KR20020024537A - Refrigeration cycle - Google Patents

Abstract

PURPOSE: A refrigeration cycle is provided to prevent compressor overload and increase the dryness of refrigerant introduced into the compressor by performing heat exchange operation between the refrigerant passed through the evaporator and the refrigerant passed through the condenser. CONSTITUTION: A refrigeration cycle comprises a compressor(11) for refrigerant compression; a condenser(13) for condensing the compressed refrigerant; an evaporator(31) for evaporating the refrigerant; an internal heat exchanger(15) for performing heat exchange operation between the refrigerant passed through the evaporator and the refrigerant passed through the condenser; and an expander(25) for expanding the refrigerant which is heat exchanged by the internal heat exchanger and introduced into the evaporator. The internal heat exchanger includes a casing(17) of a closed container type having a refrigerant inlet port(17a) and a refrigerant outlet port(17b) for the refrigerant passed through the evaporator; and a thermal conductive coil conduit(19) accommodated into the casing so as to allow the refrigerant discharged from the condenser to passe through the thermal conductive coil conduit.

Description

Refrigeration Cycle {REFRIGERATION CYCLE}

The present invention relates to a refrigerant circulation refrigeration cycle.

In the refrigerant circulation refrigeration cycle, as shown in FIG. 8, the refrigerant circulates in a closed circuit including a compressor 611, a condenser 613, an expander 625, and an evaporator 631.

The low pressure gaseous refrigerant is compressed in the compressor 611 and then delivered to the condenser 613 in a high pressure gaseous state, where it is condensed into the liquid phase by releasing heat. The condensed refrigerant is expanded under reduced pressure through the expander 625 and is supplied to the evaporator 631. The refrigerant absorbs heat from the outside in the evaporator 631 to be evaporated, and then returns to the compressor 611.

This refrigeration cycle mainly uses the endothermic function of the evaporator, and is called a heat pump when using the heat of the condenser discharge.

By selectively circulating the refrigerant in the forward and reverse directions by using a single refrigeration cycle, it is possible to configure, for example, a heating and cooling device, which alternately functions the evaporator and the condenser, thereby selectively performing the cooling and heating functions. .

By the way, in such a conventional refrigeration cycle, when the temperature around the condenser is excessively high, the refrigerant that is not smoothly cooled in the condenser flows into the evaporator through the expander, whereby the refrigerant evaporated in the evaporator is sufficient from the surroundings of the evaporator. There is a problem that the amount of heat can not be absorbed and the evaporation of the refrigerant is lowered. And, if the temperature around the evaporator is too low, there is a risk that the temperature difference between the ambient temperature of the evaporator and the refrigerant is increased, causing frosting on the evaporator, and also because the evaporator does not evaporate smoothly, the dryness of the refrigerant is low By entering the compressor in a state, the refrigerant is wet compressed in the compressor, and cavitation occurs in the compressor, thereby reducing the life of the compressor. Thus, the conventional refrigeration cycle has a problem that a separate heater or burner must be provided to improve the evaporation of the refrigerant.

In addition, since the conventional refrigeration cycle is difficult to control the temperature of the refrigerant flowing into the compressor, there is a problem in that the efficiency of the compressor is deteriorated when the refrigerant in the superheated and supercooled state is introduced into the compressor.

Accordingly, an object of the present invention is to provide a refrigeration cycle that can increase the dryness of the refrigerant flowing into the compressor and to supercool the refrigerant exiting the condenser.

In addition, another object of the present invention is to provide a refrigeration cycle that can properly control the temperature of the refrigerant flowing into the compressor to prevent overload and deterioration of the compressor.

1 is a main configuration of a refrigeration cycle according to the first embodiment of the present invention,

2 is a main configuration of a refrigeration cycle according to a second embodiment of the present invention,

3 is a main configuration of a refrigeration cycle according to a third embodiment of the present invention,

4 is a main configuration of a refrigeration cycle according to a fourth embodiment of the present invention,

5 is a main configuration of a refrigeration cycle according to a fifth embodiment of the present invention,

6 is a block diagram showing a refrigerant flow at the time of cooling of the cooling and heating device using the refrigeration cycle of Figure 3, according to an embodiment of the present invention,

7 is a block diagram showing a refrigerant flow during heating of the air conditioning and heating device using the refrigeration cycle of FIG. 3 according to an embodiment of the present invention,

8 is a main configuration of a conventional refrigeration cycle.

* Explanation of symbols for the main parts of the drawings

11,111,211,311,411,511: compressor 13,113,213,313,413: condenser

15,115,215,315,415,515: Internal heat exchanger 25,125,225,325,425,525: Inflator

31,131,231,331,431: Evaporator

133,233,333,433,533: bypass conduit

135,235,335,435,535: Bypass valve

137,237,337,437,537: bypass expander

351,451: Second auxiliary heat exchanger 353,453: Second auxiliary heat exchanger

513: indoor unit 531: outdoor unit

In order to achieve the above object, the present invention, in the refrigeration cycle having a compressor, a condenser, an expander and an evaporator in which the refrigerant is sequentially circulated, includes an internal heat exchanger for mutual heat exchange between the refrigerant from the evaporator and the refrigerant from the condenser It provides a refrigeration cycle characterized in that.

Here, the internal heat exchanger has a casing in the form of a sealed container having an inlet and an outlet through which the refrigerant from the evaporator flows in and out, and a thermally conductive coil conduit accommodated in the casing and through which the refrigerant from the condenser passes. The mutual heat exchange between the refrigerant exiting the evaporator and the refrigerant exiting the condenser is facilitated.

The expander is at least one capillary tube, and further includes a capillary heat exchanger configured to mutually heat-exchange the refrigerant in the capillary and the refrigerant from the evaporator to the internal heat exchanger, thereby supercooling the refrigerant introduced into the evaporator to ambient temperature of the evaporator. When the temperature of the evaporator is low, the temperature difference between the ambient temperature of the evaporator and the refrigerant is reduced, and the conception of the evaporator is prevented. Also, when the ambient temperature of the evaporator is high, the refrigerant absorbs a sufficient amount of heat from the surroundings of the evaporator and the ambient temperature of the evaporator Can be reduced. In addition, since the refrigerant from the evaporator to the internal heat exchanger is heated, the dryness of the refrigerant can be improved.

The apparatus may further include a first auxiliary heat exchanger configured to mutually heat-exchange the refrigerant exiting the expander and the refrigerant exiting the evaporator, thereby further cooling the refrigerant flowing into the evaporator so that the ambient temperature of the evaporator is excessively low. The temperature difference between the temperature and the refrigerant is made smaller to prevent frosting on the evaporator, and when the ambient temperature of the evaporator is high, the refrigerant can absorb a sufficient amount of heat from the surroundings of the evaporator to further lower the ambient temperature of the evaporator. do.

Further, by further comprising a second auxiliary heat exchanger for mutual heat exchange between the refrigerant flowing from the internal heat exchanger toward the compressor and the refrigerant exiting the compressor, by appropriately adjusting the temperature of the refrigerant flowing into the compressor, overload and efficiency of the compressor. The fall can be prevented.

In addition, the bypass conduit for joining a portion of the refrigerant from the condenser to the refrigerant flowing into the compressor, the bypass valve for opening and closing the flow of the refrigerant in the bypass conduit, and the refrigerant passing through the bypass conduit By further including a bypass expander, it is possible to appropriately adjust the temperature of the refrigerant flowing into the compressor to prevent the overload and deterioration of the compressor.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a main configuration of a refrigeration cycle according to the first embodiment of the present invention. As shown, the refrigeration cycle according to the present invention, the compressor 11 for compressing the refrigerant, the condenser 13 for condensing the compressed refrigerant, the evaporator 31 for evaporating the refrigerant, and the evaporator 31 An internal heat exchanger (15) for exchanging the refrigerant exiting the condenser (13) and the refrigerant exiting the condenser (13), and an expander (25) for decompressively expanding a refrigerant that is heat exchanged in the internal heat exchanger (15) and flows into the evaporator (31). A closed loop is formed to circulate sequentially.

The internal heat exchanger (15) is housed in a casing (17) of a closed container having an inlet (17a) and an outlet (17b) through which refrigerant from the evaporator (31) flows in and out, and a condenser (13). It has a thermally conductive coil conduit 19 through which refrigerant from it passes.

The inflator 25 consists of a single capillary tube. Here, the inflator 25 may of course use an expansion valve.

By this configuration, the refrigerant compressed in the compressor 11 is condensed in the condenser 13 and flows into the internal heat exchanger 15. The refrigerant exiting the condenser 13 flows into the coil conduit 19 of the internal heat exchanger 15, and the refrigerant exiting the evaporator 31 flows into the inlet 17a of the casing 17 of the internal heat exchanger 15. The refrigerant exiting the condenser 13 and the refrigerant exiting the evaporator 31 exchange heat with each other, that is, the refrigerant exiting the condenser 13 radiates heat to the refrigerant exiting the evaporator 31 to be primarily cooled. In addition, the refrigerant cooled in the internal heat exchanger 15 flows toward the expander 25. The first cooled refrigerant flowing into the expander 25 is expanded under reduced pressure in the expander 25 to be second cooled, and then flows into the evaporator 31 to be evaporated. The refrigerant evaporated in the evaporator 31 is heated by mutual heat exchange in the internal heat exchanger 15 and the refrigerant leaving the condenser 13 as described above, and passes through the outlet 17b of the internal heat exchanger 15 to the compressor 11. Return to.

Thus, the refrigerant exiting the condenser 13 is subcooled in the internal heat exchanger 15 and then evaporated in the evaporator 31 via the expander 25, whereby the refrigerant evaporated in the evaporator 31 has a sufficient amount of heat from around the evaporator 31. By absorbing this, it is possible to lower the ambient temperature of the evaporator 31. In addition, when the ambient temperature of the evaporator 31 is low, the temperature difference between the ambient temperature of the evaporator 31 and the refrigerant becomes small, and the concept of the evaporator 31 is prevented. As the refrigerant leaving the evaporator 31 is heated in the internal heat exchanger 15, the refrigerant having a high dryness flows into the compressor 11, thereby preventing the wet compression of the refrigerant, thereby extending the life of the compressor 11.

2 is a main configuration of a refrigeration cycle according to a second embodiment of the present invention. As shown, in this embodiment, unlike the first embodiment described above, a bypass for joining some of the refrigerant flowing from the internal heat exchanger 115 toward the expander 125 to the refrigerant flowing into the compressor 111. Bypass valve 135 for opening and closing the flow of the refrigerant in the bypass conduit 133 by the signal of the conduit 133, the temperature sensor 139 for measuring the temperature of the refrigerant flowing into the compressor 111, The apparatus further includes a bypass expander 137 for expanding the refrigerant passing through the pass conduit 133 under reduced pressure.

By such a configuration, not only the object of the present invention can be achieved, but also when a refrigerant in an overheated state flows into the compressor 111, a part of the refrigerant flowing from the internal heat exchanger 115 toward the expander 125 is bought. After drawing out of the pass conduit 133 and expanding under reduced pressure, the temperature of the refrigerant to be compressed is controlled to be below a predetermined temperature by joining with the refrigerant flowing toward the compressor 111, thereby preventing overload and deterioration of the compressor 111. It becomes possible.

Meanwhile, as shown in FIG. 3 as a third embodiment of the present invention, in this embodiment, unlike the first embodiment described above, the refrigerant and the evaporator flowing from the internal heat exchanger 215 toward the expander 225 ( The refrigerant flowing from the 231 toward the internal heat exchanger 215 has a configuration of mutual heat exchange in the expander 225. In addition, the bypass conduit 233 for joining a portion of the refrigerant flowing from the internal heat exchanger 215 toward the expander 225 to the refrigerant flowing into the compressor 211 and the temperature of the refrigerant flowing into the compressor 211 are measured. Bypass valve 235 for opening and closing the flow of the refrigerant in the bypass conduit 233 by the signal of the temperature sensor 239 to be measured, and a bypass expander for decompressively expanding the refrigerant passing through the bypass conduit 233 ( 237).

The expander 225 has a plurality of capillary tubes 227 through which the refrigerant from the internal heat exchanger 215 passes, and an inlet 229a and an outlet 229b through which the refrigerant from the evaporator 231 flows in and out, and has a plurality of capillary tubes. A casing 229 in the form of a sealed container for accommodating 227, and includes a capillary heat exchanger for mutual heat exchange between the refrigerant in the capillary 227 and the refrigerant directed from the evaporator 231 to the internal heat exchanger 215. Accordingly, the refrigerant flowing from the internal heat exchanger 215 toward the evaporator 231 is introduced into the capillary 227 of the expander 225 and expands under reduced pressure to mutually interact with the refrigerant flowing from the evaporator 231 toward the internal heat exchanger 215. The refrigerant that undergoes heat exchange, that is, expanded under reduced pressure in the capillary tube 227, is cooled by dissipating heat to the refrigerant directed to the internal heat exchanger 215.

With this configuration, the refrigerant flowing from the internal heat exchanger 215 toward the evaporator 231 expands under reduced pressure in the expander 225 and at the same time exchanges heat with the refrigerant flowing from the evaporator 231 toward the internal heat exchanger 215. Thereby further cooling, so that the refrigerant flowing from the expander 225 toward the evaporator 231 has a lower temperature than the refrigerant flowing from the expanders 25 and 125 towards the evaporators 31 and 131 in the first and second embodiments described above. Have. In addition, the refrigerant flowing from the evaporator 231 toward the internal heat exchanger 215 is primarily heated by mutual heat exchange in the expander 225 with the refrigerant flowing from the internal heat exchanger 215 toward the evaporator 231, and then internal heat. Secondary heating at the exchanger 215 returns to the compressor 211. When the refrigerant in a superheated state flows into the compressor, a portion of the refrigerant flowing from the internal heat exchanger 215 toward the expander 225 is extracted to the bypass conduit 233 to expand under reduced pressure, and then to the compressor 211. By controlling the temperature of the refrigerant to be compressed by joining the incoming refrigerant to a predetermined temperature or less, overload and deterioration of the compressor 211 can be prevented.

4 is a main configuration of a refrigeration cycle according to a fourth embodiment of the present invention. As shown, this embodiment, unlike the third embodiment described above, includes a first auxiliary heat exchanger 351 for mutual heat exchange between the refrigerant exiting the expander 325 and the refrigerant exiting the evaporator 331. The second auxiliary heat exchanger 353 further heat-exchanges the refrigerant flowing from the internal heat exchanger 315 toward the compressor 311 and the refrigerant exiting the compressor 311. In addition, the refrigerant flowing from the internal heat exchanger 315 toward the compressor 311 through the second auxiliary heat exchanger 353 by a signal of the temperature sensor 339 measuring the temperature of the refrigerant flowing into the compressor 311. It further includes a three-way valve 355 for controlling the flow of the refrigerant to flow toward the compressor 311.

By this configuration, not only the object of the present invention can be achieved, but the refrigerant flowing into the evaporator 331 after heat exchange in the expander 325 is the refrigerant exiting the evaporator 331 and the first auxiliary heat exchanger 351. By further exchanging heat and cooling each other, the refrigerant flowing into the evaporator 331 is more subcooled than the refrigerant flowing into the evaporators 31, 131, and 231 in the above-described first to third embodiments, so that the ambient temperature of the evaporator 331 is increased. When the temperature is excessively low, the temperature difference between the ambient temperature of the evaporator 331 and the refrigerant becomes smaller, which prevents frosting on the evaporator 331. Also, when the ambient temperature of the evaporator 331 is high, the refrigerant is discharged from around the evaporator 331. It is possible to absorb a sufficient amount of heat to further lower the ambient temperature of the evaporator 331. When the temperature of the refrigerant flowing into the compressor 311 is excessively low, the three-way valve 355 receives the refrigerant flowing from the internal heat exchanger 315 toward the compressor 311 by the signal of the temperature sensor 339. By controlling the flow to the compressor 311 through the second auxiliary heat exchanger (353), the refrigerant flowing into the compressor 311 is a heat exchange between the refrigerant leaving the compressor 311 and the second auxiliary heat exchanger (351) By heating, the temperature of the refrigerant flowing into the compressor 311 can be adjusted appropriately to prevent overload and deterioration of the compressor 311.

On the other hand, Figure 5 is a main configuration of a refrigeration cycle according to a fifth embodiment of the present invention. As shown, in this embodiment, unlike the fourth embodiment described above, the refrigerant flowing from the internal heat exchanger 415 toward the evaporator 431 expands under reduced pressure in the expander 425 and then internal heat from the evaporator 431. The refrigerant flowing into the exchanger 415 and the first auxiliary heat exchanger 451 exchange heat with each other, and have a configuration that flows into the evaporator 431. In addition, the refrigerant flowing from the evaporator 431 toward the internal heat exchanger 415 exchanges heat between the refrigerant flowing from the internal heat exchanger 415 toward the evaporator 431 and the first auxiliary heat exchanger 451, and then the internal heat exchanger. 415 has a configuration that flows into. The inflator 425 is made up of a single capillary tube. Here, the expander 425 may be used as an expansion valve, of course.

With this configuration, not only the object of the present invention can be achieved, but also the refrigerant flowing from the expander 425 toward the evaporator 431 is mutually exchanged in the first auxiliary heat exchanger 451 with the refrigerant exiting the evaporator 431. After cooling by heat exchange and evaporating in the evaporator 431, when the ambient temperature of the evaporator 431 is low, the temperature difference between the ambient temperature of the evaporator 431 and the refrigerant is reduced, thereby preventing the idea of the evaporator 431. . In addition, when the ambient temperature of the evaporator 431 is high, the refrigerant absorbs a sufficient amount of heat from the surroundings of the evaporator 431 to further lower the ambient temperature of the evaporator 431. The refrigerant flowing from the evaporator 431 toward the compressor 411 is heat-exchanged with the refrigerant flowing from the expander 425 toward the evaporator 431 in the first auxiliary heat exchanger 451 to be heated. The dryness of the refrigerant flowing into the can be increased.

Hereinafter, as a representative embodiment of a cooling and heating device having a single circuit using a refrigerating cycle according to the present invention will be described for the cooling process and heating process of the cooling and heating device.

6 is a configuration diagram showing a refrigerant flow at the time of cooling of a cooling and heating device using a refrigeration cycle according to the third embodiment of the present invention. First, referring to FIG. 6, a configuration of a cooling and heating apparatus using a refrigerating cycle according to the present invention, the cooling and heating apparatus includes a compressor 511 for compressing a refrigerant and evaporating the refrigerant through heat exchange with indoor air during cooling. The indoor unit 513 cools the air and heats the indoor air by condensing the refrigerant through heat exchange with the indoor air at the time of heating, and condenses the refrigerant through heat exchange with outdoor air at the time of cooling. The outdoor unit 531 which evaporates the refrigerant through heat exchange, the expander 525 which decompresses and expands the refrigerant, and the refrigerant flowing out of the outdoor unit 531 from the outdoor unit 531 and the refrigerant flowing from the indoor unit 513 toward the compressor 511. Internal heat exchanger 515 for mutual heat exchange between the refrigerant leaving the indoor unit 513 and the refrigerant flowing from the outdoor unit 531 toward the compressor 511 at the time of mutual heat exchange and heating, and the indoor unit 513 or outdoor unit in the compressor 511. ( 531 has a cooling and heating selection valve 541 for controlling the flow of the refrigerant to the cooling and heating selectively. Here, the expander 525 includes a plurality of capillaries 527 through which the refrigerant from the internal heat exchanger 515 passes, and an inlet 529a and an outlet through which the refrigerant from the indoor unit 513 or the outdoor unit 531 flows in and out. 529b) and a casing 529 in the form of a hermetically sealed container accommodating a plurality of capillaries 527, which are evaporated from the refrigerant in the capillary 527 and the indoor unit 513 or the outdoor unit 531 to the internal heat exchanger 515. It has a capillary heat exchange part which mutually heat-exchanges the refrigerant | coolant which goes. In addition, the internal heat exchanger 515 flows in and out of the refrigerant flowing from the indoor unit 513 toward the compressor 511 at the time of cooling and the refrigerant flowing from the outdoor unit 531 toward the compressor 511 at the time of heating. A casing 517 in the form of a sealed container having an inlet 517a and an outlet 517b that flows out, and a refrigerant that is stored in the casing 517 and exits the outdoor unit 531 when cooled, passes through the indoor unit 513 when heated. It has a thermally conductive coil conduit 519 through which the refrigerant exits.

In addition, the air conditioning unit draws a part of the refrigerant flowing from the internal heat exchanger 515 toward the expander 525 and passes it to the bypass conduit 533 and the compressor 511 to join the refrigerant flowing into the compressor 511. By-pass valve 535 for opening and closing the flow of the refrigerant in the bypass conduit 533 and the refrigerant passing through the bypass conduit 533 by the signal of the temperature sensor 539 for measuring the temperature of the refrigerant flowing in It further includes an expanding expander 537.

The air conditioning unit controls the flow of the refrigerant so that the refrigerant condensed in the outdoor unit 531 flows into the internal heat exchanger 515 during cooling, and the refrigerant condensed in the indoor unit 513 passes through the internal heat exchanger 515 during heating. Condensation refrigerant supply valve 543 which controls the flow of the refrigerant to be introduced, and the refrigerant flow is controlled to be supplied to the indoor unit 513 when the refrigerant expanded in the expander 525 through the internal heat exchanger 515 to cool the room and heating The expansion refrigerant supply valve 545 for controlling the flow of the refrigerant to be supplied to the outdoor unit 531, and the cooling and control the flow of the refrigerant so as to introduce the refrigerant evaporated from the indoor unit 513 into the expander 525 when heating The city includes an evaporative refrigerant supply valve 547 that controls the flow of the refrigerant to introduce the refrigerant evaporated from the outdoor unit 531 into the expander 525. Here, the cooling and heating selection valve 541, the condensation refrigerant supply valve 543, the expansion refrigerant supply valve 545 and the evaporative refrigerant supply valve 547 is a state of cooling or heating by the operation of one drive unit during the selective operation of cooling and heating. It is desirable to have a structure that is integrally connected to switch to. Of course, the cooling and heating selection valve 541, the condensation refrigerant supply valve 543, the expansion refrigerant supply valve 545, and the evaporative refrigerant supply valve 547 may be switched to the state of cooling or heating by the operation of each drive unit. .

Meanwhile, referring to FIG. 6, the cooling process of the air conditioner is as follows.

When the air conditioner is selected to cool the air conditioner, the air conditioner is operated by a conventional controller to cool the air conditioner by the air conditioner selection valve 541, the condensation refrigerant supply valve 543, the expansion refrigerant supply valve 545, and the evaporative refrigerant supply valve 547. ) Is switched to the cooling state.

The refrigerant compressed by the compressor 511 while the valves are switched to the cooling state is introduced into the outdoor unit 531 through the air-conditioning selection valve 541 to exchange heat with the outdoor air, that is, radiate heat to the outside to condense. do. The condensed refrigerant is supplied to the internal heat exchanger 515 through the condensation refrigerant supply valve 543, and is primarily cooled by mutual heat exchange with the refrigerant flowing from the indoor unit 513 toward the compressor 511. The primary cooled refrigerant flows into the expander 525. The refrigerant that is first cooled and flows into the expander 525 is expanded in the expander 525 and at the same time, the refrigerant is evaporated in the indoor unit 513 and heat-exchanged with the refrigerant flowing toward the internal heat exchanger 515 to be second cooled. The secondary cooled refrigerant flows into the indoor unit 513 through the expansion refrigerant supply valve 545 and exchanges heat with the indoor air, that is, absorbs heat from the indoor air and evaporates.

The evaporated refrigerant is introduced into the expander 525 through the evaporative refrigerant supply valve 547, and as described above, the refrigerant is first heat-exchanged with the refrigerant flowing from the internal heat exchanger 515 toward the indoor unit 513. The first heated refrigerant is supplied to the internal heat exchanger 515, and as a result, the second refrigerant is heat-exchanged with the refrigerant flowing from the outdoor unit 531 toward the expander 525 as described above. The secondary heated refrigerant returns to the compressor 511.

Thus, by lowering the temperature of the refrigerant flowing into the indoor unit 513 and evaporated to the maximum through mutual heat exchange between the refrigerants, the refrigerant flowing into the indoor unit 513 can absorb a large amount of heat from the indoor air, thereby improving cooling efficiency. You can do it.

When the refrigerant flowing into the compressor 511 rises above a predetermined temperature, the bypass conduit 533 opens a part of the refrigerant flowing in the expander 525 from the internal heat exchanger 515 by opening the bypass valve 535. ), The extracted refrigerant is expanded under reduced pressure in the bypass expander 537, and then mixed with the refrigerant flowing from the internal heat exchanger 515 to the compressor 511, whereby the refrigerant flowing into the compressor 511 has a predetermined temperature. It is lowered below, it is possible to prevent the overload and efficiency decrease of the compressor 511.

Next, the heating process of the air conditioning and heating device will be described with reference to FIG. 7.

When the air conditioner is selected for heating operation, the air conditioner is controlled by a conventional controller to perform the heating operation. The air conditioner selection valve 541, the condensation refrigerant supply valve 543, the expansion refrigerant supply valve 545, and the evaporative refrigerant supply valve 547. ) Is switched to heating.

The refrigerant compressed by the compressor 511 while the valves are switched to the heating state is introduced into the indoor unit 513 through the air-conditioning selection valve 541 to exchange heat with the indoor air, that is, discharge heat into the room to condense. do. The condensed refrigerant flows into the internal heat exchanger 515 through the condensation refrigerant supply valve 543, and exchanges heat with the refrigerant flowing from the outdoor unit 531 to the compressor 511. The primary cooled refrigerant flows into the expander 525. The refrigerant that is first cooled and flows into the expander 525 is expanded in the expander 525 and is secondly cooled by mutual heat exchange with the refrigerant flowing from the outdoor unit 531 to the internal heat exchanger 515. The secondary cooled refrigerant flows into the outdoor unit 531 through the expansion refrigerant supply valve 545 to exchange heat with the outdoor air, that is, absorbs heat from the outdoor air and evaporates.

The evaporated refrigerant flows into the expander 525 through the evaporative refrigerant supply valve 547, and heats firstly with the refrigerant flowing from the internal heat exchanger 515 to the outdoor unit 531 as described above. The first heated refrigerant flows into the internal heat exchanger 515 and is secondarily heated by mutual heat exchange with the refrigerant flowing from the indoor unit 513 to the expander 525 as described above. The secondary heated refrigerant returns to the compressor 511.

As a result, the refrigerant that is second-cooled through mutual heat exchange between the refrigerants and introduced into the outdoor unit 531 has a small temperature difference with the outdoor air, thereby preventing the idea of the outdoor unit 531 during heat exchange in the outdoor unit 531. In addition, by reheating the refrigerant that has not been evaporated smoothly in the outdoor unit 531 according to the temperature of the outdoor air, that is, increasing the dryness of the refrigerant to prevent cavitation during the compression of the refrigerant of the compressor 511 to prevent damage to the compressor 511. It can be prevented. In addition, similar to the above-described cooling device, when the refrigerant flowing into the compressor 511 rises above a predetermined temperature, the refrigerant flowing from the internal heat exchanger 515 toward the expander 525 by opening the bypass valve 535. A portion of the refrigerant is drawn out to the bypass conduit 533, and the extracted refrigerant is expanded under reduced pressure in the bypass expander 537, and then mixed with the refrigerant flowing into the compressor 511. Since the temperature is lowered below a predetermined temperature, it is possible to prevent overload and deterioration of the compressor 511.

As described above, the refrigeration cycle according to the present invention can increase the dryness of the refrigerant flowing into the compressor through mutual heat exchange between the refrigerant, and can supercool the refrigerant from the condenser. Therefore, the refrigerant evaporated in the evaporator can absorb a sufficient amount of heat from the surroundings of the evaporator to lower the ambient temperature of the evaporator. In addition, when the ambient temperature of the evaporator is excessively low, the temperature difference between the ambient temperature of the evaporator and the refrigerant becomes small, thereby preventing frosting in the evaporator. In addition, since the refrigerant having a high dryness flows into the compressor, wet compression of the refrigerant is prevented in the compressor, thereby extending the life of the compressor. In addition, it is possible to appropriately adjust the temperature of the refrigerant supplied to the compressor to prevent overload and deterioration of the compressor.

On the other hand, although not shown in the above embodiments, by installing the internal heat exchanger so that the outlet of the internal heat exchanger is located on the lower side, the oil for compressor circulated in the refrigerant is collected at the lower side of the internal heat exchanger, the internal heat By providing an oil return line connecting the lower side of the exchanger and the compressor, the compressor oil collected at the lower side of the internal heat exchanger can be directly supplied to the compressor.

As described above, according to the present invention, there is provided a refrigerating cycle capable of increasing the dryness of the refrigerant flowing into the compressor through mutual heat exchange between the refrigerant, and supercooling the refrigerant exiting the condenser. In addition, a refrigeration cycle is provided that can properly control the temperature of the refrigerant flowing into the compressor to prevent overload and deterioration of the compressor.

Claims (6)

In a refrigeration cycle having a compressor, a condenser, an expander and an evaporator in which the refrigerant is circulated sequentially, And an internal heat exchanger for mutual heat exchange between the refrigerant exiting the evaporator and the refrigerant exiting the condenser. The method of claim 1, The internal heat exchanger, A casing in the form of a sealed container having an inlet and an outlet through which the refrigerant from the evaporator flows in and out; And a thermally conductive coil conduit accommodated in said casing and through which refrigerant from said condenser passes. The method of claim 1, The expander is at least one capillary tube, the refrigeration cycle further comprises a capillary heat exchanger for mutual heat exchange between the refrigerant in the capillary and the refrigerant from the evaporator to the internal heat exchanger. The method of claim 3, And a first auxiliary heat exchanger configured to mutually heat-exchange the refrigerant exiting the expander and the refrigerant exiting the evaporator. The method of claim 1, And a second auxiliary heat exchanger configured to mutually heat-exchange the refrigerant flowing from the internal heat exchanger toward the compressor and the refrigerant exiting the compressor. The method according to any one of claims 1 to 5, A bypass conduit for joining some of the refrigerant from the condenser to the refrigerant flowing into the compressor; Bypass valve for opening and closing the flow of the refrigerant of the bypass conduit, And a bypass expander for expanding the refrigerant passing through the bypass conduit.