Patent Publication Number: US-2023150341-A1

Title: Cooling system for electric vehicle adapted for cooling of components of vehicle

Description:
TECHNICAL FIELD 
     The present disclosure relates to the field of electric vehicles, in particular to an electric vehicle cooling system. 
     BACKGROUND 
     In order to provide a comfortable environment for the passengers, electric vehicles are usually equipped with an air-conditioning cooling system. The air conditioning cooling system typically includes a condenser, a first valve, an evaporator, and a compressor etc., connected in series. The refrigerant circulates in the air conditioning electric vehicle cooling system. Currently, the sole purpose of the air conditioning and refrigeration system of electric vehicles is to provide passengers with an environment of appropriate temperatures. However, the air conditioning and refrigeration system may be adapted for additional functions. 
     Therefore, improvement is desired. 
     SUMMARY OF THE DISCLOSURE 
     The embodiment of the present disclosure aims to provide an electric vehicle cooling system with additional functions. 
     The embodiment of the present disclosure provides an electric vehicle cooling system which includes a cooling loop and a cooling branch. The cooling loop includes a condenser, a first valve, an evaporator and a compressor etc. which are successively connected to form a loop. The cooling branch is disposed in parallel with the evaporator; wherein the cooling branch includes a cooling unit that is configured to be in contact with one or more components, such that the refrigerant flowing through the cooling unit evaporates to cool them. 
     The current electric vehicle cooling system adds a cooling branch including additional heat exchangers/pumps with a separate coolant e.g. water in the cooling loop. The cooling branch is in contact with a component such as a battery or an electric motor which generates heat, so that the electric vehicle cooling system can not only provide users with an environment of appropriate temperature through the cooling loop, but also cool those components. In the present disclosure such a complex coolant branch is not needed, we have a simple cooling branch, which can not only reduce the cost, but also improve the space utilization. Due to no need of pumps/heat exchangers and a separate coolant, the present disclosure can reduce the overall weight of the electric vehicle and the power consumption and improve the acceleration and driving speed. It can also be used to cool other electrical components such as high-power chips thanks to its high cooling capability with less delay compared with current coolant-cooled approaches. 
     In some embodiments, the cooling branch further comprises a second valve, an inlet of the second valve is connected to an outlet of the first valve, and an outlet of the second valve is connected to an inlet of a cooling unit. 
     In the electric vehicle cooling system of the above embodiment, the second valve can control the flow rate of the refrigerant into the cooling unit, so as to control the temperature of the cooling unit, so that the temperature of the cooling unit can be kept stable. 
     In some embodiments, the cooling unit comprises a cold plate and a cold pipe, the cold plate is configured to be in contact with the component, the cold pipe passes through the cold plate, the cold pipe is configured to contain and guide the refrigerant to flow, a first end of the cold pipe is connected to the first valve, and a second end of the cold pipe is connected to the compressor, the first end of the cold pipe is an inlet of the cold pipe, the second end of the cold pipe is an outlet of the cold pipe. 
     In the electric vehicle cooling system of the above embodiment, the refrigerant can transport the heat by evaporating along the cold plate and passing through the cold pipe. 
     In some embodiments, the cold pipe further comprises an entry portion, a cooling portion, and an outflow portion, the inlet of the cold pipe is disposed at the entry portion, the entry portion is connected to the outlet of the second valve; the cooling portion is located in the cold plate and connected to the entry portion, and a shape of the cooling portion is wave-like; and a first end of the outflow portion is connected to the cooling portion, and the outlet of the cold pipe is located at a second end of the outflow portion and connected to the compressor. 
     In the electric vehicle cooling system of the above embodiment, the shape of the cooling portion is wave-like, such shape increases the contact area between the cooling portion and the cold plate, so as to improve the cooling speed of the cold plate. 
     In some embodiments, the cold plate further comprises a plate body and an insulation shell. The plate body is enclosed by an insulation shell to block heat exchange between outside and the plate body. The plate body is in contact with the component through a thermal interface material, and the cold pipe penetrates the insulation shell and the plate body that is soldered with the pipe with a good thermal contact interface in between. The insulation shell can be opened to allow service or replacement of to-be-cooled components e.g. high power chips-on-board. 
     In the electric vehicle cooling system of the above embodiment, the plate body is enclosed by an insulation shell, which can effectively block the heat exchange of the plate body and reduce the loss of cooling capacity of the plate body. 
     In some embodiments, an air gap is defined between the insulation shell and the plate body. 
     In the electric vehicle cooling system of the above embodiment, there is an air gap between the insulation shell and the plate body. Such space further reduces heat exchange and further reduces the loss of cooling capacity of the plate body. 
     In some embodiments, a material of the insulation shell is plastic, and a material of the plate body and the cold pipe is copper. 
     In the electric vehicle cooling system of the above embodiment, the plastic provides better insulation, while copper has good heat conduction, the plate body and cold pipe are made of copper, which can quickly cool down when the refrigerant passes through the plate, and the insulation shell can effectively prevent the loss of cooling capacity of the plate body. 
     In some embodiments, the cooling loop further comprises a third valve, the third valve is located between the first valve and the evaporator and is disposed in parallel with the cooling branch. 
     In the electric vehicle cooling system of the above embodiment, the third valve can control the flow rate of the refrigerant through the evaporator, so that when the air conditioner is not needed (for example in winter), the refrigerant can be blocked from passing through the evaporator by the third valve, while the temperature of the component can still be reduced without using the air conditioner for the cab. 
     In some embodiments, the cooling unit further comprises an insulation sleeve, the insulation sleeve is disposed on the cold pipe to prevent coldness loss. 
     In the electric vehicle cooling system of the above embodiment, the insulation sleeve can prevent coldness loss. 
     In some embodiments, the second valve is a temperature control valve, the second valve is configured to detect temperature of the cooling unit and accordingly adjust the flow rate of the refrigerant entering the cooling unit to maintain a constant case temperature of the cooling unit. 
     The present disclosure detects the temperature of the cooling unit through the second valve, which can keep the case temperature of the cooling unit constant by optimizing the flow rate, so as to improve the cooling effect of the cooling unit. 
     The electric vehicle cooling system of the present disclosure adds a cooling branch in the cooling loop, so that the electric vehicle cooling system can not only provide users with an appropriate temperature environment, but also cool a component. Compared with the independent addition of a loop to cool a component, the present disclosure can not only save space and reduce costs, but also reduce the weight of the electric vehicle, so as to improve the acceleration of the electric vehicle, and the electric vehicle consumes less power at the same speed, so as to prolong the driving distance. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic diagram of an electric vehicle cooling system according to an embodiment of the present disclosure. 
         FIG.  2    is a schematic diagram of a cooling unit of the system in  FIG.  1   . 
         FIG.  3    is a side view of the cooling unit in  FIG.  2   . 
         FIG.  4    is a top view of a cold pipe of the system in  FIG.  1   . 
     
    
    
     DETAILED DESCRIPTION 
     The technical solutions in the embodiments of the present disclosure will be described in conjunction with the accompanying drawings in the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of them. Based on the embodiments of the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present disclosure. 
     It should be noted that when a component is considered to “connect” another component, it can be directly connected to another component or there may be intermediate components at the same time. When a component is considered to be “disposed” on another component, it can be disposed directly on another component or there may be centered components at the same time. The terms “top”, “bottom”, “top”, “bottom”, “left”, “right”, “front”, “back” and similar expressions used in this paper are for illustrative purposes only. 
     The present disclosure provides an electric vehicle cooling system, the electric vehicle cooling system includes a cooling loop, a cooling branch, and a refrigerant. The cooling loop includes a condenser, a first valve, an evaporator, and a compressor which are successively connected to form a loop. The cooling branch is disposed in parallel with the evaporator; wherein the cooling branch includes a cooling unit, the cooling unit is configured to be in contact with a component, the refrigerant is configured to flow through the cooling unit and cool the component. The electric vehicle cooling system can add a cooling branch in parallel with the evaporator in the cooling loop, the cooling branch is in contact with the component, so that the electric vehicle cooling system not only provides users with an environment of appropriate temperature through the main cooling loop, but also cools the component through the other parallel loop, so that the electric vehicle cooling system has a dual effect. In the present disclosure, a traditional loop containing heat exchanger &amp; pump with a separate coolant to cool the component is not needed, which can not only reduce the cost, but also improve the space utilization. 
       FIG.  1    illustrates an electric vehicle cooling system  100  in accordance with an embodiment of the present disclosure. 
     The electric vehicle cooling system  100  includes a cooling loop  10  and a cooling branch  20 . The cooling loop  10  includes a condenser  11 , a first valve  12 , an evaporator  13 , and a compressor  14 . The condenser  11 , the first valve  12 , the evaporator  13 , and the compressor  14  are connected in that order, and each has an inlet and an outlet to form a loop. The electric vehicle cooling system  100  includes further includes a refrigerant  40  (shown in  FIG.  2   ). A refrigerant is disposed in the cooling loop  10 . The compressor  14  compresses the refrigerant from a low temperature and pressure gaseous state to a high temperature and pressure gaseous state after absorbing heat, then transporting it to the condenser  11  for cooling. After passing through the condenser  11 , the refrigerant  40  becomes a liquid with normal temperature and high pressure, enters the first valve  12  to depressurize to form a gas-liquid mixture with low temperature and low pressure, and then enters the evaporator  13  to make the liquid refrigerant evaporate and absorb heat to turn into a gaseous state and then return to the compressor  14 . 
     The cooling branch  20  is disposed in parallel with the evaporator  13 . The cooling branch  20  includes a cooling unit  21 , the inlet of the cooling unit  21  is communicating with the first valve  12 , and the outlet of the cooling unit  21  is communicating with the compressor  14 . The cooling unit  21  is used to contact and cool the component  30  (shown in  FIG.  2   ). After passing through the first valve  12 , part of the refrigerant  40  flows into the evaporator  13  and the other part of the refrigerant  40  into the cooling unit  21 , so that the cooling unit  21  can maintain a low temperature. The refrigerant  40  from the cooling unit  21 , after absorbing heat, forms a gaseous state, so that the compressor  14  can operate stably. 
     In some embodiments, the cooling loop  10  may be an air conditioning cooling loop. The electric vehicle cooling system  100  can not only adjust the temperature in the cab of the vehicle, but also cool the component  30  of the electric vehicle through the cooling branch  20 . 
     In some embodiments, the electric vehicle may be an intelligent electric vehicle, and the component  30  may be the chip of the intelligent electric vehicle. The chip in the intelligent electric vehicle might be used to obtain images and data in real time from cameras or sensors of the intelligent electric vehicle. When in operation, the chip will generate a lot of heat. Too high a temperature of the chip will affect the data transmission and the response rate of programs in intelligent electric vehicles. Cooling the chip by the cooling branch  20  is conducive to keeping the chip in an efficient working state. 
     In some embodiments, the first valve  12  may be a thermal expansion valve, the thermal expansion valve can detect overheating of the refrigerant before its entering the compressor  14  and adjust the flow rate of the refrigerant into the compressor  14 , so as to manage the overheating status of vapor and make the compressor  14  operate stably. 
     In some embodiments, the compressor  14  may be a variable frequency compressor. The present disclosure can change the power of the variable frequency compressor by changing the speed of the variable frequency compressor. Compared with the compressor with constant relative speed, the variable frequency compressor can change the power according to the needs of users and reduce energy consumption. 
     The cooling loop  10  is used to adjust the temperature of the cab in the electric vehicle. The cooling branch  20  is used to cool the component  30  of the electric vehicle, such as the chip of the intelligent electric vehicle, so that the electric vehicle cooling system  100  has dual functions, improves the utilization rate of the electric vehicle cooling system  100 , and does not need to use a separate electric vehicle cooling system  100  to cool the component  30 , so as to reduce the cost and save space. 
     Referring to  FIG.  2    and  FIG.  3   , the cooling unit  21  includes a cold plate  211  and a cold pipe  212 . The cold pipe  212  penetrates the cold plate  211 , the cold plate  211  is in contact with the component  30  through a thermal interface material. One end of the cold pipe  212  is an inlet and connected with the first valve  12 , and the other end of the cold pipe  212  is an outlet and connected with the compressor  14 . The refrigerant  40  enters from the inlet of the cold pipe  212  and keeps the cold plate  211  at a low temperature by evaporation through the cold pipe  212 . The cold plate  211  contacts the component  30  and continues to cool the component  30 . 
     In some embodiments, there are multiple cold plates  211 , and the cold plates  211  are connected in series with each other, and the position, shape and size of the cold plate  211  are adjusted according to the position of the component  30 . 
     It can be understood that the cold plates  211  are not limited to being connected in series, but can also be connected in parallel. 
     The cold plate  211  includes a plate body  2111  and an insulation shell  2112 . The insulation shell  2112  covers the plate body  2111  with an air gap in between, and the cold pipe  212  penetrates the insulation shell  2112  and the plate body  2111  at the same time. The insulation shell  2112  is used to block heat exchange of the plate body  2111  and prolong a low temperature of the plate body  2111 . 
     In some embodiments, one inner surface of the insulation shell  2112  is fixed with the plate body  2111 , and an air gap is reserved between other inner surfaces of the insulation shell  2112  and the plate body  2111 . Compared with all the inner surfaces of the insulation shell  2112  in contact with the plate body  2111 , heat exchange of the plate body  2111  is further blocked. 
     In some embodiments, the plate body  2111  is made of copper and has better thermal conductivity. When the refrigerant cools the plate body  2111  through the cold pipe  212 , the temperature of the plate body  2111  can be quickly reduced. 
     It can be understood that the material of the plate body  2111  is not limited to copper, but can also be other materials with strong thermal conductivity, such as aluminum or aluminum copper alloy to save weight and cost. 
     In some embodiments, the material of the insulation shell  2112  is plastic, which can effectively block the heat exchange of the plate body  2111 . 
     It can be understood that the material of the insulation shell  2112  is not limited to this, but can also be glass and other materials. 
     In one embodiment, the outer surface of the insulation shell can be further sleeved by an insulation material, e.g. insulation cotton to further prevent coldness loss. 
     Referring to  FIG.  4   , the cold pipe  212  includes an entry portion  2121 , a cooling portion  2122 , and an outflow portion  2123 . The inlet of the cold pipe  212  is located at one end of the entry portion  2121 , and the other end of the entry portion  2121  is connected to the cooling portion  2122 . The cooling portion  2122  is disposed in the plate body  2111 , and one end of the cooling portion  2122  away from the entry portion  2121  is connected to the outflow portion  2123 . The outlet of the cold pipe  212  is located at one end of the outflow portion  2123  away from the cooling portion  2122 . 
     In some embodiments, the shape of the cooling portion  2122  is wave-like, which can increase the contact area with the plate body  2111 , so as to better reduce the temperature of the plate body  2111 . 
     It can be understood that the shape of the cooling portion  2122  is not limited to a wave shape, but can also be other shapes, such as a broken line shape. 
     In some embodiments, the material of the cold pipe  212  is copper, which has better thermal conductivity and can quickly transfer heat to or from the plate body  2111 . 
     It can be understood that the material of the cold pipe  212  is not limited to copper, but can also be silver, aluminum, aluminum copper alloy, and other materials. 
     Referring to  FIG.  2   , in some embodiments, the cooling unit  21  further includes an insulation sleeve  213 . The insulation sleeve  213  is sleeved on the cold pipe  212 , the insulation sleeve  213  can block the heat exchange between the cold pipe  212  and outside, so as to reduce the loss of cooling capacity and save energy. 
     In some embodiments, the material of the insulation sleeve  213  is insulating material, such as insulating cotton. 
     Referring to  FIG.  1    and  FIG.  2   , in some embodiments, the cooling branch  20  further incudes a second valve  22 . The second valve  22  is disposed in parallel with the evaporator  13 , and the inlet  222  of the second valve  22  is connected to the outlet  121  of the first valve  12 . The inlet  122  of the first valve  12  is connected to the condenser  11 . The outlet  221  of the second valve  22  is connected to the inlet of the cooling unit  21 . The second valve  22  is used to adjust the flow of refrigerant entering the plate body  2111 , so as to control the temperature of the plate body  2111 . 
     In some embodiments, the second valve  22  is a temperature control valve that automatically adjusts the flow of refrigerant by detecting the temperature of the plate body  2111 . The present disclosure can achieve the purpose of saving energy by entirely gasifying the refrigerant at the outflow portion  2123 , so as to minimize the needed flow, the plate body  2111  can maintain a constant temperature and not allow the temperature of the plate body  2111  to be too high for effective cooling of the component  30 , or the temperature of the plate body  2111  being too low, resulting in waste of resources. 
     In some embodiments, the cooling loop  10  further includes a third valve  15 , the third valve  15  is disposed between the first valve  12  and the evaporator  13  and is disposed in parallel with the cooling branch  20 . The inlet  151  of the third valve  15  is connected to the outlet  121  of the first valve  12 , the outlet  152  is connected to the evaporator  13 . The third valve  15  is used to control the flow of refrigerant into the evaporator  13 . Thus, the component  30  of the electric vehicle can still be cooled in winter when air conditioning for the cab of the vehicle is not required. 
     In some embodiments, the third valve  15  is a solenoid valve with signal feedback, which can adjust the refrigerant flow according to the needs of users. 
     In some embodiments, the cooling loop  10  further includes a receiver drier  16 , the receiver drier  16  is located between the compressor  14  and the condenser  11 , the receiver drier  16  is used for drying the refrigerant. 
     The electric vehicle cooling system  100  of the embodiment of the present disclosure can not only provide the user with appropriate temperature environment through the cooling loop  10 , but also cool the chip and other components through the cooling branch  20 , and the chip and other components do not need to establish a new or dedicated cooling system, which can not only save cost and space, but also reduce the overall weight of the electric vehicle. After the overall weight of the electric vehicle is reduced, it can not only improve the acceleration of the electric vehicle, but also reduce the power consumption and prolong the driving distance of the electric vehicle. 
     The existing water-cooling system needs additional heat exchangers and pumps to cool components such as batteries. The electric vehicle cooling system  100  of the present disclosure is cooled by refrigerant phase change, the thermal resistance of which is smaller than that of the water-cooled cooling system and the temperature of the refrigerant flowing into the cold plate  211  is typically much lower than that in water-cooled cooling system thanks to a very low temperature of the refrigerant before its entering the evaporator. As a result, the electric vehicle cooling system  100  is able to cool a component with less delay than current practice. 
     Those of ordinary skill in the art should realize that the above embodiments are only used to illustrate the present disclosure, but not to limit the present disclosure. As long as they are within the essential spirit of the present disclosure, the above embodiments are appropriately made and changes fall within the scope of protection of the present disclosure.