Enthalpy increasing control method and device for heat pump system and heat pump system

Abstract

The invention relates to the technical field of heat pump air conditioning systems, and discloses an enthalpy increasing control method for a heat pump system, which comprises the following steps: under the condition of operating in an enthalpy increasing mode, acquiring a first target exhaust temperature and a suction superheat degree of a compressor and an economizer inlet and outlet state; under the condition that the inlet and outlet state of the economizer meets the enthalpy increasing onset condition, the opening degree of a main electronic expansion valve is adjusted according to the suction gas superheat degree so that the suction gas superheat degree can be within the suction gas superheat degree range; and the opening degree of the auxiliary electronic expansion valve is adjusted according to the first predicted exhaust temperature and the first target exhaust temperature so that the first predicted exhaust temperature can reach the first target exhaust temperature. The method can maximize the heating capacity of the heat pump system and ensure the operation stability of the heat pump system. The invention further discloses an enthalpy increasing control device for the heat pump system and the heat pump system.

Description

Technical Field

[0001] This application relates to the technical field of heat pump air conditioning systems, for example, to an enthalpy-increasing control method, device, and heat pump system for a heat pump system. Background Art

[0002] Currently, heat pump air conditioners have characteristics such as high efficiency and environmental protection. However, in low-temperature and ultra-low-temperature environments, heat pump air conditioners have problems such as excessive compressor compression ratio, too low evaporation temperature, and too high exhaust temperature, which leads to attenuation of the heating capacity of the unit.

[0003] To solve the problem of attenuation of the heating capacity of the unit caused by too high compressor exhaust temperature, related technologies disclose a control method for a dual electronic expansion valve of an air-increasing enthalpy heat pump system, including: adjusting the opening of the main valve based on the superheat at the compressor suction and the superheat at the compressor exhaust, adjusting the initial opening of the auxiliary valve through the superheat at the economizer outlet, and further adjusting the opening of the auxiliary valve according to the superheat at the exhaust.

[0004] In the process of implementing the embodiments of the present disclosure, it is found that there are at least the following problems in the related technologies:

[0005] The related technologies can only control the superheat at the compressor suction or the superheat at the exhaust, and cannot ensure that while the superheat at the compressor suction is within the appropriate suction superheat range, the superheat at the exhaust is also within the appropriate exhaust superheat range. Moreover, the related technologies belong to conservative control, cannot maximize the heating capacity of the heat pump air conditioner, and it is difficult to achieve stable operation of the heat pump air conditioner.

[0006] It should be noted that the information disclosed in the above background art section is only used to enhance the understanding of the background of this application, and therefore may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Invention

[0007] To have a basic understanding of some aspects of the disclosed embodiments, a simple summary is given below. The summary is not a general review, nor is it intended to identify key / important constituent elements or delineate the protection scope of these embodiments, but rather serves as a preface to the subsequent detailed description.

[0008] The embodiments of the present disclosure provide an enthalpy-increasing control method, device, and heat pump system for a heat pump system to achieve stable operation of the heat pump system while maximizing the heating capacity of the heat pump system.

[0009] In some embodiments, the method includes: when operating in an enthalpy-increasing mode, obtaining the first target exhaust temperature of the compressor, the suction superheat degree, and the states of the inlet and outlet of the economizer; when the states of the inlet and outlet of the economizer meet the enthalpy-increasing effective condition, adjusting the opening degree of the main electronic expansion valve according to the suction superheat degree so that the suction superheat degree is within the suction superheat range; and adjusting the opening degree of the auxiliary electronic expansion valve according to the first predicted exhaust temperature and the first target exhaust temperature so that the first predicted exhaust temperature reaches the first target exhaust temperature.

[0010] In some embodiments, adjusting the opening degree of the main electronic expansion valve according to the suction superheat degree so that the suction superheat degree is within the suction superheat range includes: obtaining the difference between the suction superheat degree and the suction superheat degree threshold value of the heat absorption superheat degree; determining the percentage change in the target main circuit circulation flow rate according to the product of the difference in the suction superheat degree and the first prediction coefficient; determining the change in the main valve opening degree according to the corresponding relationship between the main valve opening degree and the main valve flow rate and the percentage change in the target main circuit circulation flow rate, and adjusting the opening degree of the main electronic expansion valve according to the change in the main valve opening degree.

[0011] In some embodiments, adjusting the opening degree of the auxiliary electronic expansion valve according to the first predicted exhaust temperature and the first target exhaust temperature so that the first predicted exhaust temperature reaches the first target exhaust temperature includes: obtaining the first exhaust temperature at the current moment of the compressor, the first exhaust temperature at the previous moment, the exhaust pressure and the suction pressure of the compressor; determining the first target exhaust temperature according to the exhaust pressure, the suction pressure, and the first suction-exhaust pressure coefficient; where the first target exhaust temperature is T d1-d = k7×P d + k8×P s + k9, P d 、P s respectively represent the exhaust pressure and the suction pressure, and k7, k8, and k9 respectively represent the first exhaust pressure coefficient, the first suction pressure coefficient, and the first constant; determining the first predicted exhaust temperature according to the first exhaust temperature at the current moment and the first exhaust temperature at the previous moment; determining the percentage change in the first target auxiliary circuit circulation flow rate according to the product of the difference between the first predicted exhaust temperature and the first target exhaust temperature and the second prediction coefficient; determining the change in the first auxiliary valve opening degree according to the corresponding relationship between the auxiliary valve opening degree and the auxiliary valve flow rate and the percentage change in the first target auxiliary circuit circulation flow rate, and adjusting the opening degree of the auxiliary electronic expansion valve according to the change in the first auxiliary valve opening degree.

[0012] In some embodiments, determining the first predicted exhaust temperature according to the first exhaust temperature at the current moment and the first exhaust temperature at the previous moment includes: determining the difference between the first exhaust temperature at the current moment and the first exhaust temperature at the previous moment as the exhaust temperature change amount; determining the first predicted exhaust temperature according to the product of the exhaust temperature change amount and the third exhaust pressure coefficient and the first exhaust temperature at the current moment.

[0013] In some embodiments, the economizer inlet and outlet states include the economizer inlet temperature, and the method further includes: when the economizer inlet and outlet states do not meet the condition for the enthalpy-increasing to take effect, obtaining the target economizer inlet temperature; determining the difference between the economizer inlet temperature and the target economizer inlet temperature as the inlet temperature difference; when the inlet temperature difference is less than the lower threshold of the inlet temperature difference, reducing the valve opening of the main electronic expansion valve and increasing the pressure in front of the main electronic expansion valve to increase the economizer inlet temperature; and increasing the valve opening of the auxiliary electronic expansion valve according to the set auxiliary valve opening to increase the economizer inlet temperature.

[0014] In some embodiments, the economizer inlet and outlet states include the economizer inlet temperature and the economizer outlet temperature, and the economizer inlet and outlet states are determined to meet the condition for the enthalpy-increasing to take effect in the following manner: determining the difference between the economizer inlet temperature and the target economizer inlet temperature as the inlet temperature difference; determining the difference between the economizer outlet temperature and the economizer inlet temperature as the inlet and outlet temperature difference; when the inlet temperature difference is greater than or equal to the lower threshold of the inlet temperature difference and the inlet and outlet temperature difference is less than the upper threshold of the inlet temperature difference, determining that the economizer inlet and outlet states meet the condition for the enthalpy-increasing to take effect; or when the inlet temperature difference is less than the lower threshold of the inlet temperature difference and the inlet and outlet temperature difference is greater than the upper threshold of the inlet temperature difference, determining that the economizer inlet and outlet states do not meet the condition for the enthalpy-increasing to take effect.

[0015] In some embodiments, it further includes: when operating in a non-enthalpy-increasing mode, obtaining the second target exhaust temperature and the second predicted exhaust temperature of the compressor; and adjusting the opening of the main electronic expansion valve according to the second target exhaust temperature and the second predicted exhaust temperature so that the second predicted exhaust temperature reaches the second target exhaust temperature.

[0016] In some embodiments, adjusting the opening of the main electronic expansion valve according to the second target exhaust temperature and the second predicted exhaust temperature so that the second predicted exhaust temperature reaches the second target exhaust temperature includes: obtaining the second current moment exhaust temperature and the second previous moment exhaust temperature of the compressor at the current moment, the exhaust pressure and the suction pressure of the compressor; determining the second target exhaust temperature according to the exhaust pressure, the suction pressure, the second suction and exhaust pressure coefficient, and the upper threshold of the exhaust temperature; determining the second predicted exhaust temperature according to the second current moment exhaust temperature and the second previous moment exhaust temperature, and determining the percentage change in the second target auxiliary circuit flow rate according to the product of the difference between the second predicted exhaust temperature and the second target exhaust temperature and the third prediction coefficient; determining the change amount of the second auxiliary valve opening according to the corresponding relationship between the auxiliary valve opening and the auxiliary valve flow rate and the percentage change in the second target auxiliary circuit flow rate, so as to adjust the opening of the auxiliary electronic expansion valve according to the change amount of the second auxiliary valve opening.

[0017] In some embodiments, determining the second target exhaust temperature according to the exhaust pressure, the suction pressure, the second suction-exhaust pressure coefficient, and the upper threshold of the exhaust temperature includes: determining a reference target exhaust temperature according to the exhaust pressure, the suction pressure, and the second suction-exhaust pressure coefficient; wherein, the reference target exhaust temperature is T d ' -d = k1×P d + k2×P s + k0; wherein, P d 、P s respectively represent the exhaust pressure and the suction pressure, and k1, k2, and k0 respectively represent the second exhaust pressure coefficient, the second suction pressure coefficient, and the second constant; select the minimum value of the reference target exhaust temperature and the upper threshold of the exhaust temperature as the second target exhaust temperature.

[0018] In some embodiments, the device includes a processor and a memory storing program instructions, and the processor is configured to execute the enthalpy-increasing control method for the heat pump system as described above when running the program instructions.

[0019] In some embodiments, the heat pump system includes: a heat pump system body; the enthalpy-increasing control device for the heat pump system as described above, installed on the heat pump system body.

[0020] The enthalpy-increasing control method, device, and heat pump system for the heat pump system provided by the embodiments of the present disclosure can achieve the following technical effects:

[0021] In the embodiments of the present disclosure, when the heat pump system operates in the enthalpy-increasing mode, the first target exhaust temperature, the suction superheat, and the states at the inlet and outlet of the economizer of the compressor are obtained. If the states at the inlet and outlet of the economizer meet the enthalpy-increasing effective conditions, the heat pump system adjusts the opening of the main electronic expansion valve according to the suction superheat, and adjusts the opening of the auxiliary electronic expansion valve according to the first predicted exhaust temperature and the first target exhaust temperature. Through the coordinated control of the main and auxiliary electronic expansion valves, the suction superheat can be within the suction superheat range and the exhaust temperature of the compressor can always be within the allowable suction superheat range, maintaining the exhaust temperature not exceeding the upper threshold of the exhaust temperature within the suction superheat range, realizing the full utilization of the compressor capacity, thereby avoiding the situation of compressor exhaust temperature exceeding the limit and heating capacity attenuation in the low-temperature operating environment of the heat pump system. While maximizing the heating capacity of the heat pump system, the embodiments of the present disclosure can also ensure the stability of the operation of the heat pump system.

[0022] The above general description and the following description are only exemplary and explanatory, and are not used to limit this application. Description of the Drawings

[0023] One or more embodiments are exemplarily illustrated by corresponding drawings. These exemplary illustrations and the drawings do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are shown as similar elements. The drawings do not constitute a scale limitation, and wherein:

[0024] Figure 1 is a schematic structural diagram of a heat pump system provided by an embodiment of the present disclosure;

[0025] Figure 2 is a schematic diagram of an enthalpy-increasing control method for a heat pump system provided by an embodiment of the present disclosure;

[0026] Figure 3 is a schematic diagram of another enthalpy-increasing control method for a heat pump system provided by an embodiment of the present disclosure;

[0027] Figure 4 is a schematic diagram of another enthalpy-increasing control method for a heat pump system provided by an embodiment of the present disclosure;

[0028] Figure 5 is a schematic diagram of another enthalpy-increasing control method for a heat pump system provided by an embodiment of the present disclosure;

[0029] Figure 6 is a schematic diagram of another enthalpy-increasing control method for a heat pump system provided by an embodiment of the present disclosure;

[0030] Figure 7 is a schematic diagram of another enthalpy-increasing control method for a heat pump system provided by an embodiment of the present disclosure;

[0031] Figure 8 is a schematic diagram of an enthalpy-increasing control device for a heat pump system provided by an embodiment of the present disclosure.

[0032] Reference numerals:

[0033] 10: Compressor; 20: Four-way reversing valve; 30: Indoor heat exchanger; 40: Economizer;

[0034] 50: Outdoor heat exchanger; 70: Enthalpy-increasing control device for a heat pump system;

[0035] 700: Processor; 701: Memory; 702: Communication interface; 703: Bus. Detailed implementation manners

[0036] In order to understand the features and technical content of the embodiments of the present disclosure in more detail, the implementation of the embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. The attached drawings are for reference and illustration only, and are not used to limit the embodiments of the present disclosure. In the following technical description, for the sake of explanation, numerous details are provided to give a thorough understanding of the disclosed embodiments. However, one or more embodiments may still be implemented without these details. In other cases, well-known structures and devices may be shown in a simplified manner to simplify the drawings.

[0037] In the description of the embodiments of the present disclosure, the terms "first", "second", etc. in the specification, claims and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so as to implement the embodiments of the present disclosure described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion.

[0038] Unless otherwise specified, the term "plurality" means two or more.

[0039] In the embodiments of the present disclosure, the character " / " indicates that the objects before and after are in an "or" relationship. For example, A / B means: A or B.

[0040] The term "and / or" is a description of the association relationship of an object, indicating that there can be three relationships. For example, A and / or B means: A or B, or, A and B these three relationships.

[0041] The term "corresponding" may refer to an association relationship or a binding relationship. A corresponding to B means that there is an association relationship or a binding relationship between A and B.

[0042] As shown in Figure 1 the embodiments of the present disclosure provide a heat pump system, including a compressor 10, a four-way reversing valve 20, an indoor heat exchanger 30, an economizer 40, an outdoor heat exchanger 50, a main electronic expansion valve EV1, and an auxiliary electronic expansion valve EV2. Among them, Ts represents the suction temperature sensor, Td represents the discharge temperature sensor, Teco_i represents the economizer inlet temperature sensor, and Teco_o represents the economizer outlet temperature sensor.

[0043] Figure 1 In

[0044] In the non-increasing enthalpy mode, the main electronic expansion valve EV1 is opened, the auxiliary electronic expansion valve EV2 is closed, and the economizer does not participate in heat exchange. At this time, no supplementary gas enters the compressor, and all the refrigerant passes through the main electronic expansion valve for throttling and then enters the outdoor heat exchanger for heat exchange.

[0045] In the increasing enthalpy mode, both the main electronic expansion valve EV1 and the auxiliary electronic expansion valve EV2 are opened, and the economizer participates in the cycle. The refrigerant flowing through the indoor heat exchanger enters the high-temperature side of the economizer and then enters the economizer, and is divided into two paths after passing through the economizer. The refrigerant flowing through the main path passes through the main electronic expansion valve EV1 for throttling and then enters the outdoor heat exchanger. At the same time, the refrigerant flowing through the auxiliary path passes through the auxiliary electronic expansion valve EV2 and then enters the low-temperature side of the economizer, and absorbs the heat of the refrigerant on the high-temperature side of the economizer. The dryness of the refrigerant in the auxiliary path increases, and it becomes a state of high dryness with a certain superheat or a small amount of liquid at the outlet of the economizer, and then enters the supplementary gas chamber of the compressor.

[0046] In the increasing enthalpy mode of the heat pump system provided by the embodiments of the present disclosure, the opening degrees of the main electronic expansion valve and the auxiliary electronic expansion valve are adjusted with the target that the exhaust temperature of the compressor approaches the target exhaust temperature and the suction superheat of the compressor is within the allowable suction superheat range. In the non-increasing enthalpy mode, the opening degree of the main electronic expansion valve is adjusted with the target that the exhaust temperature of the compressor approaches the target exhaust temperature.

[0047] Based on the above heat pump system, combined with Figure 2 As shown, the embodiments of the present disclosure provide an increasing enthalpy control method for a heat pump system, including:

[0048] S01, when operating in the increasing enthalpy mode, the heat pump system obtains the first target exhaust temperature, the suction superheat of the compressor, and the states at the inlet and outlet of the economizer.

[0049] S02, when the states at the inlet and outlet of the economizer meet the increasing enthalpy effective conditions, the heat pump system adjusts the opening degree of the main electronic expansion valve according to the suction superheat so that the suction superheat is within the suction superheat range, and adjusts the opening degree of the auxiliary electronic expansion valve according to the first predicted exhaust temperature and the first target exhaust temperature so that the first predicted exhaust temperature reaches the first target exhaust temperature.

[0050] The enthalpy increase control method for the heat pump system provided by the embodiment of the present disclosure is adopted. When the heat pump system is operated in the enthalpy increase mode, the first target exhaust temperature and suction superheat of the compressor and the inlet and outlet status of the economizer are obtained. If the inlet and outlet status of the economizer meets the enthalpy increase effect condition, the heat pump system adjusts the opening of the main electronic expansion valve according to the suction superheat, and adjusts the opening of the auxiliary electronic expansion valve according to the first predicted exhaust temperature and the first target exhaust temperature. Through the coordinated control of the main and auxiliary electronic expansion valves, the suction superheat can be within the suction superheat range and the exhaust temperature of the compressor is always within the allowable heat absorption superheat range, and the exhaust temperature is maintained within the exhaust temperature upper limit threshold within the heat absorption superheat range, so as to fully utilize the compressor capacity, thereby avoiding the occurrence of compressor exhaust temperature exceeding the limit and heating capacity attenuation in the heat pump system under low temperature operation environment. While maximizing the heating capacity of the heat pump system, the embodiment of the present disclosure can also ensure the stability of the operation of the heat pump system.

[0051] It should be noted that the economizer inlet and outlet states may include: economizer outlet temperature, economizer inlet temperature, and target economizer inlet temperature. The target economizer inlet temperature is used to reflect the target air supply pressure. When the heat pump system has the function of increasing enthalpy by supplying air, the heat pump system has the optimal air supply pressure. If a pressure sensor is configured at the economizer inlet, the system cost will increase. To this end, the embodiment of the present disclosure reduces the cost of equipping a pressure sensor by directly detecting the temperature to reflect the air supply pressure.

[0052] In addition, the first predicted exhaust temperature reaching the first target exhaust temperature may be that the first predicted exhaust temperature approaches the first target exhaust temperature, or may be that the first predicted exhaust temperature is equal to the first target exhaust temperature.

[0053] Optionally, the heat pump system adjusts the opening of the main electronic expansion valve according to the suction gas superheat, including:

[0054] When the suction superheat is less than the suction superheat lower limit threshold, the main electronic expansion valve is controlled to reduce the opening to increase the suction superheat;

[0055] When the absorption superheat is greater than the upper threshold of the suction superheat, the main electronic expansion valve is controlled to increase its opening to reduce the suction superheat.

[0056] In this way, when the suction superheat is less than the lower limit threshold of the suction superheat, it indicates that the suction superheat is on the low side and the suction superheat needs to be increased. Therefore, the main electronic expansion valve is controlled to reduce the opening degree to reduce the main circuit circulation flow rate, and finally the suction superheat is increased and rises within the range of the suction superheat. When the heat absorption superheat is greater than the upper limit threshold of the suction superheat, it indicates that the heat absorption superheat is on the high side and the suction superheat needs to be reduced. Therefore, the main electronic expansion valve is controlled to increase the opening degree to increase the main circuit circulation flow rate, and finally the suction superheat is reduced and drops within the range of the suction superheat.

[0057] Optionally, as shown in Figure 3 The heat pump system adjusts the opening degree of the main electronic expansion valve according to the suction superheat so that the suction superheat is within the range of the suction superheat, including:

[0058] S11, the heat pump system obtains the heat absorption superheat difference between the suction superheat and the suction superheat threshold.

[0059] In this step, the heat absorption superheat range includes [the lower limit threshold of the suction superheat, the upper limit threshold of the suction superheat]. The suction superheat threshold includes the above-mentioned upper limit threshold of the suction superheat and the above-mentioned lower limit threshold of the suction superheat. The heat pump system obtains the heat absorption superheat difference between the suction superheat and the suction superheat threshold, including: in the case where the suction superheat is less than the lower limit threshold of the suction superheat, the heat pump system determines that the difference between the suction superheat and the lower limit threshold of the suction superheat is the heat absorption superheat difference; or, in the case where the suction superheat is greater than the upper limit threshold of the suction superheat, the heat pump system determines that the difference between the suction superheat and the upper limit threshold of the suction superheat is the heat absorption superheat difference; in the case where the suction superheat is greater than or equal to the lower limit threshold of the suction superheat and less than or equal to the upper limit threshold of the suction superheat, the heat pump system determines that the heat absorption superheat difference is zero.

[0060] S12, the heat pump system determines the percentage change in the target main circuit circulation flow rate according to the product of the heat absorption superheat difference and the first prediction coefficient.

[0061] In this step, the percentage change in the target main circuit circulation flow rate represents the percentage change in the predicted main circuit circulation flow rate and the main circuit circulation flow rate at the previous moment. The percentage change in the target main circuit circulation flow rate is MF1 c = k6×ΔT s-sh ; where k6 and ΔT s-sh respectively represent the first prediction coefficient and the heat absorption superheat difference. It should be noted that the percentage change in the target main circuit circulation flow rate is less than or equal to 20%. The first prediction coefficient is adjustable.

[0062] S13, the heat pump system determines the change in the main valve opening degree according to the corresponding relationship between the main valve opening degree and the main valve flow rate and the percentage change in the target main circuit circulation flow rate, so as to adjust the opening degree of the main electronic expansion valve according to the change in the main valve opening degree.

[0063] In this step, the heat pump system determines the change in the main valve opening based on the correspondence between the main valve opening and the main valve flow rate and the percentage change in the target main circuit circulation flow rate, including: the heat pump system obtains the current main valve opening; the heat pump system determines the current main valve flow rate according to the current main valve opening and the correspondence between the main valve opening and the main valve flow rate; the heat pump system determines the product of the current main valve flow rate and the percentage change in the target main circuit circulation flow rate as the change in the main valve opening. Among them, the correspondence between the main valve opening and the main valve flow rate is obtained in the following manner: according to different models of electronic expansion valves, based on the valve flow rate corresponding to the maximum valve opening, the valve flow rate corresponding to each opening is determined; the functional relationship between the main valve opening and the main valve flow rate is obtained by fitting according to the valve flow rates corresponding to different openings.

[0064] In this way, the embodiment of the present disclosure determines the change in the main valve opening based on the percentage change in the target main circuit circulation flow rate, the correspondence between the main valve opening and the main valve flow rate determined by the suction superheat difference and the first prediction coefficient, and adjusts the opening of the main electronic expansion valve accordingly. When the suction superheat is less than the lower threshold of the suction superheat, it indicates that the heat absorption is relatively low. By the above-mentioned opening adjustment, the opening of the main electronic expansion valve can be reduced, thereby reducing the main circuit circulation flow rate to increase the suction superheat and make it within the range of the suction superheat. When the suction superheat is greater than the lower threshold of the suction superheat, it indicates that the heat absorption is relatively high. By the above-mentioned opening adjustment, the opening of the main electronic expansion valve can be increased, thereby increasing the main circuit circulation flow rate to reduce the suction superheat and make it within the range of the suction superheat.

[0065] As an example, the heat pump system adjusts the opening of the main electronic expansion valve according to the suction superheat and specifically performs the following steps:

[0066] When T s-sh <1, the heat pump system determines ΔT s-sh =T s-sh -1,

[0067] When 1≤T s-sh ≤5, the heat pump system determines ΔT s-sh =0,

[0068] When T s-sh >5, the heat pump system determines ΔT s-sh =T s-sh -5. Among them, ΔT s-sh 、T s-sh respectively represent the suction superheat difference and the suction superheat, 1 represents the lower threshold of the suction superheat and 5 represents the upper threshold of the suction superheat.

[0069] The heat pump system determines that the percentage change in the target main circuit circulation flow rate is MF1 c =k6×ΔT s-shAmong them, k6 represents the first prediction coefficient.

[0070] The heat pump system determines that the change in the main valve opening is ΔLeva1 = f1(Leva1) × MF1 c ; where f1(·) represents the correspondence between the main valve opening and the main valve flow rate, and Leva1 represents the current main valve opening.

[0071] The heat pump system determines the target opening of the main electronic expansion valve as: Leva1 Tar = Leva1 + ΔLeva1.

[0072] Optionally, the heat pump system adjusts the opening of the auxiliary electronic expansion valve according to the first predicted exhaust temperature and the first target exhaust temperature, including:

[0073] When the first predicted exhaust temperature is greater than the first target exhaust temperature, control the auxiliary electronic expansion valve to increase the opening;

[0074] When the first predicted exhaust temperature is less than the first target exhaust temperature, control the auxiliary electronic expansion valve to decrease the opening.

[0075] In this way, the larger the opening of the auxiliary electronic expansion valve, the larger the auxiliary air supply flow rate, and the stronger the effect of suppressing the rise of the exhaust temperature. Based on this, when the first predicted exhaust temperature is greater than the first target exhaust temperature, it indicates that the exhaust temperature at the next moment of the current moment is likely to be on the high side. At this time, control the auxiliary electronic expansion valve to increase the opening to increase the auxiliary air supply flow rate to suppress the rising trend of the exhaust temperature. When the first predicted exhaust temperature is less than the first target exhaust temperature, it indicates that there is still room for the exhaust temperature to rise. By appropriately reducing the opening of the auxiliary electronic expansion valve, the exhaust temperature continues to rise until it approaches or equals the first target exhaust temperature.

[0076] Optionally, as shown in Figure 4 The heat pump system adjusts the opening of the auxiliary electronic expansion valve according to the first predicted exhaust temperature and the first target exhaust temperature so that the first predicted exhaust temperature reaches the first target exhaust temperature, including:

[0077] S21, the heat pump system obtains the first current moment exhaust temperature and the first previous moment exhaust temperature of the compressor at the current moment, the exhaust pressure and the suction pressure of the compressor.

[0078] S22, the heat pump system determines the first target exhaust temperature according to the exhaust pressure, the suction pressure, and the first suction and exhaust pressure coefficient.

[0079] In this step, the heat pump system determines the first target exhaust temperature according to the exhaust pressure, the suction pressure, and the first suction and exhaust pressure coefficient, including: the first target exhaust temperature is T d1-d = k7 × P d+k8×P s +k9; where P d and P s represent the exhaust pressure and the suction pressure respectively, and k7, k8, and k9 represent the first exhaust pressure coefficient, the first suction pressure coefficient, and the first constant respectively. Among them, the first suction and exhaust pressure coefficient includes the first exhaust pressure coefficient and the first suction pressure coefficient. It should be noted that the above calculation method of the first exhaust temperature can be generated by fitting according to the data provided by the compressor manufacturer after obtaining the variation law of the exhaust temperature of the compressor under different suction and exhaust pressures. Among them, the first suction and exhaust pressure coefficients and the first constants generated by fitting for different models of compressors are different.

[0080] S23. The heat pump system determines the first predicted exhaust temperature according to the first current moment exhaust temperature and the first previous moment exhaust temperature.

[0081] S24. The heat pump system determines the first target auxiliary circuit flow rate change percentage according to the product of the difference between the first predicted exhaust temperature and the first target exhaust temperature and the second prediction coefficient.

[0082] In this step, the first target auxiliary circuit flow rate change percentage represents the change percentage of the predicted auxiliary circuit flow rate and the auxiliary circuit flow rate at the previous moment.

[0083] S25. The heat pump system determines the first auxiliary valve opening change amount according to the corresponding relationship between the auxiliary valve opening and the auxiliary valve flow rate and the first target auxiliary circuit flow rate change percentage, so as to adjust the opening of the auxiliary electronic expansion valve according to the first auxiliary valve opening change amount.

[0084] In this step, the heat pump system determines the first auxiliary valve opening change amount according to the corresponding relationship between the auxiliary valve opening and the auxiliary valve flow rate and the first target auxiliary circuit flow rate change percentage, including: the heat pump system obtains the first current auxiliary valve opening; the heat pump system determines the current auxiliary valve flow rate according to the first current auxiliary valve opening and the corresponding relationship between the auxiliary valve opening and the auxiliary valve flow rate; the heat pump system determines the product of the current auxiliary valve flow rate and the first target auxiliary circuit flow rate change percentage as the auxiliary valve opening change amount. Among them, the acquisition method of the corresponding relationship between the auxiliary valve opening and the auxiliary valve flow rate is the same as the acquisition method of the corresponding relationship between the main valve opening and the main valve flow rate, and this disclosure embodiment will not elaborate on this.

[0085] In this way, the embodiment of the present disclosure can obtain the percentage change in the first target auxiliary circuit circulation flow rate based on the first target exhaust temperature determined by the suction and exhaust pressures of the compressor and the product of the difference between the first predicted exhaust temperature and the second predicted coefficient predicted and generated from the exhaust temperature at the adjacent moment, and then determine the change amount of the first auxiliary valve opening based on the percentage change in the first target auxiliary circuit circulation flow rate and the corresponding relationship between the auxiliary valve opening and the auxiliary valve flow rate, so as to realize the opening adjustment of the auxiliary electronic expansion valve. In this way, the exhaust temperature of the compressor can always be within the allowable superheat range of heat absorption, and the exhaust temperature is maintained not to exceed the upper limit threshold of the exhaust temperature within the superheat range of heat absorption, thereby avoiding the situation of over-limit exhaust temperature of the compressor and attenuation of the heating capacity in the low-temperature operating environment of the heat pump system, and further maximizing the heating capacity of the heat pump system.

[0086] Optionally, the heat pump system determines the first predicted exhaust temperature according to the exhaust temperature at the first current moment and the exhaust temperature at the first previous moment, including:

[0087] The heat pump system determines the difference between the exhaust temperature at the first current moment and the exhaust temperature at the first previous moment as the exhaust temperature change amount.

[0088] The heat pump system determines the first predicted exhaust temperature according to the product of the exhaust temperature change amount and the third exhaust pressure coefficient and the exhaust temperature at the first current moment. It should be noted that the third exhaust pressure coefficient is determined by the model of the compressor.

[0089] In this way, the embodiment of the present disclosure can accurately predict and obtain the first predicted exhaust temperature according to the difference between the exhaust temperature at the first current moment and the exhaust temperature at the previous moment and the third exhaust pressure coefficient, improve the accuracy of exhaust temperature prediction, and ensure the reliability of the opening adjustment of the auxiliary electronic expansion valve.

[0090] As an example, the heat pump system adjusts the opening of the auxiliary electronic expansion valve according to the first predicted exhaust temperature and the first target exhaust temperature, which specifically includes the following steps:

[0091] The heat pump system determines that the first predicted exhaust temperature is T d1-pre = T d1 + k 10 ×ΔT d1 ; where ΔT d1 = T d1 - T d '1, ΔT d1 , T d1 , T d '1 respectively represent the exhaust temperature change amount, the exhaust temperature at the first current moment, and the exhaust temperature at the first previous moment, and k 10 represents the third exhaust pressure coefficient.

[0092] The heat pump system determines that the percentage change in the first target auxiliary circuit circulation flow rate is MF2c = k 11 ×ΔT d1-pre ; wherein, ΔT d1-pre = T d1-pre - T d1-d , T d1-d represents the first target exhaust gas temperature, and k 11 represents the second prediction coefficient.

[0093] The heat pump system determines that the change amount of the opening degree of the first auxiliary valve is ΔLeva2 = f2(Leva2) × MF2 c ; wherein, f2(·) represents the corresponding relationship between the opening degree of the auxiliary valve and the flow rate of the auxiliary valve, and Leva2 represents the current opening degree of the first auxiliary valve.

[0094] Combined with Figure 5 as shown, the embodiments of the present disclosure further provide an enthalpy-increasing control method for a heat pump system, including:

[0095] S31. When operating in the enthalpy-increasing mode, the heat pump system obtains the first target exhaust gas temperature, the suction superheat degree, and the states of the inlet and outlet of the economizer of the compressor. Among them, the states of the inlet and outlet of the economizer include the economizer inlet temperature.

[0096] S32. Determine whether the states of the inlet and outlet of the economizer meet the enthalpy-increasing effective condition; if so, execute S33, otherwise, execute S34.

[0097] S33. The heat pump system adjusts the opening degree of the main electronic expansion valve according to the suction superheat degree so that the suction superheat degree is within the suction superheat degree range, and adjusts the opening degree of the auxiliary electronic expansion valve according to the first predicted exhaust gas temperature and the first target exhaust gas temperature so that the first predicted exhaust gas temperature reaches the first target exhaust gas temperature.

[0098] S34. The heat pump system obtains the target economizer inlet temperature.

[0099] S35. The heat pump system determines the difference between the economizer inlet temperature and the target economizer inlet temperature as the inlet temperature difference.

[0100] S36. When the inlet temperature difference is less than the lower threshold value of the inlet temperature difference, the heat pump system reduces the valve opening degree of the main electronic expansion valve, increases the pressure in front of the main electronic expansion valve to increase the economizer inlet temperature, and increases the valve opening degree of the auxiliary electronic expansion valve according to the set opening degree of the auxiliary valve to increase the economizer inlet temperature.

[0101] In this step, the opening degree of the auxiliary valve is set to represent an adjustable fixed opening value. Meanwhile, the fixed opening value is the product of the upper limit threshold of the opening degree of the auxiliary electronic expansion valve and the proportionality coefficient. Among them, the proportionality coefficient is in the range of [0.5, 1). Here, a larger fixed opening value is used to increase the valve opening degree of the auxiliary electronic expansion valve, so as to weaken the throttling effect of the refrigerant in the auxiliary circuit passing through the auxiliary electronic expansion valve, reduce the flow rate of the auxiliary refrigerant, thereby increasing the inlet pressure of the economizer and increasing the inlet temperature of the economizer.

[0102] By adopting the enthalpy-increasing control method for a heat pump system provided by the embodiments of the present disclosure, under the condition that the inlet and outlet of the economizer meet the enthalpy-increasing effective conditions, through the coordinated control of the main and auxiliary electronic expansion valves, the embodiments of the present disclosure can make the suction superheat degree within the suction superheat degree range and the exhaust temperature of the compressor always within the allowable suction superheat degree range, maintain the exhaust temperature not exceeding the upper limit threshold of the exhaust temperature within the suction superheat degree range, realize the full utilization of the compressor capacity, and thus avoid the situation of the compressor exhaust temperature exceeding the limit and the heating capacity attenuation when the heat pump system operates in a low-temperature environment. While maximizing the heating capacity of the heat pump system, the embodiments of the present disclosure can also ensure the stability of the operation of the heat pump system. In addition, when the inlet and outlet states of the economizer do not meet the enthalpy-increasing effective conditions, the embodiments of the present disclosure determine the difference between the inlet temperature of the economizer and the target inlet temperature of the economizer as the inlet temperature difference, and when the inlet temperature difference is less than the lower limit threshold of the temperature difference, reduce the valve opening degree of the main electronic expansion valve and increase the valve opening degree of the auxiliary electronic expansion valve according to the set opening degree of the auxiliary valve, so as to increase the inlet temperature of the economizer through the coordinated control of the main and auxiliary electronic expansion valves, and finally make the inlet and outlet states of the economizer meet the enthalpy-increasing effective conditions for subsequent related control in the enthalpy-increasing mode.

[0103] Optionally, the inlet and outlet states of the economizer include the inlet temperature of the economizer and the outlet temperature of the economizer. The heat pump system determines whether the inlet and outlet states of the economizer meet the enthalpy-increasing effective conditions in the following manner:

[0104] The heat pump system determines the difference between the inlet temperature of the economizer and the target inlet temperature of the economizer as the inlet temperature difference.

[0105] The heat pump system determines the difference between the outlet temperature of the economizer and the inlet temperature of the economizer as the inlet and outlet temperature difference.

[0106] In the case where the inlet temperature difference is greater than or equal to the lower limit threshold of the inlet temperature difference and the inlet and outlet temperature difference is less than the upper limit threshold of the inlet temperature difference, the heat pump system determines that the inlet and outlet states of the economizer meet the enthalpy-increasing effective conditions. Or,

[0107] In the case where the inlet temperature difference is less than the lower limit threshold of the inlet temperature difference and the inlet and outlet temperature difference is greater than the upper limit threshold of the inlet temperature difference, the heat pump system determines that the inlet and outlet states of the economizer do not meet the enthalpy-increasing effective conditions.

[0108] In this way, after the embodiment of the present disclosure determines the difference between the economizer inlet temperature and the target economizer inlet temperature as the inlet temperature difference, and determines the difference between the economizer outlet temperature and the economizer inlet temperature as the inlet and outlet temperature difference, subsequent threshold judgments are made. If the inlet temperature difference is greater than or equal to the lower threshold of the inlet temperature difference and the inlet and outlet temperature difference is less than the upper threshold of the inlet temperature difference, it is determined that the state at the inlet and outlet of the economizer meets the condition for the enthalpy increase to take effect. If the inlet temperature difference is less than the lower threshold of the inlet temperature difference and the inlet and outlet temperature difference is greater than the upper threshold of the inlet temperature difference, it is determined that the state at the inlet and outlet of the economizer does not meet the condition for the enthalpy increase to take effect. In addition, by directly detecting the temperature to reflect the gas replenishing pressure, the cost of configuring a pressure sensor can be reduced.

[0109] Optionally, the lower threshold of the inlet temperature difference is greater than or equal to -6 and less than or equal to -4. The upper threshold of the inlet temperature difference is greater than or equal to 4 and less than or equal to 6. Preferably, the lower threshold of the inlet temperature difference is equal to -5, and the upper threshold of the inlet temperature difference is equal to 5. It should be noted that the lower threshold and the upper threshold of the inlet temperature difference can be adjusted according to the actual requirements of the heat pump system.

[0110] Combined with Figure 6 As shown, the embodiment of the present disclosure also provides an enthalpy increase control method for a heat pump system, including:

[0111] S41, when operating in the enthalpy increase mode, the heat pump system obtains the first target exhaust temperature of the compressor, the suction superheat degree, and the state at the inlet and outlet of the economizer. Among them, the state at the inlet and outlet of the economizer includes the economizer inlet temperature.

[0112] S42, when the state at the inlet and outlet of the economizer meets the condition for the enthalpy increase to take effect, the heat pump system adjusts the opening degree of the main electronic expansion valve according to the suction superheat degree so that the suction superheat degree is within the suction superheat degree range, and adjusts the opening degree of the auxiliary electronic expansion valve according to the first predicted exhaust temperature and the first target exhaust temperature so that the first predicted exhaust temperature reaches the first target exhaust temperature.

[0113] S43, when operating in the non-enthalpy increase mode, the heat pump system obtains the second target exhaust temperature of the compressor and the second predicted exhaust temperature.

[0114] S44, the heat pump system adjusts the opening degree of the main electronic expansion valve according to the second target exhaust temperature and the second predicted exhaust temperature so that the second predicted exhaust temperature reaches the second target exhaust temperature.

[0115] By adopting the enthalpy-increasing control method for a heat pump system provided in the embodiments of the present disclosure, under the condition that the inlet and outlet of the economizer meet the enthalpy-increasing effective conditions, through the coordinated control of the main and auxiliary electronic expansion valves, the suction superheat can be within the suction superheat range and the exhaust temperature of the compressor is always within the allowable heat absorption superheat range, maintaining the exhaust temperature not exceeding the upper limit threshold of the exhaust temperature within the heat absorption superheat range, realizing the full utilization of the compressor capacity, thereby avoiding the situation of compressor exhaust temperature exceeding the limit and heating capacity attenuation in the low-temperature operating environment of the heat pump system. While maximizing the heating capacity of the heat pump system, the embodiments of the present disclosure can also ensure the stability of the operation of the heat pump system. In addition, in the case where the heat pump system operates in a non-enthalpy-increasing mode, the second target exhaust temperature and the second predicted exhaust temperature of the compressor are obtained, and the opening of the main electronic expansion valve is adjusted according to the above exhaust temperatures so that the second predicted exhaust temperature reaches the second target exhaust temperature and maintains this predicted exhaust temperature to maintain stable operation in this state.

[0116] Optionally, as shown in Figure 7 The heat pump system adjusts the opening of the main electronic expansion valve according to the second target exhaust temperature and the second predicted exhaust temperature so that the second predicted exhaust temperature reaches the second target exhaust temperature, including:

[0117] S51, the heat pump system obtains the second exhaust temperature at the current moment and the second exhaust temperature at the previous moment of the compressor, the exhaust pressure and the suction pressure of the compressor.

[0118] S52, the heat pump system determines the second target exhaust temperature according to the exhaust pressure and the suction pressure, the second suction-exhaust pressure coefficient, and the exhaust temperature upper limit threshold.

[0119] S53, the heat pump system determines the second predicted exhaust temperature according to the second exhaust temperature at the current moment and the second exhaust temperature at the previous moment, and determines the percentage change in the second target auxiliary circuit flow rate according to the product of the difference between the second predicted exhaust temperature and the second target exhaust temperature and the third prediction coefficient.

[0120] In this step, the heat pump system determines the second predicted exhaust temperature according to the second exhaust temperature at the current moment and the second exhaust temperature at the previous moment, including: the heat pump system determines the difference between the second exhaust temperature at the current moment and the second exhaust temperature at the previous moment as the exhaust temperature change amount. The heat pump system determines the second predicted exhaust temperature according to the product of the exhaust temperature change amount and the fourth exhaust pressure coefficient and the second exhaust temperature at the current moment. It should be noted that the fourth exhaust pressure coefficient is determined by the model of the compressor.

[0121] S54. The heat pump system determines the change amount of the second auxiliary valve opening according to the corresponding relationship between the auxiliary valve opening and the auxiliary valve flow rate and the percentage change amount of the second target auxiliary circuit circulation flow rate, so as to adjust the opening of the auxiliary electronic expansion valve according to the change amount of the second auxiliary valve opening.

[0122] In this step, the heat pump system determines the change amount of the second auxiliary valve opening according to the corresponding relationship between the auxiliary valve opening and the auxiliary valve flow rate and the percentage change amount of the second target auxiliary circuit circulation flow rate, including: the heat pump system obtains the second current auxiliary valve opening; the heat pump system determines the current auxiliary valve flow rate according to the second current auxiliary valve opening and the corresponding relationship between the auxiliary valve opening and the auxiliary valve flow rate; the heat pump system determines the product of the current auxiliary valve flow rate and the percentage change amount of the second target auxiliary circuit circulation flow rate as the change amount of the auxiliary valve opening.

[0123] In this way, the embodiment of the present disclosure can obtain the percentage change amount of the second target auxiliary circuit circulation flow rate according to the product of the difference between the second target exhaust temperature determined by the compressor suction and discharge pressures and the upper limit threshold of the exhaust temperature and the second predicted exhaust temperature predicted and generated by the exhaust temperature at the adjacent moment and the second prediction coefficient, and then determine the change amount of the second auxiliary valve opening based on the percentage change amount of the second target auxiliary circuit circulation flow rate and the corresponding relationship between the auxiliary valve opening and the auxiliary valve flow rate, so as to realize the opening adjustment of the auxiliary electronic expansion valve. In this way, the exhaust temperature of the compressor can reach the second target exhaust temperature, and the exhaust temperature is maintained not to exceed the upper limit threshold of the exhaust temperature within the superheat range of heat absorption, thereby avoiding the situation of over-limit of the compressor exhaust temperature and attenuation of the heating capacity in the low-temperature operating environment of the heat pump system, and further maximizing the heating capacity of the heat pump system.

[0124] Optionally, the heat pump system determines the second target exhaust temperature according to the exhaust pressure, the suction pressure, the second suction and discharge pressure coefficient, and the upper limit threshold of the exhaust temperature, including:

[0125] The heat pump system determines the reference target exhaust temperature according to the exhaust pressure, the suction pressure, the second suction and discharge pressure coefficient, and the upper limit threshold of the exhaust temperature. Wherein, the reference target exhaust temperature is T d ' -d = k1×P d + k2×P s + k0; where, P d 、P s respectively represent the exhaust pressure and the suction pressure, and k1, k2, and k0 respectively represent the second exhaust pressure coefficient, the second suction pressure coefficient, and the second constant. Among them, the second suction and discharge pressure coefficient includes the second exhaust pressure coefficient and the second suction pressure coefficient. It should be noted that the above calculation method of the second exhaust temperature can be obtained by fitting the variation law of the exhaust temperature of the compressor at different suction and discharge pressures according to the data provided by the compressor manufacturer. Among them, the second suction and discharge pressure coefficients and the second constants generated by fitting different models of compressors are different.

[0126] The heat pump system selects the minimum value of the reference target exhaust temperature and the exhaust temperature upper limit threshold as the second target exhaust temperature.

[0127] In this way, the exhaust temperature of the compressor reaches the second target exhaust temperature, and the exhaust temperature is maintained not to exceed the exhaust temperature upper limit threshold within the endothermic superheat range, thereby avoiding the situation of compressor exhaust temperature exceeding the limit and heating capacity attenuation when the heat pump system operates in a low-temperature environment.

[0128] As an example, the heat pump system adjusts the opening of the main electronic expansion valve according to the second target exhaust temperature and the second predicted exhaust temperature, which specifically includes the following steps:

[0129] The heat pump system determines that the reference target exhaust temperature is T d ' -d = k1×P d + k2×P s + k0; where P d 、P s represent the exhaust pressure and the suction pressure respectively, and k1, k2, and k0 represent the second exhaust pressure coefficient, the second suction pressure coefficient, and the second constant respectively.

[0130] The heat pump system determines to select the minimum value of the reference target exhaust temperature and the exhaust temperature upper limit threshold as the second target exhaust temperature.

[0131] The heat pump system determines that the second predicted exhaust temperature is T d2-pre = T d2 + k4×ΔT d2 ; where ΔT d2 = T d2 - T d '2, ΔT d2 、T d2 、T d '2 represent the exhaust temperature change amount, the second current moment exhaust temperature, and the second previous moment exhaust temperature respectively, and k4 represents the fourth exhaust pressure coefficient.

[0132] The heat pump system determines that the second target auxiliary circuit flow rate change percentage is MF c = k5×ΔT d2-pre ; where ΔT d2-pre = T d2-pre - T d2-d ,T d2-d represents the second target exhaust temperature, and k5 represents the third prediction coefficient.

[0133] The heat pump system determines that the second auxiliary valve opening change amount is ΔLeva = f2(Leva)×MF c; where, f2(·) represents the corresponding relationship between the opening of the auxiliary valve and the auxiliary valve flow rate, and Leva represents the second current opening of the auxiliary valve.

[0134] The heat pump system determines the target opening of the auxiliary electronic expansion valve as: Leva Tar = Leva + ΔLeva.

[0135] Optionally, the heat pump system determines whether to operate in the enthalpy-increasing mode in the following manner:

[0136] The heat pump system obtains the exhaust temperature and exhaust superheat of the compressor, the system pressure ratio, and the ambient temperature.

[0137] When the following conditions are simultaneously satisfied, the heat pump system determines to operate in the enthalpy-increasing mode; or,

[0138] When at least one of the following conditions is not satisfied, the heat pump system determines to operate in the non-enthalpy-increasing mode;

[0139] Among them, the conditions include: the exhaust temperature is greater than the exhaust temperature upper limit threshold;

[0140] The exhaust superheat is greater than the exhaust superheat upper limit threshold;

[0141] The system pressure ratio is greater than the system pressure ratio upper limit threshold;

[0142] The ambient temperature is less than the ambient temperature lower limit threshold.

[0143] It should be noted that the exhaust superheat upper limit threshold is determined according to the compressor model, the system pressure ratio upper limit threshold is determined according to the compressor model and the system pressure ratio is adjustable, and the ambient temperature lower limit threshold is adjustable.

[0144] In this way, the heat pump system can determine whether to operate in the enthalpy-increasing mode according to whether the exhaust temperature and exhaust superheat of the compressor, whether the system pressure exceeds their respective upper limit thresholds, and whether the ambient temperature is lower than the ambient temperature lower limit threshold.

[0145] It should be noted that in specific applications, after the heat pump system is started, the main electronic expansion valve is adjusted according to the initial opening of the main valve and the auxiliary electronic expansion valve is adjusted according to the initial opening of the auxiliary valve; after the heat pump system runs for a duration threshold, the exhaust temperature and exhaust superheat of the compressor, the system pressure, and the ambient temperature are periodically obtained according to the period threshold; if the above parameters obtained periodically simultaneously satisfy the above conditions, it operates in the enthalpy-increasing mode and performs corresponding valve opening adjustments; if the above parameters obtained periodically do not simultaneously satisfy the above conditions, it operates in the non-enthalpy-increasing mode and performs corresponding valve opening adjustments.

[0146] Combined with Figure 8As shown in the figure, an enthalpy-increasing control device 70 for a heat pump system provided by an embodiment of the present disclosure includes a processor 700 and a memory 701. Optionally, the device 70 may further include a communication interface 702 and a bus 703. Among them, the processor 700, the communication interface 702, and the memory 701 can complete mutual communication through the bus 703. The communication interface 702 can be used for information transmission. The processor 700 can call the logic instructions in the memory 701 to execute the enthalpy-increasing control method for the heat pump system in the above embodiment.

[0147] In addition, when the logic instructions in the above-mentioned memory 701 are implemented in the form of software function units and sold or used as independent products, they can be stored in a computer-readable storage medium.

[0148] The memory 701, as a computer-readable storage medium, can be used to store software programs and computer-executable programs, such as the program instructions / modules corresponding to the method in the embodiment of the present disclosure. The processor 700 executes functional applications and data processing by running the program instructions / modules stored in the memory 701, that is, implements the enthalpy-increasing control method for the heat pump system in the above embodiment.

[0149] The memory 701 may include a program storage area and a data storage area. Among them, the program storage area can store an operating system and application programs required for at least one function; the data storage area can store data created according to the use of the terminal device, etc. In addition, the memory 701 may include a high-speed random access memory and may also include a non-volatile memory.

[0150] Combined with Figure 1 As shown in the figure, an embodiment of the present disclosure provides a heat pump system, including: a heat pump system body and the above-mentioned enthalpy-increasing control device 70 for the heat pump system. The enthalpy-increasing control device 70 for the heat pump system is installed on the heat pump system body. The installation relationship described here is not limited to being placed inside the heat pump system body, but also includes installation connections with other components of the heat pump system, including but not limited to physical connections, electrical connections, or signal transmission connections, etc. Those skilled in the art can understand that the enthalpy-increasing control device 70 for the heat pump system can be adapted to a feasible heat pump system main body, and then implement other feasible embodiments.

[0151] An embodiment of the present disclosure provides a computer-readable storage medium storing computer-executable instructions, and the computer-executable instructions are set to execute the above-mentioned enthalpy-increasing control method for the heat pump system.

[0152] The technical solution of the embodiments of the present disclosure can be embodied in the form of a software product, which is stored in a storage medium and includes one or more instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in the embodiments of the present disclosure. The aforementioned storage medium may be a non-transitory storage medium, such as: a USB flash drive, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk, or an optical disc, and other media that can store program codes.

[0153] The above description and the drawings fully illustrate the embodiments of the present disclosure so that those skilled in the art can practice them. Other embodiments may include structural, logical, electrical, process, and other changes. The embodiments only represent possible variations. Unless explicitly required, the individual components and functions are optional, and the order of operations can vary. Parts and features of some embodiments may be included in or substituted for parts and features of other embodiments. Moreover, the terms used in this application are only for describing the embodiments and are not used to limit the claims. As used in the description of the embodiments and the claims, unless the context clearly indicates otherwise, the singular forms "a", "an", and "the" are intended to also include the plural forms. Similarly, as used in this application, the term "and / or" refers to any and all possible combinations including one or more of the associated listed items. Additionally, when used in this application, the term "comprise" and its variants "comprises" and / or "comprising" etc. mean the presence of the stated features, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or groupings of these. Without further limitation, an element defined by the statement "comprising one..." does not exclude the presence of additional identical elements in the process, method, or device including the element. In this article, what each embodiment focuses on can be the differences from other embodiments, and the same or similar parts among the embodiments can be referred to each other. For the methods, products, etc. disclosed in the embodiments, if they correspond to the method part disclosed in the embodiments, the relevant parts can be referred to the description of the method part.

[0154] Those skilled in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner may depend on the specific application and design constraints of the technical solution. The skilled person can use different methods for each specific application to implement the described functions, but such implementation should not be considered to exceed the scope of the embodiments of the present disclosure. The skilled person can clearly understand that for the convenience and conciseness of description, the specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated herein.

[0155] In the embodiments disclosed herein, the disclosed methods, products (including but not limited to devices, equipment, etc.) can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units can be merely a logical function division, and there may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Additionally, the displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces, and the indirect couplings or communication connections of the devices or units can be in electrical, mechanical, or other forms. The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to implement this embodiment. Additionally, in the embodiments of the present disclosure, the functional units can be integrated in one processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit.

[0156] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to embodiments of the present disclosure. In this regard, each block in the flowchart or block diagram may represent a module, a segment of code, or a part thereof, which contains one or more executable instructions for implementing the specified logical function. In some alternative implementations, the functions noted in the blocks may occur in a different order than noted in the accompanying drawings. For example, two consecutive blocks may actually be executed substantially in parallel, or they may sometimes be executed in the reverse order, depending on the functions involved. In the descriptions corresponding to the flowcharts and block diagrams in the accompanying drawings, the operations or steps corresponding to different blocks may also occur in a different order than disclosed in the description, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps may actually be executed substantially in parallel, or they may sometimes be executed in the reverse order, depending on the functions involved. Each block in the block diagram and / or flowchart, as well as combinations of blocks in the block diagram and / or flowchart, can be implemented by a dedicated hardware-based system that performs the specified functions or actions, or can be implemented by a combination of dedicated hardware and computer instructions.

Claims

1. An enthalpy-increasing control method for a heat pump system, characterized in that, Including: When operating in the enthalpy-increasing mode, obtaining the first target exhaust temperature of the compressor, the suction superheat degree, and the states at the inlet and outlet of the economizer; When the states at the inlet and outlet of the economizer meet the enthalpy-increasing effective conditions, adjusting the opening degree of the main electronic expansion valve according to the suction superheat degree so that the suction superheat degree is within the suction superheat degree range; and Adjusting the opening degree of the auxiliary electronic expansion valve according to the first predicted exhaust temperature and the first target exhaust temperature so that the first predicted exhaust temperature reaches the first target exhaust temperature.

2. The method according to claim 1, characterized in that, Adjusting the opening degree of the main electronic expansion valve according to the suction superheat degree so that the suction superheat degree is within the suction superheat degree range, including: Obtaining the difference in heat absorption superheat degree between the suction superheat degree and the suction superheat degree threshold; Determining the percentage change in the target main circuit circulation flow rate according to the product of the difference in suction superheat degree and the first prediction coefficient; Determining the change in the main valve opening degree according to the corresponding relationship between the main valve opening degree and the main valve flow rate and the percentage change in the target main circuit circulation flow rate, and adjusting the opening degree of the main electronic expansion valve according to the change in the main valve opening degree.

3. The method according to claim 1, wherein Adjusting the opening degree of the auxiliary electronic expansion valve according to the first predicted exhaust temperature and the first target exhaust temperature so that the first predicted exhaust temperature reaches the first target exhaust temperature, including: Obtaining the first exhaust temperature at the current moment of the compressor, the first exhaust temperature at the previous moment, the exhaust pressure and the suction pressure of the compressor; Determine the first target exhaust temperature according to the exhaust pressure, the suction pressure, and the first suction and exhaust pressure coefficients; wherein, the first target exhaust temperature is T d1-d = k7 × P d + k8 × P s + k9, P d 、P s respectively represent the exhaust pressure and the suction pressure, and k7, k8, and k9 respectively represent the first exhaust pressure coefficient, the first suction pressure coefficient, and the first constant; Determining the first predicted exhaust temperature according to the first exhaust temperature at the current moment and the first exhaust temperature at the previous moment; Determining the percentage change in the first target auxiliary circuit circulation flow rate according to the product of the difference between the first predicted exhaust temperature and the first target exhaust temperature and the second prediction coefficient; Determining the first change in the auxiliary valve opening degree according to the corresponding relationship between the auxiliary valve opening degree and the auxiliary valve flow rate and the percentage change in the first target auxiliary circuit circulation flow rate, and adjusting the opening degree of the auxiliary electronic expansion valve according to the first change in the auxiliary valve opening degree.

4. The method according to claim 3, wherein Determining the first predicted exhaust temperature according to the first exhaust temperature at the current moment and the first exhaust temperature at the previous moment, including: Determining the difference between the first exhaust temperature at the current moment and the first exhaust temperature at the previous moment as the exhaust temperature change amount; Determining the first predicted exhaust temperature according to the product of the exhaust temperature change amount and the third exhaust pressure coefficient and the first exhaust temperature at the current moment.

5. The method according to any one of claims 1 to 4, characterized in that The states at the inlet and outlet of the economizer include the economizer inlet temperature, and the method further includes: When the states at the inlet and outlet of the economizer do not meet the enthalpy-increasing effective conditions, obtaining the target economizer inlet temperature; Determining the difference between the economizer inlet temperature and the target economizer inlet temperature as the inlet temperature difference; When the inlet temperature difference is less than the lower limit threshold of the inlet temperature difference, reducing the valve opening degree of the main electronic expansion valve and increasing the pressure at the front end of the main electronic expansion valve to increase the economizer inlet temperature; and Increasing the valve opening degree of the auxiliary electronic expansion valve according to the set auxiliary valve opening degree to increase the economizer inlet temperature.

6. The method according to any one of claims 1 to 4, characterized in that, The states at the inlet and outlet of the economizer include the economizer inlet temperature and the economizer outlet temperature, and the states at the inlet and outlet of the economizer are determined to meet the enthalpy-increasing effective conditions in the following manner: Determining the difference between the economizer inlet temperature and the target economizer inlet temperature as the inlet temperature difference; Determining the difference between the economizer outlet temperature and the economizer inlet temperature as the inlet and outlet temperature difference; When the inlet temperature difference is greater than or equal to the lower threshold of the inlet temperature difference and the inlet and outlet temperature difference is less than the upper threshold of the inlet temperature difference, it is determined that the state at the inlet and outlet of the economizer satisfies the condition for the enthalpy increase to take effect; Or, When the inlet temperature difference is less than the lower threshold of the inlet temperature difference and the inlet and outlet temperature difference is greater than the upper threshold of the inlet temperature difference, it is determined that the state at the inlet and outlet of the economizer does not satisfy the condition for the enthalpy increase to take effect.

7. The method according to any one of claims 1 to 4, characterized in that, It further includes: When operating in a non-enthalpy-increasing mode, obtain the second target exhaust temperature and the second predicted exhaust temperature of the compressor; Adjust the opening degree of the main electronic expansion valve according to the second target exhaust temperature and the second predicted exhaust temperature so that the second predicted exhaust temperature reaches the second target exhaust temperature.

8. The method according to claim 7, wherein Adjust the opening degree of the main electronic expansion valve according to the second target exhaust temperature and the second predicted exhaust temperature so that the second predicted exhaust temperature reaches the second target exhaust temperature, including: Obtain the second exhaust temperature at the current moment and the second exhaust temperature at the previous moment of the compressor, the exhaust pressure and the suction pressure of the compressor at the current moment; Determine the second target exhaust temperature according to the exhaust pressure and the suction pressure, the second suction-exhaust pressure coefficient, and the upper threshold of the exhaust temperature; Determine the second predicted exhaust temperature according to the second exhaust temperature at the current moment and the second exhaust temperature at the previous moment, and determine the percentage change in the second target auxiliary circuit circulation flow rate according to the product of the difference between the second predicted exhaust temperature and the second target exhaust temperature and the third predicted coefficient; Determine the change amount of the second auxiliary valve opening degree according to the corresponding relationship between the auxiliary valve opening degree and the auxiliary valve flow rate and the percentage change in the second target auxiliary circuit circulation flow rate, so as to adjust the opening degree of the auxiliary electronic expansion valve according to the change amount of the second auxiliary valve opening degree.

9. The method according to claim 8, wherein Determine the second target exhaust temperature according to the exhaust pressure and the suction pressure, the second suction-exhaust pressure coefficient, and the upper threshold of the exhaust temperature, including: Determine the reference target exhaust temperature according to the exhaust pressure, the suction pressure, and the second suction and exhaust pressure coefficients; wherein, the reference target exhaust temperature is T d ' -d = k1 × P d + k2 × P s + k0; wherein, P d , P s respectively represent the exhaust pressure and the suction pressure, and k1, k2, and k0 respectively represent the second exhaust pressure coefficient, the second suction pressure coefficient, and the second constant; Select the minimum value of the reference target exhaust temperature and the upper threshold of the exhaust temperature as the second target exhaust temperature.

10. An enthalpy-increasing control device for a heat pump system, comprising a processor and a memory storing program instructions, characterized in that, The processor is configured to execute the enthalpy increase control method for a heat pump system according to any one of claims 1 to 9 when running the program instructions.

11. A heat pump system, characterized in that, It includes: The heat pump system body; The enthalpy increase control device for a heat pump system according to claim 10, installed on the heat pump system body.

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