Air source heat pump unit

Abstract

The invention relates to an air source heat pump unit which comprises an outer shell, a first refrigerant system, a second refrigerant system, a water side heat exchanger and a controller. The first refrigerant system comprises a first compressor, a first air side heat exchanger and a first fan; the second refrigerant system comprises a second compressor, a second air side heat exchanger and a second fan; the controller is configured to control the start and stop of the first fan according to the exhaust pressure of the first compressor or the second compressor when the environment temperature is lower than the preset environment temperature in a refrigeration mode; or the controller controls the start and stop of the first fan according to the suction and exhaust pressure difference of the first compressor or the suction and exhaust pressure difference of the second compressor. The air source heat pump unit is used for ensuring that an air suction and exhaust pressure difference is formed between exhaust pressure and air suction pressure, so that a compressor enters a normal and stable operation state more quickly, stable operation of the compressor is ensured, the working efficiency of the air source heat pump unit is improved, and equipment faults are reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of air conditioners, and in particular relates to an air source heat pump unit. Background Art

[0002] The air source heat pump unit includes an air-side heat exchanger and a water-side heat exchanger. When the air-side heat exchanger serves as an evaporator and the water-side heat exchanger serves as a condenser, it can be used to achieve integrated hot water and heating. However, under some special conditions, it can also supply low-temperature water. In this state, the air-side heat exchanger serves as a condenser and the water-side heat exchanger serves as an evaporator. The low-temperature water after heat exchange and cooling can be used to cool factory equipment.

[0003] In order to improve the heat exchange efficiency, some air source heat pump units are designed with a common duct dual-system refrigerant system. When the refrigerant system with a common duct design is exposed to a low temperature environment for a long time and has experienced a long period of shutdown, when it is restarted, the temperature of the entire refrigerant system will be very low, and the exhaust end pressure and suction end pressure of the compressor will be very low. The compressor will be unable to engage the scroll plate and produce compressed refrigerant. The traditional design scheme uses electric heating on the compressor to heat the high-pressure chamber of the compressor, so that the high and low pressures of the compressor form a larger pressure difference, so as to quickly establish the pressure difference, but this scheme will increase the product cost and there is a certain risk of failure.

[0004] The above information disclosed in this background technology is only used to increase the understanding of the background technology of this application. Therefore, it may contain information that does not constitute the prior art known to ordinary technicians in this field. Summary of the Invention

[0005] The purpose of the present invention is to provide an air source heat pump unit to solve the problems existing in the prior art that the air source heat pump unit is designed with a common duct dual-system refrigerant system. In a harsh low-temperature environment, the scroll disk cannot be engaged normally when the compressor is started. Before the pressure difference is established between the exhaust end and the intake end of the compressor, the refrigerant system cannot cool normally.

[0006] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions: The present invention proposes an air source heat pump unit, which includes: An outer shell having an air inlet and an air outlet formed thereon, and an air duct formed between the air inlet and the air outlet; a first refrigerant system, which is installed in the outer shell and includes a first compressor, a first air-side heat exchanger, and a first fan connected by a first refrigerant pipeline, wherein the exhaust end of the first compressor is provided with a first pressure detection component, and the intake end is provided with a second pressure detection component; a second refrigerant system, which is installed in the outer shell and includes a second compressor, a second air-side heat exchanger, and a second fan connected by a second refrigerant pipeline; a third pressure detection device is provided at the exhaust end of the second compressor, and a fourth pressure detection device is provided at the intake end; the first air-side heat exchanger and the second air-side heat exchanger are both provided in the air duct; a water-side heat exchanger connected to the first refrigerant pipeline and the second refrigerant pipeline; a controller configured to, in cooling mode, when the ambient temperature is lower than a preset ambient temperature, control the start and stop of the first fan according to the exhaust pressure of the first compressor or the second compressor; or The controller controls the start and stop of the first fan according to the suction and exhaust pressure difference of the first compressor or the suction and exhaust pressure difference of the second compressor.

[0007] In some embodiments of the present application, when the ambient temperature is lower than a preset ambient temperature, the controller controls the second fan to remain shut down; The air source heat pump unit includes a cooling mode, which includes the first stage, the second stage, the third stage, the fourth stage and the fifth stage; In the first stage, the controller controls the first compressor to start and the first fan to stop; In the second stage, the controller controls the first compressor to remain on and controls the first fan to turn on; In the third stage, the controller controls the first compressor to stop, controls the second compressor to start, and controls the first fan to stop; In the fourth stage, the controller controls the second compressor to remain on and controls the first fan to turn on.

[0008] In the fifth stage, the controller controls the first compressor to start, and the first compressor and the second compressor cooperate to cool.

[0009] In some embodiments of the present application, during the first stage, the controller controls the first compressor to turn on. When the exhaust pressure of the first compressor detected by the first pressure detection component is less than a first preset pressure or the suction and exhaust pressure difference of the first compressor is less than the first preset pressure difference, the controller controls the first fan to remain turned off.

[0010] In the first stage, only the first compressor is turned on, the first fan and the second fan are turned off, and the first air-side heat exchanger and the second air-side heat exchanger do not perform heat exchange, which is conducive to quickly increasing the exhaust pressure of the first compressor, thereby increasing the suction and exhaust pressure difference between the suction end and the exhaust end of the first compressor.

[0011] In some embodiments of the present application, during the second stage, the controller controls the first compressor to operate at a first preset frequency. When the exhaust pressure of the first compressor detected by the first pressure detection component is not less than the first preset pressure or the suction and exhaust pressure difference of the first compressor is not less than the first preset pressure difference, the controller controls the first fan to turn on.

[0012] When the exhaust pressure of the first compressor detected by the first pressure detection component is not less than the first preset pressure or the suction and exhaust pressure difference of the first compressor is not less than the first preset pressure difference, it means that the compressor is now operating stably. Then, the first fan is started to exchange heat between the first air-side heat exchanger and the second air-side heat exchanger.

[0013] In some embodiments of the present application, the water-side heat exchanger includes a first refrigerant channel, a second refrigerant channel and a coolant channel. The first refrigerant channel is connected to the first refrigerant pipeline, and the second refrigerant channel is connected to the second refrigerant pipeline. The two ends of the coolant channel are respectively connected to the water inlet pipeline and the water outlet pipeline. A second temperature detection component is provided on the water outlet pipeline for detecting the outlet water temperature in the water outlet pipeline. After the first compressor or the first fan is turned on, the controller controls the start and stop of the second compressor according to the outlet water temperature and the rate of change of the outlet water temperature.

[0014] The first air-side heat exchanger and the second air-side heat exchanger both exchange heat with the water-side heat exchanger. When in cooling mode, the water-side heat exchanger acts as an evaporator, and the refrigerant in the first refrigerant channel and the second refrigerant channel exchanges heat with the water in the coolant channel. The water temperature in the coolant channel decreases and is output from the water outlet pipeline to cool the processing equipment in the factory. The heat exchange status of the water-side heat exchanger can be judged from the outlet water temperature, and then it can be determined whether the second compressor needs to be started.

[0015] In some embodiments of the present application, after the first compressor and the first fan are turned on, when the outlet water temperature is not higher than a preset outlet water temperature and / or the outlet water temperature change rate is not less than a preset change rate, the controller controls the second compressor to remain in an off state; After the first compressor and the first fan are turned on, when the outlet water temperature is greater than the preset outlet water temperature and the outlet water temperature change rate is less than the preset change rate, the controller controls the second compressor to turn on and enter the third stage.

[0016] When the outlet water temperature is greater than the preset outlet water temperature and the rate of change of the outlet water temperature is small, it indicates that the heat exchange efficiency of the water side heat exchanger is insufficient. The controller controls the second compressor to start and work together with the first compressor to improve the heat exchange efficiency.

[0017] In some embodiments of the present application, in the third stage, the controller controls the second compressor to operate at a second preset frequency and controls the first compressor to shut down. After the first compressor is shut down, the exhaust pressure of the first compressor gradually decreases. When the exhaust pressure of the first compressor drops to less than a second preset pressure or the suction and exhaust pressure difference of the first compressor is less than the second preset pressure difference, the controller controls the first fan to shut down. The second preset pressure is smaller than the first preset pressure, and the second preset pressure difference is smaller than the second preset pressure difference.

[0018] After the second compressor has been shut down for a long time in a low-temperature environment, its exhaust pressure and suction and exhaust pressure difference are insufficient. Forcing the second compressor to start working will cause it to be unable to engage the scroll plate normally. At this time, first shut down the first fan and stop the heat exchange of the air-side heat exchanger, which will help accelerate the increase of exhaust pressure, increase the suction and exhaust pressure difference, and make the second compressor run stably.

[0019] Since the first compressor is always in working condition, the exhaust end pressure of the second compressor is also low. Even if the second compressor is running, the exhaust end pressure of the second compressor cannot be increased. Therefore, it is necessary to shut down the first compressor first, and then restart the first compressor after the exhaust end pressure of the second compressor increases or the suction and exhaust pressure difference of the second compressor increases.

[0020] In some embodiments of the present application, in the fourth stage, the controller controls the second compressor to operate at a second preset frequency, and when the exhaust pressure of the second compressor detected by the second pressure detection element is not less than a first preset pressure or the suction and exhaust pressure difference of the second compressor is not less than the first preset pressure difference, the controller controls the first fan to start; In the fifth stage, the controller controls the first compressor to restart after the second compressor runs for a preset time.

[0021] In the fourth stage, when the exhaust pressure of the second compressor detected by the second pressure detection component is not less than the first preset pressure or the suction and exhaust pressure difference of the second compressor is not less than the second preset pressure difference, it means that the second compressor is now operating stably. Then, the first fan is started again to exchange heat between the first air-side heat exchanger and the second air-side heat exchanger.

[0022] After the second compressor is started for a preset time, the second compressor operates stably. At this time, restarting the first compressor can ensure that both the first compressor and the second compressor operate stably.

[0023] In some embodiments of the present application, when the ambient temperature is not lower than a preset ambient temperature, in cooling mode, the controller controls the first compressor, the first fan, and the second fan to be turned on synchronously; When the outlet water temperature is not higher than the preset outlet water temperature and / or the outlet water temperature change rate is not less than the preset change rate, the controller controls the second compressor to be in a shutdown state; When the outlet water temperature is higher than a preset outlet water temperature and the outlet water temperature change rate is lower than a preset change rate, the controller controls the second compressor to turn on.

[0024] In some embodiments of the present application, the first refrigerant system includes a first reversing member, the first reversing member includes a first interface, a second interface, a third interface, and a fourth interface, the first interface is connected to the exhaust end of the first compressor, the second interface is connected to the first air-side heat exchanger, the third interface is connected to the intake end of the first compressor, and the fourth interface is connected to the water-side heat exchanger; The second refrigerant system includes a second reversing member, which includes a first valve port, a second valve port, a third valve port, and a fourth valve port, wherein the first valve port is connected to the exhaust port of the second compressor, the second valve port is connected to the water-side heat exchanger, the third valve port is connected to the intake port of the second compressor, and the fourth valve port is connected to the first air-side heat exchanger; In the cooling state, the controller controls the first interface to be connected to the second interface, the third interface to be connected to the fourth interface; the first valve port to be connected to the fourth valve port, and the second valve port to be connected to the third valve port.

[0025] Compared with the prior art, the advantages and positive effects of the present invention are: The air source heat pump unit involved in the present application includes a first refrigerant system and a second refrigerant system. The first fan in the first refrigerant system and the second fan in the second refrigerant system are both arranged in the air duct. When the air source heat pump unit is started, in the cooling mode, when the ambient temperature is lower than the preset temperature, the controller controls the second fan to shut down, and only the first fan is turned on to realize the heat exchange of the two air-side heat exchangers. The controller controls the start and stop of the first fan according to the exhaust pressure detected by the first pressure detection component and the second pressure detection component, thereby ensuring that when the first compressor and the second compressor are started, an intake and exhaust pressure difference is formed between the exhaust pressure and the intake pressure, so that the compressor can enter the normal and stable operation state faster, provide a guarantee for the stable operation of the compressor, improve the working efficiency of the air source heat pump unit, and reduce equipment failures.

[0026] Other features and advantages of the present invention will become more apparent after reading the detailed description of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0028] Figure 1 is a perspective view of an air source heat pump air conditioning unit according to an embodiment; Figure 2 is a side view of an air source heat pump air conditioning unit according to an embodiment; Figure 3 is a front view of an air source heat pump air conditioning unit according to an embodiment; Figure 4 Schematic diagram of a refrigerant system of an air source heat pump air conditioning unit according to an embodiment; Figure 5 is a system diagram of an air source heat pump air conditioning unit according to an embodiment; Figure 6 is a schematic diagram of a first reversing valve or a second reversing valve according to an embodiment; Figure 7 is a system diagram of a heat pump air conditioning unit in a cooling state according to an embodiment; Figure 8 is a system diagram of a heat pump air conditioning unit in a heating state according to an embodiment; Figure 9 This is one of the switch status diagrams of the air source heat pump air conditioning unit components in the cooling state; Figure 10 This is the second diagram of the switch status of the air source heat pump air conditioning unit components in the cooling state; Figure 11 Schematic diagram of the switching conditions of the first fan; Figure 12 This is the cooling mode flow chart of the heat pump air conditioning unit; Reference numerals: 10. Outer shell; 110, first compressor; 111, first fan; 120, second compressor; 121, second fan; 210, first air side heat exchanger; 220, second air side heat exchanger; 310, first reversing member; 311, first interface; 312, second interface; 313, third interface; 314, fourth interface; 320, second reversing member; 321, first valve port; 322, second valve port; 323, third valve port; 324, fourth valve port; 400, water side heat exchanger; 410, water inlet pipe; 420, water outlet pipe; 510, first gas-liquid separator; 520, second gas-liquid separator; 610, first pressure detection element; 620, second pressure detection element; 630, third pressure detection element; 640, fourth pressure detection element; 710, first expansion valve group; 720, second expansion valve group; 800. Temperature detection component. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0030] In the description of this application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0031] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. Throughout this application, unless otherwise specified, "plurality" means two or more.

[0032] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0033] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0034] 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 are not intended to limit the present invention. In addition, the present invention may repeat reference numbers and / or reference letters in different examples. Such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides examples of various specific processes and materials, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0035] Air conditioners, such as air source heat pumps, perform the air conditioner's refrigeration cycle using a compressor, condenser, expansion valve, and evaporator. The refrigeration cycle involves a series of processes, including compression, condensation, expansion, and evaporation, to cool or heat the indoor space.

[0036] Low-temperature, low-pressure refrigerant enters the compressor, which compresses it into high-temperature, 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, releasing heat into the surrounding environment through the condensation process.

[0037] The expansion valve expands the high-temperature, high-pressure liquid refrigerant condensed in the condenser to a lower-pressure liquid. The evaporator evaporates the refrigerant expanded in the expansion valve and returns the low-temperature, low-pressure refrigerant gas to the compressor. The evaporator achieves cooling by utilizing the latent heat of evaporation to exchange heat with the material being cooled.

[0038] refer to Figure 1-Figure 5 The present invention proposes an air source heat pump unit, which includes an outer shell 10, a first refrigerant system, a second refrigerant system and a controller.

[0039] An air inlet and an air outlet are formed on the outer shell 10 , and an air duct is formed between the air inlet and the air outlet.

[0040] The first refrigerant system and the second refrigerant system are disposed in the outer shell 10 .

[0041] The first refrigerant system includes a first compressor 110 , a first air-side heat exchanger 210 , and a first fan 111 , which are connected via a first refrigerant pipeline.

[0042] The second refrigerant system includes a second compressor 120 , a second air-side heat exchanger 220 , and a second fan 121 , which are connected via a second refrigerant pipeline.

[0043] The air inlet is formed on the peripheral side of the outer shell 10 , and the air outlet is provided on the top of the outer shell 10 .

[0044] Specifically, the air outlet includes a first air outlet and a second air outlet, and the first fan 111 and the second fan 121 are installed on the first air outlet and the second air outlet, respectively.

[0045] The first air-side heat exchanger 210 and the second air-side heat exchanger 220 are both arranged in the air duct. In other words, the air source heat pump unit involved in this application is a common air duct dual refrigerant system, and the first air-side heat exchanger 210 and the second air-side heat exchanger 220 are both plate heat exchangers.

[0046] The first compressor 110 and the second compressor 120 are mounted at the bottom of the mounting cavity of the outer shell 10 , and the first air-side heat exchanger 210 and the second air-side heat exchanger 220 are supported at an upper position of the mounting cavity by a bracket.

[0047] In order to increase the heat exchange area of the first air-side heat exchanger 210 and the second air-side heat exchanger 220, the first air-side heat exchanger 210 and the second air-side heat exchanger 220 are designed to be combined into a V-shaped structure with the opening facing upward.

[0048] The airflow input from the air inlet on the peripheral side of the outer shell 10 is output from the first air outlet or the second air outlet on the top of the outer shell 10 after heat exchange through the first air side heat exchanger 210 or the second air side heat exchanger 220 .

[0049] The air source heat pump unit further includes a water-side heat exchanger 400 , which is connected to the first refrigerant pipeline and the second refrigerant pipeline.

[0050] Specifically, the water side heat exchanger 400 includes a first refrigerant channel, a second refrigerant channel and a coolant channel. The first refrigerant channel is connected to the first refrigerant pipeline, the second refrigerant channel is connected to the second refrigerant pipeline, and the two ends of the coolant channel are respectively connected to the water inlet pipeline 410 and the water outlet pipeline 420.

[0051] The first refrigerant pipeline further includes a first reversing member 310 and a first expansion valve group 710 . The first expansion valve group 710 is connected between the first air-side heat exchanger 210 and the water-side heat exchanger 400 .

[0052] The second refrigerant pipeline further includes a second reversing member 320 and a second expansion valve group 720 . The second expansion valve group 720 is connected between the second air-side heat exchanger 220 and the water-side heat exchanger 400 .

[0053] The first compressor 110 and the second compressor 120 are formed with a suction end and a discharge end.

[0054] refer to Figure 6 The first reversing member 310 includes a first interface 311, a second interface 312, a third interface 313 and a fourth interface 314. The first interface 311 is connected to the exhaust end of the first compressor 110, the second interface 312 is connected to the first air-side heat exchanger 210, the third interface 313 is connected to the intake end of the first compressor 110, and the fourth interface 314 is connected to the water-side heat exchanger 400.

[0055] The second refrigerant system includes a second reversing member 320, and the second reversing member 320 includes a first valve port 321, a second valve port 322, a third valve port 323 and a fourth valve port 324. The first valve port 321 is connected to the exhaust end of the second compressor 120, the second valve port 322 is connected to the water side heat exchanger 400, the third valve port 323 is connected to the intake end of the second compressor 120, and the fourth valve port 324 is connected to the first air side heat exchanger 210.

[0056] The suction end of the compressor is used for inhaling air. The refrigerant enters the compression chamber of the compressor through the suction end and is compressed by the compressor, and then forms a high-temperature and high-pressure refrigerant gas. The high-temperature and high-pressure refrigerant gas is then discharged from the compressor from the exhaust end and then enters the multi-split air-conditioning system for refrigerant circulation, realizing different modes of the multi-split air-conditioning system.

[0057] The number of the compressors may be one or more, for example, one or more compressors are connected in parallel to form a compressor group.

[0058] The compressor can be a fixed speed compressor or a variable speed compressor.

[0059] A first gas-liquid separator 510 is provided between the third interface 313 and the suction end of the first compressor 110 , and a second gas-liquid separator 520 is provided between the third valve port 323 and the suction end of the second compressor 120 .

[0060] The air source heat pump unit can realize heating and cooling functions. In the heating state, the first air side heat exchanger 210 and the second air side heat exchanger 220 serve as evaporators, and the water side heat exchanger 400 serves as a condenser.

[0061] In the heating state, the first air-side heat exchanger 210 and the second air-side heat exchanger 220 serve as evaporators, and the water-side heat exchanger 400 serves as a condenser.

[0062] refer to Figure 8 The controller controls the first interface 311 to be connected to the fourth interface 314 , the second interface 312 to be connected to the third interface 313 ; the first valve port 321 to be connected to the second valve port 322 , and the third valve port 323 to be connected to the fourth valve port 324 .

[0063] In the first refrigerant system, the refrigerant output from the exhaust end of the first compressor 110 is transported to the first refrigerant channel of the water side heat exchanger 400 through the first interface 311 and the fourth interface 314 of the first reversing member 310, and then is transported to the first air side heat exchanger 210 after passing through the first expansion valve group 710 for heat exchange, and then passes through the second interface 312 and the third interface 313 of the first reversing member 310 and is returned to the first compressor 110.

[0064] In the second refrigerant system, the refrigerant output from the exhaust end of the second compressor 120 passes through the first valve port 321 and the second valve port 322 of the second reversing member 320, and is transported to the second refrigerant channel. Then, after passing through the second expansion valve group 720, it is transported to the second air-side heat exchanger 220 for heat exchange, and finally, after passing through the fourth valve port 324 and the third valve port 323 of the second reversing member 320, it is transported back to the compressor.

[0065] The water flow transported from the water inlet pipe 410 to the brine channel exchanges heat with the refrigerant in the first refrigerant channel and the second refrigerant channel in the water-side heat exchanger 400 and is heated before being output from the water outlet pipe 420 .

[0066] The airflow input into the air duct from the air outlet is cooled by the first air-side heat exchanger 210 and the second air-side heat exchanger 220 and then output from the air outlet.

[0067] refer to Figure 7 In the cooling state, the controller controls the first interface 311 of the first reversing member 310 to be connected to the second interface 312, the third interface 313 to be connected to the fourth interface 314; the first valve port 321 to be connected to the fourth valve port 324, and the second valve port 322 to be connected to the third valve port 323.

[0068] In the first refrigerant system, the refrigerant output from the exhaust end of the first compressor 110 passes through the first interface 311 and the second interface 312 of the first reversing member 310, and is transported to the first air-side heat exchanger 210 for heat exchange. Then, it passes through the first expansion valve group 710 and is transported to the first refrigerant channel of the water-side heat exchanger 400. Thereafter, it passes through the fourth interface 314 and the third interface 313 of the first reversing member 310 and is returned to the first compressor 110.

[0069] In the second refrigerant system, the refrigerant output from the exhaust end of the second compressor 120 passes through the first valve port 321 and the fourth valve port 324 of the second reversing member 320, and is transported to the second air-side heat exchanger 220 for heat exchange. Then, it passes through the second expansion valve group 720 and is transported to the second refrigerant channel of the water-side heat exchanger 400. Thereafter, it passes through the second valve port 322 and the third valve port 323 of the second reversing member 320 and is transported back to the second compressor 120.

[0070] In the cooling state, the water flow transported from the water inlet pipe 410 to the coolant channel exchanges heat with the refrigerant in the first refrigerant channel and the second refrigerant channel in the water-side heat exchanger 400 for cooling, and then is output to the user end from the water outlet pipe 420 to cool the processing equipment in the factory.

[0071] The airflow input into the air duct from the air outlet is heated by the first air-side heat exchanger 210 and the second air-side heat exchanger 220 and then output from the air outlet.

[0072] Since the air source heat pump unit may be exposed to a low temperature environment for a long time and has experienced a long period of shutdown, when it is restarted, the temperature of the entire refrigerant system will be very low, and the exhaust end pressure and the suction end pressure of the first compressor 110 and the second compressor 120 will be very low. The compressor will not be able to engage the scroll plate and produce compressed refrigerant.

[0073] In order to solve the above problem, the air source heat pump unit of the present application is provided with a first pressure detection member 610 at the exhaust end of the first compressor 110 and a second pressure detection member 620 at the intake end. The first pressure detection member 610 is used to detect the exhaust pressure P of the first compressor 110. 排1 The second pressure detection element 620 is used to detect the suction pressure P of the first compressor 110. 吸1 .

[0074] The exhaust end of the second compressor 120 is provided with a third pressure detection element 630, and the intake end is provided with a fourth pressure detection element 640. The third pressure detection element 630 is used to detect the exhaust pressure P of the second compressor 120. 排2 The fourth pressure detection element 640 is used to detect the suction pressure P of the second compressor 120. 吸2 .

[0075] A temperature detection component 800 is provided outside the air source heat pump assembly for detecting the ambient temperature.

[0076] The controller is configured to control the start and stop of the first fan 111 according to the exhaust pressure of the first compressor 110 or the second compressor 120 in the cooling mode when the ambient temperature is lower than the preset ambient temperature; or The controller controls the start and stop of the first fan 111 according to the suction and exhaust pressure difference of the first compressor 110 or the suction and exhaust pressure difference of the second compressor 120 .

[0077] In some embodiments of the present application, when the ambient temperature is lower than the preset ambient temperature, the controller controls the second fan 121 to remain shut down, and only drives the heat exchange airflow through the first fan 111 to reduce the heat exchange efficiency of the first air-side heat exchanger 210 and the second air-side heat exchanger 220, thereby avoiding the exhaust pressure being too low during the operation of the first compressor 110 and the second compressor 120, which affects the working stability of the first compressor 110 and the second compressor 120.

[0078] Combine Figures 9-11 ,The cooling modes of the air source heat pump unit include the first stage, the second stage, the third stage, the fourth stage and the fifth stage; In the first stage, the controller controls the first compressor 110 to be turned on, and the second compressor 120 and the first fan 111 to be turned off.

[0079] In the second stage, the controller controls the first compressor 110 to remain on, controls the first fan 111 to be on, and controls the second compressor 120 to be off.

[0080] In the third stage, the controller controls the first compressor 110 to be turned off, controls the second compressor 120 to be turned on, and controls the first fan 111 to be turned off.

[0081] In the fourth stage, the controller controls the second compressor 120 to remain on, controls the first fan 111 to be on, and keeps the first compressor 110 in the off state.

[0082] In the fifth stage, the controller controls the first compressor 110 to start, and the first compressor 110 and the second compressor 120 cooperate to cool.

[0083] The following is an explanation of the startup process of the air source heat pump unit in a low temperature environment and cooling mode: At ambient temperature T h In an environment lower than the preset ambient temperature T1, after receiving the refrigeration start signal, the controller controls the first interface 311 of the first reversing member 310 to be connected with the second interface 312, and the third interface 313 to be connected with the fourth interface 314; the first valve port 321 to be connected with the fourth valve port 324, and the second valve port 322 to be connected with the third valve port 323.

[0084] During the first stage, the controller controls the first compressor 110 to start. When the exhaust pressure P of the first compressor 110 detected by the first pressure detection element 610 is 排1 is less than the first preset pressure P1 or the suction and exhaust pressure difference ΔP of the first compressor 110 排1When the pressure difference is less than the first preset pressure difference △P1, the controller controls the first fan 111 to remain shut down.

[0085] That is, when P 排1 < P1 or △P 排1 < △P1, the first fan 111 does not start and remains shut down.

[0086] In the first stage, only the first compressor 110 is turned on, the second compressor 120, the first fan 111, and the second fan 121 are in the shut-down state, and the first air-side heat exchanger 210 and the second air-side heat exchanger 220 do not exchange heat, which is beneficial to quickly increase the exhaust pressure of the first compressor 110, and then increase the suction and exhaust pressure difference between the suction end and the exhaust end of the first compressor 110.

[0087] In some embodiments of the present application, during the second stage, the controller controls the first compressor 110 to operate at a first preset frequency. When the exhaust pressure P of the first compressor 110 detected by the first pressure detector 610 排1 is not less than the first preset pressure P1 or the suction and exhaust pressure difference △P of the first compressor 110 排1 is not less than the first preset pressure difference △P1, the controller controls the first fan 111 to start.

[0088] That is, when P 排1 ≥ P1 or △P 排1 ≥ △P1, the first fan 111 starts.

[0089] When the exhaust pressure of the first compressor 110 detected by the first pressure detector 610 is not less than the first preset pressure or the suction and exhaust pressure difference of the first compressor 110 is not less than the first preset pressure difference, in other words, when the exhaust pressure of the first compressor 110 is greater than or equal to the first preset pressure or the suction and exhaust pressure difference of the first compressor 110 is greater than or equal to the first preset pressure difference, it means that the compressor has been operating stably at this time. Then, the first fan 111 is started to exchange heat between the first air-side heat exchanger 210 and the second air-side heat exchanger 220.

[0090] In order to monitor the water temperature after heat exchange in the outlet water pipeline 420, a second temperature detector 800 is provided on the outlet water pipeline 420 to detect the outlet water temperature in the outlet water pipeline 420.

[0091] After the first compressor 110 or the first fan 111 is turned on, the controller controls the start and stop of the second compressor 120 according to the outlet water temperature and the change rate of the outlet water temperature.

[0092] Specifically, in some embodiments of the present application, both the first air-side heat exchanger 210 and the second air-side heat exchanger 220 exchange heat with the water-side heat exchanger 400. In the refrigeration mode, the water-side heat exchanger 400 serves as an evaporator, and the refrigerant in the first refrigerant channel and the second refrigerant channel exchanges heat with the water in the coolant channel. The temperature of the water in the coolant channel decreases and is output from the water outlet pipe 420 for cooling the processing equipment in the factory. The heat exchange state of the water-side heat exchanger 400 can be judged from the outlet water temperature, and then it can be judged whether the second compressor 120 needs to be started.

[0093] After the first compressor 110 and the first fan 111 are turned on, when the outlet water temperature is not higher than the preset outlet water temperature and / or the outlet water temperature change rate is not less than the preset change rate, the controller controls the second compressor 120 to remain shut down.

[0094] After the first compressor 110 and the first fan 111 are turned on, when the outlet water temperature is greater than the preset outlet water temperature and the outlet water temperature change rate is less than the preset change rate, the controller controls the second compressor 120 to turn on and enters the third stage.

[0095] When the outlet water temperature is greater than the preset outlet water temperature and the change rate of the outlet water temperature is small, it indicates that the heat exchange efficiency of the water-side heat exchanger 400 is insufficient. The controller controls the second compressor 120 to turn on and work in coordination with the first compressor 110 to improve the heat exchange efficiency.

[0096] In some embodiments of the present application, during the third stage, the controller controls the second compressor 120 to operate at the second preset frequency and controls the first compressor 110 to shut down. After the first compressor 110 shuts down, the discharge pressure of the first compressor 110 gradually decreases. When the discharge pressure P 排1 of the first compressor 110 drops to less than the second preset pressure P2 or the suction-discharge pressure difference △P 排1 of the first compressor 110 is less than the second preset pressure difference △P2, the controller controls the first fan 111 to shut down.

[0097] In other words, when P 排1 < P2 or △P 排1 < △P2, the controller controls the first fan 111 to shut down.

[0098] Among them, the second preset pressure is less than the first preset pressure, and the second preset pressure difference is less than the first preset pressure difference. That is, P2 < P1, △P2 < △P1. A pressure hysteresis is formed between P2 and P1, and between △P2 and △P1 to prevent fluctuations in the discharge pressure or the suction-discharge pressure difference during the operation of the first compressor 110, resulting in frequent start and stop of the first fan 111.

[0099] After the second compressor 120 has been shut down for a long time in a low-temperature environment, its discharge pressure and the differential pressure between the suction and discharge are insufficient. If the second compressor 120 is forced to start working, it will cause its scroll plates to fail to mesh properly. At this time, first shut down the first blower 111 to stop the heat exchange of the air-side heat exchanger, which is beneficial to accelerating the increase of the discharge pressure, increasing the differential pressure between the suction and discharge, and making the operation of the second compressor 120 stable.

[0100] Since the first compressor 110 is always in the working state, the discharge pressure at the discharge end of the second compressor 120 is also relatively low. Even if the second compressor 120 operates, it cannot increase the discharge pressure at the discharge end of the second compressor 120. Therefore, it is necessary to first shut down the first compressor 110, and then restart the first compressor 110 after the discharge pressure at the discharge end of the second compressor 120 increases or the differential pressure between the suction and discharge of the second compressor 120 increases.

[0101] In some embodiments of the present application, in the fourth stage, the controller controls the second compressor 120 to operate at a second preset frequency. When the discharge pressure P₂ of the second compressor 120 detected by the second pressure detector 620 is not less than the first preset pressure P₁ or the differential pressure ΔP₂ between the suction and discharge of the second compressor 120 is not less than the first preset differential pressure, the controller controls the first blower 111 to start.

[0102] In other words, when P 排2 ≥P₁, or ΔP 排2 ≥ΔP₁, the controller controls the first blower 111 to start.

[0103] In the fourth stage, when the discharge pressure of the second compressor 120 detected by the second pressure detector 620 is not less than the first preset pressure or the differential pressure between the suction and discharge of the second compressor 120 is not less than the second preset differential pressure, it indicates that the second compressor 120 has been operating stably at this time. Then, start the first blower 111 to conduct heat exchange for the first air-side heat exchanger 210 and the second air-side heat exchanger 220.

[0104] In the fifth stage, after the second compressor 120 has been operating for a preset time, the controller controls the first compressor 110 to restart.

[0105] Or, on the basis of starting the second compressor 120, when the first blower 111 restarts, control the first compressor 110 to restart simultaneously, that is, refer to Figure 10 , in the fourth stage, when the first blower 111 starts, start the first compressor 110 simultaneously.

[0106] The second compressor 120 operates stably. At this time, restart the first compressor 110, which can ensure that both the first compressor 110 and the second compressor 120 operate stably.

[0107] In some embodiments of the present application, when the ambient temperature is not lower than the preset ambient temperature, that is, when Th≥T1, it means that the ambient temperature is relatively high. In the cooling mode, the controller controls the first compressor 110, the first fan 111 and the second fan 121 to start synchronously.

[0108] When the outlet water temperature is not higher than the preset outlet water temperature and / or the outlet water temperature change rate is not less than the preset change rate, the controller controls the second compressor 120 to be in the shutdown state.

[0109] When the outlet water temperature is higher than the preset outlet water temperature and the outlet water temperature change rate is lower than the preset change rate, the controller controls the second compressor 120 to turn on.

[0110] The air source heat pump unit involved in the present application includes a first refrigerant system and a second refrigerant system. The first fan 111 in the first refrigerant system and the second fan 121 in the second refrigerant system are both arranged in the air duct. When the air source heat pump unit is started, in the cooling mode, when the ambient temperature is lower than the preset temperature, the controller controls the second fan 121 to shut down, and only realizes the heat exchange of the two air-side heat exchangers by turning on the first fan 111. The controller controls the start and stop of the first fan 111 according to the exhaust pressure detected by the first pressure detection component 610 and the second pressure detection component 620, thereby ensuring that when the first compressor 110 and the second compressor 120 are started, an intake and exhaust pressure difference is formed between the exhaust pressure and the intake pressure, so that the compressor can enter the normal and stable operation state faster, provide a guarantee for the stable operation of the compressor, improve the working efficiency of the air source heat pump unit, and reduce equipment failures.

[0111] Wherever possible, the various aspects and features described and illustrated in this specification may be applied separately, and these separate aspects may be made the subject of divisional applications.

[0112] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0113] The above are only specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. An air source heat pump unit, characterized in that: include: outer shell; An air inlet and an air outlet are formed thereon, and an air duct is formed between the air inlet and the air outlet; a first refrigerant system, which is installed in the outer shell and includes a first compressor, a first air-side heat exchanger, and a first fan connected by a first refrigerant pipeline, wherein the exhaust end of the first compressor is provided with a first pressure detection component, and the intake end is provided with a second pressure detection component; a second refrigerant system, which is installed in the outer shell and includes a second compressor, a second air-side heat exchanger, and a second fan connected by a second refrigerant pipeline; a third pressure detection device is provided at the exhaust end of the second compressor, and a fourth pressure detection device is provided at the intake end; the first air-side heat exchanger and the second air-side heat exchanger are both provided in the air duct; a water-side heat exchanger connected to the first refrigerant pipeline and the second refrigerant pipeline; a controller configured to, in cooling mode, control the start and stop of the first fan according to the exhaust pressure of the first compressor or the second compressor when the ambient temperature is lower than a preset ambient temperature; or The controller controls the start and stop of the first fan according to the suction and exhaust pressure difference of the first compressor or the suction and exhaust pressure difference of the second compressor.

2. The air source heat pump unit according to claim 1, characterized in that: When the ambient temperature is lower than the preset ambient temperature, the controller controls the second fan to remain shut down; The air source heat pump unit includes a cooling mode, which includes the first stage, the second stage, the third stage, the fourth stage and the fifth stage; In the first stage, the controller controls the first compressor to start and the first fan to stop; In the second stage, the controller controls the first compressor to remain on and controls the first fan to turn on; In the third stage, the controller controls the first compressor to stop, controls the second compressor to start, and controls the first fan to stop; In the fourth stage, the controller controls the second compressor to remain on and controls the first fan to turn on; In the fifth stage, the controller controls the first compressor to start, and the first compressor and the second compressor cooperate to cool.

3. The air source heat pump unit according to claim 2, characterized in that: During the first stage, the controller controls the first compressor to turn on. When the exhaust pressure of the first compressor detected by the first pressure detection component is lower than the first preset pressure or the suction and exhaust pressure difference of the first compressor is lower than the first preset pressure difference, the controller controls the first fan to remain shut down.

4. The air source heat pump unit according to claim 2, characterized in that: During the second stage, the controller controls the first compressor to operate at a first preset frequency. When the exhaust pressure of the first compressor detected by the first pressure detection component is not less than the first preset pressure or the suction and exhaust pressure difference of the first compressor is not less than the first preset pressure difference, the controller controls the first fan to turn on.

5. The air source heat pump unit according to claim 3, characterized in that: The water-side heat exchanger includes a first refrigerant channel, a second refrigerant channel and a coolant channel. The first refrigerant channel is connected to the first refrigerant pipeline, and the second refrigerant channel is connected to the second refrigerant pipeline. The two ends of the coolant channel are respectively connected to the water inlet pipeline and the water outlet pipeline. A second temperature detection component is provided on the water outlet pipeline for detecting the outlet water temperature in the water outlet pipeline. After the first compressor or the first fan is turned on, the controller controls the start and stop of the second compressor according to the outlet water temperature and the outlet water temperature change rate.

6. The air source heat pump unit according to claim 5, characterized in that: After the first compressor and the first fan are turned on, when the outlet water temperature is not higher than a preset outlet water temperature and / or the outlet water temperature change rate is not less than a preset change rate, the controller controls the second compressor to remain in an off state; After the first compressor and the first fan are turned on, when the outlet water temperature is greater than the preset outlet water temperature and the outlet water temperature change rate is less than the preset change rate, the controller controls the second compressor to turn on and enter the third stage.

7. The air source heat pump unit according to claim 6, characterized in that: In the third stage, the controller controls the second compressor to operate at a second preset frequency and controls the first compressor to shut down. After the first compressor is shut down, the exhaust pressure of the first compressor gradually decreases. When the exhaust pressure of the first compressor drops to less than a second preset pressure or the suction and exhaust pressure difference of the first compressor is less than the second preset pressure difference, the controller controls the first fan to shut down. The second preset pressure is smaller than the first preset pressure, and the second preset pressure difference is smaller than the second preset pressure difference.

8. The air source heat pump unit according to claim 6, characterized in that: In the fourth stage, the controller controls the second compressor to operate at a second preset frequency. When the exhaust pressure of the second compressor detected by the second pressure detection element is not less than the first preset pressure or the suction and exhaust pressure difference of the second compressor is not less than the first preset pressure difference, the controller controls the first fan to start. In the fifth stage, the controller controls the first compressor to restart after the second compressor runs for a preset time.

9. The air source heat pump unit according to claim 7, characterized in that: When the ambient temperature is not lower than the preset ambient temperature, in cooling mode, the controller controls the first compressor, the first fan and the second fan to start synchronously; When the outlet water temperature is not higher than the preset outlet water temperature and / or the outlet water temperature change rate is not less than the preset change rate, the controller controls the second compressor to be in a shutdown state; When the outlet water temperature is higher than a preset outlet water temperature and the outlet water temperature change rate is lower than a preset change rate, the controller controls the second compressor to turn on.

10. The air source heat pump unit according to any one of claims 1 to 9, characterized in that: The first refrigerant system includes a first reversing member, which includes a first interface, a second interface, a third interface, and a fourth interface, wherein the first interface is connected to the exhaust end of the first compressor, the second interface is connected to the first air-side heat exchanger, the third interface is connected to the intake end of the first compressor, and the fourth interface is connected to the water-side heat exchanger; The second refrigerant system includes a second reversing member, which includes a first valve port, a second valve port, a third valve port, and a fourth valve port, wherein the first valve port is connected to the exhaust port of the second compressor, the second valve port is connected to the water-side heat exchanger, the third valve port is connected to the intake port of the second compressor, and the fourth valve port is connected to the first air-side heat exchanger; In the cooling state, the controller controls the first interface to be connected to the second interface, the third interface to be connected to the fourth interface; the first valve port to be connected to the fourth valve port, and the second valve port to be connected to the third valve port.

Images