Heat pump system, temperature adjusting equipment and control method of temperature adjusting equipment

Abstract

The invention relates to the field of temperature adjusting equipment, in particular to a heat pump system, temperature adjusting equipment and a control method of the temperature adjusting equipment, and aims to solve the problem that the structure of existing temperature adjusting equipment cannot be simplified on the premise that the heating performance under the normal heating working condition and the ultralow-temperature heating working condition cannot be guaranteed. The heat pump system comprises a refrigerant loop, a first compressor, a condenser, a first throttling device, an evaporator, a second compressor and a throttling structure. The first compressor, the condenser, the first throttling device and the evaporator are sequentially arranged on the refrigerant loop; the second compressor is used for blowing hot air to the evaporator, the throttling structure is provided with a first passage structure and a second passage structure, the first passage structure is provided with a first throttling hole, the second passage structure is provided with a second throttling hole, and the first throttling hole is smaller than the second throttling hole; the throttling structure is arranged to be capable of selectively communicating with the output end of the second compressor through one of the first passage structure and the second passage structure.

Description

Technical Field

[0001] The present invention relates to the field of temperature regulating equipment, and specifically provides a heat pump system, a temperature regulating equipment and a control method for the temperature regulating equipment. Background Art

[0002] Current heat pump temperature control equipment (air conditioners, heaters) can maintain good heating performance in heating mode if the external ambient temperature is above the temperature threshold (such as -20°C), usually with a COP of around 2-5. When the external ambient temperature is lower than the temperature threshold, the heating capacity and COP will be greatly reduced. The current solution is generally to increase enthalpy by adding air, but its heating COP is still less than 2. For users, the lower the temperature, the greater the heating demand.

[0003] In order to ensure the heating performance of the heat pump system under normal heating conditions and ultra-low temperature heating conditions, the heat pump system currently used includes a cascade heat pump system. Although the cascade heat pump system has improved the heating performance under ultra-low temperature heating conditions, its structure is complex and occupies a large volume.

[0004] Accordingly, the art needs a new heat pump system, temperature control device and control method of the temperature control device to solve the problem that the existing temperature control device cannot guarantee the heating performance under normal heating conditions and ultra-low temperature heating conditions while simplifying the structure. Summary of the invention

[0005] The present invention aims to solve the above technical problem, that is, to solve the problem that the existing temperature regulating equipment cannot guarantee the heating performance under normal heating conditions and ultra-low temperature heating conditions while simplifying the structure.

[0006] In a first aspect, the present invention provides a heat pump system, characterized in that the heat pump system comprises: a refrigerant circuit, a first compressor, a condenser, a first throttling device and an evaporator, wherein the first compressor, the condenser, the first throttling device and the evaporator are sequentially arranged on the refrigerant circuit; a second compressor, wherein the second compressor is used to blow hot air to the evaporator; a throttling structure, wherein the throttling structure has a first passage structure and a second passage structure, wherein the first passage structure has a first throttling hole, and the second passage structure has a second throttling hole, and the first throttling hole is smaller than the second throttling hole; the throttling structure is configured to be selectively connected to the output end of the second compressor with one of the first passage structure and the second passage structure.

[0007] In the preferred technical solution of the above-mentioned heat pump system, the first passage structure includes a first pipe, one end of the first pipe is connected to the output end, the other end of the first pipe faces the evaporator, and a second throttling device is provided on the first pipe, and the second throttling device has a first throttling hole; the second passage structure includes a second pipe, one end of the second pipe is connected to the output end, the other end of the second pipe faces the evaporator, and a third throttling device is provided on the second pipe, and the third throttling device has a second throttling hole.

[0008] In the preferred technical solution of the above-mentioned heat pump system, the throttling structure includes an electronic expansion valve and an exhaust pipeline, one end of the exhaust pipeline is connected to the output end, and the other end of the exhaust pipeline faces the evaporator, and the electronic expansion valve is arranged on the exhaust pipeline, and the electronic expansion valve is configured to be selectively adjustable to the first throttling hole state and the second throttling hole state; the electronic expansion valve in the first throttling hole state and the exhaust pipeline constitute the first passage structure, and the electronic expansion valve in the second throttling hole state and the exhaust pipeline constitute the second passage structure.

[0009] On the other hand, the present invention further provides a temperature regulating device, which comprises the heat pump system described in any one of the above embodiments.

[0010] On the other hand, the present invention also provides a control method for a temperature regulating device, characterized in that the temperature regulating device includes a heat pump system, and the heat pump system includes: a refrigerant circuit, a first compressor, a condenser, a first throttling device and an evaporator, wherein the first compressor, the condenser, the first throttling device and the evaporator are arranged in sequence on the refrigerant circuit; a second compressor, the second compressor is used to blow hot air to the evaporator; a throttling structure, the throttling structure has a first passage structure and a second passage structure, the first passage structure has a first throttling hole, the second passage structure has a second throttling hole, and the first throttling hole is smaller than the second throttling hole; the throttling structure is configured to be selectively connected to the output end of the second compressor with one of the first passage structure and the second passage structure; the control method includes: when the heating mode is enabled, controlling the first compressor and the second compressor to turn on; obtaining the outdoor ambient temperature; based on the outdoor ambient temperature, selectively controlling the throttling structure to be connected to the output end of the second compressor with one of the first passage structure and the second passage structure.

[0011] In the preferred technical solution of the control method of the above-mentioned temperature regulating device, the step of "selectively controlling the throttling structure to be connected to the output end of the second compressor with one of the first passage structure and the second passage structure" further includes: when the outdoor ambient temperature is greater than the external ring temperature threshold, controlling the throttling structure to be connected to the output end of the second compressor only with the second passage structure.

[0012] In the preferred technical solution of the control method of the above-mentioned temperature regulating device, the step of "selectively controlling the throttling structure to be connected to the output end of the second compressor with one of the first passage structure and the second passage structure" further includes: when the outdoor ambient temperature is less than or equal to the external ring temperature threshold, controlling the throttling structure to be connected to the output end of the second compressor only with the first passage structure.

[0013] In the preferred technical solution of the control method of the above-mentioned temperature control device, at the same time or after the step of "controlling the first compressor and the second compressor to turn on", the control method also includes: obtaining the superheat of the first compressor; and adjusting the frequency of the second compressor based on the superheat.

[0014] In the preferred technical solution of the control method of the above-mentioned temperature regulating device, the step of "adjusting the frequency of the second compressor based on the superheat" further includes: when the superheat is less than a preset value, controlling the frequency of the second compressor to increase.

[0015] In the preferred technical solution of the control method of the above-mentioned temperature control device, the step of "adjusting the frequency of the second compressor based on the superheat" further includes: when the superheat is greater than a preset value, controlling the frequency of the second compressor to decrease; and / or when the superheat is equal to a preset value, controlling the frequency of the second compressor to remain unchanged.

[0016] Those skilled in the art will appreciate that the present invention provides a heat pump system of a temperature regulating device, the heat pump system comprising a refrigerant circuit, a first compressor, a condenser, a first throttling device, an evaporator, a second compressor and a throttling structure; the first compressor, the condenser, the first throttling device and the evaporator are sequentially arranged on the refrigerant circuit; the second compressor is used to blow hot air to the evaporator, the throttling structure has a first passage structure and a second passage structure, the first passage structure has a first throttling hole, the second passage structure has a second throttling hole, the first throttling hole is smaller than the second throttling hole; the throttling structure is configured to be selectively connected to the output end of the second compressor with one of the first passage structure and the second passage structure. With this arrangement, in the heating mode, the refrigerant flow direction in the refrigerant circuit is that the refrigerant compressed by the first compressor flows to the condenser, flows to the evaporator after being throttled by the first throttling device, and returns to the first compressor after passing through the evaporator, so that the condenser heats the indoor air. In this case, if the external ambient temperature is greater than the external ring temperature threshold, that is, the heat pump system is in a normal heating condition, the throttling structure is controlled to be connected to the output end of the second compressor with a second passage structure having a larger second throttling hole, so that the second compressor acts as a fan and slightly heats the air at the same time, thereby ensuring the heating performance of the heat pump system under normal heating conditions and avoiding damage to the first compressor; when the external ambient temperature is less than or equal to the external ring temperature threshold, that is, the heat pump system is in an ultra-low temperature heating condition, the throttling structure is controlled to be connected to the output end of the second compressor with a first passage structure having a smaller first throttling hole, thereby allowing the second compressor to blow out hot air, and the hot air exchanges heat with the evaporator, thereby improving the heat exchange efficiency between the air and the evaporator, and ensuring the heating performance of the heat pump system under ultra-low temperature heating conditions. Moreover, the above arrangement greatly simplifies the structure of the heat pump system and reduces the volume occupied by the heat pump system because no additional fan, other heat exchangers and related components are required. In addition, the above arrangement can delay frosting and increase the heating time of the heat pump system because it can increase the ambient temperature around the evaporator. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings, in which:

[0018] Figure 1 is a schematic structural diagram of a heat pump system of the present invention;

[0019] Figure 2 is a main flow chart of the control method of the temperature adjustment device of the present invention;

[0020] Figure 3 are two pressure-enthalpy diagrams of the second compressor of the present invention;

[0021] Figure 4It is a possible logic diagram of the control method of the temperature adjustment device of the present invention.

[0022] Description of reference numerals:

[0023] 1-refrigerant circuit; 2-first compressor; 3-condenser; 4-first throttling device; 5-evaporator; 6-second compressor; 7-throttling structure; 71-first passage structure; 711-first pipeline; 712-second throttling device; 72-second passage structure; 721-second pipeline; 722-third throttling device. DETAILED DESCRIPTION

[0024] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. Those skilled in the art can make adjustments to them as needed to adapt to specific application scenarios, which do not deviate from the principles of the present invention and are within the scope of protection of the present invention.

[0025] It should be noted that, in the description of the present invention, unless otherwise clearly specified and limited, the terms "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 directly connected or indirectly connected through an intermediate medium. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. In addition, in the description of the present invention, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0026] In order to solve the problem that the existing temperature control equipment cannot guarantee the heating performance under normal heating conditions and ultra-low temperature heating conditions and can also simplify the structure. Figure 1As shown, the present invention provides a heat pump system of a temperature regulating device, the heat pump system comprises a refrigerant circuit 1, a first compressor 2, a condenser 3, a first throttling device 4, an evaporator 5, a second compressor 6 and a throttling structure 7; the first compressor 2 may be a steam compressor, and the second compressor 6 may be an air compressor; the first compressor 2, the condenser 3, the first throttling device 4 and the evaporator 5 are sequentially arranged on the refrigerant circuit 1; the second compressor 6 is used to blow hot air to the evaporator 5, the throttling structure 7 has a first passage structure 71 and a second passage structure 72, the first passage structure 71 has a first throttling hole, the second passage structure 72 has a second throttling hole, the first throttling hole is smaller than the second throttling hole, so that the throttling effect of the first passage structure 71 is higher than the throttling effect of the second passage structure 72; in addition, the throttling structure 7 is arranged to be selectively connected to the output end of the second compressor 6 with one of the first passage structure 71 and the second passage structure 72. Since the exhaust pressure of the second compressor 6 increases, the exhaust temperature will increase, so the throttling structure 7 connected to the output end of the second compressor 6 is added to maintain the pressure difference.

[0027] The first throttling device 4 of the present invention is preferably an electronic expansion valve. In a lesser case, the first throttling device 4 can also be a first throttling device 4 such as a capillary tube. As long as the first throttling device 4 can throttle, it does not deviate from the principle of the present invention and is within the protection scope of the present invention. In addition, the present invention does not limit the shape of the first throttling hole and the second throttling hole, which can be a round hole, a square hole, a special-shaped hole, etc. The judgment standard that the first throttling hole is smaller than the second throttling hole is that the gas flow rate flowing out of the first throttling hole is smaller than the gas flow rate flowing out of the second throttling hole, so that the throttling effect of the first throttling hole is better than that of the second throttling hole, such as the area of ​​the first throttling hole is smaller than the area of ​​the second throttling hole. In addition, the present invention can determine the first throttling hole and the second throttling hole according to experiments or experience, because by adjusting the size of the throttling hole of the throttling structure 7, the temperature of the hot gas output by the second compressor 6 can be changed. Therefore, when the ideal temperature of the hot gas output by the second compressor 6 is T, the size of the throttling hole corresponding to the ideal temperature T can be determined, and then the specifications of the throttling structure 7 can be determined according to the different ideal temperatures to be obtained. Of course, the specifications of the throttling structure 7 can also be determined according to the exhaust pressure of the second compressor 6. For example, the first throttling hole in the first passage structure 71 corresponding to the exhaust pressure of the second compressor 6 of 0.3MPA can be determined, and the second throttling hole in the second passage structure 72 corresponding to the exhaust pressure of the second compressor 6 of 0.1MPA can be determined.

[0028] In the above-mentioned arrangement, in the heating mode, the refrigerant in the refrigerant circuit 1 flows in the following direction: the refrigerant compressed by the first compressor 2 flows to the condenser 3, flows to the evaporator 5 after being throttled by the first throttling device 4, and returns to the first compressor 2 after passing through the evaporator 5, so that the condenser 3 heats the indoor air. In this case, if the external ambient temperature is greater than the external ring temperature threshold, that is, the heat pump system is in normal heating condition at this time, the throttling structure 7 is controlled to be connected with the output end of the second compressor 6 through the second passage structure 72 with a larger second throttling hole, so that the second compressor The compressor 6 acts as a fan and slightly heats the air at the same time, ensuring the heating performance of the heat pump system under normal heating conditions and avoiding damage to the first compressor 2; when the external ambient temperature is less than or equal to the external ring temperature threshold, that is, when the heat pump system is in an ultra-low temperature heating condition, the throttling structure 7 is controlled to be connected to the output end of the second compressor 6 with a first passage structure 71 having a smaller first throttling hole, so that the second compressor 6 blows out hot air, and the hot air exchanges heat with the evaporator 5, thereby improving the heat exchange efficiency between the air and the evaporator 5 and ensuring the heating performance of the heat pump system under ultra-low temperature heating conditions. Moreover, the above-mentioned setting method greatly simplifies the structure of the heat pump system and reduces the occupied volume of the heat pump system because there is no need to additionally set up a fan, other heat exchangers and related components. In addition, the above-mentioned setting method can also delay frosting and increase the heating time of the heat pump system because it can increase the ambient temperature around the evaporator 5.

[0029] The throttling structure 7 may be in various specific forms, and two possible implementations will be described below as examples.

[0030] The first possible implementation:

[0031] The first passage structure 71 includes a first pipe 711, one end of which is connected to the output end, and the other end of the first pipe 711 faces the evaporator 5. The first pipe 711 is provided with a second throttling device 712, and the second throttling device 712 has a first throttling hole; the second passage structure 72 includes a second pipe 721, one end of which is connected to the output end, and the other end of the second pipe 721 faces the evaporator 5. The second pipe 721 is provided with a third throttling device 722, and the third throttling device 722 has a second throttling hole.

[0032] Possibly, the second throttling device 712 may be an electronic expansion valve. When the second throttling device 712 is an electronic expansion valve, the electronic expansion valve is configured to have a first throttling hole. When the first passage structure 71 is connected to the output end of the second compressor 6, the second throttling device 712 is adjusted to the first throttling hole by adjusting the opening of the second throttling device 712. When the first passage structure 71 is not connected to the output end of the second compressor 6, the second throttling device 712 can be controlled to be closed. The third throttling device 722 may also be an electronic expansion valve. When the third throttling device 722 is an electronic expansion valve, the electronic expansion valve has a second throttling hole. When the second passage structure 72 is connected to the output end of the second compressor 6, the third throttling device 722 is adjusted to the second throttling hole by adjusting the opening of the third throttling device 722. When the second passage structure 72 is not connected to the output end of the second compressor 6, the third throttling device 722 can be controlled to be closed.

[0033] As an alternative embodiment, the second throttling device 712 may be a first valve plate, and the third throttling device 722 may be a second valve plate. The first valve plate has a first throttling hole, and the second valve plate has a second throttling hole. The first valve plate is arranged in the first pipeline 711, and the second valve plate is arranged in the second pipeline 721. In addition, a first solenoid valve may be arranged in the first pipeline 711, and a second solenoid valve may be arranged in the second pipeline 721. When only the first passage structure 71 is connected to the output end of the second compressor 6, the first solenoid valve is controlled to be opened, and the second solenoid valve is controlled to be closed. When only the second passage structure 72 is connected to the output end of the second compressor 6, the first solenoid valve is controlled to be closed, and the second solenoid valve is controlled to be opened.

[0034] A second possible implementation is

[0035] The throttling structure 7 includes an electronic expansion valve and an exhaust pipeline, one end of the exhaust pipeline is connected to the output end, and the other end of the exhaust pipeline faces the evaporator 5. The electronic expansion valve is arranged on the exhaust pipeline, and the electronic expansion valve is configured to be selectively adjusted to a first throttling hole state and a second throttling hole state; the electronic expansion valve in the first throttling hole state and the exhaust pipeline constitute a first passage structure 71, and the electronic expansion valve in the second throttling hole state and the exhaust pipeline constitute a second passage structure 72.

[0036] That is to say, only one exhaust pipeline connected to the output end of the second compressor 6 may be provided, and an electronic expansion valve may be provided on the exhaust pipeline; when only the first passage structure 71 is connected to the output end of the second compressor 6, the opening of the electronic expansion valve is adjusted to be in a first throttling hole state; and when only the second passage structure 72 is connected to the output end of the second compressor 6, the opening of the electronic expansion valve is adjusted to be in a second throttling hole state.

[0037] It should be noted that the throttling structure 7 of the present invention is configured to selectively communicate with the output end of the second compressor 6 with one of the first passage structure 71 and the second passage structure 72. Not only are the first passage structure 71 and the second passage structure 72 arranged outside the second compressor 6, but the first passage structure 71 and the second passage structure 72 can also be arranged inside the second compressor 6. As long as the first passage structure 71 and the second passage structure 72 can communicate with the output end of the second compressor 6, these adjustments do not deviate from the principle of the present invention and are within the protection scope of the present invention. In addition, the input end of the second compressor 6 can be connected to the intake pipe so that air enters the second compressor 6 from the intake pipe.

[0038] On the other hand, the present invention also provides a temperature regulating device, which includes the heat pump system described in any of the above embodiments. After the temperature regulating device of the present invention has the above heat pump system, it only needs to add a second compressor 6 and a throttling structure 7. When the external environment temperature is low enough, the surrounding air is pressurized and heated and then blown to the windward side. On the one hand, it can improve the heat exchange efficiency and ensure the heating performance under ultra-low temperature conditions, and can also ensure the heating performance under normal heating conditions and simplify the structure; on the other hand, it can also delay frosting and increase the heating time.

[0039] As a possible embodiment, the temperature regulating device of the present invention is an air conditioner, for example, the air conditioner is a split air conditioner, and the above-mentioned first compressor 2, second compressor 6 and evaporator 5 can be arranged in the outdoor unit housing. Since the first compressor 2 and the second compressor 6 are the main noise sources, placing these main noise-generating components in the outdoor unit housing can reduce indoor noise. Among them, an air inlet and an air outlet are provided on the outdoor unit housing, the second compressor 6 can be arranged on the side close to the air inlet, and the evaporator 5 is arranged between the air outlet and the second compressor 6, that is, the outside air can enter the second compressor 6 from the air inlet, so that the air on the air inlet side can be heated, thereby increasing the ambient temperature, and then discharged from the air outlet after passing through the evaporator 5. In addition, the first throttling device 4 of the present invention can also be arranged in the outdoor unit housing, and the condenser 3 is arranged in the indoor unit housing. It can be understood that although the air conditioner of the present invention is introduced by taking a split-type air conditioner as an example, this is not intended to limit the scope of protection of the present invention. For example, the air conditioner can also be an integrated air conditioner. In this case, the shell of the integrated air conditioner located on the outdoor side is equivalent to the outdoor unit shell introduced above.

[0040] As an alternative embodiment, although the temperature control device of the present invention is introduced by taking an air conditioner as an example, this is not intended to limit the scope of protection of the present invention. As long as the temperature control device can perform temperature control, its specific device form can be adjusted. For example, the temperature control device can also be a heater, etc. These adjustments do not deviate from the principles of the present invention and are within the scope of protection of the present invention.

[0041] Those skilled in the art can understand that the above-mentioned temperature regulating device also includes some other well-known structures, such as a processor, a controller, a memory, etc., wherein the memory includes but is not limited to a random access memory, a flash memory, a read-only memory, a programmable read-only memory, a volatile memory, a non-volatile memory, a serial memory, a parallel memory or a register, etc., and the processor includes but is not limited to a CPLD / FPGA, a DSP, an ARM processor, a MIPS processor, etc. In order to unnecessarily obscure the embodiments of the present disclosure, these well-known structures are not shown in the drawings.

[0042] In addition, the present invention also provides a control method for a temperature regulating device, the temperature regulating device may be the air conditioner described above, or a heater, etc. Figure 2 As shown, the control method of the temperature regulating device of the present invention includes the following steps.

[0043] Step S100: When the heating mode is enabled, the first compressor and the second compressor are controlled to start.

[0044] Among them, a control button for the heating mode can be set on the control terminal, for example, a remote control or a mobile phone terminal APP is provided with a selection button for the heating mode, and when the selection button for the heating mode is selected, the heating mode is executed. Of course, this is not restrictive, for example, the heating mode is automatically executed after the program meets a certain condition, such as when the outdoor temperature is lower than a preset value (such as 15°C), after the temperature adjustment device is started, the heating mode is automatically controlled to start.

[0045] Step S200: Obtain the outdoor ambient temperature.

[0046] Possibly, the temperature regulating device of the present invention may include a temperature sensor. For example, when the temperature regulating device is an air conditioner, the temperature sensor may be arranged on the outdoor unit housing or at the air outlet of the outdoor unit housing, etc., as long as the outdoor ambient temperature can be obtained through the temperature sensor. Of course, this is not restrictive, and the method of obtaining the outdoor ambient temperature is not limited to this. For example, if the temperature sensor is not arranged, but the temperature regulating device is connected to the cloud controller for communication, the temperature regulating device can obtain the outdoor ambient temperature of the current address in real time through the cloud controller. As long as the outdoor ambient temperature can be obtained, these obtaining methods do not deviate from the principle of the present invention and are within the protection scope of the present invention.

[0047] Step S300: Based on the outdoor ambient temperature, selectively control the throttling structure to be connected to the output end of the second compressor via one of the first passage structure and the second passage structure.

[0048] When the first passage structure is connected to the output end of the second compressor, the throttling effect is greater, the output temperature of the second compressor is higher, and the second compressor outputs hot air; when the second passage structure is connected to the output end of the second compressor, the throttling effect is smaller, and the second compressor can act as a fan and slightly heat the air. That is, by selectively controlling the throttling structure to connect one of the first passage structure and the second passage structure to the output end of the second compressor, the heating performance under normal heating conditions and ultra-low temperature heating conditions can be guaranteed through the different air outlet states of the second compressor. At the same time, there is no need to set up additional components such as fans and heat exchangers, which greatly simplifies the structure and reduces space occupancy.

[0049] For example, when the outdoor ambient temperature is greater than the outer ring temperature threshold, the throttling structure is controlled to be connected to the output end of the second compressor only through the second passage structure. When the outdoor ambient temperature is less than or equal to the outer ring temperature threshold, the throttling structure is controlled to be connected to the output end of the second compressor only through the first passage structure. Among them, the outer ring temperature threshold can be based on the operating status of the temperature control device, or based on big data acquisition, etc. If the heating performance of more than half of the local temperature control devices decreases below a certain temperature, the temperature is defined as the outer ring temperature threshold. For example, the outer ring temperature threshold is minus 20 degrees Celsius, or minus 7 degrees Celsius, etc.

[0050] When the outdoor ambient temperature is greater than the outer ring temperature threshold, that is, the heat pump system is in a normal heating condition, the throttling structure is controlled to be connected to the output end of the second compressor only through the second passage structure, so that the second compressor acts as a fan, improves the heat exchange efficiency between the evaporator and the air, and ensures the heating performance of the heat pump system. At the same time, the air is slightly heated to ensure the heating performance of the system while avoiding damage to the first compressor. When the outdoor ambient temperature is less than or equal to the outer ring temperature threshold, that is, the heat pump system is in an ultra-low temperature heating condition, the throttling structure is controlled to be connected to the output end of the second compressor only through the first passage structure, so that the second evaporator blows out hot air, increases the air temperature on the windward side, ensures the heat exchange effect of the evaporator, and thus improves the heating performance.

[0051] If the first passage structure includes a first pipeline, one end of the first pipeline is connected to the output end, the other end of the first pipeline faces the evaporator, and a second throttling device is provided on the first pipeline, and the second throttling device has a first throttling hole; the second passage structure includes a second pipeline, one end of the second pipeline is connected to the output end, the other end of the second pipeline faces the evaporator, and a third throttling device is provided on the second pipeline, and the third throttling device has a second throttling hole; when the second throttling device and the third throttling device are both electronic expansion valves, the throttling structure is controlled to be connected to the output end of the second compressor only through the second passage structure, in which case the second throttling device is controlled to be closed, and the third throttling device is controlled to be adjusted to the state of the second throttling hole; the throttling structure is controlled to be connected to the output end of the second compressor only through the first passage structure, in which case the second throttling device is controlled to be adjusted to the state of the first throttling hole, and the third throttling device is controlled to be closed. When the second throttling device is the first valve plate and the third throttling device is the second valve plate, the first solenoid valve is arranged in the first pipeline and the second solenoid valve is arranged in the second pipeline, the throttling structure is controlled to be connected with the output end of the second compressor only through the second passage structure, in order to control the first solenoid valve to be closed and the second solenoid valve to be opened; the throttling structure is controlled to be connected with the output end of the second compressor only through the first passage structure, in order to control the first solenoid valve to be opened and the second solenoid valve to be closed.

[0052] If the throttling structure includes an electronic expansion valve and an exhaust pipeline, one end of the exhaust pipeline is connected to the output end, and the other end of the exhaust pipeline faces the evaporator, and the electronic expansion valve is arranged on the exhaust pipeline; if the throttling structure is controlled to be connected to the output end of the second compressor only through the second passage structure, the electronic expansion valve is controlled to be adjusted to the second throttling hole state; if the throttling structure is controlled to be connected to the output end of the second compressor only through the first passage structure, the electronic expansion valve is controlled to be adjusted to the first throttling hole state.

[0053] At the same time or after step S100, the control method of the temperature adjustment device of the present invention further includes:

[0054] Step S400: Obtain the superheat of the first compressor.

[0055] The superheat of the first compressor is preferably the suction superheat of the first compressor. It can also be the exhaust superheat of the first compressor. The present invention does not limit the implementation method of obtaining the superheat of the first compressor, and it can be various acquisition methods in the prior art. For example, a first temperature sensor is provided at the input end of the first compressor, and the first temperature sensor is used to obtain the actual temperature. A second temperature sensor is provided on the evaporator coil, and the second temperature sensor is used to obtain the saturation temperature. The superheat is the actual temperature minus the saturation temperature. Or the superheat is the temperature difference between the temperature of the exhaust pipe or the condenser inlet of the first compressor and the saturation temperature corresponding to the actual condensing pressure, etc.

[0056] Step S500: adjusting the frequency of the second compressor based on the superheat degree.

[0057] Since the superheat of the first compressor affects the heating performance of the heat pump system, and the air output of the second compressor can be adjusted by adjusting the frequency of the second compressor, the superheat is associated with the frequency of the second compressor. The heat exchange efficiency of the evaporator can be ensured by superheating and adjusting the air output on the windward side, thereby improving the heating performance of the system.

[0058] Possibly, step S500 further includes "when the superheat is less than a preset value, controlling the frequency of the second compressor to increase", "when the superheat is greater than a preset value, controlling the frequency of the second compressor to decrease". When the superheat of the first compressor is less than the preset value, it is proved that the heating performance of the system has deteriorated. At this time, by increasing the frequency of the second compressor, the heat exchange of the evaporator can be increased, so that the superheat is kept within a reasonable range, and the heating performance of the system is guaranteed. When the superheat of the first compressor is greater than the preset value, at this time, by reducing the frequency of the second compressor, the heat exchange of the evaporator is reduced to avoid the first compressor from being burned. Among them, the above-mentioned preset value can be obtained based on experience or experiment, which can be a numerical value or a range value. When the preset value is a range value, it is greater than the preset value, which is greater than the maximum value of the range value, and it is less than the preset value, which is less than the minimum value of the range value. Possibly, the control method of the temperature regulating device of the present invention also includes: when the superheat is equal to the preset value, controlling the frequency of the second compressor to remain unchanged to ensure the heating performance of the heat pump system.

[0059] Figure 3 These are two pressure-enthalpy diagrams of the second compressor of the present invention. Among them, "1" represents the initial state of the air (such as -20°C, 0.1MPa), "2" represents the exhaust point (such as 70°C, 0.29MPa), "3" represents the state point before the second compressor blows (such as 68°C, 0.29MPa), "4" represents the state of the air after the second compressor blows (such as 68°C, 0.1MPa), and "5" represents the state of the air after passing through the evaporator (such as 15°C, 0.1MPa).

[0060] The process from "1" to "2" is isentropic compression, which compresses the air into high-temperature and high-pressure gas. The process from "2" to "3" is the heat leakage process of the second compressor system (the smaller the better). The process from "3" to "4" is the isenthalpic pressure reduction process (air blowing out). The pressure of the air is greatly reduced after passing through the throttling structure. "4"-"5" is the heat exchange process between the air and the evaporator (temperature reduction). After passing through the second compressor, the enthalpy value of the air increases, and the increment is h4-h1. The high-temperature gas exchanges heat with the evaporator, which can greatly increase the heat exchange and ensure the heating capacity of the indoor side at low temperatures. When the evaporator only exchanges heat with the exhaust gas of the second compressor, the refrigeration capacity of the vapor compression cycle is equal to the heat exchange of the air discharged by the second compressor, that is, Qm*(h4-h5). When the compressor is frequency-increased, the exhaust pressure increases, and the temperature of the blown air increases. At the same time, due to the increase in pressure difference, the amount of air blown out will also increase, and the heat exchange with the evaporator will increase, thereby increasing the heating capacity of the system.

[0061] Figure 4 A possible control method for the temperature regulating device of the present invention includes the following steps.

[0062] Step S601: When the heating mode is enabled, control the first compressor and the second compressor to start.

[0063] Step S602: Obtain the outdoor ambient temperature.

[0064] Step S603: Obtain the superheat of the first compressor.

[0065] Step S604: When the outdoor ambient temperature is greater than the external ring temperature threshold, the throttling structure is controlled to be connected to the output end of the second compressor only through the second passage structure.

[0066] Step S605: When the outdoor ambient temperature is less than or equal to the external ring temperature threshold, the throttling structure is controlled to be connected to the output end of the second compressor only through the first passage structure.

[0067] Step S606: When the superheat degree is less than a preset value, the frequency of the second compressor is controlled to increase.

[0068] Step S607: When the degree of superheat is greater than a preset value, the frequency of the second compressor is controlled to decrease.

[0069] Step S608: When the superheat degree is equal to the preset value, the frequency of the second compressor is controlled to remain unchanged.

[0070] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A heat pump system, characterized in that: The heat pump system comprises: A refrigerant circuit, a first compressor, a condenser, a first throttling device and an evaporator, wherein the first compressor, the condenser, the first throttling device and the evaporator are sequentially arranged on the refrigerant circuit; a second compressor, the second compressor being used to blow hot air to the evaporator; A throttling structure, wherein the throttling structure has a first passage structure and a second passage structure, wherein the first passage structure has a first throttling hole, and the second passage structure has a second throttling hole, wherein the first throttling hole is smaller than the second throttling hole; The throttling structure is configured to be selectively connected to the output end of the second compressor via one of the first passage structure and the second passage structure.

2. The heat pump system according to claim 1, characterized in that: The first passage structure comprises a first pipe, one end of the first pipe is connected to the output end, the other end of the first pipe faces the evaporator, a second throttling device is provided on the first pipe, and the second throttling device has a first throttling hole; The second passage structure includes a second pipe, one end of the second pipe is connected to the output end, the other end of the second pipe faces the evaporator, and a third throttling device is provided on the second pipe, and the third throttling device has a second throttling hole.

3. The heat pump system according to claim 1, characterized in that: The throttling structure comprises an electronic expansion valve and an exhaust pipeline, one end of the exhaust pipeline is connected to the output end, the other end of the exhaust pipeline faces the evaporator, the electronic expansion valve is arranged on the exhaust pipeline, and the electronic expansion valve is arranged to be selectively adjustable to the first throttling hole state and the second throttling hole state; The electronic expansion valve in the first throttle hole state and the exhaust pipe constitute the first passage structure, and the electronic expansion valve in the second throttle hole state and the exhaust pipe constitute the second passage structure.

4. A temperature regulating device, characterized in that: The temperature regulating device comprises the heat pump system according to any one of claims 1 to 3.

5. A method for controlling a temperature regulating device, characterized in that: The temperature regulating device comprises a heat pump system, and the heat pump system comprises: A refrigerant circuit, a first compressor, a condenser, a first throttling device and an evaporator, wherein the first compressor, the condenser, the first throttling device and the evaporator are sequentially arranged on the refrigerant circuit; a second compressor, the second compressor being used to blow hot air to the evaporator; A throttling structure, wherein the throttling structure has a first passage structure and a second passage structure, wherein the first passage structure has a first throttling hole, and the second passage structure has a second throttling hole, wherein the first throttling hole is smaller than the second throttling hole; The throttling structure is configured to be selectively connected to the output end of the second compressor via one of the first passage structure and the second passage structure; The control method comprises: When the heating mode is enabled, controlling the first compressor and the second compressor to turn on; Get the outdoor ambient temperature; Based on the outdoor ambient temperature, the throttling structure is selectively controlled to be connected to the output end of the second compressor through one of the first passage structure and the second passage structure.

6. The control method of the temperature adjustment device according to claim 5, characterized in that: The step of "selectively controlling the throttling structure to connect one of the first passage structure and the second passage structure to the output end of the second compressor" further includes: When the outdoor ambient temperature is greater than the external ring temperature threshold, the throttling structure is controlled to be connected to the output end of the second compressor only through the second passage structure.

7. The control method of the temperature adjustment device according to claim 5, characterized in that: The step of "selectively controlling the throttling structure to connect one of the first passage structure and the second passage structure to the output end of the second compressor" further includes: When the outdoor ambient temperature is less than or equal to the external ring temperature threshold, the throttling structure is controlled to be connected to the output end of the second compressor only through the first passage structure.

8. The control method of the temperature adjustment device according to claim 5, characterized in that: At the same time or after the step of "controlling the first compressor and the second compressor to start", the control method further includes: obtaining a superheat degree of the first compressor; Based on the superheat, the frequency of the second compressor is adjusted.

9. The control method of the temperature adjustment device according to claim 8, characterized in that: The step of "adjusting the frequency of the second compressor based on the superheat" further includes: When the superheat degree is less than a preset value, the frequency of the second compressor is controlled to increase.

10. The control method of the temperature adjustment device according to claim 8, characterized in that: The step of "adjusting the frequency of the second compressor based on the superheat" further includes: When the superheat degree is greater than a preset value, controlling the frequency of the second compressor to decrease; and / or When the superheat degree is equal to a preset value, the frequency of the second compressor is controlled to remain unchanged.

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