阅读说明：本技术 一种电池冷却与乘员舱制冷的制冷量分配方法及系统 (Refrigerating capacity distribution method and system for battery cooling and passenger compartment refrigeration ) 是由 马自会 林逸峰 李倩琳 柯云宝 曹家怡 于 2020-04-17 设计创作，主要内容包括：本发明公开了一种电池液冷系统与乘员舱制冷的制冷量分配方法及系统；通过设置一电动比例三通阀,并合理的控制流经电池冷却器侧冷却液流量,进而调节电池冷却器侧热负荷,实现双蒸系统中冷媒的分配,使整个空调系统的制冷量合理分配于电池冷却及乘员舱制冷。实施本发明,可使电池在合适的温度范围内工作的同时,保证了整车制冷热舒适性基本不受电池液冷的影响。提升了电池热安全性,以及提高了乘员舱的舒适性,且结构简单,成本低,容易标定。(The invention discloses a battery liquid cooling system and a refrigerating capacity distribution method and system for refrigerating a passenger compartment; the electric proportional three-way valve is arranged, the flow of cooling liquid flowing through the battery cooler side is reasonably controlled, the side heat load of the battery cooler is further adjusted, the distribution of refrigerants in the double-evaporation system is realized, and the refrigerating capacity of the whole air conditioning system is reasonably distributed in battery cooling and passenger compartment refrigeration. By implementing the invention, the battery can work in a proper temperature range, and meanwhile, the cooling and heating comfort of the whole vehicle is ensured not to be influenced by the liquid cooling of the battery basically. The thermal safety of the battery is improved, the comfort of the passenger compartment is improved, and the passenger compartment has the advantages of simple structure, low cost and easy calibration.)

1. The method is characterized in that a battery coolant loop at least comprises a bypass branch and a battery cooler branch which are arranged at two ends of a high-voltage power battery and are mutually connected in parallel, and an electric proportional three-way valve is arranged among the bypass branch, the battery cooler branch and the high-voltage power battery; the battery coolant loop and the passenger compartment refrigeration loop are coupled at a battery cooler, the method comprising the steps of:

step S10, when the cooling loop of the passenger compartment works, monitoring the information fed back by the sensors in the battery cooling liquid loop and the passenger compartment refrigerating loop in real time, wherein the information at least comprises the temperature of an evaporator, the highest temperature of a battery and the water inlet temperature of the battery;

step S11, when the highest temperature of the battery exceeds a preset threshold value, the BMS sends a cooling request to the VCU of the whole vehicle controller;

step S11, after the vehicle control unit VCU receives the cooling request, if the vehicle control unit VCU judges that quick cooling needs to be started, the electric proportional three-way valve is reset, and the position of the electric proportional three-way valve is 100% and communicated with the bypass branch; and informing a heating ventilation air conditioning system controller HVAC to increase the rotating speed of the compressor to the target rotating speed of the compressor;

step S13, the VCU of the vehicle controller calculates the cooling priority of the battery according to the highest temperature of the battery and the temperature of the battery inlet water, and the HVAC calculates the cooling priority of the passenger compartment according to the temperature of the evaporator;

step S14, the VCU of the vehicle control unit determines the position of the latest electric proportional three-way valve according to the cooling priority of the passenger compartment and the cooling priority of the battery;

and step S15, the VCU of the vehicle control unit controls to open the electromagnetic valve at the battery cooler side, operates the battery cooling water pump and controls the position of the electric proportional three-way valve to be switched from the bypass branch to the battery cooler branch at a preset speed until the position of the determined latest electric proportional three-way valve is determined.

2. The method of claim 1, wherein the step S14 further comprises:

when the battery cooling priority is the highest level, directly determining the position of the latest electric proportional three-way valve as 100% of the battery cooling branch; and otherwise, inquiring according to the cooling priority of the battery to obtain the position of a first electric proportional three-way valve, inquiring according to the cooling priority of the passenger compartment to obtain the position of a second electric proportional three-way valve, and determining the smaller one of the position of the first electric proportional three-way valve and the position of the second electric proportional three-way valve as the position of the latest electric proportional three-way valve.

3. The method of claim 1, wherein a relationship between a passenger compartment refrigeration priority and a difference between an actual evaporator temperature and a target temperature is predetermined, wherein a difference is inversely related to the passenger compartment refrigeration priority; the target temperature of the evaporator is determined according to the ambient temperature and the set value of the temperature in the vehicle.

4. The method of claim 1, wherein the relationship between the priority of battery cooling and the difference between the maximum battery temperature, the actual temperature of the battery inlet water and the target temperature is predetermined; wherein the battery cooling priority is determined to be a fixed low value when the battery temperature is below a predetermined threshold; when the temperature of the battery exceeds the preset threshold value, inversely correlating the cooling priority of the battery with the difference value between the actual temperature of the battery inlet water and the target temperature; wherein the battery cooling target water temperature is determined according to the battery maximum temperature.

5. The method of claim 1, wherein a table of correspondence of battery cooling priority to electric proportional three-way valve position and a table of correspondence of passenger compartment cooling priority to electric proportional three-way valve position are pre-calibrated.

6. The method of any one of claims 1 to 5, further comprising the step of determining a target compressor speed comprising:

based on the bench refrigeration data of the standard working condition, obtaining the required rotating speed SPD1 of the compressor according to the target temperature of the evaporator; based on the bench refrigeration data of the standard working condition, obtaining the required rotating speed SPD2 of the compressor according to the quick cooling power request; obtaining a compressor rotation speed limit SPD3 based on NVH constraint;

when the maximum battery temperature is below the trigger temperature threshold TBD1, the compressor target speed is determined in the following manner: SPD min (SPD3, max (SPD1, SPD 2)); when the battery maximum temperature is above the trigger temperature threshold TBD1, the compressor target speed is determined in the following manner: SPD max (SPD1, SPD 2).

7. A refrigerating capacity distribution system for battery cooling and passenger compartment refrigeration is characterized in that a battery cooling liquid loop at least comprises a bypass branch and a battery cooler branch which are arranged at two ends of a high-voltage power battery and are connected in parallel, and an electric proportional three-way valve is arranged among the bypass branch, the battery cooler branch and the high-voltage power battery; the battery coolant loop is coupled with the passenger compartment refrigeration loop at a battery cooler, further comprising:

the real-time monitoring unit is used for monitoring information fed back by sensors and execution components in the battery cooling liquid loop and the passenger compartment refrigerating loop in real time when the passenger compartment cooling loop works, wherein the information at least comprises the temperature of an evaporator, the temperature setting in the vehicle, the highest temperature of the battery and the actual temperature of water inlet of the battery;

the cooling request sending unit is used for controlling the battery management system BMS to send a cooling request to the VCU of the whole vehicle controller when the highest temperature of the battery exceeds a preset threshold value;

the cooling request processing unit is used for controlling the VCU of the vehicle control unit to reset the electric proportional three-way valve if the VCU needs to start quick cooling after receiving a cooling request, so that the position of the electric proportional three-way valve is 100% and is communicated with the bypass branch; and informing a heating ventilation air conditioning system controller HVAC to increase the rotating speed of the compressor to the target rotating speed of the compressor;

the battery cooling priority obtaining unit is used for controlling the VCU of the vehicle control unit to calculate the battery cooling priority according to the highest temperature of the battery and the temperature of the inlet water of the battery;

the passenger compartment refrigeration priority obtaining unit is used for controlling the heating, ventilating and air conditioning system to calculate the passenger compartment refrigeration priority according to the temperature of the evaporator;

the electric proportional three-way valve position determining unit is used for controlling the VCU of the vehicle controller to determine the latest electric proportional three-way valve position according to the passenger compartment refrigeration priority and the battery cooling priority;

and the position adjusting unit of the electric proportional three-way valve is used for controlling the VCU of the vehicle controller to open the electromagnetic valve at the battery cooler side, operating the battery cooling water pump and controlling the position of the electric proportional three-way valve to be switched from the bypass branch to the battery cooler branch at a preset speed until the position of the determined latest electric proportional three-way valve is positioned.

8. The system of claim 7, wherein the electric proportional three-way valve position determining unit further comprises:

the first determination unit is used for directly determining the position of the latest electric proportional three-way valve as 100% of the position of the battery cooler branch when the battery cooling priority is the highest level;

and the second determining unit is used for inquiring to obtain the position of the first electric proportional three-way valve according to the battery cooling priority when the battery cooling priority is not the highest level, inquiring to obtain the position of the second electric proportional three-way valve according to the passenger compartment refrigeration priority, and determining the smaller one of the position of the first electric proportional three-way valve and the position of the second electric proportional three-way valve as the position of the latest electric proportional three-way valve.

9. The system of claim 8, further comprising a preset unit comprising:

the system comprises a first presetting unit, a first control unit and a second presetting unit, wherein the first presetting unit is used for presetting the relation between the passenger compartment refrigeration priority and the difference between the actual temperature and the target temperature of an evaporator, and the difference is inversely related to the passenger compartment refrigeration priority; the target temperature of the evaporator is determined according to the ambient temperature and the set value of the temperature in the vehicle;

the second presetting unit is used for presetting the relationship between the battery cooling priority and the highest temperature of the battery as well as the difference between the actual temperature of the battery inlet water and the target temperature; wherein said battery cooling priority is determined to be a fixed low value when the battery maximum temperature is below a predetermined threshold; when the highest temperature of the battery exceeds the preset threshold value, inversely correlating the cooling priority of the battery with the difference value between the actual temperature of the battery inlet water and the target temperature; wherein the battery cooling target water temperature is determined according to the battery maximum temperature.

And the calibration unit is used for calibrating a corresponding relation table of the battery cooling priority and the position of the electric proportional three-way valve and a corresponding relation table of the passenger compartment refrigeration priority and the position of the electric proportional three-way valve in advance.

10. The system of any one of claims 7 to 9, further comprising a compressor target rotation speed determination unit including:

the compressor required rotating speed obtaining unit is used for obtaining the compressor required rotating speed SPD1 according to the target temperature of the evaporator based on the rack refrigeration data of the standard working condition; the stand refrigeration data based on the standard working condition is used for obtaining the required rotating speed SPD2 of the compressor according to the quick cooling power request;

the compressor rotation speed limit obtaining unit is used for obtaining a compressor rotation speed limit SPD3 based on NVH constraint;

a calculating unit for determining the target rotation speed of the compressor when the highest temperature of the battery is lower than a trigger temperature threshold TBD1 in the following manner: SPD min (SPD3, max (SPD1, SPD 2)); and when the highest battery temperature is higher than the trigger temperature threshold TBD1, determining the target compressor speed in the following manner: SPD max (SPD1, SPD 2).

Technical Field

The invention relates to the technical field of battery cooling of new energy vehicles, in particular to a method and a system for distributing refrigerating capacity of battery cooling and passenger compartment refrigeration.

Background

With the increasing popularization of new energy vehicles (such as pure electric vehicles and hybrid electric vehicles), the requirements for the endurance mileage of the new energy vehicles are continuously increased. However, due to the limitation of the space of the whole vehicle, the scheme for increasing the volume of the battery is not strong in operability, so that the increase of the energy density of the power battery becomes a main solution for improving the endurance mileage of the new energy vehicle in the industry. Due to the fact that the energy density of the power battery is improved, the heat productivity of the battery is increased, the temperature is increased, and therefore the electric quantity, the service life and the like of the battery are adversely affected. In order to solve the above problem of high temperature of the battery, a battery cooling system is required. In the prior art, a battery cooling system mainly includes a liquid-cooled coupled air conditioning system, and a liquid-cooled battery cooling liquid loop and an air conditioning refrigerant loop are coupled by a heat exchanger, i.e., a battery cooler (childler), so as to achieve rapid cooling.

In the prior art, considering factors such as cost, technical maturity and complexity, the expansion valve on the battery cooler side mostly uses the technical scheme of the thermal expansion valve integrated with the electromagnetic switch valve, and the scheme has disadvantages, specifically, because the battery liquid cooling cooler branch is connected with the passenger compartment evaporator branch in parallel, during the refrigerating of the passenger compartment, if the battery is cooled and opened (the electromagnetic valve is opened), the system heat load is increased instantly, the refrigerant pressure is increased, the refrigerating capacity of the passenger compartment evaporator is reduced, the evaporator temperature is increased instantly, and then the temperature fluctuation of the air outlet of the passenger compartment is induced, and the thermal comfort experience of the user is influenced.

In addition, when the battery is cooled, in order to distribute the cooling capacity for cooling the battery and refrigerating the passenger compartment, an electronic expansion valve technology is used in the current stage, that is, an electronic expansion valve is respectively arranged at the sides of the battery cooler and the evaporator or is separately arranged at the side of the battery cooler. For the technical scheme of the single electronic expansion valve, refrigerant pressure and temperature sensors are required to be arranged at the outlet of a battery cooler, and the superheat degree is calculated by collecting the pressure and the temperature of the refrigerant at the low-pressure side of the outlet of the cooler so as to realize the opening control of the electronic expansion valve. When the battery is cooled and just started, the opening degree of the electronic expansion valve is actively controlled to be slowly opened (during opening, the control is not dependent on the superheat degree), the flow of a refrigerant flowing through the cooler cannot be greatly changed in a short time, and therefore the influence on the thermal comfort of a passenger compartment when the battery is cooled and started is reduced. The use of the above-mentioned electronic expansion valve technical scheme requires the cooperation of pressure and temperature sensors, and can raise the cost of the system. And the control strategy of the electronic expansion valve is complex, the calibration period is long, and when the working environment of the system changes, if the control parameters are not adjusted properly, the situations that the valve body acts frequently and the system works unstably can occur, so that the robustness of the system is influenced.

Disclosure of Invention

The technical problem to be solved by the embodiment of the invention is to provide a method and a system for distributing the refrigerating capacity of battery cooling and passenger compartment refrigeration.

As one aspect of the present invention, a method for distributing cooling capacity of battery cooling and passenger compartment refrigeration is provided, in which a battery coolant loop at least includes a bypass branch and a battery cooler branch which are arranged at two ends of a high-voltage power battery and are connected in parallel, and an electric proportional three-way valve is arranged between the bypass branch, the battery cooler branch and the high-voltage power battery; the battery coolant loop and the passenger compartment refrigeration loop are coupled at a battery cooler, the method comprising the steps of:

step S10, when the cooling loop of the passenger compartment works, monitoring the information fed back by the sensors and the executive components in the battery cooling liquid loop and the passenger compartment cooling loop in real time, wherein the information at least comprises the temperature of an evaporator, the temperature setting in the vehicle, the highest temperature of the battery and the actual temperature of the water inlet of the battery;

step S11, when the highest temperature of the battery exceeds a preset threshold value, the BMS sends a cooling request to the VCU of the whole vehicle controller;

step S11, after the vehicle control unit VCU receives the cooling request, if the vehicle control unit VCU judges that quick cooling (coupled air conditioning system) needs to be started, the electric proportional three-way valve is reset, and the position of the electric proportional three-way valve is 100% to be communicated with the bypass branch; and informing a heating ventilation air conditioning system controller HVAC to quickly compensate and increase the rotating speed of the compressor;

step S13, the VCU of the vehicle controller calculates the cooling priority of the battery according to the highest temperature of the battery and the temperature of the battery inlet water, and the HVAC calculates the cooling priority of the passenger compartment according to the temperature of the evaporator;

step S14, the VCU of the vehicle control unit determines the position of the latest electric proportional three-way valve according to the cooling priority of the passenger compartment and the cooling priority of the battery;

and step S15, the VCU of the vehicle control unit controls to open the electromagnetic valve at the battery cooler side, operates the battery cooling water pump and controls the position of the electric proportional three-way valve to be switched from the bypass branch to the battery cooler branch at a preset speed until the position of the determined latest electric proportional three-way valve is determined.

Preferably, the step S14 further includes:

when the battery cooling priority is the highest level, directly determining the position of the latest electric proportional three-way valve as 100% of the battery cooling branch; and otherwise, inquiring according to the cooling priority of the battery to obtain the position of a first electric proportional three-way valve, inquiring according to the cooling priority of the passenger compartment to obtain the position of a second electric proportional three-way valve, and determining the smaller one of the position of the first electric proportional three-way valve and the position of the second electric proportional three-way valve as the position of the latest electric proportional three-way valve.

Preferably, a relationship between a passenger compartment cooling priority and a difference between an actual evaporator temperature and a target temperature is predetermined, wherein the difference is inversely related to the passenger compartment cooling priority; the target temperature of the evaporator is determined according to the ambient temperature, the set value of the temperature in the vehicle and the like.

Preferably, the relationship between the battery cooling priority and the battery highest temperature and the difference between the actual temperature of the battery inlet water and the target temperature are predetermined; wherein said battery cooling priority is determined to be a fixed low value when the battery maximum temperature is below a predetermined threshold; when the highest temperature of the battery exceeds the preset threshold value, inversely correlating the cooling priority of the battery with the difference value between the actual temperature of the battery inlet water and the target temperature; wherein the battery cooling target water temperature is determined according to the battery maximum temperature.

Preferably, a correspondence table of the battery cooling priority and the position of the electric proportional three-way valve, and a correspondence table of the passenger compartment cooling priority and the position of the electric proportional three-way valve are calibrated in advance.

Further comprising the step of determining a target compressor speed comprising:

based on the bench refrigeration data of the standard working condition, obtaining the required rotating speed SPD1 of the compressor according to the target temperature of the evaporator; based on the bench refrigeration data of the standard working condition, obtaining the required rotating speed SPD2 of the compressor according to the quick cooling power request; obtaining a compressor rotation speed limit SPD3 based on NVH constraint;

when the maximum battery temperature is below the trigger temperature threshold TBD1, the compressor target speed is determined in the following manner: SPD min (SPD3, max (SPD1, SPD 2)); when the battery maximum temperature is above the trigger temperature threshold TBD1, the compressor target speed is determined in the following manner: SPD max (SPD1, SPD 2).

Correspondingly, the invention also provides a refrigerating capacity distribution system for battery cooling and passenger compartment refrigeration, wherein the battery coolant loop at least comprises a bypass branch and a battery cooler branch which are arranged at two ends of the high-voltage power battery and are connected in parallel, and an electric proportional three-way valve is arranged among the bypass branch, the battery cooler branch and the high-voltage power battery; the battery coolant loop is coupled with the passenger compartment refrigeration loop at a battery cooler, further comprising:

the real-time monitoring unit is used for monitoring information fed back by sensors and execution components in the battery cooling liquid loop and the passenger compartment refrigerating loop in real time when the passenger compartment cooling loop works, wherein the information at least comprises the temperature of an evaporator, the temperature setting in the vehicle, the highest temperature of the battery and the actual temperature of water inlet of the battery;

the cooling request sending unit is used for controlling the battery management system BMS to send a cooling request to the VCU of the whole vehicle controller when the highest temperature of the battery exceeds a preset threshold value;

the cooling request processing unit is used for controlling the VCU of the vehicle controller to reset the electric proportional three-way valve if the VCU needs to start the quick cooling (coupled air conditioning system) after receiving the cooling request, so that the position of the electric proportional three-way valve is 100% and is communicated with the bypass branch; and informing a heating ventilation air conditioning system controller HVAC to increase the rotating speed of the compressor to the target rotating speed of the compressor;

the battery cooling priority obtaining unit is used for controlling the VCU of the vehicle control unit to calculate the battery cooling priority according to the highest temperature of the battery and the temperature of the inlet water of the battery;

the passenger compartment refrigeration priority obtaining unit is used for controlling the heating, ventilating and air conditioning system to calculate the passenger compartment refrigeration priority according to the temperature of the evaporator;

the electric proportional three-way valve position determining unit is used for controlling the VCU of the vehicle controller to determine the latest electric proportional three-way valve position according to the passenger compartment refrigeration priority and the battery cooling priority;

and the position adjusting unit of the electric proportional three-way valve is used for controlling the VCU of the vehicle controller to open the electromagnetic valve at the battery cooler side, operating the battery cooling water pump and controlling the position of the electric proportional three-way valve to be switched from the bypass branch to the battery cooler branch at a preset speed until the position of the determined latest electric proportional three-way valve is positioned.

Preferably, the electric proportional three-way valve position determining unit further includes:

the first determination unit is used for directly determining the position of the latest electric proportional three-way valve as 100% of the position of the battery cooler branch when the battery cooling priority is the highest level;

and the second determining unit is used for inquiring to obtain the position of the first electric proportional three-way valve according to the battery cooling priority when the battery cooling priority is not the highest level, inquiring to obtain the position of the second electric proportional three-way valve according to the passenger compartment refrigeration priority, and determining the smaller one of the position of the first electric proportional three-way valve and the position of the second electric proportional three-way valve as the position of the latest electric proportional three-way valve.

Preferably, the method further comprises a presetting unit comprising:

the system comprises a first presetting unit, a first control unit and a second presetting unit, wherein the first presetting unit is used for presetting the relation between the passenger compartment refrigeration priority and the difference between the actual temperature and the target temperature of an evaporator, and the difference is inversely related to the passenger compartment refrigeration priority; the target temperature of the evaporator is determined according to the ambient temperature, the set value of the temperature in the vehicle and the like;

the second presetting unit is used for presetting the relationship between the battery cooling priority and the highest temperature of the battery as well as the difference between the actual temperature of the battery inlet water and the target temperature; wherein said battery cooling priority is determined to be a fixed low value when the battery maximum temperature is below a predetermined threshold; when the highest temperature of the battery exceeds the preset threshold value, inversely correlating the cooling priority of the battery with the difference value between the actual temperature of the battery inlet water and the target temperature; wherein the battery cooling target water temperature is determined according to the battery maximum temperature.

And the calibration unit is used for calibrating a corresponding relation table of the battery cooling priority and the position of the electric proportional three-way valve and a corresponding relation table of the passenger compartment refrigeration priority and the position of the electric proportional three-way valve in advance.

Preferably, the control device further comprises a compressor target rotation speed determination unit including:

the compressor required rotating speed obtaining unit is used for obtaining the compressor required rotating speed SPD1 according to the target temperature of the evaporator based on the rack refrigeration data of the standard working condition; the stand refrigeration data based on the standard working condition is used for obtaining the required rotating speed SPD2 of the compressor according to the quick cooling power request;

the compressor rotation speed limit obtaining unit is used for obtaining a compressor rotation speed limit SPD3 based on NVH constraint;

a calculating unit for determining the target rotation speed of the compressor when the highest temperature of the battery is lower than a trigger temperature threshold TBD1 in the following manner: SPD min (SPD3, max (SPD1, SPD 2)); and when the highest battery temperature is higher than the trigger temperature threshold TBD1, determining the target compressor speed in the following manner: SPD max (SPD1, SPD 2).

The embodiment of the invention has the following beneficial effects:

the invention provides a refrigerating capacity distribution method and system for battery cooling and passenger compartment refrigeration, wherein an air conditioning system is coupled to cool a power battery under a high-temperature working condition, so that the power battery can quickly reach a proper working temperature, the charge-discharge performance of the power battery under a high-temperature environment is improved, the service life of the battery is prolonged, and the whole vehicle dynamic performance of the whole vehicle under a high temperature is improved;

when the battery is cooled, the position of the electric proportional three-way valve is controlled to switch from the bypass branch to the battery cooler branch at a preset speed (slow speed), and the negative influence on the refrigeration of a passenger compartment in the processes of battery cooling starting and cooling is suppressed by adopting low cost; when the passenger compartment refrigeration and the liquid cooling battery system are started simultaneously in a high-temperature environment, the comfort of the passenger compartment is well balanced, and the performance and the safety of the battery are ensured; the comfort of the passenger compartment is improved, and the passenger compartment has the advantages of simple structure, low cost and easy calibration;

the refrigerating capacity distribution method for battery cooling and passenger compartment refrigeration provided by the invention considers the comfort feeling of a user in the use process of a vehicle and simultaneously considers the factors of the battery cooling performance and safety, so that the whole thermal management system is always in the optimal state.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is within the scope of the present invention for those skilled in the art to obtain other drawings based on the drawings without inventive exercise.

Fig. 1 is a schematic diagram illustrating connection between a battery coolant circuit and a passenger compartment refrigeration circuit according to a refrigeration capacity distribution method for battery cooling and passenger compartment refrigeration provided by the present invention;

FIG. 2 is a schematic flow chart diagram illustrating an embodiment of a method for distributing cooling capacity for cooling a battery and cooling a passenger compartment according to the present invention;

FIG. 3 is a schematic time-sequential diagram of the actions referred to in FIG. 2;

FIG. 4 is a schematic diagram of an embodiment of a cooling capacity distribution system for battery cooling and passenger compartment cooling according to the present invention;

FIG. 5 is a schematic diagram of the electric proportional three-way valve position determining unit of FIG. 4;

FIG. 6 is a schematic structural diagram of the presetting unit in FIG. 4;

fig. 7 is a schematic structural diagram of a target rotation speed determination unit of the compressor in fig. 4.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings.

As an aspect of the present invention, a method for distributing cooling capacity of battery cooling and passenger compartment refrigeration is provided, as shown in fig. 1, where the battery cooling liquid loop at least includes a bypass branch and a battery cooler branch that are disposed at two ends of a high-voltage power battery and are connected in parallel, where a high-voltage power battery 20, a battery cooling water pump 21, a battery heater 22, a battery cooler 23, an electric proportional three-way valve 24, and a connecting pipeline 25 form the battery cooling liquid loop together; the battery cooler 22 and the battery heater 23 are connected in parallel, the branch where the battery heater 23 is located is a bypass branch, and the branch where the battery cooler 22 is located is a battery cooler branch; the electric proportional three-way valve 24 is arranged among the bypass branch, the battery cooler branch and the high-voltage power battery 20, and the electric proportional three-way valve 24 is provided with three ports P1, P2 and P3; the flow of the cooling liquid flowing into the P3 and P1 interfaces can be controlled by adjusting the position of the electric proportional three-way valve 24; a battery inlet water temperature sensor 26 and a battery outlet water temperature sensor 27 are arranged at two ends of the high-voltage power battery 20 and are respectively used for monitoring the temperature of cooling liquid entering and flowing out of the high-voltage power battery 20; an expansion tank assembly 28, a coolant filling pipe 20, and a cooling system degassing pipe 290 are further connected to both ends of the high-voltage power battery 20. It is understood that, in some examples, in the battery coolant loop, the coolant flows through a cooling plate inside the battery pack of the high-voltage power battery 20, a heat conduction pad is disposed between the cooling plate and the battery pack, and heat generated by the battery pack is transferred to the cooling plate and then transferred to the coolant along the heat conduction pad, so as to bring the heat out of the battery pack, thereby achieving the effect of cooling the high-voltage power battery 20.

The electric compressor 30, the condenser 31, the air conditioner box 32 and the refrigerant pipe 33 form a passenger compartment refrigeration loop, meanwhile, the battery coolant loop and the passenger compartment refrigeration loop are coupled at the battery cooler 23, namely, a refrigerant pipe branch parallel to the air conditioner box 32 is branched from the passenger compartment refrigeration loop through a tee joint 34 and passes through the battery cooler 23, and the refrigerant in the refrigerant pipe branch can exchange heat in the battery cooler 23 to cool the coolant in the battery coolant loop, so that the high-voltage power battery 20 is cooled. Further, an air conditioner evaporator is arranged in the air conditioner box body 32, and the air conditioner evaporator is further connected with an air conditioner evaporator side electromagnetic valve 35 and an air conditioner evaporator side thermal expansion valve 36; a battery cooler-side electromagnetic valve 37 and a battery cooler-side heat expansion valve 38 are similarly connected to the battery cooler 23. A cooling fan 39 is provided at the condenser, and an air conditioner high pressure sensor 390 is provided at the refrigerant pipe.

More specifically, as shown in fig. 2, a main flow diagram of the method provided by the present invention is shown. Specifically, the method for distributing the refrigerating capacity of the battery cooling and the passenger compartment refrigeration comprises the following steps:

step S10, when the cooling loop of the passenger compartment works (namely the automobile starts the air conditioner in the automobile), monitoring the information fed back by each sensor and executive component in the battery cooling liquid loop and the passenger compartment refrigerating loop in real time, wherein the information at least comprises the temperature of an evaporator, the highest temperature of a battery, the water inlet temperature of the battery and the like;

step S11, when the maximum Battery temperature exceeds a predetermined threshold, the Battery Management System (BMS) sends a cooling request to a Vehicle Control Unit (VCU), wherein the predetermined threshold is calibrated according to different Vehicle types;

it will be appreciated that the battery rapid cooling power request is primarily used to supplement compressor speed control (since battery cooling removes a portion of the cooling capacity, the compressor speed needs to be increased appropriately to ensure that passenger compartment cooling is not significantly affected). The battery fast cooling power request depends on the water temperature of the water inlet of the battery, and is obtained by a table look-up of the water temperature, because the fast cooling directly acts on the cooling liquid to cool the cooling liquid and maintain the cooling liquid in a lower temperature range.

Step S12, after the vehicle control unit VCU receives the cooling request, if the vehicle control unit VCU judges that quick cooling (coupled air conditioning system) needs to be started, the electric proportional three-way valve is reset, the position of the electric proportional three-way valve is 100% and is communicated with a bypass branch, namely the flow of the P2 interface is completely opened, and the flow of the P3 interface is closed; and informing a Heating, ventilating and Air Conditioning (HVAC) system to quickly compensate for the increased compressor speed; the notification here may include sending a fast cool enable flag bit to the HVAC along with a fast cool power request.

Step S13, the VCU of the vehicle controller calculates the cooling priority of the battery according to the highest temperature of the battery and the temperature of the battery inlet water, and the HVAC calculates the cooling priority of the passenger compartment according to the temperature of the evaporator;

determining in advance a relationship between a passenger compartment refrigeration priority and a difference between an actual evaporator temperature and a target temperature, wherein the difference is inversely related to the passenger compartment refrigeration priority; the target temperature of the evaporator is determined according to the ambient temperature and the set value of the temperature in the vehicle. For example, in one specific example, the passenger compartment cooling priority is divided into 3 levels, indicated by the numbers "0", "1" and "2", respectively, with the higher the number, the higher the priority level. The priority is determined according to the difference between the actual temperature of the evaporator and the target temperature, and the smaller the difference is, the lower the priority is; the larger the difference, the higher the priority.

Meanwhile, the relationship between the battery cooling priority and the highest battery temperature and the difference between the actual battery water inlet temperature and the target temperature are required to be determined in advance; wherein said battery cooling priority is determined to be a fixed low value when the battery maximum temperature is below a predetermined threshold; when the highest temperature of the battery exceeds the preset threshold value, inversely correlating the cooling priority of the battery with the difference value between the actual temperature of the battery inlet water and the target temperature; wherein the battery cooling target water temperature is determined according to the battery maximum temperature. For example, in one example, the battery cooling priority is divided into 4 levels, which are indicated by the numbers "0", "1", "2" and "3", respectively, and the larger the number, the higher the priority level. The priority is determined according to the difference between the highest temperature of the battery, the actual temperature of the inlet water of the battery and the target temperature. When the highest temperature of the battery is not high, the priority is low regardless of the water temperature; when the highest temperature of the battery is high, the difference of the water temperature difference is larger, the priority is higher, and otherwise, the difference is smaller, the priority is lower.

Step S14, the VCU of the vehicle control unit determines the position of the latest electric proportional three-way valve according to the cooling priority of the passenger compartment and the cooling priority of the battery;

specifically, the step S14 further includes:

when the battery cooling priority is at the highest level (e.g., level 3), directly determining the position of the latest electric proportional three-way valve as 100% flowing through the battery cooler branch; and otherwise, inquiring according to the cooling priority of the battery to obtain the position of a first electric proportional three-way valve, inquiring according to the cooling priority of the passenger compartment to obtain the position of a second electric proportional three-way valve, and determining the smaller one of the position of the first electric proportional three-way valve and the position of the second electric proportional three-way valve as the position of the latest electric proportional three-way valve.

It can be understood that the correspondence table of the battery cooling priority and the position of the electric proportional three-way valve, and the correspondence table of the passenger compartment cooling priority and the position of the electric proportional three-way valve need to be calibrated in advance.

In a practical example, one of the main functions of the electric proportional three-way valve is to control the cooling capacity by regulating the battery cooler side heat load. In particular, the battery inlet water temperature is prevented from being excessively lower than the target water temperature to ensure that the cooling of the passenger compartment is not negatively affected. The correspondence table (MAP1) of battery cooling priority and electric proportional three-way valve position may be pre-calibrated, and the electric proportional three-way valve position may be obtained with the battery inlet water temperature and the target temperature as inputs.

Accordingly, the use of the electric proportional three-way valve can suppress the negative influence on the passenger compartment refrigeration when the battery is cooled and opened to a certain extent, and the electric proportional three-way valve position can be output by making the passenger compartment refrigeration priority as an input in advance by using the passenger compartment refrigeration priority as a correspondence table (MAP2) of the passenger compartment refrigeration priority and the electric proportional three-way valve position.

During a rapid cool, when the battery cooling priority is "3", the electric proportional three-way valve position is set to cause 100% flow of coolant through the battery cooler, regardless of whether the passenger compartment cooling priority is high or low.

When the battery cooling priority is lower than '3', the position of the electric proportional three-way valve is determined by the battery cooling water temperature and the passenger compartment cooling priority. The electric proportional three-way valve position is taken small, i.e. min, between MAP1 and MAP2 (MAP1, MAP 2).

And step S15, the VCU of the vehicle control unit controls to open the electromagnetic valve at the battery cooler side, operates the battery cooling water pump and controls the position of the electric proportional three-way valve to be switched from the bypass branch to the battery cooler branch at a preset speed until the position of the determined latest electric proportional three-way valve is determined.

Further comprising the step of determining the target rotation speed of the compressor in step S11, comprising:

based on the bench refrigeration data of the standard working condition, obtaining the required rotating speed SPD1 of the compressor according to the target temperature of the evaporator; based on the bench refrigeration data of the standard working condition, obtaining the required rotating speed SPD2 of the compressor according to the quick cooling power request; obtaining a compressor rotation speed limit SPD3 based on NVH constraint;

when the maximum battery temperature is below the trigger temperature threshold TBD1, the compressor target speed is determined in the following manner: SPD min (SPD3, max (SPD1, SPD 2)); when the battery maximum temperature is above the trigger temperature threshold TBD1, the compressor target speed is determined in the following manner: SPD max (SPD1, SPD 2).

It will be appreciated that the most important application of the method of the present invention is generally in a rapid cold start process (with the passenger compartment air conditioner on), when the VCU determines that a battery rapid cold needs to be started, the VCU first places the electric proportional three-way valve in 100% communication with the bypass branch (i.e., the battery heater). The VCU then sends a fast cool enable bit and a fast cool power request to the HVAC to cause the HVAC to quickly compensate for the boost in compressor speed. After a short time delay, the electromagnetic valve at the battery cooler side is opened, and the battery cooling water pump is operated at the same time. And finally, controlling the position of the electric proportional three-way valve to be slowly switched from the HVH branch to the battery cooler branch. The sequence of the actions of this process can be seen with reference to fig. 3.

Fig. 4 is a schematic structural diagram of an embodiment of a cooling capacity distribution system for cooling a battery and cooling a passenger compartment according to the present invention; as shown in fig. 5 to 7.

With reference to the above drawings, the present invention further provides a refrigerating capacity distribution system 1 for battery cooling and passenger compartment refrigeration, which comprises a battery coolant loop and a passenger compartment refrigerating loop coupled with each other, wherein the battery coolant loop at least comprises a bypass branch and a battery cooler branch which are arranged at two ends of a high-voltage power battery and are connected in parallel, and an electric proportional three-way valve is arranged among the bypass branch, the battery cooler branch and the high-voltage power battery; the battery coolant loop and the passenger compartment refrigeration loop are coupled at the battery cooler, and the structure of the two loops may be combined as described above in connection with fig. 1.

Specifically, the cooling capacity distribution system for cooling the battery and cooling the passenger compartment further comprises:

the real-time monitoring unit 11 is used for monitoring information fed back by sensors and execution components in the battery cooling liquid loop and the passenger compartment refrigerating loop in real time when the passenger compartment cooling loop works, wherein the information at least comprises evaporator temperature, temperature setting in the vehicle, battery highest temperature and actual temperature of battery water inlet;

a cooling request sending unit 12, configured to control the battery management system BMS to send a cooling request to the vehicle control unit VCU when the maximum battery temperature exceeds a predetermined threshold;

the cooling request processing unit 13 is configured to control the vehicle control unit VCU to reset the electric proportional three-way valve if it is determined that quick cooling (coupling of the air conditioning system) needs to be started after receiving the cooling request, so that the position of the electric proportional three-way valve is 100% and the bypass branch is communicated; and informing the heating, ventilating and air conditioning system to quickly compensate and increase the rotating speed of the compressor;

a battery cooling priority obtaining unit 14, configured to control the vehicle control unit VCU to calculate a battery cooling priority according to the maximum battery temperature and the battery inlet water temperature;

a passenger compartment refrigeration priority obtaining unit 15 for controlling the heating, ventilating and air conditioning system to calculate the passenger compartment refrigeration priority according to the evaporator temperature;

the position determining unit 16 of the electric proportional three-way valve is used for controlling the VCU of the vehicle controller to determine the position of the latest electric proportional three-way valve according to the cooling priority of the passenger compartment and the cooling priority of the battery;

and the position adjusting unit 17 of the electric proportional three-way valve is used for controlling the VCU of the vehicle controller to open the electromagnetic valve at the battery cooler side, operating the battery cooling water pump and controlling the position of the electric proportional three-way valve to be switched from the bypass branch to the battery cooler branch at a preset speed until the position of the determined latest electric proportional three-way valve is positioned.

In a specific example, the electric proportional three-way valve position determining unit 16 further includes:

a first determination unit 160 for directly determining a position of the latest electro proportional three-way valve as 100% flowing through the battery cooler bypass when the battery cooling priority is the highest level;

the second determining unit 161 is configured to, when the battery cooling priority is not the highest level, obtain a position of the first electric proportional three-way valve according to a query of the battery cooling priority, obtain a position of the second electric proportional three-way valve according to a query of the passenger compartment cooling priority, and determine a smaller one of the position of the first electric proportional three-way valve and the position of the second electric proportional three-way valve as a latest electric proportional three-way valve position.

In a specific example, the preset unit 18 is further included, and includes:

a first presetting unit 180 for predetermining a relationship between a passenger compartment refrigeration priority and a difference between an actual evaporator temperature and a target temperature, wherein the difference is inversely related to the passenger compartment refrigeration priority; the target temperature of the evaporator is determined according to the ambient temperature and the set value of the temperature in the vehicle;

the second presetting unit 181 is used for presetting the relationship between the battery cooling priority and the battery highest temperature, and the difference between the actual temperature of the battery inlet water and the target temperature; wherein said battery cooling priority is determined to be a fixed low value when the battery maximum temperature is below a predetermined threshold; when the highest temperature of the battery exceeds the preset threshold value, inversely correlating the cooling priority of the battery with the difference value between the actual temperature of the battery inlet water and the target temperature; wherein the battery cooling target water temperature is determined according to the battery maximum temperature.

The calibration unit 182 is configured to calibrate a correspondence table between the battery cooling priority and the position of the electric proportional three-way valve, and a correspondence table between the passenger compartment cooling priority and the position of the electric proportional three-way valve in advance.

In a specific example, the present invention further includes a compressor target rotation speed determination unit 19 including:

the compressor required rotating speed obtaining unit 190 is used for obtaining the compressor required rotating speed SPD1 according to the target temperature of the evaporator based on the rack refrigeration data of the standard working condition; the stand refrigeration data based on the standard working condition is used for obtaining the required rotating speed SPD2 of the compressor according to the quick cooling power request;

a compressor rotation speed limit obtaining unit 191, configured to obtain a compressor rotation speed limit SPD3 based on NVH constraints;

a calculating unit 192 for determining the target rotation speed of the compressor when the highest temperature of the battery is lower than the trigger temperature threshold TBD1 in the following manner: SPD min (SPD3, max (SPD1, SPD 2)); and when the highest battery temperature is higher than the trigger temperature threshold TBD1, determining the target compressor speed in the following manner: SPD max (SPD1, SPD 2).

For more details, please refer to the foregoing description of fig. 1 to 3, which will not be described in detail herein.

The embodiment of the invention has the following beneficial effects:

the invention provides a refrigerating capacity distribution method and system for battery cooling and passenger compartment refrigeration, wherein an air conditioning system is coupled to cool a power battery under a high-temperature working condition, so that the power battery can quickly reach a proper working temperature, the charge-discharge performance of the power battery under a high-temperature environment is improved, the service life of the battery is prolonged, and the whole vehicle dynamic performance of the whole vehicle under a high temperature is improved;

when the battery is cooled, the position of the electric proportional three-way valve is controlled to switch from the bypass branch to the battery cooler branch at a preset speed (slow speed), and the negative influence on the refrigeration of a passenger compartment in the processes of battery cooling starting and cooling is suppressed by adopting low cost; when the passenger compartment refrigeration and the liquid cooling battery system are started simultaneously in a high-temperature environment, the comfort of the passenger compartment is well balanced, and the performance and the safety of the battery are ensured; the comfort of the passenger compartment is improved, and the passenger compartment has the advantages of simple structure, low cost and easy calibration;

the refrigerating capacity distribution method for battery cooling and passenger compartment refrigeration provided by the invention considers the comfort feeling of a user in the use process of a vehicle and simultaneously considers the factors of the battery cooling performance and safety, so that the whole thermal management system is always in the optimal state.

While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.