Air source heat pump device

Abstract

The utility model provides an air source heat pump device which comprises an outdoor unit, a heat pump unit and a heat pump unit. The first gas-liquid separator and the second gas-liquid separator are respectively connected with the suction sides of the first compressor and the second compressor; the first oil separator and the second oil separator are respectively connected with the discharge sides of the first compressor and the second compressor; the switching valve is connected with the discharge sides of the first oil separator and the second oil separator; one end of the first gas-separation gas suction pipe is connected with the switching valve, and the other end is connected with the first gas-liquid separator; one end of the second gas-liquid separator suction pipe is connected with the switching valve, and the other end of the second gas-liquid separator suction pipe is connected with the switching valve; the inlet ends of the first oil return branch and the second oil return branch are respectively connected with the first oil separator and the second oil separator; the inlet end of one path of the junction station is connected with the first oil return branch, the inlet end of the other path of the junction station is connected with the second oil return branch, and the outlet end of the junction station is connected with the first air-separation air suction pipe and the second air-separation air suction pipe respectively; the reliability and performance of the compressor can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of air conditioning, in particular to an air source heat pump device. Background Art

[0002] In an air source heat pump device, one or more outdoor units and one or more indoor units are connected by piping, and the outdoor unit and the indoor unit together form a refrigerant circuit. As the number of outdoor unit systems increases, the amount of refrigerant required and the displacement of the compressor increase, and more and more outdoor units equipped with two gas-liquid separators and two compressors appear in the market. When the evaporation capacity of this type of outdoor unit is weak (for example, in cooling conditions, the indoor ambient temperature is too low or the indoor evaporator is dirty and blocked, or in heating conditions, the outdoor ambient temperature is too low, the outdoor evaporator is frosted or dirty, and the outdoor evaporator area is too small, etc.), the low-temperature and low-pressure gas-liquid two-phase refrigerant does not evaporate completely in the evaporator, and the liquid phase ratio is large. Due to differences in system pipeline design, manufacturing and processing industry, and installation conditions, incompletely evaporated gas-liquid two-phase refrigerant is prone to flow deviation in the two gas-liquid separators. One gas-liquid separator stores more gas-liquid two-phase refrigerant, while the other gas-liquid separator stores less gas-liquid two-phase refrigerant, which results in the dilution of the lubricating oil in the gas-liquid separator storing more gas-liquid two-phase refrigerant, and the concentration of the lubricating oil in the mixture of refrigerant and lubricating oil is reduced, and the viscosity of the lubricating oil is low. Therefore, the oil viscosity in the compressor connected to this gas-liquid separator is low, the oil discharge of the compressor will increase, the amount of lubricating oil discharged from the oil separator connected to the compressor into the system will increase, and the amount of oil returning to the gas-liquid separator from the oil return capillary will decrease. Over time, the compressor will be empty of oil, and the compressor lacks lubrication, posing a great risk to the reliability of the compressor. The other gas-liquid separator storing less gas-liquid two-phase refrigerant has a higher oil concentration and oil viscosity, and the compressor discharges less oil. The oil level of this compressor is good, and there will be no reliability problems. Utility Model Content

[0003] The utility model aims to provide an air source heat pump device to solve the problem that the oil amount of dual compressors is uneven and one of the compressors is short of oil due to the uneven liquid return of dual gas-liquid separators.

[0004] The air source heat pump device includes an outdoor unit; the outdoor unit has a first compressor, a second compressor, a first gas-liquid separator connected to the suction side of the first compressor, a second gas-liquid separator connected to the suction side of the second compressor, a first oil separator connected to the discharge side of the first compressor, a second oil separator connected to the discharge side of the second compressor, and a switching valve connecting the discharge sides of the first oil separator and the second oil separator.

[0005] In one or more embodiments of the present application, the outdoor unit also has a first gas-dividing air intake pipe and a second gas-dividing air intake pipe, wherein one end of the first gas-dividing air intake pipe is connected to the switching valve, and the other end is connected to the first gas-liquid separator; one end of the second gas-dividing air intake pipe is connected to the switching valve, and the other end is connected to the second gas-liquid separator.

[0006] In one or more embodiments of the present application, the outdoor unit also has a first oil return branch and a second oil return branch; the inlet end of the first oil return branch is connected to the first oil separator; the inlet end of the second oil return branch is connected to the second oil separator.

[0007] In one or more embodiments of the present application, the outdoor unit also has a flow combiner, one inlet end of which is connected to the first oil return branch, the other inlet end of which is connected to the second oil return branch, and the outlet end of which is respectively connected to the first gas suction pipe and the second gas suction pipe.

[0008] In one or more embodiments of the present application, the outdoor unit also has a low-pressure side piping and a first distributor; the inlet end of the low-pressure side piping is connected to the switching valve, the inlet end of the first distributor is connected to the low-pressure side piping, one outlet end is connected to the first air intake pipe, and the other outlet end is connected to the second air intake pipe; wherein the outlet end of the flow combiner is connected to the low-pressure side piping, and the first air intake pipe and the second air intake pipe have the same pipe length and pipe diameter.

[0009] In one or more embodiments of the present application, the outdoor unit also has a redistributor, whose inlet end is connected to the outlet end of the combiner through an extended pipe section, one outlet end is connected to the first gas distribution suction pipe, and the other outlet end is connected to the second gas distribution suction pipe.

[0010] In one or more embodiments of the present application, a first oil return capillary and a first filter are provided on the first oil return branch, and the first oil return capillary and the first filter are connected in series.

[0011] In one or more embodiments of the present application, a second oil return capillary and a second filter are provided on the second oil return branch, and the second oil return capillary and the second filter are connected in series.

[0012] In one or more embodiments of the present application, the outdoor unit further comprises: a first exhaust temperature sensor and a second exhaust temperature sensor; wherein the first exhaust temperature sensor is arranged at the exhaust end of the first compressor; and the second exhaust temperature sensor is arranged at the exhaust end of the second compressor.

[0013] In one or more embodiments of the present application, the outdoor unit also has: a first liquid level sensor and a second liquid level sensor; the first liquid level sensor is arranged in the first compressor to detect the liquid level in the first compressor, and the second liquid level sensor is arranged in the second compressor to detect the liquid level in the second compressor.

[0014] In one or more embodiments of the present application, the extended pipe section is a straight pipe section.

[0015] In one or more embodiments of the present application, the outdoor unit also includes: a liquid pipe, a first outdoor heat exchanger and a second outdoor heat exchanger; one end of the first outdoor heat exchanger is connected to the switching valve through a first gas-side piping, and the other end is connected to the liquid pipe through a first liquid-side piping; the first outdoor heat exchanger has a first heat exchange body and a first subcooling section, and a first outdoor throttling element is arranged between the first heat exchange body and the first subcooling section; the second outdoor heat exchanger, one end of which is connected to the switching valve through a second gas-side piping, and the other end is connected to the liquid pipe through a second liquid-side piping; the second outdoor heat exchanger has a second heat exchange body and a second subcooling section, and a second outdoor throttling element is arranged between the second heat exchange body and the second subcooling section.

[0016] In one or more embodiments of the present application, the outdoor unit also has: a first air side temperature sensor, which is arranged on the first air side piping; a first liquid side temperature sensor, which is arranged on the first liquid side piping; a second air side temperature sensor, which is arranged on the second air side piping; and a second liquid side temperature sensor, which is arranged on the second air side piping.

[0017] In one or more embodiments of the present application, the outdoor unit also has: a gas connecting pipe and a liquid connecting pipe; the gas connecting pipe connects the first gas-liquid separator and the second gas-liquid separator, the liquid connecting pipe connects the first gas-liquid separator and the second gas-liquid separator, and the gas connecting pipe is arranged above the liquid connecting pipe.

[0018] The present application can improve the reliability and performance of the compressor.

[0019] After reading the specific embodiments of the present invention in conjunction with the accompanying drawings, other features and advantages of the present invention will become more clear. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0021] Figure 1 is a schematic structural diagram of an air source heat pump device provided by one or more embodiments of the present application;

[0022] Figure 2 is a schematic structural diagram of an air source heat pump device provided by one or more embodiments of the present application;

[0023] Figure 3 is a schematic structural diagram of an air source heat pump device provided by one or more embodiments of the present application;

[0024] Figure 4 is a schematic structural diagram of an air source heat pump device provided by one or more embodiments of the present application;

[0025] Figure 5 is a schematic structural diagram of an air source heat pump device provided by one or more embodiments of the present application;

[0026] Figure 6 is a schematic structural diagram of an air source heat pump device provided by one or more embodiments of the present application;

[0027] Figure 7 is a schematic structural diagram of an air source heat pump device provided by one or more embodiments of the present application;

[0028] Figure 8 is a schematic structural diagram of an air source heat pump device provided by one or more embodiments of the present application;

[0029] Fig. 9 is a schematic structural diagram of an air source heat pump device provided by one or more embodiments of the present application;

[0030] Fig.10 is a schematic structural diagram of an air source heat pump device provided by one or more embodiments of the present application;

[0031] Fig.11 is a schematic structural diagram of an air source heat pump device provided by one or more embodiments of the present application;

[0032] In the figure: 10, outdoor unit; 101, first compressor; 102, second compressor; 103, first exhaust temperature sensor; 104, second exhaust temperature sensor; 105, first oil separator; 106, second oil separator; 107, high pressure side pressure sensor; 108, switching valve; 109, low pressure side pressure sensor; 110, outdoor fan; 111, first gas-liquid separator; 112, second gas-liquid separator; 113, first gas suction pipe; 114, second gas suction pipe; 115, first oil return branch; 116, second oil return branch; 117, first valve element; 118, second valve element; 119, low pressure side piping; 120, first distributor; 121, second distributor; 122, third distributor; 123, first oil return capillary tube; 124, first filter; 125, second oil return capillary tube; 126, second filter; 127, first liquid level sensor; 128, second liquid level sensor; 129, first outdoor heat exchanger; 130, first heat exchange body; 131, first subcooling section; 132, first outdoor throttling element; 133, first gas side temperature sensor; 134, first liquid side temperature sensor; 135, second outdoor heat exchanger; 136, second heat exchange body; 137, second subcooling section; 138, second outdoor throttling element; 139, second gas side temperature sensor; 140, second liquid side temperature sensor; 141, gas connecting pipe; 142, liquid connecting pipe; 143, gas pipe; 144, gas side stop valve; 145, liquid pipe; 146, liquid side stop valve;

[0033] 147. Combiner; 148. Extension pipe section; 149. Redistributor. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0035] In the description of the present application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0036] The terms "first", "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0037] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0038] In the present utility model, unless otherwise clearly stipulated and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0039] The disclosure below provides many different embodiments or examples for realizing different structures of the present invention. In order to simplify the disclosure of the present invention, the components and settings of specific examples are described below. Of course, they are merely examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and reference letters in different examples, and this repetition is for the purpose of simplification and clarity, and does not indicate the relationship between the various embodiments and settings discussed in itself. In addition, the present invention provides various specific examples of processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and the use of other materials.

[0040] Below, we will refer to the attached Figures 1 to 7 One or more embodiments of the present invention are described in detail.

[0041] The present application relates to an air source heat pump device. An air source heat pump device is a system that uses heat in the air for heating or cooling. It is an efficient heating and cooling device that is widely used in household, commercial and industrial fields. It extracts heat from outdoor air and transfers the heat to the interior of a building to provide heat for heating. In summer, it can also transfer heat from indoor air to provide cooling for the building. Compared with traditional heating systems that use a combustion process, air source heat pump devices use clean energy, thereby reducing greenhouse gas emissions, and are characterized by high efficiency, cleanliness and economy.

[0042] From a principle perspective, an air source heat pump device is a system that performs a refrigeration cycle by using a compressor, a condenser, a throttling device, and an evaporator. The refrigeration cycle includes a series of processes involving compression, condensation, expansion, and evaporation to cool or heat a medium (such as indoor air or water).

[0043] From the perspective of principle, low-temperature and low-pressure refrigerant enters the compressor, which compresses it into high-temperature and high-pressure refrigerant gas and discharges the compressed refrigerant gas. The discharged refrigerant gas flows into the condenser. The condenser condenses the compressed refrigerant into a liquid phase, and the heat is released to the surrounding environment through the condensation process.

[0044] The throttling device expands the high-temperature and high-pressure liquid refrigerant condensed in the condenser into a low-pressure liquid refrigerant. The evaporator evaporates the refrigerant expanded in the throttling device and returns the refrigerant gas in a low-temperature and low-pressure state to the compressor. The evaporator can achieve a refrigeration effect by utilizing the latent heat of evaporation of the refrigerant to exchange heat with the material to be cooled. In the entire cycle, the air source heat pump device can adjust the temperature of the medium (such as indoor air or water).

[0045] The outdoor unit of the air source heat pump device refers to the part of the refrigeration cycle including the compressor and the outdoor heat exchanger.

[0046] In one or more embodiments of the present application, the indoor unit (not shown) of the air source heat pump device includes a floor heating system, and temperature-regulated warm water circulates through pre-buried pipes under the floor, thereby providing uniform radiant heating for the house.

[0047] In one or more embodiments of the present application, the indoor unit of the air source heat pump device includes an air handling unit, which includes a return air outlet, an air supply outlet and an indoor fan, for example, to deliver temperature-regulated air to different rooms. The air handling unit includes a wall-mounted air handling unit, a ceiling-mounted air handling unit, a ducted air handling unit, and the like. The wall-mounted air handling unit is usually installed on the indoor wall, with a flat shell as the main body, a built-in indoor fan and an indoor heat exchanger, and has the advantages of small footprint and easy installation. The ceiling-mounted air handling unit can better distribute the air flow and is suitable for use in commercial and industrial places. The ducted air handling unit is installed in a hidden manner, usually with only the air outlet and the return air outlet exposed, for example, arranged in the ceiling.

[0048] In one or more embodiments of the present application, the indoor unit of the air source heat pump device includes a hot water unit. The hot water unit can provide hot water for showering, washing, etc. The air source heat pump device can transfer heat to a water storage tank as a source of hot water for the house.

[0049] like Figure 1 and Figure 4 As shown, the outdoor unit 10 and the indoor unit are connected via a liquid pipe 145 and a gas pipe 143. The liquid pipe 145 is provided with a liquid side stop valve 146, and the gas pipe 143 is provided with a gas side stop valve 144.

[0050] The indoor heat exchanger and the outdoor heat exchanger are used as a condenser or an evaporator. When the indoor heat exchanger is used as an evaporator, the air source heat pump device is used as a cooler in the cooling mode. The refrigerant cycle in the cooling mode is as follows Figure 2 When the indoor heat exchanger is used as a condenser, the air source heat pump device is used as a heater in the heating mode. The refrigerant cycle in the heating mode is as follows: Figure 3 shown.

[0051] In one or more embodiments of the present application, the outdoor unit 10 includes a first compressor 101 and a second compressor 102, and an inverter device supplies AC power to the working first compressor 101 or the second compressor 102. When the output frequency of the inverter device changes, the rotation speeds of the first compressor 101 and the second compressor 102 change, thereby achieving different air conditioning capacities.

[0052] In one or more embodiments of the present application, a first exhaust temperature sensor 103 is provided at the discharge side of the first compressor 101, and a second exhaust temperature sensor 104 is provided at the discharge side of the second compressor 102. The first exhaust temperature sensor 103 and the second exhaust temperature sensor 104 are used to detect the exhaust temperature of the first compressor 101 and the exhaust temperature of the second compressor 102, respectively.

[0053] In one or more embodiments of the present application, a first oil separator 105 and a second oil separator 106 are further provided in the outdoor unit 10. The first oil separator 105 is connected to the discharge side of the first compressor 101, and the second oil separator 106 is connected to the discharge side of the second compressor 102. The first oil separator 105 and the second oil separator 106 are used to separate the lubricating oil from the refrigerant. The first compressor 101 and the second compressor 102 require lubricating oil to reduce friction and wear to ensure normal operation, and the lubricating oil will be mixed with the refrigerant when the first compressor 101 and the second compressor 102 are working. The first oil separator 105 and the second oil separator 106 recover and recycle the separated lubricating oil through the principle of physical separation (such as centrifugal force or gravity), while the refrigerant continues to flow.

[0054] In one or more embodiments of the present application, a high-pressure side pressure sensor 107 is further provided in the outdoor unit 10. The refrigerant flowing out of the first oil separator 105 and the second oil separator 106 merges and flows through the high-pressure side pressure sensor 107.

[0055] In one or more embodiments of the present application, a switching valve 108 is further provided in the outdoor unit 10. The switching valve 108 is usually a four-way valve, which enables the air source heat pump device to switch between the cooling mode and the heating mode. The switching valve 108 connects the discharge side of the first oil separator 105 and the second oil separator 106.

[0056] In one or more embodiments of the present application, the outdoor unit 10 further includes a low-pressure side pressure sensor 109 .

[0057] In one or more embodiments of the present application, the outdoor unit 10 is further provided with an outdoor fan 110, the speed of which can be controlled to change the flow rate of air heat exchanged with the outdoor heat exchanger by adjusting the speed, and the outdoor fan 110 can be an axial flow fan, a cross flow fan or other optional fan forms. The outdoor fan 110 is arranged near the outdoor heat exchanger.

[0058] In one or more embodiments of the present application, a first gas-liquid separator 111 and a second gas-liquid separator 112 are further provided in the outdoor unit 10. The first gas-liquid separator 111 is connected to the suction side of the first compressor 101, and the second gas-liquid separator 112 is connected to the suction side of the second compressor 102. The first gas-liquid separator 111 and the second gas-liquid separator 112 achieve separation based on the density difference between gas and liquid. When the refrigerant mixed with gas and liquid flowing out of the evaporator enters the first gas-liquid separator 111 and the second gas-liquid separator 112, due to the effect of gravity, the liquid refrigerant with a larger density will sink, while the gas refrigerant with a lighter density will rise. In this way, the first gas-liquid separator 111 and the second gas-liquid separator 112 can effectively separate the liquid refrigerant from the gaseous refrigerant.

[0059] In one or more embodiments of the present application, the outdoor unit 10 further includes a first gas-dividing air intake pipe 113 and a second gas-dividing air intake pipe 114. One end of the first gas-dividing air intake pipe 113 is connected to the switching valve 108, and the other end is connected to the first gas-liquid separator 111, and one end of the second gas-dividing air intake pipe 114 is connected to the switching valve 108, and the other end is connected to the second gas-liquid separator 112.

[0060] In one or more embodiments of the present application, the outdoor unit 10 is further provided with a first oil return branch 115 and a second oil return branch 116. The inlet end of the first oil return branch 115 is connected to the first oil separator 105, one outlet end is connected to the first gas suction pipe 113 through the first valve element 117, and the other outlet end is connected to the second gas suction pipe 114; the inlet end of the second oil return branch 116 is connected to the second oil separator 106, one outlet end is connected to the second gas suction pipe 114 through the second valve element 118, and the other outlet end is connected to the first gas suction pipe 113.

[0061] In one or more embodiments of the present application, the outdoor unit 10 further includes a low-pressure side pipe 119. The inlet end of the low-pressure side pipe 119 is connected to the switching valve 108. The inlet end of the first distributor 120 in the outdoor unit 10 is connected to the low-pressure side pipe 119, one outlet end is connected to the first gas distribution suction pipe 113, and the other outlet end is connected to the second gas distribution suction pipe 114.

[0062] In one or more embodiments of the present application, the first gas-fraction suction pipe 113 and the second gas-fraction suction pipe 114 have the same pipe length and pipe diameter.

[0063] In one or more embodiments of the present application, the outdoor unit 10 further comprises a second distributor 121. An inlet end of the second distributor 121 is connected to the first oil return branch 115, one outlet end of the second distributor 121 is connected to the first valve element 117, and another outlet end of the second distributor 121 is connected to the second gas suction pipe 114.

[0064] In one or more embodiments of the present application, the length of the pipeline between the second distributor 121 and the first gas-separation suction pipe 113 is shorter than the length of the pipeline between the second distributor 121 and the second gas-separation suction pipe 114 .

[0065] In one or more embodiments of the present application, the outdoor unit 10 further comprises a third distributor 122. An inlet end of the third distributor 122 is connected to the second oil return branch 116, one outlet end of the third distributor 122 is connected to the second valve element 118, and another outlet end of the third distributor 122 is connected to the first gas suction pipe 113.

[0066] In one or more embodiments of the present application, the length of the pipeline between the third distributor 122 and the first gas-dividing suction pipe 113 is longer than the length of the pipeline between the third distributor 122 and the second gas-dividing suction pipe 114 .

[0067] In one or more embodiments of the present application, the pipeline between the second distributor 121 and the second gas suction pipe 114 at least partially extends from bottom to top. For example, it first extends obliquely from bottom to top and then vertically connects to the second gas suction pipe 114 downward.

[0068] In one or more embodiments of the present application, at least part of the pipeline between the third distributor 122 and the first gas suction pipe 113 extends from bottom to top. For example, it first extends obliquely from bottom to top and then vertically connects to the first gas suction pipe 113 downward.

[0069] In one or more embodiments of the present application, the first valve element 117 is a solenoid valve.

[0070] In one or more embodiments of the present application, the second valve element 118 is a solenoid valve.

[0071] In one or more embodiments of the present application, a first oil return capillary 123 and a first filter 124 are sequentially disposed between the inlet end of the second distributor 121 and the first oil separator 105 , and the first oil return capillary 123 and the first filter 124 are connected in series.

[0072] In one or more embodiments of the present application, a second oil return capillary 125 and a second filter 126 are sequentially disposed between the inlet end of the third distributor 122 and the second oil separator 106 , and the second oil return capillary 125 and the second filter 126 are connected in series.

[0073] In one or more embodiments of the present application, a first oil return capillary 123 and a first filter 124 are disposed on the first oil return branch 115 , and the first oil return capillary 123 and the first filter 124 are connected in series.

[0074] In one or more embodiments of the present application, a second oil return capillary 125 and a second filter 126 are provided on the second oil return branch 116 , and the second oil return capillary 125 and the second filter 126 are connected in series.

[0075] In one or more embodiments of the present application, the outdoor unit 10 further includes a first liquid level sensor 127 and a second liquid level sensor 128. The first liquid level sensor 127 is disposed in the first compressor 101 to detect the oil level in the first compressor 101, and the second liquid level sensor 128 is disposed in the second compressor 102 to detect the oil level in the second compressor 102.

[0076] In one or more embodiments of the present application, the first liquid level sensor 127 and the second liquid level sensor 128 are infrared liquid level sensors.

[0077] In one or more embodiments of the present application, a first outdoor heat exchanger 129 and a second outdoor heat exchanger 135 are provided in the outdoor unit 10. One end of the first outdoor heat exchanger 129 is connected to the switching valve 108 through a first gas-side piping, and the other end is connected to the liquid pipe through a first liquid-side piping. The first outdoor heat exchanger 129 has a first heat exchange body 130 and a first subcooling section 131, and a first outdoor throttling element 132 is provided between the first heat exchange body 130 and the first subcooling section 131. One end of the second outdoor heat exchanger 135 is connected to the switching valve 108 through a second gas-side piping, and the other end is connected to the liquid pipe through a second liquid-side piping. The second outdoor heat exchanger 135 has a second heat exchange body 136 and a second subcooling section 137, and a second outdoor throttling element 138 is provided between the second heat exchange body 136 and the second subcooling section 137.

[0078] In one or more embodiments of the present application, the outdoor unit 10 further includes a first air-side temperature sensor 133 , and the first air-side temperature sensor 133 is provided on the first air-side pipe.

[0079] In one or more embodiments of the present application, the outdoor unit 10 further includes a first liquid-side temperature sensor 134 , and the first liquid-side temperature sensor 134 is provided in the first liquid-side pipe.

[0080] In one or more embodiments of the present application, the outdoor unit 10 further includes a second air-side temperature sensor 139 , and the second air-side temperature sensor 139 is provided on the second air-side pipe.

[0081] In one or more embodiments of the present application, the outdoor unit 10 further includes a second liquid-side temperature sensor 140 , and the second liquid-side temperature sensor 140 is provided in the second gas-side pipe.

[0082] In one or more embodiments of the present application, the outdoor unit 10 further includes a gas connecting pipe 141 and a liquid connecting pipe 142. The gas connecting pipe 141 connects the first gas-liquid separator 111 and the second gas-liquid separator 112, and the liquid connecting pipe 142 connects the first gas-liquid separator 111 and the second gas-liquid separator 112, and the gas connecting pipe 141 is disposed above the liquid connecting pipe 142.

[0083] The operation process of the air source heat pump device is introduced below in conjunction with the accompanying drawings.

[0084] When the air source heat pump device operates in the heating mode, the first outdoor heat exchanger 129 and the second outdoor heat exchanger 135 serve as evaporators. The outdoor ambient temperature is relatively high, the outdoor heat exchanger is not dirty or blocked, and the outdoor fan 110 operates normally to provide sufficient air volume. At this time, the first outdoor heat exchanger 129 and the second outdoor heat exchanger 135 have strong evaporation capabilities, and the refrigerant is a superheated gaseous refrigerant after passing through the evaporator, and liquid refrigerant bias will not occur at this time. The detection temperatures of the first exhaust temperature sensor 103 and the second exhaust temperature sensor 104 are basically the same, the operating states of the first compressor 101 and the second compressor 102 are slightly different, and the oil concentration and viscosity in the first compressor 101 and the second compressor 102 are close to the same state, and there will be no problem of one of the compressors being empty of oil.

[0085] On the contrary, when liquid refrigerant bias occurs, the detection temperature difference between the first exhaust temperature sensor 103 and the second exhaust temperature sensor 104 is obvious, the operating conditions of the first compressor 101 and the second compressor 102 are greatly different, and there are obvious differences in the oil concentration and viscosity of the first compressor 101 and the second compressor 102. The oil discharge volume of the compressor with low oil concentration and viscosity is large, and this compressor will have an oil shortage problem, while the other compressor operates normally.

[0086] Taking the heating mode as an example, the high-temperature and high-pressure refrigerant discharged from the first compressor 101 and the second compressor 102 passes through the first oil separator 105 and the second oil separator 106, and the high-temperature and high-pressure gaseous refrigerant flowing out of the first oil separator 105 and the second oil separator 106 enters the indoor unit through the switching valve 108 and the gas side stop valve. The high-temperature and high-pressure gaseous refrigerant is condensed into a high-temperature and high-pressure supercooled liquid refrigerant after sufficient heat exchange in the indoor unit, and then flows through the liquid pipe and enters the indoor unit through the liquid side stop valve. The supercooled liquid refrigerant is throttled by the first outdoor throttling element 132 and the second outdoor throttling element 138 into a low-temperature and low-pressure two-phase refrigerant, and the two-phase refrigerant evaporates into a low-temperature and low-pressure superheated gaseous refrigerant in the first outdoor heat exchanger 129 and the second outdoor heat exchanger 135. The low-temperature and low-pressure superheated gaseous refrigerant flows out of the first outdoor heat exchanger 129 and the second outdoor heat exchanger 135 respectively, and returns to the first distributor 120 through the switching valve 108 and the low-pressure side pipe 119. Since the pipe length and diameter of the first gas suction pipe 113 and the second gas suction pipe 114 are the same, the superheated gaseous refrigerant passes through the first gas suction pipe 113 and the second gas suction pipe 114 evenly, enters the first gas-liquid separator 111 and the second gas-liquid separator 112, and then enters the first compressor 101 and the second compressor 102 respectively, completing the refrigerant cycle of the heating mode. At the same time, the lubricating oil discharged from the first compressor 101 and the second compressor 102 is separated by the first oil separator 105 and the second oil separator 106, and only a small amount of oil is discharged into the refrigerant cycle with the high-pressure exhaust gas, and most of the oil returns from the first oil return branch 115 and the second oil return branch 116, through the first oil return capillary 123 and the first filter 124, and the second oil return capillary 125 and the second filter 126.

[0087] The first valve element 117 and the second valve element 118 are in the open valve state. The oil in the first oil return branch 115 flows into the inlet end of the second distributor 121, passes through a relatively short pipeline, that is, passes through the first valve element 117, enters the first gas suction pipe 113, and then enters the first gas-liquid separator 111; the other way passes through a relatively long pipeline, that is, enters the second gas suction pipe 114, and then enters the second gas-liquid separator 112. The oil in the second oil return branch 116 flows into the inlet end of the third distributor 122, passes through a relatively short pipeline, that is, passes through the second valve element 118, enters the second gas suction pipe 114, and then enters the second gas-liquid separator 112; the other way passes through a relatively long pipeline, that is, enters the first gas suction pipe 113, and then enters the first gas-liquid separator 111.

[0088] Under normal working conditions, that is, when there is no liquid refrigerant bias in the air source heat pump device, the detection temperatures of the first exhaust temperature sensor 103 and the second exhaust temperature sensor 104 are basically the same, and the temperature difference is very small. The difference in oil concentration and viscosity in the first gas-liquid separator 111 and the second gas-liquid separator 112 is small, and there will be no situation where a large amount of oil discharge from one compressor causes a significant oil level difference or even one of the compressors is short of oil. The difference in the operating states of the first compressor 101 and the second compressor 102 is small. Figure 5 As shown, at this time, the first valve element 117 and the second valve element 118 are in the open valve state. Since the pipeline between the second distributor 121 and the first gas suction pipe 113 is relatively short, the pressure loss is small, and the pipeline between the second distributor 121 and the second gas suction pipe 114 is relatively long, the pressure loss is large, and the refrigerant needs to overcome gravity, most of the oil returned from the first oil separator 105 will pass through the first valve element 117 and enter the first gas-liquid separator 111. Similarly, since the pipeline between the third distributor 122 and the second gas suction pipe 114 is relatively short, the pressure loss is small, and the pipeline between the third distributor 122 and the first gas suction pipe 113 is relatively long, the pressure loss is large, and the refrigerant needs to overcome gravity, most of the oil returned from the second oil separator 106 will pass through the second valve element 118 and enter the second gas-liquid separator 112. Under this operating condition, the oil discharged from the first compressor 101 passes through the first oil separator 105 and mainly returns to the first gas-liquid separator 111 and the first compressor 101, and the oil discharged from the second compressor 102 passes through the second oil separator 106 and mainly returns to the second gas-liquid separator 112 and the second compressor 102.

[0089] like Figure 6As shown, when the liquid refrigerant is biased, the first valve element 117 and the second valve element 118 are in the closed valve state. The oil returned from the first oil separator 105 will enter the second gas-liquid separator 112 through the pipeline between the second distributor 121 and the second gas suction pipe 114, and the oil returned from the second oil separator 106 will enter the first gas-liquid separator 111 through the pipeline between the third distributor 122 and the first gas suction pipe 113. Specifically, if the oil concentration and viscosity of the first compressor 101 are low due to the return of the first gas-liquid separator 111, the amount of oil discharged by the first compressor 101 is large, most of the oil escapes from the first oil separator 105 into the refrigerant cycle, and a small amount of oil returns to the second gas-liquid separator 112 through the first oil return branch 115 and the second distributor 121; the oil concentration in the second gas-liquid separator 112 is high, and the oil concentration, content and liquid level in the second gas-liquid separator 112 are moderate after mixing, and the oil concentration and viscosity of the second compressor 102 are normal, and more oil will be separated from the second oil separator 106 and return to the first gas-liquid separator 111 through the second oil return branch 116, and the oil concentration and viscosity in the first gas-liquid separator 111 are also normal after mixing. At this time, although the first compressor 101 has a large amount of oil discharge, the first gas-liquid separator 111 can ensure sufficient oil supply, and the final liquid level of the first gas-liquid separator 111 also returns to normal.

[0090] like Figure 7 As shown, when only one compressor is running, the first valve element 117 and the second valve element 118 are in the open valve state. For example, when the first compressor 101 is running, the oil discharged by the first compressor 101 is separated by the first oil separator 105. Due to the suction of the first compressor 101, the pressure of the first gas-liquid separator 111 is very low. The oil separated by the first oil separator 105 passes through the first oil return branch 115 and the second distributor 121, and is sucked into the first gas-liquid separator 111 through the first valve element 117, and then returns to the first compressor 101.

[0091] In one or more embodiments of the present application, the first valve element 117 and the second valve element 118 may be driven based on the liquid levels in the first compressor 101 and the second compressor 102. For example, when the liquid levels of the first compressor 101 and the second compressor 102 are nearly the same, the first valve element 117 and the second valve element 118 are in an open valve state; when the liquid levels of the first compressor 101 and the second compressor 102 differ greatly, the first valve element 117 and the second valve element 118 are in a closed valve state.

[0092] The comparison of the liquid levels of the first compressor 101 and the second compressor 102 can be implemented by a comparator circuit or by a control chip. The comparison accuracy can be set according to the actual working conditions.

[0093] In one or more embodiments of the present application, the first valve element 117 and the second valve element 118 may be driven based on the detected temperatures of the first exhaust temperature sensor 103 and the second exhaust temperature sensor 104. For example, when the detected temperatures of the first exhaust temperature sensor 103 and the second exhaust temperature sensor 104 are approximately the same, the first valve element 117 and the second valve element 118 are approximately the same, and the first valve element 117 and the second valve element 118 are in an open valve state; when the detected temperatures of the first exhaust temperature sensor 103 and the second exhaust temperature sensor 104 are significantly different, the first valve element 117 and the second valve element 118 are in a closed valve state.

[0094] The comparison of the detected temperatures of the first exhaust temperature sensor 103 and the second exhaust temperature sensor 104 can be implemented by a comparator circuit or by a control chip. The comparison accuracy can be set according to the actual working conditions.

[0095] like Figure 8 and Fig. 9 As shown, in one or more embodiments of the present application, the outdoor unit 10 further includes a flow combiner 147. One inlet end of the flow combiner 147 is connected to the first oil return branch 115, and the other inlet end is connected to the second oil return branch 116, and the outlet end of the flow combiner 147 is respectively connected to the first gas suction pipe 113 and the second gas suction pipe 114.

[0096] Specifically, the outlet end of the flow combiner 147 is connected to the low-pressure side piping 119. The return oil of the first oil return branch 115 and the second oil return branch 116 are collected and introduced to the upstream of the first distributor 120 through the flow combiner 147. In this way, even if there is a return liquid bias in the first gas-liquid separator 111 and the second gas-liquid separator 112, that is, one of the compressors has more return liquid, the oil concentration and viscosity are reduced, and the oil discharge volume is increased, the oil in the corresponding oil separator returns less oil from the corresponding oil return branch, while the other compressor has no return liquid, the oil viscosity and concentration are normal, and the compressor exhaust oil volume and capillary return oil volume are normal, the return oil volume can be balanced through the flow combiner 147, and before re-entering the first distributor 120, it is ensured that the oil entering the first gas-liquid separator 111 and the second gas-liquid separator 112 will not have obvious deviations, so as to prevent the uneven oil level of the first compressor 101 and the second compressor 102, or even the problem of one compressor being empty of oil.

[0097] During long-term use, impurities will accumulate on the inner wall of the first distributor 120, and the distribution of the impurities will be uneven, which will cause uneven liquid distribution in the first distributor 120 and may also cause uneven oil distribution. Fig.10 and Fig.11As shown, a redistributor 149 is also provided in the outdoor unit 10. The inlet end of the redistributor 149 is connected to the outlet end of the flow combiner 147 through an extension pipe section 148, one outlet end of the redistributor 149 is connected to the first gas distribution suction pipe 113, and the other outlet end of the redistributor 149 is connected to the second gas distribution suction pipe 114.

[0098] In one or more embodiments of the present application, the extended pipe section 148 is a straight pipe section.

[0099] Through the redistributor 149, even if the first gas-liquid separator 111 and the second gas-liquid separator 112 have a liquid return bias, one of the compressors has a large amount of liquid return, low oil concentration, low viscosity, and increased oil discharge, the amount of oil returned from the corresponding oil separator from the corresponding oil return branch is small, while the other compressor has no liquid return, the oil concentration and viscosity are normal, and the amount of oil returned from the corresponding oil separator from the corresponding oil return branch is normal. The oil returned from the two oil return branches can be balanced through the combiner 147 before entering the extension pipe section 148, and then enter the redistributor 149 and evenly distributed to the first gas-liquid separator 111 and the second gas-liquid separator 112, ensuring that the oil entering the first gas-liquid separator 111 and the second gas-liquid separator 112 will not have a significant deviation, thereby preventing the uneven oil level of the first compressor 101 and the second compressor 102, or even the problem of a single compressor being empty of oil.

[0100] When the first valve element 117 and the second valve element 118 are closed, the outdoor fan 110 can also be driven to operate at the highest gear, while increasing the target superheat of the first outdoor throttling element 132 and the second outdoor throttling element 138, reducing the flow of refrigerant entering the evaporator, thereby enhancing the evaporation capacity of the evaporator, allowing the two-phase refrigerant to evaporate completely in the evaporator, and the evaporator outlet is a superheated gaseous refrigerant, so that the operating states of the two gas-liquid separators and compressors are consistent.

[0101] When the first valve element 117 and the second valve element 118 are closed, the operating frequency of a compressor with a lower exhaust temperature can be driven to decrease, thereby reducing the oil discharge amount and restoring the oil level of the compressor as soon as possible.

[0102] Adjusting the working gear of the outdoor fan 110, the target superheat of the first outdoor throttling element 132 and the second outdoor throttling element 138, and reducing the operating frequency of the first compressor 101 and the second compressor 102 are all well-known technical means in the prior art, which are not the focus of protection of the present utility model and will not be elaborated here.

[0103] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in a suitable manner in any one or more embodiments or examples.

[0104] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. Air source heat pump device, comprising: The outdoor unit has: The first compressor; Second compressor; a first gas-liquid separator connected to the suction side of the first compressor; a second gas-liquid separator connected to the suction side of the second compressor; a first oil separator connected to a discharge side of the first compressor; a second oil separator connected to the discharge side of the second compressor; and a switching valve connecting the discharge sides of the first oil separator and the second oil separator; It is characterized in that the outdoor unit also has: a first gas separation suction pipe, one end of which is connected to the switching valve, and the other end of which is connected to the first gas-liquid separator; a second gas separation suction pipe, one end of which is connected to the switching valve, and the other end of which is connected to the second gas-liquid separator; a first oil return branch, an inlet end of which is connected to the first oil separator; A second oil return branch, an inlet end of which is connected to the second oil separator; and A flow combiner, one inlet end of which is connected to the first oil return branch, another inlet end of which is connected to the second oil return branch, and an outlet end of which is respectively connected to the first gas suction pipe and the second gas suction pipe.

2. The air source heat pump device according to claim 1, characterized in that: The outdoor unit also has: A low-pressure side pipe, an inlet end of which is connected to the switching valve; and A first distributor, an inlet end of which is connected to the low-pressure side pipe, one outlet end of which is connected to the first gas distribution suction pipe, and another outlet end of which is connected to the second gas distribution suction pipe; The outlet end of the flow combiner is connected to the low-pressure side pipe, and the first gas-dividing air intake pipe and the second gas-dividing air intake pipe have the same pipe length and pipe diameter.

3. The air source heat pump device according to claim 2, characterized in that: The outdoor unit also has: The redistributor has an inlet end connected to the outlet end of the flow combiner through an extended pipe section, one outlet end is connected to the first gas distribution suction pipe, and the other outlet end is connected to the second gas distribution suction pipe.

4. The air source heat pump device according to claim 3, characterized in that: The first oil return branch is provided with a first oil return capillary and a first filter, and the first oil return capillary and the first filter are connected in series; The second oil return branch line is provided with a second oil return capillary tube and a second filter, and the second oil return capillary tube and the second filter are connected in series.

5. The air source heat pump device according to claim 4, characterized in that: The outdoor unit also has: A first exhaust gas temperature sensor disposed at the exhaust end of the first compressor; and The second exhaust gas temperature sensor is disposed at the exhaust end of the second compressor.

6. The air source heat pump device according to claim 5, characterized in that: The outdoor unit also has: A first liquid level sensor is disposed in the first compressor to detect a liquid level in the first compressor; and The second liquid level sensor is disposed in the second compressor to detect the liquid level in the second compressor.

7. The air source heat pump device according to claim 3, characterized in that: The extended pipe section is a straight pipe section.

8. The air source heat pump device according to any one of claims 1 to 7, characterized in that: The outdoor unit also has: liquid pipe; A first outdoor heat exchanger, one end of which is connected to the switching valve via a first gas-side pipe, and the other end of which is connected to the liquid pipe via a first liquid-side pipe; the first outdoor heat exchanger has a first heat exchange body and a first subcooling section, and a first outdoor throttling element is provided between the first heat exchange body and the first subcooling section; and The second outdoor heat exchanger has one end connected to the switching valve via a second gas-side pipe and the other end connected to the liquid pipe via a second liquid-side pipe; the second outdoor heat exchanger has a second heat exchange body and a second subcooling section, and a second outdoor throttling element is arranged between the second heat exchange body and the second subcooling section.

9. The air source heat pump device according to claim 8, characterized in that: The outdoor unit also has: A first gas-side temperature sensor, which is disposed on the first gas-side piping; A first liquid-side temperature sensor, which is disposed on the first liquid-side pipe; A second gas-side temperature sensor, which is disposed on the second gas-side piping; and The second liquid-side temperature sensor is provided on the second gas-side pipe.

10. The air source heat pump device according to any one of claims 1 to 7, characterized in that: The outdoor unit also has: a gas connecting pipe connecting the first gas-liquid separator and the second gas-liquid separator; a liquid connecting pipe connecting the first gas-liquid separator and the second gas-liquid separator; The gas connecting pipe is arranged above the liquid connecting pipe.

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