US20110120179A1

US20110120179A1 - Heat pump type cooling/heating apparatus

Info

Publication number: US20110120179A1
Application number: US12/847,603
Authority: US
Inventors: Sim Won Chin; Eung Yul Lee; Bum Suk Kim; Sang Kyoung Park
Original assignee: LG Electronics Inc
Current assignee: LG Electronics Inc
Priority date: 2009-11-20
Filing date: 2010-07-30
Publication date: 2011-05-26
Also published as: EP2330368A3; EP2330368A2; CN102072559B; KR20110056061A; CN102072559A

Abstract

A heat pump type cooling/heating apparatus comprises a coolant injection path and a gaseous coolant adjustment valve. The coolant injection path may be split between a cascade heat exchanger and an evaporator of a low-temperature refrigeration cycle to inject coolant into a low pressure side compressor, or between a water coolant heat exchanger and cascade heat exchanger to inject coolant into a high pressure side compressor of a high temperature refrigeration cycle. The gaseous coolant adjustment valve may be provided in the coolant injection path and is adjusted to correspond to a load of a

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 U.S.C. §119 to Korean Patent Application No. 10-2009-0112740, filed on Nov. 20, 2009 in Korea, the entirety of which is hereby incorporated by reference.

BACKGROUND

1. Field
One or more embodiments described herein relate to thermal control.
2. Background
Heat pumps are in widespread use for heating and cooling homes. However, they have drawbacks. For example, heat pumps fail to provide sufficient cooling/heating performance for many homes or buildings, especially those of larger size. Also, operational efficiency is compromised because of the need to perform frequent defrosting operations for the evaporator.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a diagram of one embodiment of a cooling/heating apparatus.

FIG. 2 is a block diagram of the cooling/heating apparatus of FIG. 1.

FIG. 3 is a diagram of one type of cascade cycle unit for use in FIG. 1.

FIG. 4 is a graph of a P-H relationship obtained for a cooling/heating apparatus according to one or more of the embodiments herein.

FIG. 5 is a diagram of another embodiment of a cooling/heating apparatus.

FIG. 6 is a diagram of another embodiment of a cooling/heating apparatus.

FIG. 7 is a diagram showing a manner in which a cascade unit and outdoor unit may be separately provided in the apparatus of FIG. 6.

FIG. 8 is a diagram showing a manner in which the outdoor unit may be attached to the cascade unit in the apparatus of FIG. 6.

DETAILED DESCRIPTION

FIG. 1 shows a first embodiment of a heat pump type cooling/heating apparatus which includes a refrigeration cycle apparatus 3 that heats water using a coolant, circulates the heated water, and supplies the heated water to destinations 1 and 2 requiring hot water.
Destinations 1 and 2 include a room heating unit 1 that heats a room using the water heated by the coolant and a water heating unit 2 that discharges the heated water to the outside through a discharging device, such as a shower head. The room heating unit and the water heating unit will be described in greater detail below.
The refrigeration cycle apparatus 3 may include a cascade cycle unit 4 and a gas injection mechanism 5.
The cascade cycle unit 4 may include a cascade heat exchanger that performs a heat exchange between a first coolant of a low temperature refrigeration cycle A and a second coolant of a high temperature refrigeration cycle B, and a water coolant heat exchanger in which the second coolant of the high temperature refrigeration cycle B is condensed while heating water.
The first and second coolants have different condensation temperature and evaporation temperature. For example, in a case where theist coolant has a low condensation temperature and evaporation temperature of R410A, the second coolant may have a higher condensation temperature and evaporation temperature of R134a than the first coolant.
The gas injection mechanism 5 expands the coolant condensed in one of the low temperature refrigeration cycle A and the high temperature refrigeration cycle B, separates a gaseous coolant from the condensed coolant, and then injects the separated gaseous coolant into a compressor in the refrigeration cycle in which the gas injection mechanism is provided. The gas injection mechanism may be included in at least one of the low temperature refrigeration cycle A and the high temperature refrigeration cycle B.
The low temperature refrigeration cycle A, the high temperature refrigeration cycle B, and the gas injection mechanism will now be described in greater detail with the assumption that the gas injection mechanism is provided in the low temperature refrigeration cycle A.
The low temperature refrigeration cycle A forms a closed path running from a low pressure side compressor 6 through a cascade heat exchanger 10 and a first expansion mechanism 12 to an evaporator 14. The first coolant is compressed in the low pressure side compressor 6, condensed in the cascade heat exchanger 10, expanded in the first expansion mechanism 12, and evaporated in the evaporator 14. The second coolant may be evaporated while the first coolant repeats the compression, condensation, expansion, and evaporation.
The low pressure side compressor 6, which compresses the first coolant, is connected to the cascade heat exchanger 10 and a low pressure side compressor discharge pipe 7. The low pressure side compressor 6 may be connected to the evaporator 14 and a low pressure side compressor suction pipe 8.
The low pressure side compressor may be configured as a two stage compressor, a twin rotary compressor, a screw compressor, or a scroll compressor, so that the gaseous coolant is gas injected to low pressure side compressor 6 in a case where gas injection mechanism 5 is provided in the low temperature refrigeration cycle A.
A two stage compressor, which is connected in series with a coolant path, includes a first compression part and a second compression part. A coolant is first condensed in the first compression part and then re-condensed in the second compression part. The coolant evaporated in evaporator 14 is sucked and compressed in the first compression part before discharge.
The gas injection mechanism 5 is connected to a connection path between the first compression part and second compression part. The gaseous coolant injected from the gas injection mechanism is mixed with the coolant that is compressed and discharged by the first compression part, and then the mixed material may be compressed and discharged by the second compression part.
A twin rotary compressor includes first and second compression parts that perform compression by the same motor. The coolant evaporated in the evaporator 14 is sucked, compressed, and discharged by the first compression part. The gas injection mechanism 5 is connected to the second compression part. The coolant evaporated in the evaporator 14 is compressed and discharged by the first compression part. The gaseous coolant injected by the gas injection mechanism may be compressed and discharged by the second compression part.
A screw compressor is a rotary displacement compressor that includes a pair of male and female screw rotors engaged with each other, with a gaseous coolant compressed between the male and female screw rotors. The coolant evaporated in evaporator 14 is sucked and compressed in a compression chamber of the compressor.
The gas injection mechanism is connected to an injection port communicating with one side of the compression chamber of the screw compressor. The gaseous coolant injected from the gas injection mechanism may be mixed with the coolant compressed in the screw compressor and the resultant material may be compressed and discharged.
A scroll compressor compresses a coolant by rotating a rotational scroll in a compression chamber. The coolant evaporated in evaporator 14 is sucked and compressed in the compression chamber of the scroll compressor. The gas injection mechanism is connected to an injection port communicating with one side of the compression chamber of the scroll compressor. The gaseous coolant injected from the gas injection mechanism is mixed with the coolant condensed in the scroll compressor, and the resultant material may be compressed and discharged.
The cascade heat exchanger 10 includes a condensation path to condense the first coolant and an evaporation path to evaporate the second coolant passing therethrough. A heat transfer member may be provided between the condensation and evaporation paths for heat exchange between the first and second coolants.
The cascade heat exchanger 10 may be configured as a double pipe heat exchanger where a condensation path and an evaporation path are located inside and outside of a heat transfer member, or a plate type heat exchanger where a condensation path and an evaporation path are located alternate to each other with a heat transfer member therebetween.
The cascade heat exchanger may be connected to first expansion mechanism 12 and gas injection mechanism 5. The first expansion mechanism expands the first coolant sucked into evaporator 14 and may be configured as an electronic expansion valve that may adjust the degree of opening to control the suction superheat of the low temperature refrigeration cycle A.
The first expansion mechanism 12 may be connected to evaporator 14 through a pipe 13 between the first expansion mechanism and the evaporator. The evaporator may be configured as an air-cooled heat exchanger that introduces external air into the evaporator and evaporates the coolant using the introduced air. The cascade cycle unit 4 may also include outdoor fan 15 that blows external air into the evaporator.
The high temperature refrigeration cycle B forms a closed path running from a high pressure side compressor 16 through a water coolant heat exchanger 20 and a second expansion mechanism 22 to the cascade heat exchanger 10. The second coolant is compressed in the high pressure side compressor 16, heat exchanged with water and condensed in the water coolant heat exchanger 20, expanded in the second expansion mechanism 22, and heat exchanged with the first coolant and evaporated in the cascade heat exchanger. The water may be heated while the second coolant repeats the compression, condensation, expansion, and evaporation.
The high pressure side compressor 16, which compresses the second coolant, may be connected to the water coolant heat exchanger 20 via a high pressure side compressor discharge pipe 17. The high pressure side compressor may be connected to the cascade heat exchanger 10 via a high pressure side compressor suction pipe 18.
The water coolant heat exchanger 20 is connected to a water circulation path that is a closed path including the room heating unit 1 and the water heating unit 2.
The water coolant heat exchanger includes a condensation path to condense a coolant passing therethrough and a water heating path to heat water passing therethrough. The water coolant heat exchanger may be configured as a double pipe heat exchanger where the condensation path and the water heating path are located inside and outside of a heat transfer member, or a plate type heat exchanger where the condensation path and the water heating path are located alternate to each other with a heat transfer member therebetween.
The water coolant heat exchanger may be connected to second expansion mechanism 22 through a pipe 21 between water coolant heat exchanger 20 and second expansion mechanism 22. The second expansion mechanism expands the second coolant sucked into cascade heat exchanger 10 and may be configured as an electronic expansion valve that may adjust the degree of opening to control the suction superheat of the high temperature refrigeration cycle B.
The second expansion mechanism may be connected to cascade heat exchanger 10 through a pipe 23 between second expansion mechanism 22 and cascade heat exchanger 10.
The gas injection mechanism 5 may expand the first coolant condensed in the cascade heat exchanger 10, separate a liquid coolant and a gaseous coolant from the first coolant, and inject only the gaseous coolant to low pressure side compressor 6.
The gas injection mechanism 5 may include a gas/liquid separator 24 that separates a liquid coolant and a gaseous coolant from the coolant condensed in the cascade heat exchanger 10, a coolant injection path 26 that injects the gaseous coolant separated by the gas/liquid separator 24 to the low pressure side compressor 6, an auxiliary expansion mechanism 28 that expands the coolant flowing from the cascade heat exchanger 10 to the gas/liquid separator 24, and a gaseous coolant adjustment valve 30 that is provided over the coolant injection path 26.
The gas/liquid separator 24 may be provided between cascade heat exchanger 10 and first expansion mechanism 12. The gas/liquid separator may be connected to auxiliary expansion mechanism 28 through gas/liquid separator suction pipe 25, connected to the first expansion mechanism through a liquid phase pipe 27, and connected to the low pressure side compressor 6 through the coolant injection path 26.
The coolant having passed through the auxiliary expansion mechanism 28 flows into the gas/liquid separator 24 via a gas/liquid separator suction pipe 25 and separates into a gaseous coolant and a liquid coolant in the gas/liquid separator 24. The gaseous coolant may be injected to the low pressure side compressor 6 through coolant injection path 26 and liquid coolant may flow into first expansion mechanism 12 through the liquid phase pipe 27.
One end of coolant injection path 26 may be connected to gas/liquid separator 24 and the other end may be connected to low pressure side compressor 6.
The coolant injection path 26 may include a plurality of gas injection pipes 26A and 26B. The gas injection pipes may include a first gas injection pipe 26A that connects between gas/liquid separator 24 and gaseous coolant adjustment valve 30, and a second gas injection pipe 26B that connects between the gaseous coolant adjustment valve 30 and the low pressure side compressor 6.
The auxiliary expansion mechanism 28 expands the coolant condensed in the cascade heat exchanger 10 before the coolant is sucked into the gas/liquid separator 24. The auxiliary expansion mechanism may be provided between the cascade heat exchanger and gas/liquid separator.
The auxiliary expansion mechanism 28 may be configured as an electronic expansion valve that may adjust the degree of opening to prevent the liquid coolant in the gas/liquid separator 24 from flowing to the coolant injection path 26. The auxiliary expansion mechanism may be connected to cascade heat exchanger 10 through a pipe 29 between cascade heat exchanger 10 and auxiliary expansion mechanism 28.
The gaseous coolant adjustment valve 30 controls the gaseous coolant discharged from the second expansion mechanism 22. The gaseous coolant adjustment valve 30 may be configured as an opening/closing valve that performs the opening/closing operation under the On/Off control, or an electronic expansion valve that may control the degree of opening.
The water circulation path runs through the water coolant heat exchanger 20, room heating unit 1, and water heating unit 2, so that water heated in water coolant heat exchanger 20 passes through at least one of the room heating unit 1 or the water heating unit 2 and then returns to the water coolant heat exchanger 20.
The water circulation path may include a cascade cycle unit pipe 32 that is located inside the refrigeration cycle apparatus 3, a water heating pipe 33 that allows water to pass through the water heating unit 2, a room heating pipe 34 that allows water to pass through the room heating unit 1, and a connection pipe 35 that connects the cascade cycle unit pipe 32 to the water heating pipe 33 and the room heating pipe 34.
A hot water adjustment valve 36 may be positioned over the connection pipe 35 to guide the water heated in the water coolant heat exchanger 20 to at least one of water heating pipe 33 and room heating pipe 34. The water heating pipe and room heating pipe may be connected to the water coolant heat exchanger through the connection pipe.
The cascade cycle unit 4, room heating unit 1, and water heating unit 2 will now be described in greater detail. The cascade cycle unit may include a flow switch 37 that senses the flow of water passing through the cascade cycle unit pipe 32 and a circulation pump 38 that is positioned over the cascade cycle unit pipe 32 to pump water for circulation.
The room heating unit may include a floor heating unit 41 that heats the floor of a room and an air heating unit 42 that heats air in the room. The floor heating unit may be configured as a meander line embedded in the floor of the room. The air heating unit 42 may be configured as a fan coil unit or a radiator.
Room heating water adjustment valves 43 and 44 may be positioned over the room heating pipe 34 to guide water to at least one of the floor heating unit 41 and the air heating unit 42. The floor heating unit 41 may be connected to the room heating water adjustment valves via an air heating pipe 45, and the air heating unit may be connected to the room heating water adjustment valves via a floor heating pipe 46.
The water heating unit 2 supplies hot water required for a user to take a shower or wash the dishes, and may include a hot water tank 51 that contains water and a hot water auxiliary heater 52 that is provided in the hot water tank. The hot water tank may be connected to a cool water inlet 53 that introduces cool water to the hot water tank and a hot water outlet 54 that discharges hot water out of the hot water tank 51. The water heating pipe 33 may be provided in the hot water tank.
The hot water outlet 54 may be connected to a hot water discharging device 55, such as a shower head. A cool water inlet 56 may be connected to the hot water outlet 54 so that cool water may be discharged to the outside through the hot water discharging device 55.
In the cascade cycle unit 4, the room healing unit 1, and the water heating unit 2 as described above, if the hot water adjustment valve 36 is subjected to a water heating mode for supplying hot water when a circulation pump 39 is driven, water heated in the water coolant heat exchanger 20 may flow through the cascade cycle unit pipe 32 and the connection pipe 35 into the water heating pipe 33 to heat water in the hot water tank 51 and then return to the water coolant heat exchanger 20 via the connection pipe 35 and the cascade cycle unit pipe 32.
If the hot water adjustment valve 36 is subjected to a room heating mode for heating the room when the circulation pump 39 is driven, the water heated through heat transfer with the second coolant in the water coolant heat exchanger 20 may pass through the cascade cycle unit pipe 32 and the connection pipe 35 into the room heating pipe 34 to heat at least one of the floor heating unit 41 and the air heating unit 42 and then return to the water coolant heat exchanger via the room heating pipe, the connection pipe, and the cascade cycle unit pipe.
If the room heating water adjustment valves 43 and 44 are subjected to an air heating mode for heating air in the room, the water passes through the air heating pipe 45, the air heating unit 42, and the air heating pipe 45 to the room heating pipe 34, and if the room heating water adjustment valves are subjected to a floor heating mode for heating the floor in the room, the water passes through the floor heating pipe 46, the floor heating unit 41, and the floor heating pipe 46 to the room heating pipe.
In the first embodiment of the heat pump type cooling/heating apparatus, the low pressure side compressor 6, cascade heat exchanger 10, first expansion mechanism 12, evaporator 14, high pressure side compressor 16, water coolant heat exchanger 20, second expansion mechanism 22, coolant injection path 26, gaseous coolant adjustment valve 30, gas/liquid separator 24, and auxiliary expansion mechanism 28 may be installed together in a single unit to constitute refrigeration cycle apparatus 3.
FIG. 2 shows a block diagram of the cooling/heating apparatus of FIG. 1, FIG. 3 is an expanded view of the cascade cycle unit of this apparatus, and FIG. 4 is a graph showing a P-H relationship that may be obtained for the cooling/heating apparatus.
As shown, the cooling/heating apparatus includes a manipulation unit 60 that inputs instructions including operation/stop instructions, a load sensor 70 that senses the load of the apparatus, and a controller 80 that controls the low pressure side compressor 6, first expansion mechanism 12, outdoor fan 15, high pressure side compressor 16, second expansion mechanism 22, auxiliary expansion mechanism 28, and gaseous coolant adjustment valve 30 based on the operation of the manipulation unit and the sensing result of the load sensor.
The load sensor 70 may include a hot water temperature sensor that senses the load of room heating unit 1 and water heating unit 2.
The hot water temperature sensor may be provided at a side of the water circulation path to sense the temperature of water circulating through the water coolant heat exchanger 20 and at least one of the room heating unit or the water heating unit. In one embodiment, the hot water temperature sensor senses the temperature of water that is cooled in at least one of room heating unit 1 or water heating unit 2 and then returns to the water coolant heat exchanger. For example, the hot water temperature sensor may be installed in the cascade cycle unit pipe 32.
The load sensor 70 may also include an outdoor temperature sensor that determines whether the outdoor temperature is low or not. This sensor may be in evaporator 14 to sense the temperature of air blowing from the exterior to the evaporator.
If the load sensed by the load sensor is not less than a predetermined load value, controller 80 may operate in an injection mode in which gaseous coolant is injected through gas injection mechanism 5. And, if the load sensed by the load sensor is not more than a predetermined load value, the controller may operate in a general mode that stops injecting the gaseous coolant through the gas injection mechanism.
The controller controls the gaseous coolant adjustment valve 30 based on whether the operation mode is the general mode or gas injection mode. In the general mode, the controller may close gaseous coolant adjustment valve 30, and in the gas injection mode the controller may open the gaseous coolant adjustment valve.
If the temperature of hot water sensed by the hot water temperature sensor is less than a predetermined temperature value, the controller may determine that the load is not less than the predetermined load value to operate the cooling/heating apparatus, especially the refrigeration cycle apparatus 3, in the gas injection mode.
If the temperature of hot water sensed by the hot water temperature sensor is not less than the predetermined temperature value, the controller may determine that the load is less than the predetermined load value to operate the cooling/heating apparatus, especially the refrigeration cycle apparatus 3, in general mode.
If the temperature of hot water sensed by the outdoor temperature sensor is not more than a predetermined temperature value, the controller may determine that the load is not less than the predetermined load value to operate the cooling/heating apparatus, especially the refrigeration cycle apparatus 3, in the gas injection mode.
If the temperature of hot water sensed by the outdoor temperature sensor is more than the predetermined temperature value, the controller may determine that the load is less than the predetermined load value to operate the cooling/heating apparatus, especially the refrigeration cycle apparatus 3, in general mode.
In response to an instruction from manipulation unit 60, the controller drives low pressure side compressor 6 and high pressure side compressor 16 and controls first expansion mechanism 12 and second expansion mechanism 22 to enable the first and second expansion mechanisms to expand the coolant. Further, the controller may drive outdoor fan 15.
If the temperature sensed by load sensor 70 exceeds a predetermined temperature value, the controller may close the gaseous coolant adjustment valve 30. At this moment or shortly thereafter, the controller may fully turn off the auxiliary expansion mechanism 28.
During operation, the first coolant is compressed in low pressure side compressor 6, condensed in cascade heat exchanger 10, and directed to sequentially pass through auxiliary expansion mechanism 28 and second expansion mechanism 22. The first coolant is then expanded while passing through first expansion mechanism 12 and then a heat-exchange operation is performed with external air to be evaporated while passing through evaporator 14. The first coolant then returns to the low pressure side compressor.
While the first coolant is compressed in the low pressure side compressor, the second coolant may be compressed in high pressure side compressor 16, condensed in water coolant heat exchanger 20 while heating water, expanded in second expansion mechanism 22, evaporated while passing through cascade heat exchanger 10 to exchange heat with the first coolant, and then returned to the high pressure side compressor.
The refrigeration cycle apparatus 3 may heat water at higher temperature than a case where low temperature refrigeration cycle A alone or high temperature refrigeration cycle B alone is included.
On the other hand, if the temperature sensed by load sensor 70 is not more than a predetermined temperature value, controller 80 may open gaseous coolant adjustment valve 30. At this moment or shortly thereafter, the controller controls the auxiliary expansion mechanism 28 to have a predetermined degree of opening in order to enable the auxiliary expansion mechanism to expand the first coolant. In addition to controlling the gaseous coolant adjustment valve and auxiliary expansion mechanism, the controller may control the other components in the same way as the general mode.
During the above-mentioned control, the first coolant may be compressed in low pressure side compressor 6, condensed in cascade heat exchanger 10, expanded in auxiliary expansion mechanism 28, and then introduced into second expansion mechanism 22.
The first coolant is separated into a gaseous coolant and a liquid coolant in the second expansion mechanism. The liquid coolant may be expanded while flowing into first expansion mechanism 12, evaporate in evaporator 14, and then sucked and compressed in low pressure side compressor 6. On the other hand, the gaseous coolant may pass from second expansion mechanism 22 through coolant injection path 26 and gaseous coolant adjustment valve 30 and injected into the low pressure side compressor for compression.
In general mode, while the first coolant goes through compression, condensation, expansion, and evaporation procedures, refrigeration cycle apparatus 3 is subjected to a cycle: a->b->c->f->a, as depicted by the dashed lines in FIG. 4.
In gas injection mode, while the first coolant goes through compression, condensation, expansion, expansion, and evaporation procedures, the refrigeration cycle apparatus 3 is subjected to a cycle: a->b->c->d->e->f->a, as depicted by the solid lines in FIG. 4. Also, part of the coolant discharged from cascade heat exchanger 10 is subjected to a procedure: c->d->g->b as depicted in FIG. 4 while going through expansion and compression, so that the cascade heat exchanger may have an increased condensation volume compared to the normal mode.
On the other hand, the second coolant may be compressed in high pressure side compressor 16 while the first coolant is compressed in low pressure side compressor 6. The second coolant may be condensed while water is heated in water coolant heat exchanger 20, expanded in second expansion mechanism 22, heat exchanged with the first coolant and evaporated while passing through cascade heat exchanger 10, and then returned to high pressure side compressor 16. The refrigeration cycle apparatus 3 perform compression, condensation, expansion, and evaporation while the second coolant goes through a cycle: h->I->j->k->h.
That is, the refrigeration cycle apparatus may have further reduced compression work in the gas injection mode than the general mode, and may supply hot water to the refrigeration cycle apparatus even when the temperature at the exterior is low and the apparatus is located in a cold site.
FIG. 5 shows a second embodiment of a heat pump type cooling/heating apparatus, wherein a gas injection mechanism 5′ may be provided in high temperature refrigeration cycle B. The gas injection mechanism 5′ may be provided between second expansion mechanism 22 and water coolant heat exchanger 20 of the high temperature refrigeration cycle B and connected to high pressure side compressor 16′ of high temperature refrigeration cycle B.
In low temperature refrigeration cycle A, a low pressure side compressor 6′ may be connected to cascade heat exchanger 10 via a low pressure side compressor discharge pipe 7 and connected to evaporator 14 via a low pressure side compressor suction pipe 8.
In low temperature refrigeration cycle A, first expansion mechanism 12 may be connected to cascade heat exchanger 10 via a pipe 11 between first expansion mechanism 12 and cascade heat exchanger 10 and connected to evaporator 14 via a pipe 13 between the first expansion mechanism and evaporator 14.
In high temperature refrigeration cycle B, high pressure side compressor 16′ may be configured as a two stage compressor, a twin rotary compressor, a screw compressor, or a scroll compressor so that the gaseous coolant having passed through gas injection mechanism 5′ is gas injected to high pressure side compressor 16′.
The high pressure side compressor 16′ may be similar to high pressure side compressor 16, and may be connected to water coolant heat exchanger 20 via high pressure side compressor discharge pipe 17 and to cascade heat exchanger 10 via high pressure side compressor suction pipe 18.
The gas injection mechanism 5′ may expand the second coolant condensed in water coolant heat exchanger 20, separate the second coolant into a gaseous coolant and a liquid coolant, and then inject only the gaseous coolant into high pressure side compressor 16′.
The gas injection mechanism 5′ may include a gas/liquid separator 24′ that separates a liquid coolant and a gaseous coolant from the coolant condensed in water coolant heat exchanger 20, a coolant injection path 26′ that injects the gaseous coolant separated by gas/liquid separator 24′ to high pressure side compressor 16′, an auxiliary expansion mechanism 28′ that expands the coolant flowing from water coolant heat exchanger 20 to gas/liquid separator 24′, and a gaseous coolant adjustment valve 30′ that is provided over gas/liquid separator 24′.
The gas/liquid separator 24′ may be provided between water coolant heat exchanger 20 and second expansion mechanism 22, and may be connected to auxiliary expansion mechanism 28′ through a gas/liquid separator suction pipe 25′, to second expansion mechanism 22 through a liquid phase pipe 27′, and to high pressure side compressor 16′ through a coolant injection path 26′.
Once having passed through the auxiliary expansion mechanism 28′, the coolant flows into gas/liquid separator 24′ via gas/liquid separator suction pipe 25′ and separates into a gaseous coolant and a liquid coolant in the gas/liquid separator 24′. The gaseous coolant may be injected to high pressure side compressor 16′ through coolant injection path 26′ and the liquid coolant may flow into second expansion mechanism 22 through liquid phase pipe 27′. One end of coolant injection path 26′ may be connected to gas/liquid separator 24′ and the other end may be connected to high pressure side compressor 16′.
The coolant injection path 26′ may include a plurality of gas injection pipes 26A′ and 26B′. These pipes may include a first gas injection pipe 26A′ that is connected between gas/liquid separator 24′ and gaseous coolant adjustment valve 30′ and a second gas injection pipe 26B′ that is connected between gaseous coolant adjustment valve 30′ and high pressure side compressor 16′.
The auxiliary expansion mechanism 28′ expands the coolant condensed in water coolant heat exchanger 20 before the coolant is sucked into gas/liquid separator 24′. The auxiliary expansion mechanism may be provided between water coolant heat exchanger 20 and gas/liquid separator 24′, and may be configured as an electronic expansion valve for adjusting the degree of opening to prevent the liquid coolant in gas/liquid separator 24′ from flowing to coolant injection path 26′.
The auxiliary expansion mechanism 28′ may be connected to water coolant heat exchanger 20 through a pipe 29′ between the water coolant heat exchanger and the auxiliary expansion mechanism. The gaseous coolant adjustment valve 30′ controls the gaseous coolant discharged from the gas/liquid separator 24′, and may be configured as an opening/closing valve that performs the opening/closing operation under the On/Off control, or an electronic expansion valve that may control the degree of opening.
FIG. 6 shows a third embodiment of a heat pump type cooling/heating apparatus, FIG. 7 shows a manner in which a cascade unit and outdoor unit may be separately provided in this apparatus, and FIG. 8 shows a manner in which the outdoor unit may be attached to the cascade unit in this apparatus.
As shown, the third embodiment may include an outdoor unit O and a cascade unit C. The outdoor unit O may include low pressure side compressor 6, first expansion mechanism 12, evaporator 14, and outdoor fan 15. The cascade unit C may include cascade heat exchanger 10, high pressure side compressor 16, water coolant heat exchanger 20, and second expansion mechanism 22.
In case of being provided in low temperature refrigeration cycle A, gas injection mechanism 5 may be included in the outdoor unit O, and in case of being provided in high temperature refrigeration cycle B the gas injection mechanism may be included in the cascade unit C.
The cascade unit C may be separated from outdoor unit C as shown in FIG. 7, in which the refrigeration cycle apparatus 3 may be considered as a separation type. Alternatively, the cascade unit may be attached to the outdoor unit C as shown in FIG. 8, in which case the refrigeration cycle apparatus 3 may be considered as an integration type. The cascade unit C may be selectively mounted on the outdoor unit O.
One or more embodiments described herein, therefore, provides a heat pump type cooling/heating apparatus that may efficiently provide a supply of hot water as needed. One or more of these embodiments may also provide a heat pump type cooling/heating apparatus that enhances heating performance by preventing a lowering in efficiency in cold regions in which the apparatus is being used.
In accordance with one embodiment, a heat pump type cooling/heating apparatus includes a cascade cycle unit that includes a cascade heat exchanger that performs a heat exchange between a first coolant of a low temperature refrigeration cycle and a second coolant of a high temperature refrigeration cycle, and a water coolant heat exchanger that heats water while the second coolant of the high temperature refrigeration cycle is condensed.
The water coolant heat exchanger is connected to a destination via a water circulation path including: a coolant injection path that is split between the cascade heat exchanger and an evaporator of the low temperature refrigeration cycle to inject a coolant into a low pressure side compressor of the low temperature refrigeration cycle or split between the water coolant heat exchanger and the cascade heat exchanger to inject a coolant into a high pressure side compressor of the high temperature refrigeration cycle; and a gaseous coolant adjustment valve that is provided in the coolant injection path and adjusted corresponding to the load of the destination.
In another embodiment, a heat pump type cooling/heating apparatus includes a gas/liquid separator that separates a coolant condensed in the cascade heat exchanger into a liquid coolant and a gaseous coolant; and an auxiliary expansion mechanism that is provided between the cascade heat exchanger and the gas/liquid separator to expand a coolant.
The low temperature refrigeration cycle may forms a closed path running from a low pressure side compressor through the cascade heat exchanger and a first expansion mechanism to an evaporator, and the high temperature refrigeration cycle forms a closed path running from a high pressure side compressor through the water coolant heat exchanger and a second expansion mechanism to the cascade heat exchanger, and wherein the gas/liquid separator is provided between the cascade heat exchanger and the first expansion mechanism.
In another embodiment, the heat pump type cooling/heating apparatus further includes a gas/liquid separator that separates a coolant condensed in the water coolant heat exchanger into a liquid coolant and a gaseous coolant; and an auxiliary expansion mechanism that is provided between the water coolant heat exchanger and the gas/liquid separator to expand a coolant.
The low temperature refrigeration cycle forms a closed path running from a low pressure side compressor through the cascade heat exchanger and a first expansion mechanism to an evaporator, and the high temperature refrigeration cycle forms a closed path running from a high pressure side compressor through the water coolant heat exchanger and a second expansion mechanism to the cascade heat exchanger, and wherein the gas/liquid separator is provided between the water coolant heat exchanger and the second expansion mechanism.
The low pressure side compressor, the cascade heat exchanger, the first expansion mechanism, the evaporator, the high pressure side compressor, the second expansion mechanism, the water coolant heat exchanger, the coolant injection path, the gaseous coolant adjustment valve, the gas/liquid separator, and the auxiliary expansion mechanism are installed in a single unit.
The low pressure compressor, the first expansion mechanism, and the evaporator are installed in an outdoor unit, and wherein the cascade heat exchanger, the high pressure side compressor, the second expansion mechanism, and the water coolant heat exchanger are installed in a cascade unit, and wherein the coolant injection path, the gaseous coolant adjustment valve, the gas/liquid separator, and the auxiliary expansion mechanism are installed in one of the outdoor unit and the cascade unit. The cascade unit may be integrally mounted on the outdoor unit or may be provided separately from the outdoor unit.
The heat pump type cooling/heating apparatus further includes a load sensor that senses the load of the destination; and a controller that controls the gaseous coolant adjust valve according to a sensing result of the load sensor. The load sensor is provided over the water circulation path. The controller opens the gaseous coolant adjustment valve when a temperature sensed by the load sensor is less than a predetermined valve, and closes the gaseous coolant adjustment valve when a temperature sensed by the load sensor is more than the predetermined valve. The destination includes a room heating unit connected to the water circulation path and a water heating unit connected to the water circulation path.
At least one of the low pressure side compressor and the high pressure compressor, which is connected to the coolant injection path, is configured as a two stage compressor.
At least one of the low pressure side compressor and the high pressure compressor, which is connected to the coolant injection path, is configured as a screw compressor.
At least one of the low pressure side compressor and the high pressure compressor, which is connected to the coolant injection path, is configured as a scroll compressor.
At least one of the low pressure side compressor and the high pressure compressor, which is connected to the coolant injection path, is configured as a twin rotary compressor.
One or more embodiments of the heat pump type cooling/heating apparatus may include the cascade heat exchanger with the low temperature refrigeration cycle and the high temperature refrigeration cycle, and thus, may make the temperature of water supplied to the apparatus higher than the conventional apparatuses having a single refrigeration cycle. Further, since the gaseous coolant is gas injected into the compressor over the low temperature cycle or compressor over the high temperature cycle, thus capable of enhancing heating performance.
Since the gaseous coolant is gas injected into the low pressure side compressor over the low temperature refrigeration cycle, it may be possible to minimize a lowering in volume flow rate that occurs at the evaporator over the low temperature refrigeration cycle when the temperature of the exterior is low. Additionally, the condensation volume of the cascade heat exchanger may be raised, and this allows for efficient room heating and high defrosting performance.
Since the gaseous coolant is gas injected into the compressor over the low temperature refrigeration cycle, it may be possible to lower the maximum management temperature of the compressor over the low temperature refrigeration cycle and enhance reliability of the compressor over the low temperature refrigeration cycle.
Since the gaseous coolant is gas injected into the high pressure side compressor over the high temperature refrigeration cycle, it may be possible to increase the condensation volume of the water coolant heat exchanger, thus leading to improving room heating performance and supplying water at higher temperature.
Any reference in this specification to “one embodiment,” “an embodiment,” “example embodiment,” etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the purview of one skilled in the art to effect such feature, structure, or characteristic in connection with other ones of the embodiments.
Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.

Claims

1. A heat pump type cooling/heating apparatus comprising:

a cascade cycle unit that includes a cascade heat exchanger that performs a heat exchange between a first coolant of a low temperature refrigeration cycle and a second coolant of a high temperature refrigeration cycle, and

a water coolant heat exchanger that heats water while the second coolant of the high temperature refrigeration cycle is condensed, wherein the water coolant heat exchanger is coupled to a destination via a water circulation path, the heat pump type cooling/heating apparatus further comprising:

a coolant injection path that is split between the cascade heat exchanger and an evaporator of the low temperature refrigeration cycle to inject a coolant into a low pressure side compressor of the low temperature refrigeration cycle, or split between the water coolant heat exchanger and the cascade heat exchanger to inject a coolant into a high pressure side compressor of the high temperature refrigeration cycle; and

a gaseous coolant adjustment valve provided in the coolant injection path and adjusted corresponding to a load of the destination.

2. The apparatus of claim 1, further comprising:

a gas/liquid separator to separate a coolant condensed in the cascade heat exchanger into a liquid coolant and a gaseous coolant; and

an auxiliary expansion mechanism, provided between the cascade heat exchanger and the gas/liquid separator, to expand a coolant.

3. The apparatus of claim 2, wherein:

the low temperature refrigeration cycle forms a closed path running from a low pressure side compressor through the cascade heat exchanger and a first expansion mechanism to an evaporator,

the high temperature refrigeration cycle forms a closed path running from a high pressure side compressor through the water coolant heat exchanger and a second expansion mechanism to the cascade heat exchanger, and

the gas/liquid separator is provided between the cascade heat exchanger and the first expansion mechanism.

4. The apparatus of claim 3, wherein the low pressure side compressor, the cascade heat exchanger, the first expansion mechanism, the evaporator, the high pressure side compressor, the second expansion mechanism, the water coolant heat exchanger, the coolant injection path, the gaseous coolant adjustment valve, the gas/liquid separator, and the auxiliary expansion mechanism are installed in a single unit.

5. The apparatus of claim 3, wherein:

the low pressure compressor, first expansion mechanism, and evaporator are installed in an outdoor unit,

the cascade heat exchanger, high pressure side compressor, second expansion mechanism, and water coolant heat exchanger are installed in a cascade unit, and

the coolant injection path, gaseous coolant adjustment valve, gas/liquid separator, and auxiliary expansion mechanism are installed in one of the outdoor unit or the cascade unit.

6. The apparatus of claim 1, further comprising:

a gas/liquid separator to separate a coolant condensed in the water coolant heat exchanger into a liquid coolant and a gaseous coolant; and

an auxiliary expansion mechanism, provided between the water coolant heat exchanger and the gas/liquid separator, to expand a coolant.

7. The apparatus of claim 6, wherein:

the gas/liquid separator is provided between the water coolant heat exchanger and the second expansion mechanism.

8. The apparatus of claim 7, wherein:

the low pressure side compressor, cascade heat exchanger, first expansion mechanism, evaporator, high pressure side compressor, second expansion mechanism, water coolant heat exchanger, coolant injection path, gaseous coolant adjustment valve, gas/liquid separator, and auxiliary expansion mechanism are installed in a single unit.

9. The apparatus of claim 7, wherein:

10. The apparatus of claim 9, wherein the cascade unit is integrally mounted on the outdoor unit.

11. The apparatus of claim 9, wherein the cascade unit is separated from the outdoor unit.

12. The apparatus of claim 1, further comprising:

a load sensor to sense the load of the destination; and

a controller to control the gaseous coolant adjust valve according to a sensing result of the load sensor.

13. The apparatus of claim 12, wherein the load sensor is provided over the water circulation path.

14. The apparatus of claim 13, wherein the controller opens the gaseous coolant adjustment valve when a temperature sensed by the load sensor is less than a predetermined valve, and closes the gaseous coolant adjustment valve when a temperature sensed by the load sensor is more than the predetermined valve.

15. The apparatus of claim 1, wherein the destination includes a room heating unit coupled to the water circulation path and a water heating unit connected to the water circulation path.

16. The apparatus of claim 1, wherein at least one of the low pressure side compressor or the high pressure compressor, which is coupled to the coolant injection path, is configured as a two-stage compressor.

17. The apparatus of claim 1, wherein at least one of the low pressure side compressor or the high pressure compressor, which is coupled to the coolant injection path, is configured as a screw compressor.

18. The apparatus of claim 1, wherein at least one of the low pressure side compressor or the high pressure compressor, which is coupled to the coolant injection path, is configured as a scroll compressor.

19. The apparatus of claim 1, wherein at least one of the low pressure side compressor or the high pressure compressor, which is coupled to the coolant injection path, is configured as a twin rotary compressor.