Heat pump device

Abstract

The present invention relates to a heat pump device and provides a heat pump device comprising: a compressor for compressing refrigerant; a switching valve for switching an operation mode; an outdoor heat exchanger that performs heat exchange between outdoor air and the refrigerant; an indoor heat exchanger that performs heat exchange between indoor air and the refrigerant; an expansion valve for expanding the refrigerant; and a gas-liquid separator that is installed inside the outdoor heat exchanger and, depending on the operation mode, separates gas-phase refrigerant from two-phase refrigerant or guides the refrigerant to the outdoor heat exchanger to defrost the outdoor heat exchanger.

Description

heat pump device

[0001] The present invention relates to a heat pump device, and more particularly, to a heat pump device that applies a vapor-liquid separator capable of separating a liquid refrigerant and a vapor refrigerant by utilizing the flow characteristics of the refrigerant.

[0002]

[0003] In general, a heat pump device is a device that incorporates a cooling cycle and a heating cycle into the same unit, so that cooling and heating are performed simultaneously. It is a device that performs cooling through a cooling cycle in the summer with one unit, and performs heating and hot water supply by switching to the reverse cycle in the winter.

[0004] In particular, when the heat pump device is powered on, the compressor and indoor and outdoor fans are driven, the refrigerant flowing in from the evaporator is compressed and the high-temperature, high-pressure refrigerant is supplied to the condenser, the refrigerant condensed into a liquid in the condenser is expanded through an expansion valve and reintroduced into the evaporator as a two-phase refrigerant of liquid and gas phases, and the refrigerant in the gas phase that has been phase-changed into a gas phase in the evaporator is circulated to the compressor, forming a refrigerant cycle.

[0005] Conventional heat pumps, when operating in a radiant mode, can suffer from frost formation on the outdoor heat exchanger, which degrades its heat exchange performance as moisture in the air passing through the outdoor heat exchanger, condensing and freezing. This, in turn, significantly reduces the heating efficiency of the heat pump.

[0006] To address these issues, conventional heat pumps, when defrosting is required, operate as a cooling circuit by switching a switching valve, operating the outdoor unit as a condenser and the indoor unit as an evaporator. This allows high-temperature, high-pressure liquid refrigerant to flow into the outdoor unit, removing frost formed on the outdoor heat exchanger.

[0007] However, since the heating operation is performed again in the defrosting operation mode of the cooling operation that defrosts the evaporator that has been conceived, there was a problem that the heating performance was reduced because further heating supply was not easy.

[0008] In addition, there was a problem that the high-temperature refrigerant discharged from the compressor was directly supplied to the outdoor heat exchanger, and as the temperature of the refrigerant decreased toward the inlet during heating operation and toward the outlet during cooling operation, the defrosting operation mode did not operate normally at the end of the outdoor heat exchanger, resulting in a long defrosting operation time.

[0009] In addition, conventional heat pump devices have problems in that, when in heating operation mode in low-temperature cold regions, they operate at a high compression ratio of the compressor, which may cause the discharge temperature to rise excessively and damage internal components, the density of the refrigerant is lower than that at room temperature, which reduces the flow rate of the refrigerant, and the specific volume increases, which increases the pressure loss of the refrigerant, thereby lowering the heating performance.

[0010]

[0011] The purpose of the present invention is to provide a heat pump device that can maximize heating performance by increasing the bypass flow rate of gaseous refrigerant by applying a plurality of gas-liquid separators to an outdoor heat exchanger and bypassing the gaseous refrigerant to a compressor without pressure loss of the refrigerant during heating operation mode.

[0012] In addition, the purpose of the present invention is to provide a heat pump device that can shorten the defrosting operation time and improve the defrosting efficiency by supplying the high-temperature refrigerant discharged from the compressor to the entire internal flow path of the outdoor heat exchanger by applying a refrigerant guide flow path having a plurality of flow paths in the defrosting operation mode.

[0013]

[0014] In order to achieve the above purpose, the heat pump device according to the present invention is characterized in that it maximizes heating performance by increasing the bypass flow rate of the gaseous refrigerant in the outdoor heat exchanger, thereby bypassing the gaseous refrigerant to the compressor without pressure loss of the refrigerant.

[0015] In addition, the present invention is characterized in that it can shorten the defrosting operation time by applying a refrigerant guide passage having multiple passages to an outdoor heat exchanger to supply high-temperature refrigerant discharged from a compressor to the entire passage inside the outdoor heat exchanger.

[0016] A heat pump device according to an embodiment of the present invention may include a compressor for compressing a refrigerant; a switching valve for switching an operation mode; an outdoor heat exchanger for performing heat exchange between outdoor air and a refrigerant; an indoor heat exchanger for performing heat exchange between indoor air and a refrigerant; an expansion valve for expanding the refrigerant; and a gas-liquid separator installed inside the outdoor heat exchanger and separating a gaseous refrigerant among two-phase refrigerants depending on the operation mode or guiding the refrigerant to the outdoor heat exchanger for defrosting the outdoor heat exchanger.

[0017] According to an embodiment of the present invention, the gas-liquid separator may include a refrigerant guide path that separates a gaseous refrigerant from the two-phase refrigerant supplied to the outdoor heat exchanger and guides it to the compressor in a heating operation mode, or guides a high-temperature refrigerant discharged from the compressor into the interior of the outdoor heat exchanger in a defrosting operation mode.

[0018] According to an embodiment of the present invention, the refrigerant guide path may include a first path connected to a refrigerant path between the switching valve and the outdoor heat exchanger, and a plurality of second paths branched from the first path and connected in parallel to a path inside the outdoor heat exchanger.

[0019] According to an embodiment of the present invention, the second flow path can be connected to the refrigerant pipes inside the outdoor heat exchanger so that gas and liquid can be separated at the inlet and outlet sides of the outdoor heat exchanger during the heating operation mode.

[0020] According to an embodiment of the present invention, in the second flow path, when the refrigerant flowing in the refrigerant pipe inside the outdoor heat exchanger flows into the refrigerant flow path in the heating operation mode, a portion of the refrigerant can be distributed.

[0021] According to an embodiment of the present invention, the two-phase refrigerant flowing through the refrigerant pipe inside the outdoor heat exchanger can flow in an annular flow pattern.

[0022] According to an embodiment of the present invention, the refrigerant guide path can be installed at a position corresponding to a dryness range of 0.4 to 0.6 of the two-phase refrigerant flowing inside the outdoor heat exchanger.

[0023] According to an embodiment of the present invention, the outdoor heat exchanger may include a plurality of refrigerant pipes and a plurality of fins connected to the plurality of refrigerant pipes.

[0024] According to an embodiment of the present invention, the system may further include a bypass passage that guides the refrigerant flowing through the outdoor heat exchanger or the indoor heat exchanger, which functions as an evaporator, to the compressor; a flow control valve installed in the bypass passage that controls the flow rate of the refrigerant; and a subcooler that superheats the refrigerant flowing through the bypass passage.

[0025]

[0026] According to the heat pump device according to the present invention having the configuration described above, there is an effect of maximizing heating performance by increasing the bypass flow rate of the gaseous refrigerant in the outdoor heat exchanger and bypassing the gaseous refrigerant to the compressor without pressure loss of the refrigerant.

[0027] In addition, by applying a refrigerant guide path having multiple paths to the outdoor heat exchanger to supply the high-temperature refrigerant discharged from the compressor to the entire path inside the outdoor heat exchanger, the defrosting operation time can be shortened, and there is an effect of enabling continuous heating operation without a time delay when switching to heating operation mode after defrosting operation.

[0028] By eliminating the need for suction pipes and valves installed between the conventional outdoor heat exchanger and the compressor, there is no risk of compressor failure and the effect of reducing parts is achieved.

[0029]

[0030] Figure 1 is a schematic diagram showing a heat pump device according to an embodiment of the present invention.

[0031] Figure 2 is a cycle diagram showing a heating operation mode of a heat pump device according to an embodiment of the present invention.

[0032] Figure 3 is a cycle diagram showing the defrosting operation mode of a heat pump device according to an embodiment of the present invention.

[0033] Figure 4 is an experimental result graph showing the defrosting performance of a heat pump device according to an embodiment of the present invention.

[0034]

[0035] Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. However, the spirit of the present invention is not limited to the presented embodiments, and those skilled in the art who understand the spirit of the present invention will be able to easily propose other embodiments within the scope of the same spirit by adding, deleting, modifying, or adding components, etc., but these will also be considered to be within the scope of the present invention.

[0036] When assigning reference numerals to components in each drawing, it should be noted that identical components are assigned the same numerals whenever possible, even if they appear on different drawings. Furthermore, when describing embodiments of the present invention, if a detailed description of a related known configuration or function is deemed to hinder understanding of the embodiments of the present invention, the detailed description will be omitted.

[0037] Additionally, terms such as first, second, A, B, (a), (b), etc. may be used to describe components of embodiments of the present invention. These terms are only intended to distinguish the components from other components, and the nature, order, or sequence of the components are not limited by the terms. When it is described that a component is "connected," "coupled," or "connected" to another component, it should be understood that the component may be directly connected or connected to the other component, but another component may also be "connected," "coupled," or "connected" between each component.

[0038] FIG. 1 is a schematic diagram showing a heat pump device according to an embodiment of the present invention, FIG. 2 is a cycle diagram showing a heating operation mode of a heat pump device according to an embodiment of the present invention, and FIG. 3 is a cycle diagram showing a defrosting operation mode of a heat pump device according to an embodiment of the present invention.

[0039] Before explaining with reference to the drawings of the present invention, a heat pump device including an outdoor unit and an indoor unit in which an air conditioning phenomenon occurs will be described.

[0040]

[0041] [Heat pump device configuration]

[0042] The heat pump device (100) includes an indoor unit and an outdoor unit. The indoor unit in the heat pump device (100) may be a stand-alone type, a wall-mounted type, or a ceiling-mounted type. However, the indoor unit is not limited to a stand-alone type, a wall-mounted type, or a ceiling-mounted type, and may be adopted in various shapes and installed indoors.

[0043] The outdoor unit is connected to the indoor unit and can deliver the refrigerant needed to condition the air in the indoor unit. The indoor unit can perform heat exchange between the delivered refrigerant and the air, and discharge the heat-exchanged air into the room.

[0044] The indoor and outdoor units are connected to each other through a refrigerant passage (200), so that the refrigerant can circulate between the indoor and outdoor units through the refrigerant passage (200).

[0045] Depending on the circulation of the refrigerant, high-temperature or low-temperature air can be discharged indoors from an indoor unit operating in heating or cooling mode. At this time, the outdoor unit can be connected to at least one indoor unit.

[0046] As illustrated in FIG. 1, a heat pump device (100) including an indoor unit and an outdoor unit may include a compressor (110), a switching valve (120), an indoor heat exchanger (130), an outdoor heat exchanger (140), an expansion mechanism (150), a flow control valve (160), a supercooler (170), and an accumulator (180).

[0047] A heat pump device (100) according to an embodiment of the present invention may be fluidly connected to a working fluid. For example, the working fluid may include a refrigerant. Here, the refrigerant may flow so as to pass through each component and circulate through a refrigerant passage (200).

[0048] Here, the refrigerant can be used as R410A, which has low condensing and evaporating temperatures and high efficiency in relatively low-temperature areas.

[0049] The compressor (110) can compress the refrigerant to high temperature and high pressure. As an example of such a compressor (110), it may be a scroll compressor configured to compress the refrigerant by the relative phase difference between a fixed scroll and a rotating scroll, or a reciprocating compressor configured to compress the refrigerant using a cylinder and a piston.

[0050] The indoor heat exchanger (130) can function as a condenser that condenses the refrigerant that has passed through the compressor (110) or as an evaporator that evaporates the refrigerant.

[0051] The outdoor heat exchanger (140) can function as an evaporator that evaporates the refrigerant that has passed through the indoor heat exchanger (130) and the expansion device, or as a condenser that condenses the refrigerant.

[0052] The outdoor heat exchanger (140) may be configured as a fin-tube type heat exchanger. The outdoor heat exchanger (140) may include a refrigerant pipe (141) formed of a plurality of tubes and a plurality of fins connected to the plurality of refrigerant pipes (141). The refrigerant pipe (141) is formed of a zigzag-shaped tube.

[0053] The expansion device (150) may be an expansion valve that can reduce the pressure of the refrigerant that has passed through the outdoor heat exchanger (140) to a pressure that can cause evaporation by expanding it, and at the same time, supply an appropriate amount of refrigerant that can absorb sufficient heat in the evaporator.

[0054] Here, the first expansion valve (151) may be installed in the refrigerant passage (200) between the subcooler (170) and the outdoor heat exchanger (140). The second expansion valve (152) may be installed in the refrigerant passage (200) between the subcooler (170) and the indoor heat exchanger (130).

[0055] The first expansion valve (151) and the second expansion valve (152) can be opened and closed to expand or not expand the refrigerant flowing through the refrigerant passage (200) by adjusting the opening amount. For example, when the heat pump device (100) is operated in the heating operation mode, the second expansion valve (152) is fully opened so as not to expand the refrigerant that has passed through the indoor heat exchanger (130), and the first expansion valve (151) can be opened only partially so as to adjust the opening amount so as to expand the refrigerant that has passed through the indoor heat exchanger (130).

[0056] Additionally, when the heat pump device (100) operates in the cooling operation mode and the defrosting operation mode, the outdoor heat exchanger (140) can function as a condenser and the indoor heat exchanger (130) can function as an evaporator.

[0057] When the heat pump device (100) operates in the cooling operation mode and the defrosting operation mode, the refrigerant can circulate in the order of the compressor (110), the outdoor heat exchanger (140), the expansion device (150), the indoor heat exchanger (130), the accumulator (180), and the compressor (110).

[0058] On the other hand, when the heat pump device (100) is operated in heating operation mode, the outdoor heat exchanger (140) can function as an evaporator and the indoor heat exchanger (130) can function as a condenser.

[0059] When the heat pump device (100) operates in heating operation mode, the refrigerant can circulate in the order of the compressor (110), indoor heat exchanger (130), expansion device (150), outdoor heat exchanger (140), accumulator (180), and compressor (110).

[0060] In this way, the heat pump device (100) may be a device capable of both cooling and heating operation.

[0061]

[0062] [Heating operation mode of heat pump device]

[0063] FIG. 2 illustrates a case where a heat pump device (100) is operated in a heating operation mode. Referring to FIG. 2, when the heat pump device (100) is operated in a heating operation mode, the indoor heat exchanger (130) can function as a condenser and the outdoor heat exchanger (140) can function as an evaporator. In addition, the outdoor unit can include a compressor (110), a switching valve (120), a subcooler (170), and an accumulator (180).

[0064] The switching valve (120) can direct the flow of refrigerant discharged from the compressor (110) to either the indoor heat exchanger (130) or the outdoor heat exchanger (140). As an example, the switching valve (120) can be a four-way valve having four flow paths. The switching valve (120) can have three outlets for one inlet, or can have two inlets and two outlets. For example, when one inlet and outlet are selected and the refrigerant flows, the refrigerant can also flow through the remaining inlets and outlets, or the refrigerant can be prevented from flowing.

[0065] Additionally, if the outlet is changed for one inlet, the refrigerant flow path is changed, and the refrigerant paths of the remaining inlets and outlets can also be converted. In other words, the refrigerant flow path can be switched.

[0066] Referring to the attached drawing, in the indoor heating operation mode, the switching valve (120) can be adjusted so that the refrigerant discharged from the compressor (110) is guided to the indoor heat exchanger (130), and in the indoor cooling operation mode, the switching valve (120) can be adjusted so that the refrigerant discharged from the compressor (110) is guided to the outdoor heat exchanger (140).

[0067] An accumulator (180) is a gas-liquid separator capable of separating a gaseous refrigerant from a two-phase refrigerant including a liquid refrigerant and a gaseous refrigerant. The separated gaseous refrigerant can be supplied to a compressor (110). The accumulator (180) can prevent a decrease in efficiency due to liquid intrusion into the compressor (110).

[0068] The liquid refrigerant separated from the accumulator (180) can be accommodated in the lower portion of the accumulator (180), and the gaseous refrigerant can be placed above the separated liquid refrigerant. The gaseous refrigerant separated from the accumulator (180) can flow to the compressor (110), and the liquid refrigerant separated from the accumulator (180) can remain in the accumulator (180).

[0069] When the heat pump device (100) operates in heating operation mode, the refrigerant passes through the compressor (110) and the indoor heat exchanger (130), is expanded in the first expansion valve (151), and can exchange heat with the outdoor air in the outdoor heat exchanger (140). At this time, the second expansion valve (152) is fully open, and the opening amount of the first expansion valve (151) can be adjusted to expand the refrigerant.

[0070] Specifically, when the heat pump device (100) operates in a heating operation mode, the refrigerant discharged from the compressor (110) can flow to the indoor heat exchanger (130) by the switching valve (120). The refrigerant condensed in the indoor heat exchanger (130) can flow to the outdoor heat exchanger (140) after being supercooled in the supercooler (170).

[0071] As an example, the refrigerant condensed in the indoor heat exchanger (130) may flow through the refrigerant passage (200). The refrigerant may flow to the subcooler (170) through the refrigerant passage (200). In addition, the refrigerant that has passed through the subcooler (170) may flow to the outdoor heat exchanger (140) that functions as an evaporator through the refrigerant passage (200). Here, the refrigerant flowing through the refrigerant passage (200) is referred to as the primary refrigerant.

[0072] In order to supply refrigerant to the compressor (110), some refrigerant may be branched from the primary refrigerant through the bypass passage (210). The refrigerant branched from the primary refrigerant is referred to as secondary refrigerant. In other words, the secondary refrigerant may be refrigerant flowing along the bypass passage (210).

[0073] A flow control valve (160) can be installed in a bypass path (210), and the amount of secondary refrigerant flowing in the bypass path (210) can be determined by adjusting the opening amount of the flow control valve (160).

[0074] When the flow control valve (160) is open, the secondary refrigerant can flow to the subcooler (170) through the bypass path (210), and can be discharged from the subcooler (170) and flow to the compressor (110). At this time, the secondary refrigerant discharged from the subcooler (170) can be introduced into the compressor (110).

[0075] The primary refrigerant flowing in the refrigerant passage (200) can flow through a plurality of internal pipes within the subcooler (170), and the secondary refrigerant can flow through the external pipe. At this time, the internal pipes are arranged in the inner space of the subcooler (170), and the primary refrigerant flowing in the internal pipes can exchange heat with the secondary refrigerant flowing in the external pipes. Specifically, the secondary refrigerant can be expanded by the flow control valve (160) to have a lower temperature and lower pressure than the primary refrigerant, and the secondary refrigerant changed to a lower temperature and lower pressure can exchange heat with the primary refrigerant flowing in the internal pipes while flowing in the external pipes. At this time, the primary refrigerant can be subcooled, and the secondary refrigerant can be superheated. The subcooled primary refrigerant can flow to the outdoor heat exchanger (140) through the refrigerant passage (200). The outdoor heat exchanger (140) can evaporate liquid refrigerant into gaseous refrigerant through heat exchange with outdoor air. That is, the outdoor heat exchanger (140) can function as an evaporator.

[0076] The heat pump device (100) according to the present invention may include a vapor-liquid separator (300). Here, the vapor-liquid separator (300) is installed inside an outdoor heat exchanger (140), and may separate the vapor-liquid refrigerant from the liquid-liquid refrigerant and guide it to a compressor (110) in the outdoor heat exchanger (140). The vapor-liquid separator (300) may include a refrigerant guide passage (310) that guides the vapor-liquid refrigerant to the compressor (110).

[0077] Meanwhile, the refrigerant guide path (310) in the heating operation mode can be connected to the refrigerant path (200) that guides the gaseous refrigerant of the outdoor heat exchanger (140) to the compressor (110). At this time, the liquid refrigerant and gaseous refrigerant can be separated from the two-phase refrigerant by the gas-liquid separator (300), and the separated gaseous refrigerant can be guided to the compressor (110).

[0078] In a gas-liquid separator (300) like this, the flow pattern of the two-phase refrigerant may vary depending on the dryness and flow rate.

[0079] The vapor-liquid separator (300) can separate the liquid refrigerant and vapor refrigerant by allowing the liquid refrigerant to flow along the wall of the refrigerant passage (200) and the vapor refrigerant to flow in the center of the inside of the liquid refrigerant, respectively, when a certain dryness and a certain flow rate are secured. The flow pattern in which the liquid refrigerant and vapor refrigerant are separated and flow within the refrigerant passage (200) is called annular flow.

[0080] When annular flow occurs, the liquid refrigerant in the refrigerant passage (200) may flow toward the wall of the passage, and the gaseous refrigerant may flow toward the inner center of the liquid refrigerant flowing through the refrigerant passage (200). Through this, the gaseous refrigerant may be separated from the two-phase refrigerant flowing within the outdoor heat exchanger (140) and may flow toward a connecting passage (not shown) and a header (not shown). At this time, not only the gaseous refrigerant but also a small amount of the liquid refrigerant may flow toward the connecting passage and the header.

[0081] The gaseous refrigerant separated from the two-phase refrigerant flowing inside the outdoor heat exchanger (140) flows to the compressor (110) through the refrigerant guide passage (310), and the liquid refrigerant that is not separated can be bypassed.

[0082] Previously, a heat pump device was proposed that connected a suction pipe to the suction end of an outdoor heat exchanger and a compressor and additionally installed a valve in the pipe. However, the conventional method had a disadvantage in that, when the valve failed, there was no configuration to block the refrigerant, so liquid refrigerant penetrated into the compressor, resulting in a decrease in performance or even a failure of the compressor due to the liquid intrusion.

[0083] The refrigerant guide passage (310) connected to the gas-liquid separator (300) includes a first passage (311) connected to the refrigerant passage (200) between the switching valve (120) and the outdoor heat exchanger (140), and a second passage (312) branched from the first passage (311) and connected to the refrigerant passage (200) of the gas-liquid separator (300) inside the outdoor heat exchanger (140). That is, the second passage (312) of the refrigerant guide passage (310) is connected to the inlet side (lower part) and the outlet side (upper part) of the outdoor heat exchanger (140), respectively, so that when a multi-stage (two-stage) gas-liquid separation technology is applied, the flow rate of the gaseous refrigerant can be increased compared to the past, thereby preventing performance degradation or compressor failure due to liquid intrusion and improving cold region performance.

[0084] This refrigerant guide path (310) is installed at a position corresponding to a dryness range of 0.4 to 0.6 of the two-phase refrigerant flowing inside the outdoor heat exchanger (140), and the above-mentioned dryness range can be understood as a dryness point where an annular flow is formed.

[0085] Since the refrigerant guide passage (310) is composed of a plurality of second passages (312), when the gaseous refrigerant separated by the gas-liquid separator (300) inside the outdoor heat exchanger (140) is discharged from the outdoor heat exchanger (140), some of it is distributed to the second passage (312) on the inlet side and discharged, and the remainder is distributed to the second passage (312) on the outlet side and discharged.

[0086] And, all gaseous refrigerants except for the gaseous refrigerant discharged through the refrigerant guide channel (310) can be discharged through the refrigerant passage (200) connected to the refrigerant pipe (141) inside the outdoor heat exchanger (140) and guided to the compressor (110).

[0087] As the flowing refrigerant flow rate undergoes gas-liquid separation in the gas-liquid separator (300), the total refrigerant flow rate flowing through the refrigerant passage (200) and the refrigerant guide passage (310) connected in parallel from the refrigerant pipe (141) of the outdoor heat exchanger (140) increases, so the outlet pressure of the refrigerant guide passage (310) and the suction pressure and suction density of the compressor (110) decrease. Accordingly, by bypassing the gaseous refrigerant to the compressor (110) without any pressure loss of the refrigerant, the heating performance can be maximized in the heating operation mode.

[0088] In addition, the total refrigerant flow rate flowing through the outdoor heat exchanger (140) increases, so cold region performance can be improved.

[0089]

[0090] [Heat pump device defrost operation mode]

[0091] FIG. 3 illustrates a case where the heat pump device (100) is operated in a defrosting operation mode. Referring to FIG. 3, when the heat pump device (100) is operated in a defrosting operation mode, i.e., a cooling operation mode, the outdoor heat exchanger (140) can function as a condenser and the indoor heat exchanger (130) can function as an evaporator.

[0092] The switching valve (120) can direct the flow of refrigerant discharged from the compressor (110) to an outdoor heat exchanger. In addition, the accumulator (180) can separate the gaseous refrigerant from the two-phase refrigerant including the liquid refrigerant and the gaseous refrigerant.

[0093] When the heat pump device (100) operates in the defrost operation mode, the refrigerant passes through the compressor (110) and the outdoor heat exchanger (140), expands in the second expansion valve (152), and can exchange heat with indoor air in the indoor heat exchanger (130). At this time, the first expansion valve (151) is fully open, and the opening amount of the second expansion valve (152) can be adjusted to expand the refrigerant.

[0094] Specifically, when the heat pump device (100) operates in the defrost operation mode, the refrigerant discharged from the compressor (110) can flow to the outdoor heat exchanger (140) by the switching valve (120). The refrigerant condensed in the outdoor heat exchanger (140) can flow to the indoor heat exchanger (130) after being supercooled in the supercooler (170).

[0095] The refrigerant condensed in the outdoor heat exchanger (140) can flow through the refrigerant passage (200). The refrigerant can flow to the subcooler (170) through the refrigerant passage (200). In addition, the refrigerant that has passed through the subcooler (170) can flow to the indoor heat exchanger (130) that functions as an evaporator through the refrigerant passage (200). Here, the refrigerant flowing through the refrigerant passage (200) is referred to as the primary refrigerant.

[0096] In order to supply refrigerant to the compressor (110), some refrigerant may be branched from the primary refrigerant through the bypass passage (210). The refrigerant branched from the primary refrigerant is referred to as secondary refrigerant. In other words, the secondary refrigerant may be refrigerant flowing along the bypass passage (210).

[0097] A flow control valve (160) can be installed in a bypass path (210), and the amount of secondary refrigerant flowing in the bypass path (210) can be determined by adjusting the opening amount of the flow control valve (160).

[0098] When the flow control valve (160) is open, the secondary refrigerant can flow to the subcooler (170) through the bypass path (210), and can be discharged from the subcooler (170) and flow to the compressor (110). At this time, the secondary refrigerant discharged from the subcooler (170) can be introduced into the compressor (110).

[0099] The primary refrigerant flowing in the refrigerant passage (200) can flow through a plurality of internal pipes within the subcooler (170), and the secondary refrigerant can flow through the external pipe. At this time, the internal pipes are arranged in the inner space of the subcooler (170), and the primary refrigerant flowing in the internal pipes can exchange heat with the secondary refrigerant flowing in the external pipes. Specifically, the secondary refrigerant can be expanded by the flow control valve (160) to have a lower temperature and lower pressure than the primary refrigerant, and the secondary refrigerant changed to a lower temperature and lower pressure can exchange heat with the primary refrigerant flowing in the internal pipes while flowing in the external pipes. At this time, the primary refrigerant can be subcooled, and the secondary refrigerant can be superheated. The subcooled primary refrigerant can flow to the indoor heat exchanger (130) through the refrigerant passage (200). The indoor heat exchanger (130) can evaporate liquid refrigerant into gaseous refrigerant through heat exchange with indoor air. That is, the indoor heat exchanger (130) can function as an evaporator.

[0100] According to the heat pump device of the present invention, when the outdoor temperature is low and the heating operation mode is performed, moisture in the air passing through the outdoor heat exchanger (140) used as an evaporator condenses and freezes, causing frost to form on the outdoor heat exchanger (140), thereby lowering the heat exchange performance of the outdoor heat exchanger (140) and significantly reducing the heating efficiency of the heat pump device (100).

[0101] The present invention aims to solve the problem of reduced heating efficiency by performing a defrosting operation mode for an outdoor heat exchanger (140) to remove frost that has formed on the outdoor heat exchanger (140).

[0102] The heat pump device (100) according to the present invention may include a gas-liquid separator (300). The gas-liquid separator (300) is installed inside the outdoor heat exchanger (140) and guides the high-temperature gaseous refrigerant (hot gas) discharged from the compressor (110) to the outdoor heat exchanger (140) to remove frost formed inside the outdoor heat exchanger (140). Here, the gas-liquid separator (300) does not apply a gas-liquid separation technology for separating the gaseous refrigerant among the two-phase refrigerants in the defrosting operation mode, but only exhibits the performance of a path that guides the high-temperature refrigerant of the compressor (110) into the inside of the outdoor heat exchanger (140).

[0103] The vapor-liquid separator (300) may include a refrigerant guide channel (310). Meanwhile, the refrigerant guide channel (310) in the defrost operation mode may be connected to a refrigerant channel (200) that guides the refrigerant discharged from the compressor (110) to the outdoor heat exchanger (140). At this time, the refrigerant that passes through the refrigerant guide channel (310) and flows into the vapor-liquid separator (300) may be connected to and guided by a plurality of refrigerant pipes (141) inside the outdoor heat exchanger (140).

[0104] The refrigerant guide path (310) connected to the gas-liquid separator (300) includes a first path (311) connected to the refrigerant path (200) between the switching valve (120) and the outdoor heat exchanger (140), and a second path (312) branched from the first path (311) and connected in parallel to the refrigerant pipe (141) inside the outdoor heat exchanger (140).

[0105] This refrigerant guide passage (310) is composed of a second passage (312) and multiple passages. Accordingly, when high-temperature gaseous refrigerant is guided into the outdoor heat exchanger (140), it can be configured to be guided through the refrigerant pipe (141) connected to the inlet side (upper part) and the outlet side (lower part) of the outdoor heat exchanger (140) connected to the second passage (312).

[0106] The refrigerant flowing along the refrigerant guide passage (310) can easily perform defrosting and shorten the defrosting operation time because the flow rate increases throughout the refrigerant pipe (141) of the outdoor heat exchanger (140), thereby causing the refrigerant to flow. At this time, the frost formed inside the outdoor heat exchanger (140) changes into water and remains in the lower part of the outdoor heat exchanger (140), and the refrigerant flowing through the second passage (312) of the refrigerant guide passage (310) provided at the outlet side of the outdoor heat exchanger (140) can dry the water remaining inside the outdoor heat exchanger (140). Accordingly, there is an effect of completely removing not only the frost that impedes the performance of the heat exchanger but also the water inside the outdoor heat exchanger (140).

[0107] FIG. 4 is an experimental result graph showing the refrigerant evaporation temperature versus the operating time of the heat pump device (100) according to an embodiment of the present invention.

[0108] Referring to the attached drawing, the evaporation temperature of the heat pump device (100) of both the present invention and the prior art is the same at approximately 14°C, and the heating capacity is the same at approximately 17.5 kW.

[0109] However, in both the present invention and the prior art, although the defrosting operation begins at approximately 33 minutes of the operation time of the heat pump device (100), the prior art completes the defrosting operation in approximately 41 minutes. On the other hand, the present invention completes the defrosting operation in approximately 39 minutes.

[0110] Compared to the prior art, the present invention can shorten the defrosting operation time by several minutes, thereby enabling continuous heating without time delay when switching to heating operation mode after defrosting operation.

[0111] Accordingly, the embodiment of the present invention can maximize heating performance by increasing the bypass flow rate of the gaseous refrigerant in the outdoor heat exchanger (140) in the heating operation mode, thereby bypassing the gaseous refrigerant to the compressor (110) without pressure loss of the refrigerant.

[0112] In addition, in the defrosting operation mode, by applying a refrigerant guide passage (310) having multiple passages to the outdoor heat exchanger (140), the high-temperature refrigerant discharged from the compressor (110) is supplied throughout the internal passages of the outdoor heat exchanger (140), thereby shortening the defrosting operation time and enabling continuous heating operation without a time delay when switching to the heating operation mode after the defrosting operation.

[0113] In addition, since the installation of suction pipes and valves between the conventional outdoor heat exchanger and the compressor is eliminated, there is no risk of compressor failure and the effect of reducing parts is achieved.

[0114] The above description of the present invention is for illustrative purposes only, and those skilled in the art will readily appreciate that the present invention can be readily modified into other specific forms without altering the technical spirit or essential characteristics of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. The scope of the present invention is defined by the following claims, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present invention.

Claims

1. Compressor that compresses refrigerant; A switching valve for switching the operating mode; An outdoor heat exchanger that performs heat exchange between outdoor air and refrigerant; Indoor heat exchanger that performs heat exchange between indoor air and refrigerant; An expansion valve that expands the refrigerant; and A heat pump device including a vapor-liquid separator installed inside the outdoor heat exchanger and separating a vapor-liquid refrigerant among two-phase refrigerants according to the operation mode or guiding the refrigerant to the outdoor heat exchanger for defrosting the outdoor heat exchanger.

2. In paragraph 1, The above gas-liquid separation device is, In heating operation mode, the gaseous refrigerant among the two-phase refrigerants supplied to the outdoor heat exchanger is separated and guided to the compressor, or A heat pump device including a refrigerant guide passage that guides high-temperature refrigerant discharged from the compressor into the interior of the outdoor heat exchanger during a defrost operation mode.

3. In paragraph 2, A heat pump device comprising a first refrigerant passage connected to a refrigerant passage between the switching valve and the outdoor heat exchanger, and a plurality of second passages branched from the first passage and connected in parallel to passages inside the outdoor heat exchanger.

4. In paragraph 3, The above second euro is a heat pump device connected to the refrigerant pipe inside the outdoor heat exchanger so that gas and liquid can be separated at the inlet and outlet sides of the outdoor heat exchanger when in heating operation mode.

5. In paragraph 4, A heat pump device in which, in the above second refrigerant flow mode, a portion of the refrigerant flowing through the refrigerant pipe inside the outdoor heat exchanger is distributed when the refrigerant flows into the refrigerant flow path.

6. In paragraph 5, A heat pump device in which the two-phase refrigerant flowing through the refrigerant pipe inside the outdoor heat exchanger flows in an annular flow pattern.

7. In paragraph 6, A heat pump device in which the above refrigerant guide path is installed at a position corresponding to a dryness range of 0.4 to 0.6 of the two-phase refrigerant flowing inside the outdoor heat exchanger.

8. In paragraph 6, The above outdoor heat exchanger is a heat pump device including a plurality of refrigerant pipes and a plurality of fins connected to the plurality of refrigerant pipes.

9. In paragraph 1, A bypass path that guides the refrigerant flowing through the outdoor heat exchanger or the indoor heat exchanger functioning as an evaporator to the compressor; A flow control valve installed in the above bypass path to control the flow rate of the refrigerant; and A heat pump device further comprising a subcooler in which the refrigerant flowing through the bypass path is superheated.

Images