Heat pump device

Abstract

The present application relates to a heat pump device, and provides a heat pump device including: a compressor that compresses refrigerant; a switching valve that switches an operation mode; an outdoor heat exchanger that performs heat exchange between outdoor air and refrigerant; an indoor heat exchanger that performs heat exchange between indoor air and refrigerant; an expansion valve that expands refrigerant; and a gas-liquid separation device that is provided inside the outdoor heat exchanger, separates gaseous refrigerant in two-phase refrigerant according to an operation mode, or guides the refrigerant to the outdoor heat exchanger for defrosting of the outdoor heat exchanger.

Description

Technical Field

[0001] This invention relates to heat pump devices, and more specifically, to a heat pump device using a gas-liquid separation device capable of separating liquid and gaseous refrigerants by utilizing the flow characteristics of the refrigerant. Background Technology

[0002] Typically, a heat pump unit integrates the cooling and heating cycles into the same unit, serving both cooling and heating purposes. In summer, one unit performs cooling through the cooling cycle, while in winter, it switches to a reverse cycle to perform heating and hot water supply.

[0003] In particular, when the heat pump unit is powered, the compressor, indoor fan, and outdoor fan are driven, the refrigerant flowing in from the evaporator is compressed, and high-temperature and high-pressure refrigerant is supplied to the condenser. After the refrigerant is condensed into liquid in the condenser, it is expanded through the expansion valve and becomes a two-phase refrigerant in liquid and gaseous states, and then flows back into the evaporator. In the evaporator, the gaseous refrigerant changes phase to gaseous state and circulates to the compressor, thereby forming a refrigerant cycle.

[0004] In existing heat pump systems, moisture in the air flowing through the outdoor heat exchanger (which acts as an evaporator) condenses and freezes during heating operation, causing frost to form on the outdoor heat exchanger. This can lead to a decrease in the heat exchanger's performance, ultimately resulting in a significant reduction in the heating efficiency of the heat pump system.

[0005] To address this issue, existing heat pump systems, when defrosting is required, switch a valve to operate in a refrigeration circuit, using the outdoor unit as a condenser and the indoor unit as an evaporator. This allows high-temperature, high-pressure liquid refrigerant to flow to the outdoor unit, removing the frost condensed on the outdoor heat exchanger.

[0006] However, since the defrosting operation mode of the refrigeration operation, which defrosts the evaporator that has already frosted, will then switch to heating operation, there is a problem that it is difficult to provide further heating, resulting in a decrease in heating performance.

[0007] In addition, the high-temperature refrigerant discharged from the compressor is directly supplied to the outdoor heat exchanger. During heating operation, the temperature of the refrigerant decreases as it gets closer to the inlet end, and during cooling operation, it gets closer to the outlet end. Therefore, at the end of the outdoor heat exchanger, the defrosting mode cannot operate normally, resulting in a longer defrosting time.

[0008] Furthermore, when existing heat pump devices operate in heating mode in low-temperature and cold regions, the compressor operates at a high compression ratio, which leads to an excessive rise in exhaust temperature. This may damage internal components. Also, because the refrigerant density is lower than that at room temperature, the refrigerant flow rate decreases while the specific volume increases, resulting in increased refrigerant pressure loss. Therefore, there is a problem of decreased heating performance. Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] The purpose of this invention is to provide a heat pump device that increases the bypass flow of gaseous refrigerant by applying multiple gas-liquid separation devices to the outdoor heat exchanger, thereby maximizing heating performance by bypassing gaseous refrigerant to the compressor in heating operation mode without refrigerant pressure loss.

[0011] In addition, the present invention aims to provide a heat pump device that, in defrost operation mode, supplies high-temperature refrigerant discharged from the compressor to the entire internal flow path of the outdoor heat exchanger by employing a refrigerant guide flow path with multiple flow paths, thereby shortening the defrost operation time and improving the defrost efficiency.

[0012] means for solving problems

[0013] To achieve the above objectives, the heat pump device of the present invention is characterized in that, by increasing the bypass flow rate of gaseous refrigerant in the outdoor heat exchanger, gaseous refrigerant is bypassed to the compressor without refrigerant pressure loss, thereby maximizing the heating performance.

[0014] Furthermore, the present invention is characterized in that a refrigerant guide flow path with multiple flow paths is used to supply high-temperature refrigerant discharged from the compressor into the overall flow path inside the outdoor heat exchanger, thereby shortening the defrost operation time.

[0015] The heat pump device of this invention may include: a compressor for compressing refrigerant; a switching valve for switching operating modes; an outdoor heat exchanger for performing heat exchange between outdoor air and refrigerant; an indoor heat exchanger for performing heat exchange between indoor air and refrigerant; an expansion valve for expanding the refrigerant; and a gas-liquid separation device disposed inside the outdoor heat exchanger for separating gaseous refrigerant from the two-phase refrigerant according to the operating mode, or directing the refrigerant to the outdoor heat exchanger for defrosting the outdoor heat exchanger.

[0016] According to an embodiment of the present invention, the gas-liquid separation device may include a refrigerant guiding flow path. In the heating operation mode, the refrigerant guiding flow path is used to separate the gaseous refrigerant from the two-phase refrigerant supplied from the outdoor heat exchanger and guide it to the compressor. Alternatively, in the defrosting operation mode, the refrigerant guiding flow path is used to guide the high-temperature refrigerant discharged from the compressor into the interior of the outdoor heat exchanger.

[0017] According to an embodiment of the present invention, the refrigerant guiding flow path may include: a first flow path connected to the refrigerant flow path between the switching valve and the outdoor heat exchanger; and a plurality of second flow paths branching from the first flow path and connected in parallel to the internal flow path of the outdoor heat exchanger.

[0018] According to an embodiment of the present invention, the second flow path can be connected to the refrigerant piping inside the outdoor heat exchanger, so that gas-liquid separation can be performed on the inlet and outlet sides of the outdoor heat exchanger respectively during the heating operation mode.

[0019] According to an embodiment of the present invention, in the second flow path, during the heating operation mode, when the refrigerant flowing through the refrigerant piping inside the outdoor heat exchanger flows to the refrigerant flow path, a portion of the refrigerant branches into the second flow path.

[0020] According to an embodiment of the present invention, the two-phase refrigerant flowing in the refrigerant piping inside the outdoor heat exchanger can flow in an annular flow mode.

[0021] According to an embodiment of the present invention, the refrigerant guiding flow path can be located at a position corresponding to the dryness range of 0.4 to 0.6 of the two-phase refrigerant flowing inside the outdoor heat exchanger.

[0022] 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.

[0023] According to an embodiment of the present invention, it may further include: a bypass flow path that directs the refrigerant flowing to the outdoor heat exchanger or the indoor heat exchanger that functions as an evaporator to the compressor; a flow control valve disposed in the bypass flow path that controls the flow rate of the refrigerant; and a subcooler that superheats the refrigerant flowing in the bypass flow path.

[0024] The effects of the invention

[0025] According to the heat pump device of the present invention configured as described above, by increasing the bypass flow rate of gaseous refrigerant in the outdoor heat exchanger, gaseous refrigerant is bypassed to the compressor without refrigerant pressure loss, thereby maximizing the heating performance.

[0026] In addition, the outdoor heat exchanger uses a refrigerant guide flow path with multiple flow paths to supply high-temperature refrigerant discharged from the compressor to the entire internal flow path of the outdoor heat exchanger, which can shorten the defrost operation time and enable continuous heating without delay when switching to the heating operation mode after defrost operation.

[0027] By eliminating the existing suction piping and valves located between the outdoor heat exchanger and the compressor, there is no risk of compressor failure, resulting in component savings. Attached Figure Description

[0028] Figure 1 This is a system diagram illustrating a heat pump device according to an embodiment of the present invention.

[0029] Figure 2 This is a cycle diagram illustrating the heating operation mode of the heat pump device according to an embodiment of the present invention.

[0030] Figure 3 This is a cycle diagram illustrating the defrosting operation mode of the heat pump device according to an embodiment of the present invention.

[0031] Figure 4 The curves show the experimental results of the defrosting performance of the heat pump device according to an embodiment of the present invention. Detailed Implementation

[0032] Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings. However, the concept of the present invention is not limited to the disclosed embodiments. Those skilled in the art who understand the concept of the present invention can readily propose other embodiments within the same conceptual scope by adding, deleting, modifying, and supplementing the constituent elements, and these are also included within the scope of the present invention.

[0033] It should be noted that when affixing reference numerals to the constituent elements of the various figures, the same numerals are used as much as possible for the same constituent element, even if it is shown in different figures. Furthermore, when describing embodiments of the present invention, detailed descriptions of related well-known structures or functions are omitted if it is determined that such detailed descriptions may hinder understanding of the embodiments of the present invention.

[0034] Furthermore, when describing the constituent elements of embodiments of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only used to distinguish the constituent element from other constituent elements, and they do not limit the nature, order, or sequence of the constituent elements. When it is described that any constituent element is "connected," "combined," or "in contact" with another constituent element, it should be understood that the constituent element can be directly connected or in contact with other constituent elements, but the constituent elements can also be "connected," "combined," or "in contact" with other constituent elements.

[0035] Figure 1 This is a system diagram illustrating a heat pump device according to an embodiment of the present invention. Figure 2 This is a cycle diagram illustrating the heating operation mode of the heat pump device according to an embodiment of the present invention. Figure 3 This is a cycle diagram illustrating the defrosting operation mode of the heat pump device according to an embodiment of the present invention.

[0036] Before proceeding with the description with reference to the accompanying drawings of the present invention, a heat pump device including an outdoor unit and an indoor unit that generates air conditioning phenomena will be described first.

[0037] [Composition of a heat pump unit]

[0038] The heat pump unit 100 includes an indoor unit and an outdoor unit. In the heat pump unit 100, the indoor unit can be freestanding, wall-mounted, or ceiling-mounted, etc. However, the indoor unit is not limited to freestanding, wall-mounted, or ceiling-mounted types and can take various shapes and be installed indoors.

[0039] The outdoor unit can be connected to the indoor unit, allowing the outdoor unit to transfer the refrigerant needed for air conditioning to the indoor unit. The indoor unit can then perform heat exchange between the transferred refrigerant and the air, and discharge the heat-exchanged air back into the room.

[0040] The indoor and outdoor units can be connected via a refrigerant flow path 200, allowing the refrigerant to circulate between the indoor and outdoor units through the refrigerant flow path 200.

[0041] Depending on the refrigerant cycle, high-temperature or low-temperature air can be discharged from the indoor unit, which is operating in heating or cooling mode, into the room. At this time, the outdoor unit can be connected to at least one indoor unit.

[0042] like Figure 1 As shown, the heat pump device 100, which includes 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 subcooler 170, and a liquid receiver 180.

[0043] In an embodiment of the present invention, the heat pump device 100 may be flowably connected to a working fluid. For example, the working fluid may include a refrigerant. Here, the refrigerant may flow through the various components and circulate in the refrigerant flow path 200.

[0044] Here, the refrigerant can be R410A, which has a low condensation and evaporation temperature and is highly efficient in the relatively low temperature range.

[0045] The compressor 110 can compress refrigerant at high temperature and high pressure. As an example of such a compressor 110, it can be a scroll compressor or a reciprocating compressor. The scroll compressor mechanism compresses the refrigerant by utilizing the relative phase difference between a fixed scroll and a rotating scroll, while the reciprocating compressor mechanism compresses the refrigerant by utilizing a cylinder and a piston.

[0046] The indoor heat exchanger 130 can function as a condenser to condense the refrigerant flowing through the compressor 110 or as an evaporator to evaporate the refrigerant.

[0047] The outdoor heat exchanger 140 can function as an evaporator to evaporate or a condenser to condense the refrigerant flowing through the indoor heat exchanger 130 and the expansion mechanism.

[0048] The outdoor heat exchanger 140 may be constructed from a finned tube heat exchanger. The outdoor heat exchanger 140 may include refrigerant piping 141 consisting of a plurality of tubes and a plurality of fins connected to the plurality of refrigerant piping 141. The refrigerant piping 141 is constructed from zigzag-shaped tubes.

[0049] The expansion mechanism 150 may be an expansion valve that expands the refrigerant passing through the outdoor heat exchanger 140, depressurizes the refrigerant to a pressure that allows evaporation, and regulates and supplies an appropriate amount of refrigerant that can fully absorb heat in the evaporator.

[0050] Here, the first expansion valve 151 can be provided in the refrigerant flow path 200 between the subcooler 170 and the outdoor heat exchanger 140. The second expansion valve 152 can be provided in the refrigerant flow path 200 between the subcooler 170 and the indoor heat exchanger 130.

[0051] The first expansion valve 151 and the second expansion valve 152 can adjust their opening to allow the refrigerant flowing in the refrigerant flow path 200 to expand or not expand. For example, when the heat pump unit 100 is operating in heating mode, the second expansion valve 152 is fully open, preventing the refrigerant flowing through the indoor heat exchanger 130 from expanding, while the first expansion valve 151 is adjusted to open only partially, allowing the refrigerant flowing through the indoor heat exchanger 130 to expand.

[0052] In addition, when the heat pump unit 100 is running in cooling operation mode and defrosting operation mode, the outdoor heat exchanger 140 can function as a condenser, and the indoor heat exchanger 130 can function as an evaporator.

[0053] When the heat pump unit 100 is running in cooling operation mode and defrosting operation mode, the refrigerant can circulate sequentially through the compressor 110, outdoor heat exchanger 140, expansion mechanism 150, indoor heat exchanger 130, liquid receiver 180 and compressor 110.

[0054] Conversely, when the heat pump unit 100 is running in heating mode, the outdoor heat exchanger 140 can function as an evaporator, and the indoor heat exchanger 130 can function as a condenser.

[0055] When the heat pump unit 100 is running in heating mode, the refrigerant can circulate in the order of compressor 110, indoor heat exchanger 130, expansion mechanism 150, outdoor heat exchanger 140, liquid receiver 180 and compressor 110.

[0056] Thus, the heat pump device 100 can be a device that has both cooling and heating functions.

[0057] [Heating Operation Mode of Heat Pump Unit]

[0058] Figure 2 The diagram shows the heat pump unit 100 operating in heating mode. (Refer to...) Figure 2 When the heat pump unit 100 operates in heating mode, the indoor heat exchanger 130 functions as a condenser, and the outdoor heat exchanger 140 functions as an evaporator. Additionally, the outdoor unit may include a compressor 110, a switching valve 120, a subcooler 170, and a liquid receiver 180.

[0059] 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. For example, the switching valve 120 can be a four-way valve with four flow paths. The switching valve 120 can be configured with one inlet and three outlets, or with two inlets and two outlets. For example, if either inlet or outlet is selected and refrigerant is allowed to flow, the refrigerant can also flow through the other inlets and outlets, or the refrigerant can be kept still.

[0060] Furthermore, when changing the outlet for any inlet, the refrigerant flow path can be altered, and the refrigerant path for other inlets and outlets can also be switched. In other words, the refrigerant flow path can be switched.

[0061] Referring to the attached diagram, in the indoor heating operation mode, the switching valve 120 can be adjusted so that the refrigerant discharged from the compressor 110 is directed to the indoor heat exchanger 130; in the indoor cooling operation mode, the switching valve 120 can be adjusted so that the refrigerant discharged from the compressor 110 is directed to the outdoor heat exchanger 140.

[0062] The receiver 180 is a gas-liquid separator capable of separating gaseous refrigerant from a two-phase refrigerant consisting of liquid and gaseous refrigerant. The separated gaseous refrigerant can be supplied to the compressor 110. The receiver 180 prevents efficiency reduction caused by liquid entering the compressor 110.

[0063] The liquid refrigerant separated from the receiver 180 can be contained in the lower part of the receiver 180, and the gaseous refrigerant can be disposed above the separated liquid refrigerant. The gaseous refrigerant separated from the receiver 180 can flow to the compressor 110, and the liquid refrigerant separated from the receiver 180 can remain in the receiver 180.

[0064] When the heat pump unit 100 operates in heating mode, the refrigerant can flow through the compressor 110 and the indoor heat exchanger 130, expand in the first expansion valve 151, and then exchange heat with the outdoor air in the outdoor heat exchanger 140. At this time, the second expansion valve 152 can be fully open, and the opening degree of the first expansion valve 151 can be adjusted to expand the refrigerant.

[0065] Specifically, when the heat pump unit 100 operates in heating mode, the refrigerant discharged from the compressor 110 flows to the indoor heat exchanger 130 under the action of the switching valve 120. The refrigerant condensed in the indoor heat exchanger 130 can be subcooled in the subcooler 170 and then flow to the outdoor heat exchanger 140.

[0066] For example, the refrigerant condensed in the indoor heat exchanger 130 can flow through the refrigerant flow path 200. The refrigerant can then flow through the refrigerant flow path 200 to the subcooler 170. Additionally, the refrigerant flowing through the subcooler 170 can flow through the refrigerant flow path 200 to the outdoor heat exchanger 140, which functions as an evaporator. Here, the refrigerant flowing through the refrigerant flow path 200 is referred to as the primary refrigerant.

[0067] To supply refrigerant to compressor 110, a portion of the refrigerant can be diverted from the primary refrigerant via bypass flow path 210. This diverted portion of refrigerant is called secondary refrigerant. That is, the secondary refrigerant can be the refrigerant flowing along bypass flow path 210.

[0068] The flow control valve 160 can be installed in the bypass flow path 210, and the amount of secondary refrigerant flowing in the bypass flow path 210 can be determined by adjusting the opening degree of the flow control valve 160.

[0069] With the flow control valve 160 open, the secondary refrigerant can flow through the bypass path 210 to the subcooler 170, and after being discharged from the subcooler 170, it flows to the compressor 110. At this time, the secondary refrigerant discharged from the subcooler 170 can flow into the compressor 110.

[0070] The primary refrigerant flowing in refrigerant flow path 200 can flow through a plurality of internal pipes inside subcooler 170, while the secondary refrigerant can flow through an external pipe. The internal pipes can be positioned within the inner space of subcooler 170, allowing the primary refrigerant flowing in the internal pipes to exchange heat with the secondary refrigerant flowing in the external pipes. Specifically, the secondary refrigerant expands under the action of flow control valve 160, becoming at a lower temperature and pressure than the primary refrigerant. This low-temperature, low-pressure secondary refrigerant flows through the external pipe while simultaneously exchanging heat with the primary refrigerant flowing in the internal pipes. At this point, the primary refrigerant can be overcooled, and the secondary refrigerant can be overheated. The overcooled primary refrigerant can then flow through refrigerant flow path 200 to outdoor heat exchanger 140. Outdoor heat exchanger 140 can evaporate the liquid refrigerant into a gaseous refrigerant through heat exchange with outdoor air. In other words, outdoor heat exchanger 140 functions as an evaporator.

[0071] The heat pump device 100 according to the present invention may include a gas-liquid separation device 300. Here, the gas-liquid separation device 300 may be disposed inside the outdoor heat exchanger 140, and may separate the gaseous refrigerant from the liquid refrigerant and gaseous refrigerant in the outdoor heat exchanger 140 and then direct it to the compressor 110. The gas-liquid separation device 300 may include a refrigerant guiding flow path 310 for directing the gaseous refrigerant to the compressor 110.

[0072] On the other hand, the refrigerant guide path 310 in heating operation mode can be connected to the refrigerant flow path 200 that leads the gaseous refrigerant from the outdoor heat exchanger 140 to the compressor 110. At this time, under the action of the gas-liquid separation device 300, liquid refrigerant and gaseous refrigerant can be separated from the two-phase refrigerant, and the separated gaseous refrigerant can be led to the compressor 110.

[0073] In this gas-liquid separation device 300, the two-phase refrigerant can change its flow pattern according to its dryness and flow rate.

[0074] The gas-liquid separation device 300 can separate the liquid refrigerant and the gaseous refrigerant by allowing the liquid refrigerant to flow towards the wall of the refrigerant flow path 200 while ensuring a predetermined dryness and flow rate, and by allowing the gaseous refrigerant to flow separately within the liquid refrigerant flow path 200. This flow pattern, where the liquid and gaseous refrigerants are separated and flow within the refrigerant flow path 200, is called annular flow.

[0075] In the case of annular flow, within the refrigerant flow path 200, liquid refrigerant can flow towards the wall of the flow path, while gaseous refrigerant can flow towards the center of the liquid refrigerant flowing through the refrigerant flow path 200. This allows the gaseous refrigerant to be separated from the two-phase refrigerant flowing inside the outdoor heat exchanger 140, and then flows towards the connecting flow path (not shown) and the manifold (not shown). At this time, in addition to the gaseous refrigerant, a small amount of liquid refrigerant can also flow together towards the connecting flow path and the manifold.

[0076] Gaseous refrigerant separated from the two-phase refrigerant flowing inside the outdoor heat exchanger 140 can flow to the compressor 110 through the refrigerant guide path 310, while unseparated liquid refrigerant can be bypassed.

[0077] Existing technologies propose connecting the outdoor heat exchanger to the suction end of the compressor with a suction pipe and adding a valve to the piping for a heat pump device. However, when the valve in the existing method fails, the liquid refrigerant can seep into the compressor because there is no constraint on the composition of the refrigerant. Therefore, there is a disadvantage that liquid seepage can lead to performance degradation or even compressor failure.

[0078] The refrigerant guiding flow path 310 connected to the gas-liquid separation device 300 includes: a first flow path 311 connected to the refrigerant flow path 200 between the switching valve 120 and the outdoor heat exchanger 140; and a second flow path 312 branching from the first flow path 311 and connected to the refrigerant flow path 200 of the gas-liquid separation device 300 inside the outdoor heat exchanger 140. That is, with the second flow path 312 of the refrigerant guiding flow path 310 connected to the inlet side (lower part) and outlet side (upper part) of the outdoor heat exchanger 140 respectively, and with the use of multi-stage (two-stage) gas-liquid separation technology, not only can the flow rate of gaseous refrigerant be increased compared to the prior art to prevent performance degradation or compressor failure caused by liquid infiltration, but also performance in cold regions can be improved.

[0079] This refrigerant guide path 310 can be positioned at a location corresponding to a dryness range of 0.4 to 0.6 for the two-phase refrigerant flowing inside the outdoor heat exchanger 140, which can be understood as the dryness position that forms an annular flow.

[0080] The refrigerant guiding flow path 310 can be configured such that, since the second flow path 312 is composed of a plurality of flow paths, when the gaseous refrigerant separated by the gas-liquid separation device 300 inside the outdoor heat exchanger 140 is discharged from the outdoor heat exchanger 140, a portion is allocated to the second flow path 312 on the inlet side and is discharged, and the remainder is allocated to the second flow path 312 on the outlet side and is discharged.

[0081] In addition, all gaseous refrigerants other than those discharged through the refrigerant guide path 310 can be discharged to the refrigerant flow path 200, which is connected to the refrigerant piping 141 inside the outdoor heat exchanger 140 and led to the compressor 110.

[0082] Because the overall refrigerant flow rate increases in the refrigerant flow path 200 and the refrigerant guiding flow path 310 connected in parallel with the refrigerant piping 141 of the outdoor heat exchanger 140 whenever gas-liquid separation occurs in the gas-liquid separator 300, the outlet pressure of the refrigerant guiding flow path 310 and the suction pressure and suction density of the compressor 110 decrease. Therefore, the heating performance in the heating operation mode can be maximized by bypassing gaseous refrigerant to the compressor 110 without refrigerant pressure loss.

[0083] In addition, the increased overall refrigerant flow in the outdoor heat exchanger 140 improves performance in cold regions.

[0084] [Defrosting Operation Mode of Heat Pump Unit]

[0085] Figure 3 The diagram shows the heat pump unit 100 operating in defrost mode. (Refer to...) Figure 3 When the heat pump unit 100 operates in defrost mode, i.e. refrigeration mode, the outdoor heat exchanger 140 can function as a condenser, and the indoor heat exchanger 130 can function as an evaporator.

[0086] The switching valve 120 directs the flow of refrigerant discharged from the compressor 110 to the outdoor heat exchanger. Additionally, the receiver 180 can separate gaseous refrigerant from a two-phase refrigerant system comprising liquid and gaseous refrigerant.

[0087] When the heat pump unit 100 operates in defrost mode, the refrigerant flows through the compressor 110 and the outdoor heat exchanger 140, is expanded in the second expansion valve 152, and then exchanges heat with the indoor air in the indoor heat exchanger 130. At this time, the first expansion valve 151 is fully open, and the opening degree of the second expansion valve 152 can be adjusted to allow the refrigerant to expand.

[0088] Specifically, when the heat pump unit 100 operates in defrost mode, the refrigerant discharged from the compressor 110 can flow to the outdoor heat exchanger 140 under the action of the switching valve 120. The refrigerant condensed in the outdoor heat exchanger 140 can be subcooled in the subcooler 170 and then flow to the indoor heat exchanger 130.

[0089] The refrigerant condensed in the outdoor heat exchanger 140 can flow through the refrigerant flow path 200. The refrigerant can then flow through the refrigerant flow path 200 to the subcooler 170. Furthermore, the refrigerant passing through the subcooler 170 can flow through the refrigerant flow path 200 to the indoor heat exchanger 130, which functions as an evaporator. Here, the refrigerant flowing through the refrigerant flow path 200 is referred to as the primary refrigerant.

[0090] To supply refrigerant to compressor 110, a portion of the refrigerant can be diverted from the primary refrigerant via bypass flow path 210. This diverted portion of refrigerant is called secondary refrigerant. That is, the secondary refrigerant can be the refrigerant flowing along bypass flow path 210.

[0091] The flow control valve 160 can be installed in the bypass flow path 210, and the amount of secondary refrigerant flowing in the bypass flow path 210 can be determined by adjusting the opening degree of the flow control valve 160.

[0092] When the flow control valve 160 is open, the secondary refrigerant can flow through the bypass flow path 210 to the subcooler 170, and after being discharged from the subcooler 170, it flows to the compressor 110. At this time, the secondary refrigerant discharged from the subcooler 170 can flow into the compressor 110.

[0093] The primary refrigerant flowing in refrigerant flow path 200 can flow through a plurality of internal pipes inside subcooler 170, while the secondary refrigerant can flow through an external pipe. The internal pipes can be positioned within the inner space of subcooler 170, allowing the primary refrigerant flowing in the internal pipes to exchange heat with the secondary refrigerant flowing in the external pipes. Specifically, under the action of flow control valve 160, the secondary refrigerant expands, becoming at a lower temperature and pressure than the primary refrigerant. This low-temperature, low-pressure secondary refrigerant flows through the external pipe while simultaneously exchanging heat with the primary refrigerant flowing in the internal pipes. At this point, the primary refrigerant can be overcooled, and the secondary refrigerant can be overheated. The overcooled primary refrigerant flows through refrigerant flow path 200 to indoor heat exchanger 130. Indoor heat exchanger 130 can evaporate the liquid refrigerant into gaseous refrigerant through heat exchange with indoor air. That is, indoor heat exchanger 130 functions as an evaporator.

[0094] According to the heat pump device of the present invention, when the heating operation mode is executed under low outdoor temperature conditions, the moisture in the air flowing through the outdoor heat exchanger 140, which serves as an evaporator, is condensed and frozen, causing the outdoor heat exchanger 140 to frost over, thereby reducing the heat exchange performance of the outdoor heat exchanger 140 and significantly reducing the heating efficiency of the heat pump device 100.

[0095] To address this problem of reduced heating efficiency, the present invention implements a defrosting operation mode for the outdoor heat exchanger 140 to remove the frost that has formed on the outdoor heat exchanger 140.

[0096] The heat pump device 100 according to the present invention may include a gas-liquid separation device 300. The gas-liquid separation device 300 is disposed inside the outdoor heat exchanger 140 and can remove frost buildup inside the outdoor heat exchanger 140 by directing the high-temperature gaseous refrigerant (hot gas) discharged from the compressor 110 to the outdoor heat exchanger 140. Here, in defrosting operation mode, the gas-liquid separation device 300 does not use gas-liquid separation technology to separate gaseous refrigerant from two-phase refrigerant; it only performs the function of directing the high-temperature refrigerant from the compressor 110 to the interior of the outdoor heat exchanger 140.

[0097] The gas-liquid separator 300 may include a refrigerant guiding flow path 310. Alternatively, in defrost mode, the refrigerant guiding flow path 310 may be connected to a refrigerant flow path 200 that directs refrigerant discharged from the compressor 110 to the outdoor heat exchanger 140. In this case, the refrigerant flowing into the gas-liquid separator 300 through the refrigerant guiding flow path 310 may be connected to and guided by a plurality of refrigerant pipes 141 inside the outdoor heat exchanger 140.

[0098] The refrigerant guide flow path 310 connected to the gas-liquid separator 300 includes: a first flow path 311 connected to the refrigerant flow path 200 between the switching valve 120 and the outdoor heat exchanger 140; and a second flow path 312 branching from the first flow path 311 and connected in parallel with the refrigerant piping 141 inside the outdoor heat exchanger 140.

[0099] The second flow path 312 of this refrigerant guiding flow path 310 is composed of a plurality of flow paths. Thus, it can be configured such that when high-temperature gaseous refrigerant is introduced into the outdoor heat exchanger 140, it is guided via the refrigerant piping 141 connected to the inlet side (upper part) and the outlet side (lower part) of the outdoor heat exchanger 140 connected to the second flow path 312.

[0100] Because the refrigerant flowing along the refrigerant guide flow path 310 has its flow rate increased by passing through the entire refrigerant piping 141 of the outdoor heat exchanger 140, defrosting can be easily performed and the defrosting operation time can be shortened. At this time, the frost that has formed inside the outdoor heat exchanger 140 turns into water and remains on the lower side inside the outdoor heat exchanger 140, while the refrigerant flowing to the second flow path 312 of the refrigerant guide flow path 310 provided on the outlet side of the outdoor heat exchanger 140 can dry the water remaining inside the outdoor heat exchanger 140. Thus, it has the effect of not only completely removing the frost that hinders the performance of the heat exchanger inside the outdoor heat exchanger 140, but also completely removing the water.

[0101] Figure 4 The curves show the experimental results of the defrosting performance of the heat pump device 100 according to an embodiment of the present invention, and show the refrigerant evaporation temperature corresponding to the operating time of the heat pump device 100.

[0102] Referring to the accompanying drawings, in both the present invention and the prior art, the evaporation temperature of the heat pump device 100 is approximately the same at 14°C, and the heating capacity is approximately the same at 17.5 kW.

[0103] However, in both the present invention and the prior art, although the heat pump device 100 starts defrosting operation at approximately 33 minutes, the prior art completes defrosting operation after approximately 41 minutes. In contrast, the present invention completes defrosting operation at approximately 39 minutes.

[0104] Compared with the prior art, the present invention can shorten the defrosting operation time by several minutes, so that when switching to the heating operation mode after defrosting, heating can be carried out continuously without time delay.

[0105] Therefore, in the heating operation mode, embodiments of the present invention can maximize heating performance by increasing the bypass flow rate of gaseous refrigerant in the outdoor heat exchanger 140 and bypassing gaseous refrigerant to the compressor 110 without refrigerant pressure loss.

[0106] In addition, it has the following effects: In the defrost operation mode, by using a refrigerant guide flow path 310 with multiple flow paths in the outdoor heat exchanger 140, the high-temperature refrigerant discharged from the compressor 110 is supplied to the entire flow path inside the outdoor heat exchanger 140, thereby shortening the defrost operation time, and when switching to the heating operation mode after defrost operation, the heating operation can be continuously performed without time delay.

[0107] In addition, since the suction pipe and valve located between the outdoor heat exchanger and the compressor in the prior art are eliminated, there is no risk of compressor failure, and the components can be saved.

[0108] The above description of the present invention is illustrative and should be understood as allowing those skilled in the art to readily modify it into other specific forms without altering the technical concept or essential features of the invention. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not limiting. It should be interpreted that the scope of the invention is defined by the appended claims, and all modifications or variations derived from the meaning and scope of the claims and their equivalents are included within the scope of the invention.

Claims

1. A heat pump device, wherein, include: Compressor, which compresses refrigerant; A switching valve is used to switch operating modes; Outdoor heat exchanger, which performs heat exchange between outdoor air and refrigerant; Indoor heat exchanger, which performs heat exchange between indoor air and refrigerant; Expansion valve, which causes the refrigerant to expand; as well as A gas-liquid separation device is installed inside the outdoor heat exchanger to separate the gaseous refrigerant in the two-phase refrigerant according to the operating mode, or to direct the refrigerant to the outdoor heat exchanger for defrosting.

2. The heat pump device according to claim 1, wherein, The gas-liquid separation device includes a refrigerant guiding flow path. When in heating mode, the refrigerant guide path is used to separate the gaseous refrigerant from the two-phase refrigerant supplied from the outdoor heat exchanger and direct it to the compressor; or When in defrost mode, the refrigerant guide path is used to direct the high-temperature refrigerant discharged from the compressor to the interior of the outdoor heat exchanger.

3. The heat pump device according to claim 2, wherein, The refrigerant guiding flow path includes: a first flow path connected to the refrigerant flow path between the switching valve and the outdoor heat exchanger; and a plurality of second flow paths branching from the first flow path and connected in parallel to the internal flow path of the outdoor heat exchanger.

4. The heat pump device according to claim 3, wherein, The second flow path is connected to the refrigerant piping inside the outdoor heat exchanger, so that gas-liquid separation can be performed on the inlet and outlet sides of the outdoor heat exchanger during heating operation.

5. The heat pump device according to claim 4, wherein, In heating operation mode, when the refrigerant flowing through the refrigerant piping inside the outdoor heat exchanger flows into the refrigerant flow path, a portion of the refrigerant branches into the second flow path.

6. The heat pump device according to claim 5, wherein, The two-phase refrigerant flowing through the refrigerant piping inside the outdoor heat exchanger flows in a ring-shaped flow pattern.

7. The heat pump device according to claim 6, wherein, The refrigerant guide path is located at a position corresponding to the dryness range of 0.4 to 0.6 for the two-phase refrigerant flowing inside the outdoor heat exchanger.

8. The heat pump device according to claim 6, wherein, The outdoor heat exchanger includes a plurality of refrigerant pipes and a plurality of fins connected to the plurality of refrigerant pipes.

9. The heat pump device according to claim 1, wherein, Also includes: A bypass path is used to direct the refrigerant flowing to the outdoor heat exchanger or the indoor heat exchanger, which functions as an evaporator, to the compressor. A flow control valve is installed in the bypass flow path to control the flow rate of the refrigerant; as well as The refrigerant flowing in the bypass path is superheated by a subcooler.

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