demonstrated. In addition, even when non-azeotropic mixed refrigerants in which two or more refrigerants are selected and mixed from R32, R125, R134a, R143a, which are HFC refrigerants, and R290, R600, R600a, which are HC refrigerants, It is possible to provide a refrigeration cycle apparatus capable of changing the circulation composition friendly to the environment.

  In addition, in the present embodiment, an example in which the control of the refrigerant composition to the target value is performed by the opening time of the solenoid valve is shown, but the refrigerant is circulated in the refrigeration cycle as disclosed in JP-A-11-63747. The composition change operation may be performed until the refrigerant composition is detected and the circulating composition in the refrigeration cycle reaches the target value. In this case, the control to the more accurate target value is possible.

Embodiment 2. FIG.
The refrigeration cycle apparatus showing Embodiment 2 of the present invention will be described below.
FIG. 4 is a block diagram showing a refrigeration cycle apparatus according to Embodiment 2, and since it has a configuration substantially similar to that of Embodiment 1, detailed description thereof is omitted. In this embodiment, the two capillaries 32 and 33 required in the first embodiment are integrated into one capillary 34. That is, the liquid refrigerant that has flowed out of the refrigerant rectifier 11 is reduced in pressure by the capillary tube 34, and then converted into a two-phase refrigerant that is supplied to the second cooler 12 and a two-phase refrigerant that is supplied to the first cooler 13. It will be branched.
With the above configuration, two capillaries can be integrated into one, the refrigerant circuit can be simplified, and the cost can be reduced.

Embodiment 3 FIG.
The refrigeration cycle apparatus showing Embodiment 3 of the present invention will be described below.
FIG. 5 is a configuration diagram showing the refrigeration cycle apparatus according to the present embodiment, and since the configuration is almost the same as that of the first embodiment, detailed description thereof is omitted. This embodiment is used when the circulation composition is changed only during hot water supply (hot water supply) operation. That is, in the present embodiment, the liquid refrigerant that has flowed out of the refrigerant rectifier 11 as in the first embodiment does not flow into the inlet of the accumulator 6, but between the expansion valve 4 and the use side heat exchanger 5. It is configured to flow into the piping. Accordingly, during the hot water supply operation in which the piping between the expansion valve 4 and the use side heat exchanger 5 is at a low pressure, the solenoid valves 21 and 22 are opened to change the circulation composition. However, the expansion valve 4 and the use side heat exchanger are changed. At the time of a chiller (cold water supply) operation in which the pipe between 5 becomes high pressure, the solenoid valves 21 and 22 are closed and the circulation composition is not changed.

  As described above, in the present embodiment, the refrigerant that has flowed out of the refrigerant rectifier 11 flows into the pipe between the expansion valve 4 and the use-side heat exchanger 5, and therefore flows out of the refrigerant rectifier 11. Even if the liquid refrigerant thus obtained does not evaporate completely in the second cooler 12 or the first cooler 13, the non-evaporated liquid can be evaporated in the use-side heat exchanger 5, and the reliability decreases due to liquid return to the compressor. In addition, it is possible to suppress a phenomenon such as a decrease in performance due to a decrease in discharge temperature.

  In the present embodiment, the refrigerant that has flowed out of the refrigerant rectifier 11 flows into the pipe between the expansion valve 4 and the use-side heat exchanger 5, but the refrigerant that has flowed out of the refrigerant rectifier 11 May flow into the pipe between the expansion valve 4 and the heat source side heat exchanger 3.

Embodiment 4 FIG.
Hereinafter, a refrigeration cycle apparatus showing Embodiment 4 of the present invention will be described.
FIG. 6 is a block diagram showing the refrigeration cycle apparatus according to the present embodiment, and detailed description of the same components as those in the first embodiment is omitted. In the present embodiment, the liquid refrigerant flowing out from the refrigerant rectifier 11 is decompressed by the capillary tube 33, and the decompressed low-temperature and low-pressure two-phase refrigerant flows into the first cooler 13, and the upper part of the refrigerant rectifier 11 After the saturated gas flowing out from the refrigerant is cooled, it flows into the second cooler 12 to cool the discharge gas. Therefore, as shown in the first to third embodiments, it is not necessary to branch the liquid refrigerant flowing out from the refrigerant rectifier 11, the number of pipes can be reduced, the refrigerant circuit configuration can be simplified, and the low-cost refrigerant It can be a circuit.

Embodiment 5. FIG.
Hereinafter, a refrigeration cycle apparatus according to Embodiment 5 of the present invention will be described.
FIG. 7 is a configuration diagram showing a refrigeration cycle apparatus according to the present embodiment. In the present embodiment, reference numeral 60 denotes an outdoor unit, which includes a compressor 1, a four-way valve 2, a heat source side heat exchanger 3, and an accumulator 6. 61a and 61b are indoor units, and two indoor units are installed in this embodiment. Indoor unit 61a, 61b is comprised by the expansion valves 4a and 4b which are 1st pressure reduction apparatuses, and the utilization side heat exchangers 5a and 5b. The outdoor unit 60 and the indoor unit 61 are connected by two extension pipes to form a refrigeration cycle. This refrigeration cycle is filled with a non-azeotropic refrigerant mixture such as R407C composed of a high-boiling component and a low-boiling component. The heat source side heat exchanger 3 operates as an evaporator during heating operation, and operates as a condenser during cooling operation. The use side heat exchanger 5 operates as a condenser during the heating operation, and operates as an evaporator during the cooling operation. The above configuration is the same as that of a normal refrigeration cycle apparatus in which the circulation composition cannot be changed, and a detailed description regarding the operation is omitted.

  63 is a composition separation unit, which is connected between the outdoor unit 60 and two pipes via T-shaped branch pipes A and B. The composition separation unit 63 is configured as shown in FIG. 6, for example, and the circulation composition can be changed by opening and closing the electromagnetic valves 21 and 22. This embodiment is used when the circulation composition is changed only during heating operation. That is, in the present embodiment, the solenoid valve 21 and 22 are opened and the circulation composition is changed during heating operation in which the part A is in the high pressure gas state and the part B is in the low pressure two-phase state. During the cooling operation in which the part A is in a low pressure gas state, the solenoid valves 21 and 22 are closed and the circulation composition is not changed.

  That is, during normal heating operation, excess refrigerant in the refrigeration cycle is stored in the accumulator 6. The refrigerant in the accumulator 6 is separated into a liquid refrigerant rich in high-boiling components and a vapor refrigerant rich in low-boiling components. For this reason, when a liquid refrigerant is stored in the accumulator 6, the low boiling point component of the refrigerant composition circulating in the cycle increases as compared with the filling composition.

  On the other hand, when increasing the high-boiling components of the refrigerant composition circulating in the refrigeration cycle, a part of the high-temperature and high-pressure vapor refrigerant exiting the compressor 1 is passed through the A-part T-shaped branch pipe to the composition separation unit 63. In the same manner as in the first embodiment, the liquid refrigerant rich in low-boiling components is stored in the refrigerant reservoir 14. At this time, as the low-boiling component composition in the liquid refrigerant stored in the refrigerant reservoir 14 increases, the liquid refrigerant rich in high-boiling components stored in the accumulator 6 is released into the cycle, and the low-boiling components are discharged. The liquid refrigerant rich in the amount is stored in the refrigerant reservoir 14. As a result, the refrigerant composition circulating in the refrigeration cycle can be enriched with high-boiling components.

  As described above, in the present embodiment, in the existing refrigeration cycle apparatus, by adding a composition separation unit to the connection part (two places) between the outdoor unit 60 and the extension pipe via the T-shaped branch pipe, It is possible to reduce the high pressure and improve the performance without modifying the existing refrigeration cycle apparatus.

  In the above embodiment, the configuration using a four-way valve in the refrigerant circuit has been described. However, the present invention can also be applied to a cooling-only machine, a chiller-only machine, a heating-only machine, or a heat pump water heater that does not use a four-way valve. Needless to say. In addition, a pipe for connecting the lower part of the refrigerant reservoir 14 and a low-pressure pipe from the first pressure reducing device to the compressor suction via a capillary tube is added, and the circulation composition in the refrigeration cycle is increased from the state where the high boiling point component is increased. It is good also as a structure which changes quickly to the state in which the low boiling point component increased.

It is a figure which shows the refrigerant circuit structure of the refrigerating-cycle apparatus which shows Embodiment 1 of this invention. It is a figure which shows the relationship between the composition of the low boiling point component which shows Embodiment 1 of this invention, and a high pressure. It is a figure which shows the relationship between the composition change operation time which shows Embodiment 1 of this invention, and the composition of a low boiling-point component. It is a figure which shows the refrigerant circuit structure of the refrigerating-cycle apparatus which shows Embodiment 2 of this invention. It is a figure which shows the refrigerant circuit structure of the refrigerating-cycle apparatus which shows Embodiment 3 of this invention. It is a figure which shows the refrigerant circuit structure of the refrigerating-cycle apparatus which shows Embodiment 4 of this invention. It is a figure which shows the refrigerant circuit structure of the refrigerating-cycle apparatus which shows Embodiment 5 of this invention. It is a figure which shows the refrigerant circuit structure of the conventional air conditioner.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Compressor, 2 Four way valve, 3 Heat source side heat exchanger 4, 4a, 4b Expansion valve 5, 5a, 5b Use side heat exchanger, 6 Accumulator, 11 Refrigerating fractionator, 12 2nd cooler, 13 First cooler, 14 Refrigerant reservoir, 21, 22 Solenoid valve, 31, 32, 33 Capillary tube, 60 Outdoor unit, 61, 61a, 61b Indoor unit, 62 Heat source unit, 63 Composition separation unit.

Claims (6)

Refrigeration in which a compressor, a refrigerant flow switching means, a use side heat exchanger, a first pressure reducing device, and a heat source side heat exchanger are connected in an annular manner to circulate a non-azeotropic refrigerant mixture composed of a low boiling point refrigerant and a high boiling point refrigerant. A heat source unit consisting of a cycle;
A first cooler and a refrigerant reservoir are connected in an annular shape at the upper part, a second cooler is connected at the lower part, and a composition separating means for separating the composition of the non-azeotropic refrigerant mixture is provided, A composition separation unit comprising a composition separation circuit configured to use the non-azeotropic refrigerant mixture flowing out from as a cooling source for the first cooler and the second cooler;
The first pipe connected via the second cooler to the pipe between the lower part of the composition separation means, the discharge section of the compressor and the refrigerant flow switching means;
A second pipe connected via a first cooler to a pipe between the lower part of the composition separating means and the refrigerant flow switching means and the suction part of the compressor;
The second pipe is connected to the pipe between the lower part of the composition separation means and the first cooler and to the outlet side pipe of the first cooler of the second pipe via the second cooler. A third pipe,
With
The heat source unit and the composition separation unit are connected at two locations of the first pipe and the second pipe,
Based on the change in the composition of the non-azeotropic refrigerant mixture, a part of the non-azeotropic refrigerant mixture discharged from the compressor of the heat source unit through the first pipe is introduced into the composition separation unit, Changing the composition of the non-azeotropic refrigerant mixture in a composition separation unit;
Part of the non-azeotropic refrigerant mixture with the changed composition flows through the first cooler through the second pipe, and the other part flows through the second cooler through the third pipe, and then A refrigeration cycle apparatus using a non-azeotropic refrigerant mixture that joins the second pipe and is supplied to the heat source unit through the second pipe.   A second pressure reducing device is provided in a pipe between the second cooler and the lower part of the composition separation means, and a third pressure reduction is provided in a pipe between the lower part of the composition separation means and the connection portion with the third pipe. The refrigeration cycle apparatus using the non-azeotropic mixed refrigerant according to claim 1, further comprising an apparatus.   A second pressure reducing device is provided in a pipe between the second cooler and the lower part of the composition separation means, and a connection between the lower part of the composition separation means and the third pipe and the first cooler. A third decompression device is provided in the pipe, and a fourth decompression device is provided in the pipe between the connection portion between the second pipe and the third pipe and the second cooler. A refrigeration cycle apparatus using the non-azeotropic refrigerant mixture according to 1.   A second decompression device is provided in a pipe between the second cooler and the lower part of the composition separation means, and a third decompression device is provided in a pipe between the lower part of the composition separation means and the first cooler. A refrigeration cycle apparatus using the non-azeotropic refrigerant mixture according to claim 1.   A first on-off valve is provided in a pipe between the refrigeration cycle of the first pipe and the second cooler inlet, and a pipe between the first cooler outlet of the second pipe and the refrigeration cycle is provided. The refrigeration cycle apparatus using the non-azeotropic refrigerant mixture according to any one of claims 1 to 4, wherein a second on-off valve is provided.   6. The refrigeration cycle apparatus using a non-azeotropic refrigerant mixture according to claim 5, wherein the heat source unit storing the refrigeration cycle and the composition separation unit storing the composition separation circuit are installed separately.

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