Heat pump auxiliary system and control method thereof

Abstract

This application proposes a heat pump auxiliary system and its control method. The heat pump auxiliary system includes a four-way valve, an LTR (Liquid Coolant Regulator), a battery, a water pump, and a heating water tank connected via piping. Port A of the four-way valve is connected to port B of the water pump, port B of the four-way valve is connected to port B of the battery, port C of the four-way valve is connected to port B of the heating water tank, port D of the four-way valve is connected to port LTR, and port A of the battery is connected to port LTR. The four-way valve is used to distribute the coolant flow ratio among the heating water tank, the battery, and the LTR. This application improves control stability under low-load conditions, reduces the cost of control stability, and enhances the user experience.

Description

Technical Field

[0001] This invention relates to the field of heat pump systems, and more particularly to a heat pump auxiliary system and control method. Background Technology

[0002] With the rapid development of electric vehicles, the displacement of electric compressors is showing a gradual increasing trend. Previously, the commonly used compressor displacement was 33 or 30cc, but it has now evolved into 43 or 45cc compressors. The application of 4C or even faster super-fast charging may lead to a further increase in maximum heat dissipation, and the compressor displacement may also increase further.

[0003] Meanwhile, electric compressors have minimum speed requirements, typically 800 RPM or 600 RPM. This can lead to excessive heat generation due to the compressor's excessive minimum speed during low-load conditions in spring and autumn, resulting in decreased stability or even loss of control of the vehicle's thermal management system.

[0004] To address the above issues, different heat pump systems within electric vehicles employ different strategies. For parallel condenser systems, existing technologies use a control method that involves switching the outdoor condenser shut-off valve on and off. The problem with this method is that it may lead to decreased control stability, and frequent valve switching may cause noise problems and damage to the valve components.

[0005] In addition, to solve this problem, existing technologies may use a fully open electronic expansion valve to replace the outdoor condenser shut-off valve, but this method is more expensive.

[0006] Therefore, the existing technology still needs further development. Summary of the Invention

[0007] To address the problem of poor control stability under low-load conditions in existing technologies, this application proposes a heat pump auxiliary management system and its control method, which improves control stability under low-load conditions, reduces the cost of control stability, and enhances user experience.

[0008] A first aspect of this application provides a heat pump auxiliary system, comprising:

[0009] The system includes a four-way valve, LTR, battery, water pump, and heating water tank connected via piping, among which:

[0010] The four-way valve has four ports, including four-way valve A port, four-way valve B port, four-way valve C port and four-way valve D port;

[0011] The LTR has two ports, including an LTRA port and an LTRB port;

[0012] The battery has two ports, including battery port A and battery port B;

[0013] The water pump has two ports, including water pump port A and water pump port B;

[0014] The heating water tank has two ports, including heating water tank port A and heating water tank port B;

[0015] The four-way valve A port is connected to the water pump B port, the four-way valve B port is connected to the battery B port, the four-way valve C port is connected to the heating water tank B port, the four-way valve D port is connected to the LTRB port, and the battery A port is connected to the LTRA port.

[0016] The four-way valve is used to distribute the coolant flow rate ratio between the heating tank, the battery, and the LTR.

[0017] In an optional embodiment of the present invention, the LTRB port is connected to the D port of the four-way valve via the LTR bypass inlet pipe, and the LTRA port is connected to the A port of the battery via the LTR bypass outlet pipe.

[0018] In an optional embodiment of the present invention, the four-way valve is a four-way valve that proportionally distributes the water ratio between the heating water tank, the battery, and the LTR based on a control principle.

[0019] In an optional embodiment of the present invention, a water-cooled condenser, an evaporator, an electric compressor, and an outdoor condenser are also included.

[0020] The water-cooled condenser has four ports, including water-cooled condenser port A, water-cooled condenser port B, water-cooled condenser port C and water-cooled condenser port D;

[0021] The evaporator has two ports, including evaporator port A and evaporator port B;

[0022] The electric compressor has two ports, including electric compressor port A and electric compressor port B;

[0023] The outdoor condenser has two ports, including outdoor condenser port A and outdoor condenser port B;

[0024] The A port of the water-cooled condenser is connected to the A port of the outdoor condenser and the A port of the evaporator, respectively;

[0025] The B port of the water-cooled condenser is connected to the A port of the water pump;

[0026] The C port of the water-cooled condenser is connected to the A port of the heating water tank;

[0027] The D port of the water-cooled condenser is connected to the B port of the electric compressor and the B port of the outdoor condenser, respectively.

[0028] The evaporator port B is connected to the electric compressor port A.

[0029] In an optional embodiment of the present invention, the A port of the water-cooled condenser is connected to the A port of the evaporator via an electronic expansion valve.

[0030] In an optional embodiment of the present invention, the D port of the water-cooled condenser is connected to the B port of the electric compressor via a water-cooled condenser shut-off valve.

[0031] The D port of the water-cooled condenser is connected to the B port of the outdoor condenser via the outdoor condenser shut-off valve.

[0032] In an optional embodiment of the present invention, the water pump adjusts its rotational speed based on the opening degree of the four-way valve.

[0033] In an optional embodiment of the present invention, the heat pump auxiliary system further includes a fan, wherein the fan speed is adjusted based on the speed of the fan and the target temperature difference;

[0034] In a heat pump auxiliary system used in automotive air conditioning, the speed of the fan is the vehicle speed.

[0035] A second aspect of the present invention provides a control method for a heat pump auxiliary system as described in the first aspect of the present invention, comprising:

[0036] Based on the low-load operating condition, the small circulation state is locked, which includes opening the water-cooled condenser shut-off valve and closing the outdoor condenser shut-off valve.

[0037] The opening degree K of the four-way valve is controlled based on the control principle;

[0038] The corrected speed of the water pump is obtained based on the opening degree of the four-way valve. The water pump is connected to port A of the four-way valve and is used to supply refrigerant to the four-way valve.

[0039] The fan speed correction is obtained based on vehicle speed and target temperature difference, where the target temperature difference is the difference between the actual coolant temperature and the ambient temperature.

[0040] In an optional embodiment of the present invention, before locking the small cycle state based on low load conditions, the following steps are included:

[0041] Obtain the operating parameters of the current operating condition, which include at least the compressor operating status, actual outlet air temperature, target outlet air temperature, and ambient temperature;

[0042] Determine whether the operating parameters are low-load operating parameters. The low-load operating parameters include at least the compressor being at its lowest speed, the actual air outlet temperature being higher than the target air outlet temperature, and the ambient temperature being at a preset temperature threshold.

[0043] If the operating condition parameters are low-load operating condition parameters, the current operating condition is determined to be a low-load operating condition.

[0044] In an optional embodiment of the present invention, controlling the opening degree K of the four-way valve based on the control principle includes:

[0045] Calculate the feedforward FF of the four-way valve, where FF = energy required by the heating tank / (compressor power + actual evaporator energy) * 100%;

[0046] Among them, the energy required for heating the water tank = (target outlet air temperature - evaporator outlet air temperature) * air volume * air density * air specific heat capacity;

[0047] Compressor power = compressor current * compressor voltage;

[0048] Evaporator actual energy = (evaporator inlet air temperature - evaporator outlet air temperature) * air volume * air density * air specific heat capacity;

[0049] Calculate the feedback P of the four-way valve, where feedback P = calibrated p parameter * (target outlet air temperature - actual outlet air temperature).

[0050] Calculate the feedback integral I of the four-way valve, where the feedback integral I = calibration parameter i * (target outlet air temperature - actual outlet air temperature).

[0051] The opening degree K of the four-way valve is generated by the formula: feedforward FF + feedback P + feedback integral I.

[0052] In an optional embodiment of the present invention, obtaining the corrected pump speed based on the opening degree of the four-way valve includes:

[0053] The corrected speed of the water pump = normal speed of the water pump / percentage of the opening of the four-way proportional water valve.

[0054] In an optional embodiment of the present invention, obtaining the fan correction speed based on vehicle speed and target temperature difference includes:

[0055] The fan speed correction is obtained based on the relationship between vehicle speed and target temperature difference.

[0056] A third aspect of this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a computer, performs the method described in the second aspect of this application.

[0057] This application improves the adaptability to excessive minimum speed of electric compressors, which is beneficial to improving the stability of the vehicle thermal management system. In low-load conditions such as spring and autumn, it dissipates excess heat through water circuit LTR instead of outdoor condenser, improving control stability and optimizing customer experience. It can be adapted to a variety of different heat pump systems, thermal management loops or automotive application scenarios, and has high application value. Attached Figure Description

[0058] Figure 1 A schematic diagram of a heat pump auxiliary system according to an embodiment of this application is shown;

[0059] Figure 2 A schematic diagram of a heat pump system in the prior art is shown;

[0060] Figure 3 A flowchart of a control method based on a heat pump auxiliary system according to an embodiment of this application is shown;

[0061] Figure 4 A flowchart of a control method based on a heat pump auxiliary system according to an embodiment of this application is shown;

[0062] Figure 5 A flowchart of a control method based on a heat pump auxiliary system is shown in one embodiment of this application.

[0063] Figure label:

[0064] 1-Four-way valve, 2-LTR, 3-Battery, 4-Water pump, 5-Heating water tank, 6-LTR bypass inlet pipe, 7-LTR bypass outlet pipe, 8-Water-cooled condenser, 9-Evaporator, 10-Electric compressor, 11-Outdoor condenser, 12-Electronic expansion valve, 13-Water-cooled condenser shut-off valve, 14-Outdoor condenser shut-off valve, 15-Fan, 16-Temperature damper, 17-Three-way valve. Implementation

[0065] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

[0066] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0067] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the illustrations only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0068] like Figure 1-2 As shown, this invention proposes a heat pump auxiliary system, applicable to heat pump systems, thermal management loops, or automotive air conditioning systems, comprising:

[0069] The system is connected to a four-way valve 1, a battery 3, a water pump 4, an LTR2, and a heating water tank 5. The four-way valve 1 can be a four-way proportional water valve (also known as a proportional four-way valve), hereinafter referred to as a four-way valve or a four-way water valve.

[0070] The specific type of piping system is not limited, as long as it can realize the loop of this application.

[0071] The four-way valve 1 is used to distribute or proportionally distribute the coolant flow rate between the heating water tank 5, the battery 3, and the LTR2, where the coolant refers to water.

[0072] The four-way valve 1 has four ports, including four-way valve A port, four-way valve B port, four-way valve C port and four-way valve D port;

[0073] Battery 3 has two ports, including Battery A port and Battery B port;

[0074] Water pump 4 has two ports, including water pump port A and water pump port B;

[0075] The LTR2 has two ports, including the LTRA port and the LTRB port. Specifically, LTR2 stands for Low Temperature Radiator, also known as a heat exchanger. It can be used in air conditioning systems or locomotives. The Low Temperature Radiator can be used for heat exchange between the heat exchange medium and the outside air, or for heat exchange between heat exchange media.

[0076] The heating water tank 5 has two ports, including heating water tank 5A port and heating water tank 5B port;

[0077] The four-way valve A port is connected to the water pump B port, the four-way valve B port is connected to the battery B port, the four-way valve C port is connected to the heating water tank B port, the four-way valve D port is connected to the LTRB port in sequence, the battery A port is connected to the LTRA port in sequence, and the heating water tank A port and the water pump A port are connected in sequence via the water-cooled condenser 8.

[0078] The heat pump auxiliary system used in this invention can be used in both heat pump systems and thermal management loops. Its main function is to dissipate excess heat through the water circuit LTR2, replacing the heat dissipation of the outdoor condenser 11.

[0079] In one embodiment of the present invention, the heat pump auxiliary system further includes a water-cooled condenser 8, an evaporator 9, an electric compressor 10, and an outdoor condenser 11;

[0080] The water-cooled condenser 8 has four ports, including water-cooled condenser port A, water-cooled condenser port B, water-cooled condenser port C and water-cooled condenser port D;

[0081] Evaporator 9 has two ports, including evaporator port A and evaporator port B;

[0082] The electric compressor 10 has two ports, including an electric compressor A port and an electric compressor B port;

[0083] The outdoor condenser 11 has two ports, including outdoor condenser port A and outdoor condenser port B;

[0084] The A port of the water-cooled condenser is connected to the A port of the outdoor condenser and the A port of the evaporator respectively; specifically, the A port of the water-cooled condenser and the A port of the evaporator are connected via the electronic expansion valve 12.

[0085] The B port of the water-cooled condenser is connected to the A port of the water pump;

[0086] The C port of the water-cooled condenser is connected to the A port of the heating water tank;

[0087] The D port of the water-cooled condenser is connected to the B port of the electric compressor and the B port of the outdoor condenser, respectively; specifically, the D port of the water-cooled condenser is connected to the B port of the electric compressor.

[0088] The D port of the water-cooled condenser is connected to the B port of the outdoor condenser via the outdoor condenser shut-off valve 14.

[0089] The evaporator port B is connected to the electric compressor port A.

[0090] In one embodiment of the present invention, the water pump 4 adjusts its rotational speed based on the opening degree of the four-way valve 1.

[0091] Specifically, the function of water pump 4 is to deliver coolant, such as water, into four-way valve 1. The opening degree of four-way valve 1 can control the flow rate and velocity of coolant between the valve body and the valve body. The opening degree of four-way valve 1 can be obtained based on control principles such as feedforward and feedback. After obtaining the opening degree of four-way valve 1, the speed of water pump 4 can be controlled to control the flow rate of coolant flowing into four-way valve 1.

[0092] In one embodiment of the present invention, the heat pump auxiliary system further includes a fan 15, which adjusts the rotational speed of the fan 15 based on the speed of the fan 15 and the target temperature difference.

[0093] In the heat pump auxiliary system applied to automotive air conditioning, the speed of fan 15 is the vehicle speed, and the target temperature difference is the difference between the actual coolant temperature and the ambient temperature.

[0094] When used in a heat pump auxiliary system for automotive air conditioning, the target temperature difference represents the difference between the actual coolant temperature and the ambient temperature inside the vehicle.

[0095] To describe the specific technical solution of this invention in detail, the following are examples of components and their connections in the prior art related to a heat pump system, thermal management circuit, or automotive air conditioning system, specifically including:

[0096] Three-way valve 17, battery 3, water pump 4, water-cooled condenser 8, water-cooled condenser shut-off valve 13, outdoor condenser shut-off valve 14, electric compressor 10, outdoor condenser 11, heating water tank 5, evaporator 9, electronic expansion valve 12 and temperature damper 16.

[0097] It should be understood that the heat pump auxiliary system in this application can be used in the prior art, and the cross-components involved, such as water pump 4, water-cooled condenser 8, heating water tank 5 and battery 3, are the same components as those involved in this application, such as water pump 4, water-cooled condenser 8, heating water tank 5, electric compressor 10, evaporator 9, outdoor condenser 11 and battery 3.

[0098] Specifically, the three-way valve 17 has three ports, including a three-way valve A port, a three-way valve B port, and a three-way valve C port. The three-way valve A port is connected to the water pump B port, the three-way valve B port is connected to the battery B port, and the three-way valve C port is connected to the water tank B port.

[0099] Battery 3 has two ports, including Battery A port and Battery B port, with Battery B port connected to the water-cooled condenser C port;

[0100] Water pump 4 has two ports, including water pump port A and water pump port B. Water pump port A is connected to water-cooled condenser port A.

[0101] The water-cooled condenser 8 has four ports, including water-cooled condenser port A, water-cooled condenser port B, water-cooled condenser port C and water-cooled condenser port D;

[0102] The electric compressor 10 has two ports, including electric compressor port A and electric compressor port B, and the water-cooled condenser port D is connected to the electric compressor port A via the water-cooled condenser shut-off valve 13.

[0103] The outdoor condenser 11 has two ports, including outdoor condenser port A and outdoor condenser port B. The water-cooled condenser port D is connected to outdoor condenser port A via water-cooled condenser shut-off valve 13 and outdoor condenser shut-off valve 14. The electric compressor port A is connected to outdoor condenser port A via outdoor condenser shut-off valve 14.

[0104] The heating water tank 5 has two ports, including heating water tank port A and heating water tank port B. Heating water tank port A is connected to water-cooled condenser port C, and heating water tank port B is connected to three-way valve port C.

[0105] Evaporator 9 has two ports, including evaporator port A and evaporator port B. Evaporator port A is connected to electric compressor port B, and evaporator port B is connected to water-cooled condenser port A via electronic expansion valve 12.

[0106] Compared with the prior art, the heat pump auxiliary system proposed in this application, under the action of the four-way valve 1 and LTR2, is at least equipped to enable the automotive air conditioning to switch between the following two operating positions:

[0107] Workstation 1: In non-small cycle mode, please continue reading. Figure 2 The water-cooled condenser shut-off valve 13 is open, the outdoor condenser shut-off valve 14 is open, the water-cooled condenser D port is connected to the outdoor condenser B port via the water-cooled condenser shut-off valve 13 and the outdoor condenser shut-off valve 14, the water-cooled condenser A port is connected to the outdoor condenser A port, and is also connected to the evaporator A port via the electronic expansion valve 12.

[0108] Station 2: In small circulation mode, the water-cooled condenser shut-off valve 13 is open, the outdoor condenser shut-off valve 14 is closed, and the water-cooled condenser port A is connected to the evaporator port A only through the electronic expansion valve 12.

[0109] Compared with existing heat pump auxiliary systems and component connections, the main difference lies in:

[0110] In the prior art, the outdoor condenser 11 is connected in parallel with the electric compressor 10 to remove excess heat. However, during the use of the outdoor condenser 11, the outdoor condenser shut-off valve 14 is frequently switched on and off, which leads to a deterioration in the performance of the heat pump auxiliary system, a reduction in control stability, and the frequent switching may cause noise problems. Furthermore, it will cause irreversible damage to the lifespan of the outdoor condenser shut-off valve 14, reducing the user experience.

[0111] In addition, in the existing technology, there is also a control method that uses a full-flow electronic expansion valve 12 to replace the outdoor condenser shut-off valve 14, but the cost of the full-flow electronic expansion valve 12 is relatively high.

[0112] Please refer to the heat pump auxiliary system proposed in the first aspect of this application. With the increasing demands for rapid cooling and driving range of electric vehicles, especially with the emergence of faster super-fast charging applications in the market, the maximum heat generation of battery 3 is also gradually increasing, possibly reaching the order of 10 kW. As a result, the displacement of electric compressor 10 is gradually increasing.

[0113] Because the electric compressor 10 has a minimum speed requirement, typically 800 RPM or 600 RPM, the minimum speed of the compressor is too high under low load conditions in spring and autumn, resulting in excessive heat and causing a decrease in the control stability of the vehicle's thermal management system, or even loss of control.

[0114] In this application, an LTR bypass inlet pipe 7 is designed at the LTRA port and an LTR bypass inlet pipe 6 is designed at the LTRB port. By proportionally distributing the coolant flow ratio between the heating water tank 5 and the battery 3, and between the heating water tank 5 and the LTR2, heat is reduced. Furthermore, the control stability is improved by controlling the four-way valve 1, which greatly optimizes the user experience.

[0115] This heat pump auxiliary system is independent of the heat pump system and thermal management circuit in normal mode. It can add control stability under low-load conditions such as normal spring and autumn, and can also be adapted to the vehicle to improve user comfort.

[0116] like Figure 3 As shown, a second aspect of the present invention provides a control method for a heat pump auxiliary system according to the first aspect of the present invention, taking an application in an automotive air conditioning system as an example, comprising the following steps when the air conditioning is turned on:

[0117] Step S1: Obtain the current operating condition and determine whether the current operating condition parameters are under low load conditions.

[0118] Obtain the operating parameters of the current operating condition, which include at least the compressor operating status, actual outlet air temperature, target outlet air temperature, and ambient temperature.

[0119] The compressor's operating status can be referenced by compressor speed, etc. To determine whether the operating parameters are low-load operating parameters, low-load operating parameters should include at least the compressor being at its lowest speed, the actual outlet air temperature being higher than the target outlet air temperature, and the ambient temperature being at a preset temperature threshold. Specifically, the temperature threshold can be based on the actual operating conditions. For example, in spring and autumn, there are more low-load scenarios, so the temperature in spring and autumn can be referenced. For example, the temperature threshold can be set to [7℃, 20℃].

[0120] If the operating parameters are low-load operating parameters, the current operating condition is determined to be a low-load operating condition.

[0121] Step S2: Lock the small circulation state based on low load conditions. The small circulation state includes opening the water-cooled condenser shut-off valve 13 and closing the outdoor condenser shut-off valve 14.

[0122] Specifically, in non-small circulation mode, outdoor condenser 11 is still working. Only in small circulation mode, when water-cooled condenser shut-off valve 13 is opened and outdoor condenser shut-off valve 14 is closed, does LTR2 participate in the operation.

[0123] Step S3: Control the opening degree K of the four-way valve 1 based on the control principle;

[0124] Among them, such as Figure 4-5 As shown, the control logic based on control principles is as follows:

[0125] Step S31: Calculate the feedforward FF of four-way valve 1:

[0126] FF = Energy required for heating water tank 5 / (Compressor power + Actual energy of evaporator 9) * 100%;

[0127] Among them, the energy required for heating water tank 5 = (target outlet air temperature - evaporator 9 outlet air temperature) * air volume * air density * air specific heat capacity;

[0128] Compressor power = compressor current * compressor voltage;

[0129] Actual energy of evaporator 9 = (evaporator 9 inlet air temperature - evaporator 9 outlet air temperature) * air volume * air density * air specific heat capacity.

[0130] Step S32: Calculate the feedback P of the four-way valve 1: Feedback P = Calibration p parameter * (Target outlet air temperature - Actual outlet air temperature).

[0131] The air outlet path for both the target and actual outlet air temperatures is temperature damper 16. It should be noted that feedforward (FF) and feedback (P) refer to different control methods. Feedforward (FF) is an open-loop control method, while feedback (P) is a closed-loop control method, both of which are relatively common control methods in the field of control and will not be elaborated upon here.

[0132] As an explanation, the feedforward FF is based on the opening degree of the four-way valve 1, which is estimated based on energy demand. Whether the opening degree can fully meet the target outlet air temperature can be determined by calculating the difference between the actual outlet air temperature and the target outlet air temperature, and then corrected by feedback P.

[0133] Step S33: Calculate the feedback integral I of the four-way valve 1. The feedback integral I = the sum of the calibration parameter i * (target outlet air temperature - actual outlet air temperature). I is reset to 0 each time the valve exits the low-load operation in spring and autumn.

[0134] Specifically, the p and i parameters can be calibrated according to the system and the requirements and options of the four-way valve 1.

[0135] Step S34: Generate the opening degree K of the four-way valve 1 = feedforward FF + feedback P + feedback integral I.

[0136] Specifically, the opening degree K is closely related to the design of the four-way valve 1. Depending on the specific application of the four-way valve 1, its opening degree K will be completely different and needs to be modified according to the actual selection. However, the final position value will be obtained based on the feedforward FF + feedback P + integral I.

[0137] As an explanation, if a four-way valve 1 is in the full LTR position, then both feedback P and integral I are positive; or if the four-way valve 1500 is not in the full LTR position, then both feedback P and integral I are negative; or if the four-way valve 11000 is not in the full LTR position, then both feedback P and integral I are twice that of the four-way valve 1500.

[0138] Step S4: To ensure that the heating water tank 5 has sufficient water, the water pump 4 needs to be adjusted in speed when the four-way proportional water valve is opened to LTR2.

[0139] Corrected speed of water pump 4 = Normal speed of water pump 4 / Percentage of opening of four-way proportional water valve.

[0140] Step S5: Obtain the fan speed correction based on vehicle speed and target temperature difference.

[0141] To ensure the cooling capacity of the LTR2, fan 15 needs to have its speed adjusted:

[0142] The fan speed correction is obtained based on the relationship between vehicle speed and target temperature difference, for example, a lookup table can be created based on the relationship between the three.

[0143] Specifically, the target temperature difference is the difference between the actual coolant temperature and the ambient temperature. The lookup table is only one way to represent the relationship between fan correction speed, vehicle speed, and target temperature difference.

[0144] Specifically, the fan correction speed = vehicle speed and (actual coolant temperature - ambient temperature) can be obtained by matching and calibrating the actual vehicle system, and the calibration results will be output in the form of a lookup table.

[0145] It is important to note that when applied to in-vehicle air conditioning, adjusting the fan speed is necessary to ensure airflow at the front of the vehicle.

[0146] Once the fan 15 has been corrected, the corrected data will be transmitted to step S1 for continuous condition assessment, thereby improving the control stability of the system.

[0147] In this way, the control method can be applied to the heat pump auxiliary system of the first aspect of the present invention. The control method and the heat pump auxiliary system can be independent of the original thermal management system and can be adapted to a variety of different heat pump systems and thermal management loops.

[0148] To better illustrate the application, examples from real-world application scenarios are provided:

[0149] Application scenario description:

[0150] To meet low-load operating conditions when the air conditioner is on;

[0151] Ambient temperature 15℃;

[0152] Target outlet air temperature: 20℃;

[0153] With the temperature damper fully open (16), the actual outlet air temperature is 23℃.

[0154] The compressor operates at a minimum of 800 RPM.

[0155] At this time, the low-load operation condition is met. In order to compensate for the overheated outlet air temperature, the four-way valve 1 opens to the LTR2 side. Through feedforward FF + feedback P + integral I, the actual outlet air temperature = target outlet air temperature = 20℃, which meets the passenger cabin comfort.

[0156] A third aspect of this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a computer, performs the method as described in the second aspect of this application. Throughout this description, numerous specific details, such as examples of components and / or methods, are provided to provide a complete understanding of embodiments of the invention. However, those skilled in the art will recognize that embodiments of the invention can be practiced without one or more of these specific details or by other devices, systems, components, methods, parts, materials, components, etc. In other instances, well-known structures, materials, or operations have not been specifically shown or described in detail to avoid obscuring aspects of the embodiments of the invention.

[0157] Throughout this specification, the terms "an embodiment," "embodiment," or "specific embodiment" refer to a particular feature, structure, or characteristic described in connection with an embodiment that is included in at least one embodiment of the invention, but not necessarily in all embodiments. Therefore, the various representations of the phrases "in one embodiment," "in an embodiment," or "in a specific embodiment" in different places throughout the specification do not necessarily refer to the same embodiment. Furthermore, a particular feature, structure, or characteristic of any specific embodiment of the invention can be combined with one or more other embodiments in any suitable manner. It should be understood that other variations and modifications of the embodiments of the invention described and illustrated herein may be based on the teachings herein and will be considered part of the spirit and scope of the invention.

[0158] It should also be understood that one or more of the elements shown in the figures may be implemented in a more separate or more integrated manner, or may even be removed because they are inoperable in certain circumstances or provided because they may be useful for a particular application.

[0159] Furthermore, unless otherwise expressly stated, any arrows in the accompanying drawings should be considered illustrative only and not limiting. Additionally, unless otherwise stated, the term "or" as used herein is generally intended to mean "and / or". Where a term is anticipated to provide a separation or combination capability that is unclear, a combination of components or steps will also be considered as indicated.

[0160] As used herein and throughout the claims below, unless otherwise specified, “a” and “the” include the plural references. Similarly, as used herein and throughout the claims below, unless otherwise specified, “in” means “in” and “on”.

[0161] The above description of the embodiments shown in this invention (including the content set forth in the abstract of the specification) is not intended to be an exhaustive enumeration or to limit the invention to the precise forms disclosed herein. Although specific embodiments and examples of the invention have been described herein for illustrative purposes only, various equivalent modifications are possible within the spirit and scope of the invention, as will be recognized and understood by those skilled in the art. As indicated, these modifications can be made to the invention in accordance with the above description of the embodiments described herein, and such modifications will be within the spirit and scope of the invention.

[0162] This document has generally described the systems and methods in detail to aid in understanding the invention. Furthermore, various specific details have been set forth to provide a general understanding of embodiments of the invention. However, those skilled in the art will recognize that embodiments of the invention can be practiced without one or more specific details, or using other means, systems, accessories, methods, components, materials, parts, etc. In other instances, well-known structures, materials, and / or operations have not been specifically shown or described in detail to avoid obscuring aspects of embodiments of the invention.

[0163] Therefore, although the invention has been described herein with reference to specific embodiments thereof, freedom of modification, various changes and substitutions are also within the scope of the foregoing disclosure, and it should be understood that in some cases, certain features of the invention may be adopted without departing from the scope and spirit of the invention and without corresponding use of other features. Thus, many modifications can be made to adapt a particular environment or material to the essential scope and spirit of the invention. The invention is not intended to be limited to the specific terminology used in the following claims and / or the specific embodiments disclosed as the best mode for carrying out the invention, but the invention will include any and all embodiments and equivalents falling within the scope of the appended claims. Therefore, the scope of the invention will be defined only by the appended claims.

Claims

1. A heat pump auxiliary system, characterized in that, include: The system includes a four-way valve, LTR, battery, water pump, and heating water tank connected via piping, among which: The four-way valve has four ports, including four-way valve A port, four-way valve B port, four-way valve C port and four-way valve D port; The LTR has two ports, including an LTRA port and an LTRB port; The battery has two ports, including battery port A and battery port B; The water pump has two ports, including water pump port A and water pump port B; The heating water tank has two ports, including heating water tank port A and heating water tank port B; The four-way valve A port is connected to the water pump B port, the four-way valve B port is connected to the battery B port, the four-way valve C port is connected to the heating water tank B port, the four-way valve D port is connected to the LTRB port, and the battery A port is connected to the LTRA port. The four-way valve is used to distribute the coolant flow rate ratio between the heated water tank, the battery, and the LTR; and also includes: Water-cooled condensers, evaporators, electric compressors, and outdoor condensers; The water-cooled condenser has four ports, including water-cooled condenser port A, water-cooled condenser port B, water-cooled condenser port C and water-cooled condenser port D; The evaporator has two ports, including evaporator port A and evaporator port B; The electric compressor has two ports, including electric compressor port A and electric compressor port B; The outdoor condenser has two ports, including outdoor condenser port A and outdoor condenser port B; The water-cooled condenser port A is connected to the outdoor condenser port A and the evaporator port A respectively; The B port of the water-cooled condenser is connected to the A port of the water pump; The C port of the water-cooled condenser is connected to the A port of the heating water tank; The D port of the water-cooled condenser is connected to the B port of the electric compressor and the B port of the outdoor condenser, respectively. The evaporator port B is connected to the electric compressor port A.

2. The heat pump auxiliary system as described in claim 1, characterized in that, The LTRB port is connected to the D port of the four-way valve via the LTR bypass inlet pipe, and the LTRA port is connected to the A port of the battery via the LTR bypass outlet pipe.

3. The heat pump auxiliary system as described in claim 1, characterized in that, The four-way valve is a proportional four-way valve, which proportionally distributes the water ratio between the heating water tank, the battery, and the LTR based on the control principle.

4. The heat pump auxiliary system as described in claim 1, characterized in that, The A port of the water-cooled condenser is connected to the A port of the evaporator via an electronic expansion valve.

5. The heat pump auxiliary system as described in claim 1, characterized in that, The D port of the water-cooled condenser is connected to the B port of the electric compressor via a water-cooled condenser shut-off valve. The D port of the water-cooled condenser is connected to the B port of the outdoor condenser via the outdoor condenser shut-off valve.

6. The heat pump auxiliary system as described in claim 1, characterized in that, The water pump adjusts its speed based on the opening degree of the four-way valve.

7. The heat pump auxiliary system as described in claim 1, characterized in that, It also includes a fan, the fan speed of which is adjusted based on the difference between the fan's current speed and the target temperature; In a heat pump auxiliary system used in automotive air conditioning, the speed of the fan is the vehicle speed.

8. A control method for the heat pump auxiliary system according to claim 1, characterized in that, include: Based on the low-load operating condition, the small circulation state is locked, which includes opening the water-cooled condenser shut-off valve and closing the outdoor condenser shut-off valve. The opening degree K of the four-way valve is controlled based on the control principle; The corrected speed of the water pump is obtained based on the opening degree of the four-way valve. The water pump is connected to port A of the four-way valve and is used to supply refrigerant to the four-way valve. The fan speed correction is obtained based on vehicle speed and target temperature difference, where the target temperature difference is the difference between the actual coolant temperature and the ambient temperature.

9. The control method as described in claim 8, characterized in that, Before locking the small cycle state based on low-load operating conditions, the following are included: Obtain the operating parameters of the current operating condition, which include at least the compressor operating status, actual outlet air temperature, target outlet air temperature, and ambient temperature; Determine whether the operating parameters are low-load operating parameters. The low-load operating parameters include at least the compressor being at its lowest speed, the actual air outlet temperature being higher than the target air outlet temperature, and the ambient temperature being at a preset temperature threshold. If the operating condition parameters are low-load operating condition parameters, the current operating condition is determined to be a low-load operating condition.

10. The control method as described in claim 8, characterized in that, The control of the opening degree K of the four-way valve based on the control principle includes: Calculate the feedforward FF of the four-way valve, where FF = energy required by the heating tank / (compressor power + actual evaporator energy) * 100%; Among them, the energy required for heating the water tank = (target outlet air temperature - evaporator outlet air temperature) * air volume * air density * air specific heat capacity; Compressor power = compressor current * compressor voltage; Evaporator actual energy = (evaporator inlet air temperature - evaporator outlet air temperature) * air volume * air density * air specific heat capacity; Calculate the feedback P of the four-way valve, where feedback P = calibrated p parameter * (target outlet air temperature - actual outlet air temperature). Calculate the feedback integral I of the four-way valve, where the feedback integral I = calibration parameter i * (target outlet air temperature - actual outlet air temperature). The opening degree K of the four-way valve is generated by the formula: feedforward FF + feedback P + feedback integral I.

11. The control method as described in claim 8, characterized in that, The corrected pump speed is obtained based on the opening degree of the four-way valve, including: The corrected speed of the water pump = normal speed of the water pump / percentage of the opening of the four-way proportional water valve.

12. The control method as described in claim 8, characterized in that, The fan speed correction is obtained based on vehicle speed and target temperature difference, including: The fan speed correction is obtained based on the relationship between vehicle speed and target temperature difference.

13. A computer-readable storage medium, characterized in that, It stores a computer program, which, when executed by a computer, performs the method as described in any one of claims 8 to 12.

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