HEAT PUMP AND CONTROL METHOD THEREOF

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims the benefit of priority to Korean Patent Application Nos. 10-2023-0085000 and 10-2023-0095395 filed on Jun. 30, 2023, and Jul. 21, 2023, respectively, in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference in their entireties.

BACKGROUND
1. Field

The present disclosure relates to a heat pump and control method thereof.

2. Description of Related Art

Generally, a heat pump is a device cooling an indoor space during a cooling operation or heating an indoor space during a heating operation, and specifically, in the case of a cooling operation, heat passes through the compressor and is released from the outside in an outdoor heat exchanger installed outside, and an indoor heat exchanger disposed indoors absorbs indoor heat through a pressure reducing means and performs evaporation, thereby cooling the indoor space. In the case of a heating operation, a refrigerant evaporated from an outdoor heat exchanger disposed outside is compressed through a compressor, and the compressed high-temperature, high-pressure refrigerant condenses in an indoor heat exchanger disposed indoors and releases heat into the indoor space to heat the indoor space. Here, the outdoor heat exchanger uses an outdoor air heat source to operate as a condenser during a cooling operation and as an evaporator during a heating operation.

For this heat pump, specifically, during a heating operation in situations in which the outdoor temperature is low, a low-temperature refrigerant flowing through the outdoor heat exchanger may cause frost formation in the outdoor heat exchanger due to insufficient absorption of heat energy outdoors, and furthermore, a problem of reduced heating efficiency may occur due to an insufficient temperature increase of the refrigerant passing through the outdoor heat exchanger. Meanwhile, there is a need to research and develop technologies that may secure both cooling and heating performance in heat pumps.

Prior Art Reference
Patent Document

- (Patent Document 1) KR10-2004-0052049 A (Jun. 19, 2004)

SUMMARY

In order to achieve the aforementioned purpose, according to an embodiment of the present invention, provided is a heat pump including: a circulation flow path in which a flow path switching valve configured to switch a flow direction of a refrigerant according to a cooling mode or a heating mode is disposed; and a first outdoor heat exchanger and a second outdoor evaporative heat exchanger disposed on the circulation flow path, wherein the circulation flow path includes a first connection flow path, arranged in parallel with the first outdoor heat exchanger and in which a first opening/closing valve configured to open and close a flow path is disposed to bypass the first outdoor heat exchanger.

In an embodiment, the first outdoor heat exchanger and the second outdoor evaporative heat exchanger may be connected to each other in series on the circulation flow path, a first expansion valve may be disposed between the first outdoor heat exchanger and the second outdoor evaporative heat exchanger on the circulation flow path, and a second expansion valve is disposed on one side of the second outdoor evaporative heat exchanger, which is opposite to the first expansion valve, and the circulation flow path may include a bypass flow path, arranged in parallel with the first expansion valve and in which a second opening/closing valve configured to open and close a flow path is disposed to bypass the first expansion valve.

Furthermore, the heating mode may include: a first heating mode of controlling the refrigerant to be evaporated while flowing in the order of the second outdoor evaporative heat exchanger and the first outdoor heat exchanger; and a second heating mode of controlling the refrigerant to be evaporated while flowing in the order of the second outdoor evaporative heat exchanger and the first connection flow path.

In another embodiment, the circulation flow path may include a second connection flow path connected in parallel with the first connection flow path, the second outdoor evaporative heat exchanger and the second expansion valve may be disposed in the first connection flow path, and the first outdoor heat exchanger and the first expansion valve may be disposed in the second connection flow path.

Furthermore, the heating mode may include: a third heating mode of controlling the refrigerant to be evaporated while flowing through the first outdoor heat exchanger and the second outdoor evaporative heat exchanger, respectively; and a fourth heating mode of controlling the refrigerant to be evaporated while flowing alternately through the first outdoor heat exchanger and the second outdoor evaporative heat exchanger.

Furthermore, the first outdoor heat exchanger may be comprised of a first outdoor air-cooling type heat exchanger.

The first outdoor air-cooling type heat exchanger may include a tube through which refrigerant flows and a fin disposed on the tube.

The first outdoor heat exchanger and the second outdoor evaporative heat exchanger may be disposed adjacently to each other, and one outdoor fan disposed between the first outdoor heat exchanger and the second outdoor evaporative heat exchanger may be included.

The second outdoor evaporative condenser may include a water injection module configured to supply cooling water toward the second outdoor evaporative heat exchanger to perform a water injection operation in the cooling mode and configured not to perform a water injection operation in the heating mode.

Meanwhile, according to another embodiment of the present disclosure, provided is a control method of a heat pump in which a first outdoor heat exchanger and a second outdoor evaporative heat exchanger are disposed on a circulation flow path in which a flow direction of refrigerant is switched depending on a cooling mode or a heating mode, and the circulation flow path includes a first connection flow path configured to bypass the first outdoor heat exchanger. In a process in which in the heating mode, the refrigerant is evaporated while flowing through at least one of the first outdoor heat exchanger and the second outdoor evaporative heat exchanger, when frost formation occurs in the first outdoor heat exchanger, the control method of the heat pump may control the refrigerant to be evaporated while flowing through the second outdoor evaporative heat exchanger and the first connection flow path.

In an embodiment, in a process in which in the heating mode, the refrigerant is evaporated while flowing in the order of the second outdoor evaporative heat exchanger and the first outdoor heat exchanger connected in series on the circulation flow path, when the frost formation occurs in the first outdoor heat exchanger, the refrigerant may be controlled to be evaporated while flowing through the second outdoor evaporative heat exchanger and the first connection flow path.

In another embodiment, in the heating mode, the refrigerant may be controlled to be evaporated while flowing alternately through the first outdoor heat exchanger connected in parallel on the circulation flow path and the second outdoor evaporative heat exchanger disposed in the first connection flow path.

According to a heat pump and a control method thereof according to the embodiment of the present invention, cooling and heating operation may be performed in various heating and cooling modes using a first outdoor heat exchanger and a second outdoor evaporative heat exchanger, and the cooling and heating performance of the heat pump may be improved. Furthermore, in the heating mode, the heating efficiency may be improved by securing evaporation efficiency for the refrigerant by allowing the refrigerant to flow into the second outdoor evaporative heat exchanger and/or the first outdoor heat exchanger. Furthermore, normal operations of a continuous heating mode may be ensured even during the process of performing a defrosting operation for the first outdoor heat exchanger or the second outdoor evaporative heat exchanger. Heating performance may be secured by performing various heating modes as needed. Additionally, in a cooling mode, the refrigerant may be allowed to flow into the first outdoor heat exchanger and the second outdoor evaporative heat exchanger, thereby effectively improving cooling efficiency by condensing the refrigerant more efficiently through water injection in the second outdoor evaporative heat exchanger.

BRIEF DESCRIPTION OF DRAWINGS

The above and other aspects, features, and advantages of the present disclosure will be more clearly understood from the following detailed description, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a schematic view illustrating a configuration of a heat pump according to an embodiment of the present invention;

FIG. 2 is an exemplary view illustrating configuration of an example of a first outdoor heat exchanger in a heat pump according to an embodiment of the present invention;

FIG. 3 is an exemplary view illustrating a configuration of a first outdoor heat exchanger of another example in a heat pump according to an embodiment of the present invention;

FIG. 4 is an exemplary view illustrating a configuration of a first outdoor heat exchanger of another example in a heat pump according to an embodiment of the present invention;

FIG. 5 is an exemplary view illustrating a configuration of a first outdoor heat exchanger of another example in a heat pump according to an embodiment of the present invention;

FIG. 6 is a schematic view illustrating an operation process in a heating mode of a heat pump according to an embodiment of the present invention;

FIG. 7 is a schematic view illustrating another operation process in a heating mode of a heat pump according to an embodiment of the present invention;

FIG. 8 is a schematic view illustrating an operation process in a cooling mode of a heat pump according to an embodiment of the present invention;

FIG. 9 is a schematic view illustrating a configuration of a heat pump according to another embodiment of the present invention;

FIG. 10 is a schematic view illustrating an operation process in a heating mode of a heat pump according to another embodiment of the present invention;

FIG. 11 is a schematic view illustrating another operation process in a heating mode of a heat pump according to another embodiment of the present invention;

FIG. 12 is a schematic view illustrating another operation process in a heating mode of a heat pump according to another embodiment of the present invention; and

FIG. 13 is a schematic view illustrating an operation process in a cooling mode of a heat pump according to another embodiment of the present invention.

DETAILED DESCRIPTION

Hereinafter, with reference to the attached drawings, specific example embodiments of the present invention will be described. However, the concept of the present invention is not limited to the suggested embodiments. For example, those skilled in the art who understand the idea of the present invention may easily propose other degenerative inventions or other embodiments included within the scope of the concept of the present invention by adding, modifying, or deleting components in the scope of the same concept, but other degenerative inventions or other embodiments are also construed as being in the scope of the concept of the present invention.

Furthermore, throughout the specification, the terms “connected to” or “coupled to” are used to designate a connection or coupling of one element to another element and include both a case where an element is “directly connected or coupled to” another element and a case where an element is “indirectly connected or coupled to” another element via still another element. Furthermore, when a certain portion “includes” or “comprises” a certain component, this indicates that other components are not excluded and may be further included unless otherwise noted.

FIG. 1 is a schematic view illustrating a configuration of a heat pump according to an embodiment of the present invention, FIG. 2 is an exemplary view illustrating a configuration of an example of a first outdoor heat exchanger in a heat pump according to an embodiment of the present invention, FIG. 3 is an exemplary view illustrating a configuration of a first outdoor heat exchanger of another example in a heat pump according to an embodiment of the present invention, FIG. 4 is an exemplary view illustrating a configuration of a first outdoor heat exchanger of another example in a heat pump according to an embodiment of the present invention, FIG. 5 is an exemplary view illustrating a configuration of a first outdoor heat exchanger of another example in a heat pump according to an embodiment of the present invention, FIG. 6 is a schematic view illustrating an operation process in a heating mode of a heat pump according to an embodiment of the present invention, FIG. 7 is a schematic view illustrating another operation process in a heating mode of a heat pump according to an embodiment of the present invention, and FIG. 8 is a schematic view illustrating an operation process in a cooling mode of a heat pump according to an embodiment of the present invention.

Referring to FIG. 1, a heat pump 10 according to Embodiment 1 of the present invention may include a circulation indoor heat exchanger 200 disposed on the circulation flow path 100 and exchanging heat with indoor air, a compressor 300 configured to compress the refrigerant, a first expansion valve 410 and a second expansion valve 420 configured to decompress the refrigerant, a first outdoor heat exchanger 500, and a second outdoor evaporative heat exchanger 600.

In the circulation flow path 100, a flow direction of the refrigerant is switched depending on a cooling mode or a heating mode. Specifically, a flow path switching valve 700 may be disposed in the circulation flow path 100 to switch the flow direction of the refrigerant in the circulation flow path 100 depending on the cooling mode or the heating mode.

The flow path switching valve 700 is a four-way valve and may be disposed on a downstream side of the compressor 300, and may switch the flow direction of the refrigerant so that in the heating mode, the refrigerant passing through the compressor 300 may flow toward the indoor heat exchanger 200, and in the cooling mode, the refrigerant passing through the compressor 300 may flow toward the first outdoor heat exchanger 500 or the second outdoor evaporative heat exchanger 600. That is, in the heating mode, the refrigerant evaporated in the second outdoor evaporative heat exchanger 600 or the first outdoor heat exchanger 500 operating as an evaporator, may be compressed through the compressor 300, and the compressed high-temperature and high-pressure refrigerant may be condensed in the indoor heat exchanger 200 operating as a condenser, so that heat may be dissipated into an inner space, thereby performing heating operation. Additionally, in the cooling mode, the refrigerant may pass through the compressor 300 and may release heat from the first outdoor heat exchanger 500 or the second outdoor evaporative heat exchanger 600 operating as a condenser, and the refrigerant may pass through the first expansion valve 410 or the second expansion valve 420 and may absorb indoor heat and evaporate in the indoor heat exchanger 200 operating as an evaporator, thereby cooling operation the indoor space.

Additionally, the circulation flow path 100 includes a first connection flow path 110 arranged in parallel with the first outdoor heat exchanger 500. A first opening/closing valve V1 is disposed in the first connection flow path 110 configured to open and close a flow path to bypass the first outdoor heat exchanger 500.

Here, the first outdoor heat exchanger 500 may be made of various types of heat exchangers. The first outdoor heat exchanger 500 may be formed of a different type of heat exchanger from the second outdoor evaporative heat exchanger 600, and may be comprised of first outdoor air-cooling type heat exchangers 500a, 500b, 500c and 500d as illustrated in FIGS. 2 to 5.

As an example, as illustrated in FIG. 2, the first outdoor air-cooling type heat exchanger 500a may include a tube 510a through which refrigerant flows and a fin 520a disposed on the tube 510a. Here, the tube 510a may have a circular shape, and the fin 520a may be formed integrally with the tube 510a on an outer peripheral surface of the circular tube 510a and may be implemented as a structure in which a plurality of tubes 510a are spaced apart from each other in an extension direction of the tube 510a. That is, the first outdoor air-cooling type heat exchanger 500a may have a structure in which a plurality of tubes 510a penetrate through each of fins 520a.

Additionally, as another example, as illustrated in FIG. 3, the first outdoor air-cooling type heat exchanger 500b may include a tube 510b through which refrigerant flows and a fin 520b disposed on the tube 510b. Here, the tube 510b may have a flat shape, and the fins 520b may be formed integrally with the tube 510b on an outer peripheral surface of the flat tube 510b and may be implemented in a structure in which a plurality of fins 520b are spaced apart from each other in an extending direction of the tube 510b. That is, the first outdoor air-cooling type heat exchanger 500b may have a structure in which a plurality of tubes 510b penetrate through each of fins 520b.

The structure of the first outdoor air-cooling type heat exchangers 500a and 500b illustrated in FIGS. 2 and 3 may allow condensate to flow quickly when the condensate forms, so that heat transfer between outdoor air and the first outdoor air-cooling type heat exchangers 500a and 500b may be smoothly achieved, thereby performing rapid defrosting. However, the first outdoor heat exchanger 500 of the present invention is not limited to this example, and may be formed of various types and forms of heat exchangers as needed.

In another embodiment, as illustrated in FIG. 4, the first outdoor heat exchanger 500c may include a flat tube 510c in which refrigerant flow paths are formed and connected to each other or spaced apart from each other in a zigzag shape with a space therebetween, and a fin 520c disposed in a space of the flat tube 510c.

In another embodiment, as illustrated in FIG. 5, the first outdoor heat exchanger 500d may include a plurality of flat tubes 510d in which refrigerant flow paths are formed and spaced apart from each other with a space therebetween, and a fin 520d disposed in a space between the plurality of flat tubes 510d. Here, a plurality of partition walls 530d spaced apart from each other may be formed inside the flat tube 510d to form a refrigerant flow path provided with a plurality of micro channels through which the refrigerant flows.

In order for the second outdoor evaporative heat exchanger 600 to operate as an evaporative condenser in the cooling mode, a water injection module 610 including a spray portion configured to supply cooling water toward the second outdoor evaporative heat exchanger 600 may be disposed on an upper side or one side of the second outdoor evaporative heat exchanger 600, and also, a recovery module (not illustrated) including cooling water supplied through the water injection module 610 may be further disposed on a lower side of the second outdoor evaporative heat exchanger 600. Meanwhile, when the second outdoor evaporative heat exchanger 600 operates as an evaporator in the heating mode, the second outdoor evaporative heat exchanger 600 performs an evaporation operation by air cooling using the second outdoor evaporative heat exchanger 600 without water injection from the water injection module 610. The second outdoor evaporative heat exchanger 600 may have a structure including fins that prevent water from flowing down.

The second outdoor evaporative heat exchanger 600 may be an evaporative heat exchanger of various shapes, and for example, an evaporative condenser disclosed in published patents such as KR10-2019-0006781, KR10-2022-0074734, and KR10-2021-0070921 may be used, but the present disclosure is not limited thereto. By utilizing the second outdoor evaporative heat exchanger 600, the cooling performance of the heat pump 10 may be efficiently improved. Here, when the second outdoor evaporative heat exchanger 600 operates as an evaporator in the heating mode, the second outdoor evaporative heat exchanger 600 acts as an air-cooling type evaporator without water injection, and in this case, the evaporation efficiency may be insufficient due to the structure of the second outdoor evaporator heat exchanger 600 having a relatively small heat exchange area.

Accordingly, in order to improve heating efficiency in the heating mode, a structure in which the first outdoor heat exchanger 500 and the second outdoor evaporator heat exchanger 600 are disposed on the circulation flow path 100 is applied.

Here, in the heat pump 10, in the cooling mode, the indoor heat exchanger 200 operates as an evaporator and the first outdoor heat exchanger 500 or the second outdoor evaporative heat exchanger 600 operates as a condenser. Additionally, in the heat pump 10, in the heating mode, the indoor heat exchanger 200 operates as a condenser and the first outdoor heat exchanger 500 or the second outdoor evaporative heat exchanger 600 operates as an evaporator.

Specifically, if explained based on the heating mode, The heat pump 10 according to an embodiment of the present invention may include a circulation flow path 100, a compressor 300 configured to compress the refrigerant into a high-temperature and high-pressure gaseous refrigerant, an indoor heat exchanger 200 configured to heat the indoor air while allowing a refrigerant passing through the compressor 300 to exchanging heat with the indoor air and to be condensed into a medium-temperature and high-pressure liquid refrigerant and an indoor fan F1 blowing the indoor air toward the indoor heat exchanger 200, a first expansion valve 410 and a second expansion valve 420 configured to decompress the refrigerant passing through the indoor heat exchanger 200 to a low-temperature and low-pressure refrigerant, and a first outdoor heat exchanger 500 and a second outdoor evaporative heat exchanger 600 configured to allow the refrigerant passing through the first expansion valve 410 and the second expansion valve 420 to heat exchange with outdoor air and to be evaporated into a low-temperature and low-pressure gaseous refrigerant and an outdoor fan F2 blowing outdoor air toward the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600. In other words, the indoor heat exchanger 200, the compressor 300, the first expansion valve 410, the second expansion valve 420, the first outdoor heat exchanger 500, the second outdoor evaporative heat exchanger 600, and the flow path switching valve 700 may be disposed on the circulation flow path 100. Here, the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 may be implemented in a variety of operation manners as needed using the first expansion valve 410, the second expansion valve 420, the first connection flow path 110 in which the first opening/closing valve V1 is disposed, and a bypass flow path 120 in which a second opening/closing valve V2 to be described below is disposed, and at least one of the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 may operate.

Meanwhile, the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 may be disposed adjacently to each other. In this case, one outdoor fan F2 disposed between the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 may be included. Accordingly, the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 may share one outdoor fan F2, thereby compacting the structure of the heat pump 10 by and reducing manufacturing costs.

Furthermore, the second outdoor evaporative heat exchanger 600 may be disposed to be inclined at a certain angle from the vertical direction on the circulation flow path 100. Accordingly, the water injection may be performed by the water injection module 610 over a sufficient contact area of the second outdoor evaporative heat exchanger 600, thereby significantly increasing heat exchange efficiency. However, the present invention is not limited thereto, and if necessary, the first outdoor heat exchanger 500 may also be disposed to be inclined at a certain angle from the vertical direction on the circulation flow path 100. Specifically, the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 may be disposed to be inclined at a certain angle in a direction facing each other in the vertical direction on the circulation flow path 100. In other words, the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 may be disposed to be inclined at a certain angle from the vertical direction on the circulation flow path 100 toward the outdoor fan F2. According to this arrangement structure, heat exchange between the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 and outdoor air may be more smoothly performed by one outdoor fan F2, thereby further improving cooling performance. In this case, the water injection module 610 may be disposed on an outlet side of the second outdoor evaporative heat exchanger 600 in a flow direction of the refrigerant in the cooling mode. That is, the water injection module 610 may be disposed on the other side of the second outdoor evaporative heat exchanger 600, which is opposite to the one side facing the outdoor fan F2. Accordingly, the cooling performance of the second outdoor evaporative heat exchanger 600 may be improved, a water injection amount of the water injection module 610 may be reduced, and stable operation may be secured.

Additionally, the heat pump 10 according to an embodiment of the present invention may further include a gas-liquid separator 800 disposed on an upstream side of the compressor 300 in the flow direction of the refrigerant in both the cooling mode and the heating mode, and may serve to filter liquid refrigerant from the refrigerant flowing into 5 the compressor 300 by the gas-liquid separator 800. In other words, the gas-liquid separator 800 may be disposed on the circulation flow path 100 connected between the flow path switching valve 700 and the compressor 300, so that by changing the flow direction of the refrigerant by the flow path switching valve 700, the gas-liquid separator 800 may be disposed on the upstream side of the compressor 300 in both the cooling mode and the heating mode, and thus, since the refrigerant passing through the gas-liquid separator 800 may be allowed to flow into the compressor 300, thereby realizing a filtering effect for the refrigerant.

In the heat pump 10 of the present invention, the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 may be implemented in various arrangement structures.

In Embodiment 1 of the present invention, an arrangement shape in which the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 are arranged in series on the circulation flow path 100 will be described.

Specifically, referring to FIGS. 1 and 6 to 8, the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 may be connected in series on the circulation flow path 100. A first expansion valve 410 may be disposed between the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 on the circulation flow path 100. One end of the first connection flow path 110 on the circulation flow path 100 may be disposed between the first outdoor heat exchanger 500 and the first expansion valve 410, and the other end of the first connection flow path 110 may be disposed between the flow path switching valve 700 and the first outdoor heat exchanger 500. Additionally, a second expansion valve 420 may be disposed on one side of the second outdoor evaporative heat exchanger 600, which is opposite to the first expansion valve 410 on the circulation flow path 100. That is, based on the flow direction of the refrigerant in the heating mode on the circulation flow path 100, the second expansion valve 420, the second outdoor evaporative heat exchanger 600, the first expansion valve 410, and the first outdoor heat exchanger 500 are arranged sequentially. Furthermore, in order to selectively decompress the refrigerant flowing into the first outdoor heat exchanger 500, if necessary, the circulation flow path 100 may further include a bypass flow path 120 disposed in parallel with the first expansion valve 410. A second opening/closing valve V2 configured to open and close a flow path may be disposed in the bypass flow path 120 to bypass the first expansion valve 410.

Meanwhile, the present invention additionally provides a control method of the heat pump 10 according to Embodiment 1. That is, provided is the control method of the heat pump 10 in which a first outdoor heat exchanger 500 and a second outdoor evaporative heat exchanger 600 are disposed on the circulation flow path 100 in which the flow direction of the refrigerant is switched depending on the cooling mode or the heating mode, and the circulation flow path 100 includes a first connection flow path 110 configured to bypass the first outdoor heat exchanger 500. In a process in which in the heating mode, the refrigerant is evaporated while flowing through at least one of the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600, the control method of the heat pump 10 controls the refrigerant to be evaporated while flowing through the second outdoor evaporative heat exchanger 600 and the first connection flow path 110 when frost formation occurs in the first outdoor heat exchanger 500.

Specifically, in the heating mode, in the process in which the refrigerant is evaporated while flowing in the order of the second outdoor evaporative heat exchanger 600 and the first outdoor heat exchanger 500 connected in series on the circulation flow path 100, when the frost formation occurs in the first outdoor heat exchanger 500, the refrigerant is controlled to be evaporated while flowing through the second outdoor evaporative heat exchanger 600 and the first connection flow path 110.

Furthermore, in the heat pump 10 and the control method of the heat pump 10 according to Embodiment 1 of the present invention, the heating mode may include a first heating mode and a second heating mode. As illustrated in FIG. 6, in the first heating mode, the refrigerant may be evaporated while flowing in the order of the second outdoor evaporative heat exchanger 600 and the first outdoor heat exchanger 500. In other words, in the first heating mode, both the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 may be used to operate as an evaporator. Specifically, as illustrated in FIG. 6, in the first heating mode, the first opening/closing valve V1 on the first connection flow path 110 is closed to switch the flow direction of the refrigerant in the circulation flow path 100 by the flow path switching valve 700, so that the refrigerant may be evaporated while flowing in the order of the second outdoor evaporative heat exchanger 600 and the first outdoor heat exchanger 500.

In the first heating mode, various heating operations may be performed by controlling the evaporation performance of each of the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 as necessary.

As an example, in order to initially reach a target heating temperature in the first heating mode, both the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 may be used as evaporators. Specifically, in each of the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600, evaporation performance may be optimized by absorbing heat from the outdoor air and allowing both the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 to operate as evaporators while maintaining a constant temperature differential which is lower than a set temperature range, as compared with an outdoor air temperature. In this case, the refrigerant may be decompressed by the second expansion valve 420 and may pass through the second outdoor evaporative heat exchanger 600, and then, by opening the second opening/closing valve V2, the refrigerant may be evaporated while passing through the bypass flow path 120 configured to bypass the first expansion valve 410 and the first outdoor heat exchanger 500. The refrigerant evaporated while sequentially passing through the second outdoor evaporative heat exchanger 600 and the first outdoor heat exchanger 500 operating as such evaporators may be compressed through the compressor 300, and the compressed high-temperature and high-pressure refrigerant may be condensed in the indoor heat exchanger 200 operating as a condenser, thereby performing heating operation by releasing heat into the inner space. The refrigerant passing through the indoor heat exchanger 200 may flow back to the second outdoor evaporative heat exchanger 600 through the second expansion valve 420 and may be continuously circulated in the circulation flow path 100, thereby effectively improving overall heating performance of the heat pump 10. When the target heating temperature is reached by performing this heating operation method for a certain period of time, as illustrated in FIG. 6, the second outdoor evaporative heat exchanger 600 may operates as an evaporator in a state in which frost formation does not occur and may mainly operate as an evaporator using the evaporation performance of the first outdoor heat exchanger 500, thereby securing evaporation capacity corresponding to the heating load. Specifically, as illustrated in FIG. 6, the refrigerant may be decompressed to a certain temperature range which is lower than a set temperature range, as compared to the outdoor air temperature by the second expansion valve 420 and frost formation does not occur in the second outdoor evaporative heat exchanger 600, and may pass through the second outdoor evaporative heat exchanger 600, and then, by closing the second opening/closing valve V2, the refrigerant may pass through the first expansion valve 410 rather than the bypass flow path 120 and may be further decompressed to a certain temperature lower than the outdoor air temperature, so that the refrigerant may be evaporated while passing through the first outdoor heat exchanger 500, thereby sufficiently utilizing the capability of the first outdoor heat exchanger 500. Here, a degree of suction superheat of the compressor 300 may be secured through the first outdoor heat exchanger 500. When frost formation occurs in the first outdoor heat exchanger 500 after a certain period of time, in order to eliminate the frost formation of the first outdoor heat exchanger 500 because the evaporation performance of the first outdoor heat exchanger 500 is reduced, as illustrated in FIG. 7, a mode is switched to the second heating mode.

As illustrated in FIG. 7, in the second heating mode, the first opening/closing valve V1 on the first connection flow path 110 may be opened and the second opening/closing valve V2 on the bypass flow path 120 may be opened, and in the second heating mode, the refrigerant may be evaporated while flowing in the order of the second outdoor evaporative heat exchanger 600 and the first connection flow path 110. Specifically, the refrigerant may pass only through the second outdoor evaporative heat exchanger 600 and then pass through the bypass flow path 120 and the first connection flow path 110 to bypass the first outdoor heat exchanger 500. Accordingly, the first outdoor heat exchanger 500 may remove frost formation by an air inflow method of an external temperature above zero using the outdoor fan F2 or other heating means. In other words, while removing the frost formation occurring in the first outdoor heat exchanger 500 in the second heating mode, an evaporator operates using only the second outdoor evaporative heat exchanger 600, so that after the refrigerant is decompressed by the second expansion valve 420, and sequentially passes through the second outdoor evaporative heat exchanger 600, the bypass flow path 120, and the first connection flow path 110. In this case, while maintaining a temperature differential equal to or greater than the set temperature range with the outdoor air using the second outdoor evaporative heat exchanger 600, heating operation may secure the evaporation performance of the second outdoor evaporative heat exchanger 600.

When the frost formation of the first outdoor heat exchanger 500 is removed, both the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 operate as evaporators by switching back to the first heating mode. That is, the second outdoor evaporative heat exchanger 600 may be controlled to a certain temperature range in which the frost formation does not occur, and the second outdoor evaporative heat exchanger 600 may operate as an evaporator in a state in which the frost formation does not occur, and may mainly operate as an evaporator using the evaporation performance of the first outdoor heat exchanger 500, thereby securing the evaporation capacity corresponding to the heating load.

In the first heating mode, both the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 have been described as operating as evaporators, but the present invention is not limited thereto. As another example, the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 may be alternately operated as evaporators in the first heating mode, and a detailed description thereof will be omitted.

As described above, when heating operation is performed using the heating mode, in a process in which the refrigerant passing through the indoor heat exchanger 200 operating as a condenser passes through the second outdoor evaporative heat exchanger 600 and the first outdoor heat exchanger 500, each which acts as an evaporator, the refrigerant may be allowed to first pass through the second outdoor evaporative heat exchanger 600, and thus, the refrigerant pressure and refrigerant temperature may be higher in the second outdoor evaporative heat exchanger 600 than in the first outdoor heat exchanger 500, so that a relatively small amount of condensate may be generated to ensure sufficient contact between outdoor air and the second outdoor evaporative heat exchanger 600, and in a process in which the refrigerant passing through the second outdoor evaporative heat exchanger 600 passes through the first outdoor heat exchanger 500, a large amount of condensate may be induced to be generated, thereby securing heating performance. Specifically, condensate may flow quickly from the first outdoor heat exchanger 500 in which frost formation frequently occurs during defrosting, and even during the defrost operation, normal operations of continuous heating mode may be ensured. Additionally, the heating performance may be secured by performing various heating modes as needed.

Additionally, in the heat pump 10 and the control method of the heat pump 10 according to Embodiment 1 of the present invention, as illustrated in FIG. 8, in the cooling mode, both the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 may operate as condensers, so that the refrigerant may be controlled to be condensed while flowing in the order of the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 connected in series on the circulation flow path 100. In this process, cooling water may be controlled to be injected into the second outdoor evaporative heat exchanger 600.

Specifically, in the cooling mode, the first opening/closing valve V1 is closed and the second opening/closing valve V2 is opened. The flow direction of the refrigerant may be switched by the flow path switching valve 700, so that the refrigerant passing through the compressor 300 may be controlled to be condensed while flowing toward the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600. In other words, in the cooling mode, the flow direction of the refrigerant may be switched by the flow path switching valve 700, so that the refrigerant may be controlled to be circulated in the order of the compressor 300, the first outdoor heat exchanger 500, the second opening/closing valve V2, the second outdoor evaporative heat exchanger 600, the second expansion valve 420, the indoor heat exchanger 200, and the gas-liquid separator 800, on the circulation flow path 100. Accordingly, the refrigerant dissipating heat and condensing while passing through the first outdoor heat exchanger 500 operating as a condenser in the cooling mode may improve overall cooling performance by injecting cooling water into the second outdoor evaporative heat exchanger 600 operating as an evaporative condenser, through the water injection module 610.

Accordingly, according to the heat pump 10 and the control method thereof according to Embodiment 1 of the present invention, the refrigerant may be allowed to flow into the second outdoor evaporative heat exchanger 600 and/or the first outdoor heat exchanger 500 in the heating mode, heating efficiency may be improved by securing the evaporation efficiency of the refrigerant. Additionally, in the process of performing a defrost operation on the first outdoor heat exchanger 500 or the second outdoor evaporative heat exchanger 600, it may be possible to secure normal operation in a continuous heating mode and to secure the heating performance by performing various heating modes as needed. Additionally, in the cooling mode, the refrigerant may flow in the order of the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600, so that the refrigerant may be condensed more efficiently through water injection in the second outdoor evaporative heat exchanger 600, thereby improving the cooling efficiency effectively.

In this embodiment, the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 have been described by applying a structure in which the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 are arranged in series with each other on the circulation flow path 100, but the present disclosure is not limited thereto, and the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 may be connected to each other in parallel on the circulation flow path 100. In this regard, the configuration of the heat pump 20 according to Embodiment 2 will be described in detail below.

Embodiment 2

FIG. 9 is a schematic view illustrating the configuration of a heat pump according to Embodiment 2 of the present invention, FIG. 10 is a schematic view illustrating an operation process in a heating mode of a heat pump according to Embodiment 2 of the present invention, FIG. 11 is a schematic view illustrating another operation process in a heating mode of a heat pump according to Embodiment 2 of the present invention, and FIG. 12 is a schematic view illustrating another operation process in a heating mode of a heat pump according to Embodiment 2 of the present invention. FIG. 13 is a schematic view illustrating an operation process in a cooling mode of a heat pump according to Embodiment 2 of the present invention.

Referring to FIGS. 9 to 13, in a heat pump 20 according to Embodiment 2 of the present invention, other components except for an application of a structure in which the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 are connected in parallel on the circulation flow path 100 may be applied in the same manner as the components of Embodiment 1 above, and thus, in order to avoid duplication, detailed descriptions of the same components will be omitted.

As illustrated in FIG. 9, the heat pump 20 according to Embodiment 2 of the present invention may include a circulation flow path 100 including a first connection flow path 130 arranged in parallel with the first outdoor heat exchanger 500, an indoor heat exchanger 200, a compressor 300 configured to compress refrigerant into a high-temperature and high-pressure gaseous refrigerant, an indoor fan F1 blowing indoor air toward the indoor heat exchanger 200, a first expansion valve 410, a second expansion valve 420, a first outdoor heat exchanger 500, a second outdoor evaporative heat exchanger 600 including a water injection module 610 supplying cooling water, an outdoor fan F2 blowing outdoor air toward the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600, a flow path switching valve 700 configured to switch a flow direction of the refrigerant on the circulation path 100, and a gas-liquid separator 800 disposed on an upstream side of the compressor 300, and these components may be applied in the same manner as the corresponding components in Embodiment 1, and description thereof will be omitted.

In the heat pump 20 according to the second embodiment of the present invention, the second outdoor evaporative heat exchanger 600 and the second expansion valve 420 are disposed in the first connection flow path 130 of the circulation flow path 100. That is, in the first connection flow path 130, a second expansion valve 420, a second outdoor evaporative heat exchanger 600, and a first opening/closing valve V1 are sequentially disposed based on the flow direction of the refrigerant in the heating mode. In the heating mode, based on the flow direction of the refrigerant, one end of the first connection flow path 130 is disposed on a downstream side of the indoor heat exchanger 200 on the circulation flow path 100, and the other end of the first connection flow path 130 is disposed on an upstream side of the flow path switching valve 700.

Additionally, the circulation flow path 100 includes a second connection flow path 140 connected in parallel with the first connection flow path 130. The first outdoor heat exchanger 500 and the first expansion valve 410 are disposed in the second connection flow path 140. In other words, in the heating mode, the first expansion valve 410 and the first outdoor heat exchanger 500 are sequentially disposed in the second connection flow path 140 based on the flow direction of the refrigerant. In the heating mode, based on the direction of the refrigerant flow, on the circulation flow path 100, one end of the second connection flow path 140 is disposed on a downstream side of the indoor heat exchanger 200, and the other end of the second connection flow path 140 is disposed on an upstream side of the flow path switching valve 700.

In other words, in the heating mode, based on the direction of the refrigerant, both connected ends of the first connection flow path 130 and the second connection flow path 140 on the circulation flow path 100 are disposed on the downstream side of the indoor heat exchanger 200 and on the upstream side of the flow path switching valve 700, respectively.

Meanwhile, the present invention additionally provides a control method of the heat pump 20 according to Embodiment 2. In other words, provide is the control method of the heat pump 20 in which a flow direction of the refrigerant is switched depending on the cooling mode or the heating mode, and a first outdoor heat exchanger 500 and a second outdoor evaporative heat exchanger 600 are disposed on a circulation flow path 100 including a first connection flow path 130 and a second connection flow path 140. The control method of the heat pump 20 control the refrigerant to be evaporated while flowing through the second outdoor evaporative heat exchanger 600 and the first connection flow path 130 when frost formation occurs in the first outdoor heat exchanger 500, in the process in which in the heating mode, the refrigerant is evaporated while flowing through at least one of the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600.

Specifically, in the process in which in the heating mode, the refrigerant is evaporated while flowing through the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 connected in parallel on the circulation flow path 100, when the frost formation occurs in the first outdoor heat exchanger 500, the refrigerant is controlled to be evaporated so that the refrigerant does not flow into the second connection flow path 140 in which the first outdoor heat exchanger 500 is disposed, and flows through the first connection flow path 130 and the second outdoor evaporative heat exchanger 600.

Furthermore, the heat pump 20 and the control method of the heat pump 20 according to Embodiment 2 of the present invention may include a third heating mode and a fourth heating mode.

As illustrated in FIG. 10, in the third heating mode, the refrigerant may be controlled to be evaporated while flowing through the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600, respectively. In other words, in the third heating mode, both the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 may be used to operate as evaporators. Specifically, the first opening/closing valve V1 may be opened in the third heating mode, and the flow direction of the refrigerant in the circulation flow path 100 may be switched by the flow path change valve 700, so that the refrigerant may be controlled to be evaporated while flowing into the second connection flow path 140 in which the first outdoor heat exchanger 500 is disposed and the first connection flow path 130 in which the outdoor evaporative heat exchanger 600 is disposed, respectively. In each of the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 connected in parallel in the third heating mode, evaporation performance may be optimized by absorbing heat from the outdoor air and allowing both the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 to operate as evaporators while maintaining a constant temperature differential which is lower than the set temperature range, as compared to the outdoor air temperature. In this case, a portion of the refrigerant passing through the indoor heat exchanger 200 may be decompressed by the second expansion valve 420 in the process of flowing through the first connection flow path 130, may be evaporated while passing through the second outdoor evaporative heat exchanger 600, and may pass through the gas-liquid separator 800 and the flow path switching valve 700 without passing through the first outdoor heat exchanger 500, and may then flow into the compressor 300 and may be compressed, and the compressed high-temperature and high-pressure refrigerant may be condensed in the indoor heat exchanger 200 operating as a condenser, and heat may be dissipated into the inner space, thereby performing heating operation. At the same time, another portion of the refrigerant passing through the indoor heat exchanger 200 may be decompressed by the first expansion valve 410 in a process of flowing through the second connection flow path 140 and may be evaporated while passing through the first outdoor heat exchanger 500, may pass through the gas-liquid separator 800 and the flow path switching valve 700, and may then flow into the compressor 300 and may be compressed, and the compressed high-temperature and high-pressure refrigerant may be condensed in the indoor heat exchanger 200 operating as a condenser, and heat may be dissipated into the inner space, thereby performing heating operation. Here, by controlling the pressure and a flow rate of the refrigerant by the first expansion valve 410 and the second expansion valve 420, as compared to the outdoor air temperature, each of the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 may be controlled to have a constant temperature differential suitable for evaporation conditions which is lower than the set temperature range. Accordingly, the evaporation performance of each of the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 may be sufficiently utilized.

Additionally, as illustrated in FIGS. 11 and 12, in the fourth heating mode, the refrigerant may be evaporated while flowing alternately through the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 connected in parallel. In this case, when the outdoor air temperature is above freezing and the heating load is low, in order to continue heating operation, the first outdoor heat exchanger 500 and the second outdoor heat exchanger 600 may be operated alternately. Here, when operating the first outdoor heat exchanger 500, the first opening/closing valve V1 and the second expansion valve 420 are closed to block the inflow of refrigerant into the first connection flow path 130. In this case, the refrigerant passing through the indoor heat exchanger 200 may be decompressed by the first expansion valve 410 in a process of flowing through the second connection flow path 140, may be evaporated while passing through the first outdoor heat exchanger 500, and may pass through the gas-liquid separator 800 and the flow path switching valve 700, and may then flow into the compressor 300 and may be compressed, and the compressed high-temperature and high-pressure refrigerant may be condensed in the indoor heat exchanger 200 operating as a condenser, and heat may be dissipated into the inner space, thereby performing heating operation. Here, by controlling the pressure and a flow rate of the refrigerant by the first expansion valve 410, evaporation performance may be secured by allowing the refrigerant to pass only through the first outdoor heat exchanger 500. When frost formation occurs by performing heating operation for a certain period of time using the first outdoor heat exchanger 500, in order to block the refrigerant flowing into the first outdoor exchanger 500 because the evaporation performance of the first outdoor heat exchanger 500 is reduced, the first expansion valve 410 is closed and the first opening/closing valve V1 and the second expansion valve 420 are opened, so that the refrigerant may be allowed to pass through the second outdoor evaporative heat exchanger 600. Specifically, the refrigerant passing through the indoor heat exchanger 200 may be decompressed by the second expansion valve 420 in a process of flowing through the first connection flow path 130, may be evaporated while passing through the second outdoor evaporative heat exchanger 600, and may pass through the gas-liquid separator 800 and the flow path switching valve 700, and may then flow into the compressor 300 and may be compressed, and the compressed high-temperature and high-pressure refrigerant may be condensed in the indoor heat exchanger 200 operating as a condenser, and heat may be dissipated into the inner space, thereby performing heating operation. In this case, by controlling the pressure and a flow rate of the refrigerant by the second expansion valve 420, evaporation performance may be secured by allowing the refrigerant to pass through the second outdoor evaporative heat exchanger 600. The first outdoor heat exchanger 500 may remove frost formation by an air inflow method of an external temperature above zero using the outdoor fan F2 or other heating means. Accordingly, the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 may be operated independently and alternately, from which the evaporation capacity corresponding to the heating load may be secured.

Here, the control method of the heat pump 20 according to Embodiment 2 of the present invention was described in a manner in which in the fourth heating mode, the refrigerant is operated to be evaporated while flowing alternately through the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 connected in parallel, but the present disclosure is not limited thereto, and the heating operation may be performed using only the first outdoor heat exchanger 500 or the second outdoor evaporative heat exchanger 600 depending on the load and other needs.

Additionally, in the heat pump 20 and the control method of the heat pump 20 according to Embodiment 2 of the present invention, as illustrated in FIG. 13, in the cooling mode, both the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 connected in parallel may operate as condensers, so that on the circulation flow path 100, the refrigerant may be controlled to be condensed while flowing through the second connection flow path 140 in which the first outdoor heat exchanger 500 is disposed and the first connection flow path 130 in which the second outdoor evaporative heat exchanger 600 is disposed, respectively. In this process, the cooling water may be controlled to be injected into the second outdoor evaporative heat exchanger 600.

Specifically, in the cooling mode, the first opening/closing valve V1, the first expansion valve 410, and the second expansion valve 420 are opened. A portion of the refrigerant passing through the compressor 300 by switching the flow direction of the refrigerant by the flow path switching valve 700 may be condensed while passing through the second outdoor evaporative heat exchanger 600 in a process of flowing through the first connection flow path 130, and the condensed refrigerant may flow into the indoor heat exchanger 200 through the second expansion valve 420.

Another portion of the refrigerant passing through the compressor 300 by switching the flow direction of the refrigerant by the flow path switching valve 700 may be condensed while passing through the first outdoor heat exchanger 500 in the process of flowing through the second connection passage 140, and the condensed refrigerant may flow into the indoor heat exchanger 200 through the first expansion valve 410. Here, the cooling water may be injected into the second outdoor evaporative heat exchanger 600 operating as an evaporative condenser, thereby improving overall cooling performance. In the cooling mode, the flow rate of the refrigerant flowing into the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 may be controlled equally, and further, in order to allow more refrigerant to flow into the second outdoor evaporative heat exchanger 600 operating as an evaporative condenser, as needed, an opening degree of the first expansion valve 410 on the second connection flow path 140 may be adjusted so that a portion of the refrigerant flowing into the first outdoor heat exchanger 500 may be adjusted to flow into the second outdoor evaporative heat exchanger 600, thereby improving cooling performance.

Here, the control method of the heat pump 20 according to Embodiment 2 of the present invention was described in a manner in which both the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600 connected in parallel in the cooling mode operate as condensers, but the present disclosure is not limited thereto, and if necessary, cooling operation may be performed by selecting one of the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600, which may also fall within the scope of the present invention.

Accordingly, according to the heat pump and the control method thereof according to Embodiments 1 and 2 of the present invention, cooling and heating operation may be performed in various heating and cooling modes using the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600, and the cooling and heating performance of the heat pump may be improved. Additionally, by allowing the refrigerant to flow into the second outdoor evaporative heat exchanger 600 and/or the first outdoor heat exchanger 500 in the heating mode, heating efficiency may be improved by securing the evaporation efficiency of the refrigerant. Additionally, the normal operations of the continuous heating mode may be secured even during the process of performing a defrosting operation on the first outdoor heat exchanger 500 or the second outdoor evaporative heat exchanger 600. The heating performance may be secured by performing various heating modes as needed. Additionally, in the cooling mode, the refrigerant may be allowed to flow into the first outdoor heat exchanger 500 and the second outdoor evaporative heat exchanger 600, so that the refrigerant may be condensed more efficiently through water injection in the second outdoor evaporative heat exchanger 600, thereby improving cooling efficiency effectively.

Additionally, the above-described embodiments may be combined with each other as long as the technical contents do not contradict each other without departing from the technical spirit of the present invention, which may also fall within the scope of the present invention.

Number	Date	Country	Kind
10-2023-0085000	Jun 2023	KR	national
10-2023-0095395	Jul 2023	KR	national

HEAT PUMP AND CONTROL METHOD THEREOF

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