Abstract:
Disclosed is an automobile air-conditioning system, which comprises an evaporator and an electrical expansion valve in communication via pipes, with the electrical expansion valve comprising a coil and a valve body, the coil being fixedly mounted on the valve body; the system also comprises a support, the support comprising a heat-sinking bridge and a cooling ring, with the evaporator provided on one side of the heat-sinking bridge and the cooling ring provided on the other side of the heat-sinking bridge; the heat-sinking bridge and the cooling ring are formed in one piece or are connected with each other fixedly, and the coil is provided within the cooling ring. The automobile air-conditioning system has the advantages of a compact structural design, is capable of effectively cooling the electrical expansion valve, and has high system strength, stable transmission of coolant, and high security.

Description:
[0001]    This application claims the benefit of priority to Chinese patent application No. 201110161555.0 titled “AUTOMOBILE AIR-CONDITIONING SYSTEM” and filed with the Chinese State Intellectual Property Office on Jun. 9, 2011, the entire disclosure of which is incorporated herein by reference. 
       TECHNICAL FIELD 
       [0002]    The present application relates to a technical field of air conditioning, in particular to an air-conditioning system used in an automobile. 
       BACKGROUND 
       [0003]    Energy saving of an automobile air-conditioning system appears to be quite important as the requirement for the automobile energy saving becomes increasingly higher. In a conventional automobile air-conditioning system, a throttle mechanism generally includes a thermal expansion valve and a throttling short tube. Compared to the conventional throttle mechanism, the electronic expansion valve has a relatively strong advantage in overheat control and overall energy saving since the electronic expansion valve may realize an accurate control. 
         [0004]    However, there are some limitations for the application of the electronic expansion valve in the automobile air conditioner, and one main factor is that the electronic expansion valve is an electric component and is difficult to meet a requirement for temperature resistance of the automobile environment. An overly high operating environment temperature may burn and damage the coil of the electronic expansion valve and the control chip, thus the electronic expansion valve cannot work normally, which may in turn affect the operation of the whole air-conditioning system. In order to enhance the level of the temperature resistance of the electronic expansion valve, the volume of the electronic expansion valve must be increased, however the increased volume may not only increase the cost, but also fail to show the application advantages of the electronic expansion valve. 
         [0005]    At present, due to the price factor and the technical bottleneck of the electronic expansion valve, the thermal expansion valve is also applied in the new energy automobile air conditioner as well as the conventional gasoline car. Due to influences from factors of weather, road condition, thermal load, engine speed and etc., an automobile air conditioner generally works under a non-standard design working condition. However, the set value of an overheat degree of the thermal expansion valve is set according to a standard working condition. When the system is operated under a non-standard working condition, the overheat degree tends to deviate from the set value of the overheat degree, thereby causing the decrease of the system efficiency and an unstable operation, and causing dew formation or even frost formation on the evaporator under a certain condition. 
         [0006]    In an air-conditioning system of an electric automobile, an electronic expansion valve is required to cooperate with a varying speed adjustment of a variable volume electrical compressor. Especially, the electrical compressor works independently in the air-conditioning system of the electric automobile, which is different from that in the gasoline car that the compressor is driven by an engine belt pulley. However, a flow adjusting characteristic of the thermal expansion valve cannot be combined with a frequency conversion characteristic of the electrical compressor, which results in a large power load, and a low travel distance per charge of the electric automobile. 
         [0007]    Therefore, the application of the electronic expansion valve in the automobile air-conditioning field appears to be extremely important. 
       SUMMARY 
       [0008]    An object of the present application is to provide an automobile air-conditioning system to solve the defect in the prior art that the electronic expansion valve is difficult to meet the requirement for temperature resistance of the automobile environment, and the automobile air-conditioning system has a compact structural design, may effectively cool the electronic expansion valve, and has a high system strength, a stable transmission of refrigerant and a high security. 
         [0009]    In order to solve the defect in the prior art, an automobile air-conditioning system is provided, which includes an evaporator and an electronic expansion valve which are communicated with each other via a pipeline, the electronic expansion valve including a coil and a valve body, and the coil being fixedly mounted on the valve body, wherein the automobile air-conditioning system further includes a bracket, the bracket includes a heat dissipation bridge and a cooling ring, the evaporator is arranged at one side of the heat dissipation bridge, the cooling ring is arranged at the other side of the heat dissipation bridge, the heat dissipation bridge and the cooling ring are integrally formed or are fixedly connected, and the coil is arranged in the cooling ring. 
         [0010]    Preferably, the side of the heat dissipation bridge close to the evaporator is in direct contact with the evaporator. 
         [0011]    Preferably, the side of the heat dissipation bridge close to the evaporator and the evaporator are fixedly connected to be in direct contact with one another. 
         [0012]    Preferably, the coil is in direct contact with the cooling ring. 
         [0013]    Preferably, the coil and the cooling ring are fixedly connected to be in direct contact with one another. 
         [0014]    Preferably, a cover configured to enclose the coil is arranged on the cooling ring, and the cover and the cooling ring are integrally formed or are fixedly connected. 
         [0015]    Preferably, the cover has no opening and completely encloses a top portion of the coil, or the cover has an opening and partially encloses a top portion of the coil. 
         [0016]    Preferably, the cooling ring is of a complete ring body structure. 
         [0017]    Preferably, the cooling ring has a gap, the cooling ring having the gap includes two connecting ends, the two connecting ends are two ring body extending portions extending outwardly from end portions of a ring body at the gap and arranged opposite to each other, and the two connecting ends are fixedly connected via a bolt. 
         [0018]    Preferably, the bracket further includes a connecting plate, the connecting plate is arranged between the evaporator and the electronic expansion valve, the heat dissipation bridge is arranged at one side of the connecting plate close to the electronic expansion valve, and the heat dissipation bridge and the connecting plate are integrally formed or are fixedly connected. 
         [0019]    Preferably, the side of the connecting plate close to the evaporator is in direct contact with the evaporator. 
         [0020]    Preferably, the side of the connecting plate close to the evaporator and the evaporator are fixedly connected to be in direct contact with one another. 
         [0021]    Preferably, the side of the connecting plate close to the evaporator is fixedly connected to the evaporator by welding, and a welding surface is an entire contacting surface between the connecting plate and the evaporator, or a contacting surface between the evaporator and a position, corresponding to the heat dissipation bridge, at the side of the connecting plate close to the evaporator. 
         [0022]    Preferably, the bracket further includes a base, the base is horizontally arranged at a bottom of the connecting plate, the connecting plate and the base are integrally formed or are fixedly connected, the base is fixedly mounted in automobile, and the evaporator and the electronic expansion valve are, respectively, located at two sides above the base. 
         [0023]    Preferably, the evaporator is directly fixed on one side of an upper surface of the base, and the valve body of the electronic expansion valve is directly fixed on the other side of the upper surface of the base. 
         [0024]    Preferably, the bracket further includes a first supporting board, the first supporting board is fixedly mounted on the side of the connecting plate close to the evaporator, and the evaporator is fixedly mounted on the first supporting board. 
         [0025]    Preferably, the bracket further includes a second supporting board, the second supporting board is fixedly mounted on the side of the connecting plate close to the electronic expansion valve, and the valve body of the electronic expansion valve is fixedly mounted on the second supporting board. 
         [0026]    The automobile air-conditioning system according to the present application has the following beneficial effects. 
         [0027]    1) In the automobile air-conditioning system according to the present application, heat quantity from the electronic expansion valve may be rapidly transmitted to the evaporator via the heat dissipation bridge and the cooling ring, and the refrigerating capacity of the evaporator is effectively utilized to cool the electronic expansion valve, thereby effectively utilizing a cold source and reducing an energy waste. Further the level of the temperature resistance of the electronic expansion valve is not required to be improved, thereby saving cost and avoiding a valve failure caused when the electronic expansion valve is working under a nonstandard working condition. 
         [0028]    2) The automobile air-conditioning system according to the present application further includes a cooling ring having a gap, and two ends of the gap are fixedly connected, such that the cooling ring and the electronic expansion valve are abutted against each other more tightly, thereby improving the heat transfer efficiency of the cooling ring. 
         [0029]    3) The automobile air-conditioning system according to the present application further includes a cover arranged at the top of the coil and connected to the cooling ring so as to enclose the coil and further improving the heat transfer efficiency between the electronic expansion valve and the evaporator. 
         [0030]    4) The automobile air-conditioning system according to the present application further includes a connecting plate arranged between the electronic expansion valve and the evaporator so as to improve the heat transfer efficiency between the electronic expansion valve and the evaporator. 
         [0031]    5) In the automobile air-conditioning system according to the present application, the electronic expansion valve and the evaporator are fixedly mounted on the bracket, thereby further enhancing the overall structural strength of the automobile air conditioner. 
         [0032]    6) In the automobile air-conditioning system according to the present application, the electronic expansion valve is fixedly mounted next to the evaporator, which realizes a well cooperation between the evaporator and the electronic expansion valve, shortens a connection pipeline between the evaporator and the electronic expansion valve, and enhances the capability of vibration resistance; and meanwhile the automobile air-conditioning system has a compact structure, the using space of the automobile air conditioner is effectively saved, and the overall structural strength of the automobile air-conditioning system is enhanced. 
         [0033]    7) The structural design philosophy of fixedly mounting the electronic expansion valve next to the evaporator via a bracket to make the coil of the electronic expansion valve work under a standard working condition in the automobile air-conditioning system according to the present application may be applied in a traditional refrigerating system to provide a basis for realizing a comprehensive utilization of the energy of the refrigerating system. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0034]      FIG. 1  is a perspective view of an automobile air-conditioning system according to an embodiment of the present application; 
           [0035]      FIG. 2  is a left view of the automobile air-conditioning system of the embodiment shown in  FIG. 1 ; 
           [0036]      FIG. 3  is a left view of an automobile air-conditioning system according to another embodiment of the present application; 
           [0037]      FIG. 4  is a left view of an automobile air-conditioning system according to another embodiment of the present application; 
           [0038]      FIG. 5  is a left view of an automobile air-conditioning system according to another embodiment of the present application; 
           [0039]      FIG. 6  is a perspective view of an automobile air-conditioning system according to another embodiment of the present application; 
           [0040]      FIG. 7  is a perspective view of a bracket of an automobile air-conditioning system according to another embodiment of the present application; 
           [0041]      FIG. 8  is a perspective view of a bracket of an automobile air-conditioning system according to another embodiment of the present application; 
           [0042]      FIG. 9  is a perspective view of a bracket of an automobile air-conditioning system according to another embodiment of the present application; 
           [0043]      FIG. 10  is a top view of the bracket of the embodiment shown in  FIG. 1 ; 
           [0044]      FIG. 11  is a rear view of the bracket of the embodiment shown in  FIG. 1 ; 
           [0045]      FIG. 12  is a diagram showing highest temperatures of a cooling ring of the embodiment shown in  FIG. 1  in a first thermal test; and 
           [0046]      FIG. 13  is a diagram showing highest temperatures of the cooling ring of the embodiment shown in  FIG. 1  in a second thermal test. 
       
    
    
     DETAILED DESCRIPTION 
       [0047]    In the automobile air-conditioning system according to the present application, heat from an electronic expansion valve is rapidly transferred to an evaporator through a bracket having a heat dissipation bridge and a cooling ring, and the refrigerating capacity of the evaporator is effectively utilized to cool the electronic expansion valve, thereby effectively utilizing a cold source and reducing an energy waste. Further the level of the temperature resistance of the electronic expansion valve is not required to be improved, thereby saving cost and avoiding a valve failure caused when the electronic expansion valve is working under a nonstandard working condition. Embodiments of an automobile air-conditioning system of the present application will be described in detail hereinafter in conjunction with the drawings. 
         [0048]    Reference is made to  FIG. 1 , which is a perspective view of an automobile air-conditioning system according to an embodiment of the present application. The automobile air-conditioning system includes an evaporator  1  and an electronic expansion valve  2  which are communicated with each other via a pipe, the electronic expansion valve  2  includes a coil  200  and a valve body  201 , and the coil  200  is fixedly mounted on the valve body  201 . The automobile air-conditioning system further includes a bracket  3 , and the bracket  3  includes a base  300 , a connecting plate  301 , a heat dissipation bridge  303  and a cooling ring  302 . 
         [0049]    The evaporator  1  and the electronic expansion valve  2  are respectively arranged at two sides of the connecting plate  301 , and the evaporator  1  is in direct contact with the connecting plate  301 . Further, the evaporator  1  and the connecting plate  301  are fixedly connected to be in direct contact with one another. Contacting surfaces of the evaporator  1  and the connecting plate  301  may be fixedly connected by partially welding or wholly welding. As shown in  FIG. 2 , which is a left view of the automobile air-conditioning system of the embodiment shown in  FIG. 1 , the contacting surfaces of the connecting plate  301  and the evaporator  1  are connected by wholly welding. 
         [0050]    The heat dissipation bridge  303  is arranged at a top of the connecting plate  301  at a side close to the electronic expansion valve  2 , and the heat dissipation bridge  303  and the connecting plate  301  are fixedly connected or are formed integrally. It can be appreciated for those skilled in the art that, the heat dissipation bridge  303  may be arranged at any position on the connecting plate  301  at the side close to the electronic expansion valve  2 . 
         [0051]    The cooling ring  302  is of an annular structure, and the cooling ring  302  and the heat dissipation bridge  303  are fixedly connected or are formed integrally. The coil  200  of the electronic expansion valve  2  is arranged inside the cooling ring  302  and is surrounded by the cooling ring  302 , wherein the coil  200  is in direct contact with the cooling ring  302 . Further, the coil  200  and the cooling ring  302  are fixedly connected to be in direct contact with one another. In a case that the coil  200  is in direct contact with the cooling ring  302  but is not fixedly connected to the cooling ring  302 , the valve body  201  and the connecting plate  301  are fixedly connected to fixedly connect the electronic expansion valve  2  to the connecting plate  301 . In a case that the coil  200  and the cooling ring  302  are fixedly connected, the valve body  201  and the connecting plate  301  may be in direct contact with one another without being fixedly connected, or be arranged with a gap therebetween, or be fixedly connected. 
         [0052]    The side of the heat dissipation bridge  303  close to the evaporator  1  is in direct contact with the evaporator  1 , and the coil  200  is in direct contact with the cooling ring  302 , thus heat generated by the coil  200  of the electronic expansion valve  2  may be transmitted to the evaporator  1  via the heat dissipation bridge  303  and the coil  200 . 
         [0053]    Further, the heat dissipation bridge  303  and the evaporator  1  are fixedly connected, and the coil  200  and the cooling ring  302  are fixedly connected, thereby not only improving a heat transfer efficiency between the electronic expansion valve  2  and the evaporator  1 , but also making the structure of the automobile air-conditioning system more compact and improving the overall structural strength of the automobile air-conditioning system. 
         [0054]    The base  300  is horizontally arranged at a bottom of the connecting plate  301 , and the evaporator  1  and the electronic expansion valve  2  are, respectively, arranged at two sides above the base  300 . The base  300  is fixedly mounted on the automobile, and the connecting plate  301  and the base  300  are integrally formed, or the connecting plate  301  and the base  300  are formed separately and the connecting plate  301  is fixedly mounted on the base  300 . 
         [0055]    In the above embodiments, the electronic expansion valve  2  is fixedly mounted on the bracket  3 , and the bracket  3  is fixedly mounted in the automobile and is fixedly connected to the evaporator  1 . 
         [0056]    Further, the cooling ring  302  is fixedly mounted on the connecting plate  301  via the heat dissipation bridge  303 , and the coil  200  of the electronic expansion valve  2  is fixedly mounted in the cooling ring  302 . In this embodiment, the cooling ring  302  is of a complete annular structure. The connecting plate  301 , the cooling ring  302  and the heat dissipation bridge  303  are formed integrally. Alternatively, the connecting plate  301 , the cooling ring  302  and the heat dissipation bridge  303  may be formed separately. 
         [0057]    According to another embodiment of the present application, the bracket  3  may only include the heat dissipation bridge  303 , and the heat dissipation bridge  303  is arranged between the evaporator  1  and the electronic expansion valve  2 . The electronic expansion valve  2  is in contact with the evaporator  1  via the heat dissipation bridge  303  to transmit heat. Further, the coil  200  of the electronic expansion valve  2  is in contact with the evaporator  1  via the heat dissipation bridge  303  to transmit heat. 
         [0058]    Reference is made to  FIG. 3 , which is a left view of an automobile air-conditioning system according to another embodiment of the present application. The bracket  3  may only include the heat dissipation bridge  303  and the cooling ring  302 , and the heat dissipation bridge  303  and the cooling ring  302  are arranged between the evaporator  1  and the electronic expansion valve  2 . The heat dissipation bridge  303  has one side in contact with the evaporator  1  and the other side connected with the cooling ring  302  having a gap. The electronic expansion valve  2  is in contact with the cooling ring  302  and transmits heat to the evaporator  1  via the cooling ring  302  and the heat dissipation bridge  303 . 
         [0059]    The heat dissipation bridge  303  has one side fixedly connected to the evaporator  1  and the other side fixedly connected to the cooling ring  302  having the gap, and the electronic expansion valve  2  is fixedly mounted on the cooling ring  302 . The coil  200  of the electronic expansion valve  2  is fixedly mounted inside the cooling ring  302 , such that heat from the coil  200  of the electronic expansion valve  2  may be transmitted to the evaporator  1  via the cooling ring  302  and the heat dissipation bridge  303 . 
         [0060]    The heat dissipation bridge  303  and the cooling ring  302  may be formed integrally or separately. In a case that the heat dissipation bridge  303  and the cooling ring  302  are formed separately, the heat dissipation bridge  303  and the cooling ring  302  are fixedly connected, and the fixed connection may be realized by welding, threaded connection, clamping connection and etc. The evaporator  1  is directly fixed on the automobile, and the electronic expansion valve  2  is fixedly connected to the evaporator  1  via the cooling ring  302  and the heat dissipation bridge  303 , thereby making the structure of the automobile air-conditioning system more compact. 
         [0061]    Unlike the embodiment in  FIG. 1 , in this embodiment, the coil  200  and the cooling ring  302  are fixedly connected, the heat dissipation bridge  303  and the evaporator  1  are fixedly connected, and the evaporator  1  is directly mounted in the automobile, thereby shortening the connecting pipe between the evaporator  1  and the electronic expansion valve  2 , enhancing the vibration resistance, and meanwhile making the structure of the automobile air-conditioning system compact, effectively saving the usage space of the automobile air conditioner, and improving the overall structural strength of the automobile air conditioner. 
         [0062]    According to another embodiment of the present application, the bracket  3  may only include the heat dissipation bridge  303 , the cooling ring  302  and the connecting plate  301 . Reference is made to  FIG. 4 , which is a left view of an automobile air-conditioning system according to the embodiment of the present application. The evaporator  1  is fixedly mounted in the automobile in practical use, and the connecting plate  301  has one plane in direct contact with the evaporator  1  and another plane fixedly arranged with the electronic expansion valve. Contacting planes of the connecting plate  301  and the evaporator  1  may also be partially welded. 
         [0063]    Reference is made to  FIG. 5 , which is a left view of an automobile air-conditioning system according to another embodiment of the present application. Unlike the embodiment shown in  FIG. 1 , in this embodiment, besides the heat dissipation bridge  303 , the cooling ring  302  and the connecting plate  301 , the bracket  3  further includes a first supporting board  304  and a second supporting board  305  which are respectively mounted on two planes at two sides of the connecting plate. 
         [0064]    The first supporting board  304  is fixedly mounted at the side of the connecting plate  301  close to the evaporator  1  and is located below the evaporator  1 , and the evaporator  1  is fixedly mounted on the first supporting board  304 . 
         [0065]    The second supporting board  305  is fixedly mounted at the side of the connecting plate  301  close to the electronic expansion valve  2  and is located below the cooling ring  302 , and the valve body  201  of the electronic expansion valve  2  is fixedly mounted on the second supporting board  305 . 
         [0066]    Other structures of the present embodiment are the same as the first embodiment. In this embodiment, the connecting plate  301  and the evaporator  1  may be in direct contact with one another, or the contacting surfaces thereof may be wholly welded. Only one of the first supporting board  304  and the second supporting board  305  may be mounted, for example, in a case that the first supporting board  304  is not provided, the connecting plate  301  and the evaporator  1  may be directly connected by welding; and similarly, in a case that the second supporting board  305  is not provided, the connecting plate  301  and the electronic expansion valve  2  may be directly connected by welding. 
         [0067]    The connecting plate  301 , the first supporting board  304  and the second supporting board  305  may not only strengthen the automobile air-conditioning system, but also accelerate the heat transfer between the electronic expansion valve  2  and the evaporator  1 . 
         [0068]    Reference is made to  FIG. 6 , which is a perspective view of an automobile air-conditioning system according to another embodiment of the present application. Unlike the embodiment shown in  FIG. 5 , in this embodiment, the connecting plate  301  and the evaporator  1  are partially welded or are in contact with one another partially, for example, the side of the connecting plate  301  close to the evaporator  1  is welded to the evaporator  1  at a position corresponding to the heat dissipation bridge  303 . 
         [0069]    Reference is made to  FIG. 7 , which is a perspective view of the bracket according to another embodiment of an automobile air-conditioning system in the present application. To strengthen the cooling effect, a cover  307  having an opening may be further arranged on the cooling ring  302  at the top of the coil  200  to enclose the coil  200 , and the cover  307  is connected to the cooling ring  302 . The cover  307  on the cooling ring  302  may be sealed or may have an opening. 
         [0070]    Reference is made to  FIG. 8 , which is a perspective view of the bracket according to another embodiment of an automobile air-conditioning system in the present application. The cooling ring  302  has a gap, and such cooling ring  302  having the gap may facilitate the installation of the electronic expansion valve. 
         [0071]    Reference is made to  FIG. 9 , which is a perspective view of the bracket according to another embodiment of an automobile air-conditioning system in the present application. 
         [0072]    Two ends of the gap of the cooling ring  302  are fixedly connected. In this embodiment, the cooling ring  302  having the gap includes two connecting ends  306 , the two connecting ends  306  are two ring body extending portions extending outwardly from end portions of the ring body at the gap and arranged opposite to each other, and the two connecting ends  306  are fixedly connected via a bolt. Such cooling ring  302  having the gap may facilitate the installation of the electronic expansion valve  2 , and the electronic expansion valve  2  may be mounted more firmly. Since the two ends of the gap of the cooling ring  302  are fixedly connected, the cooling ring and the electronic expansion valve are abutted against each other more tightly, thereby improving the heat transfer efficiency of the cooling ring. The connection manner of the cooling ring  302  in this embodiment is simply an exemplary embodiment, and specific connection manner is not limited to the present embodiment. 
         [0073]    In the above embodiments, each of the heat dissipation bridge, the cooling ring, the connecting plate, the base, the first supporting board and the second supporting board is made of heat conduction materials, and is preferably metallic material. 
         [0074]    The operating principle of the above embodiments is as follows. When the refrigerating system is working, a surface temperature of the evaporator  1  is a constant low temperature, while the coil  200  of the electronic expansion valve  2  generates heat in operation, and when in summer or under a working environment of high temperature region, the temperature of the electronic expansion valve  2  is very likely to exceed a temperature resistance standard of 120 degree Celsius. A heat dissipation bridge  303  is provided between the evaporator  1  and the electronic expansion valve  2 , such that the heat from the electronic expansion valve  2  may be transmitted to the evaporator  1  via the cooling ring  302  and the heat dissipation bridge  303 , thereby realizing a cooling effect. Since the heat dissipation bridge  303  is in contact with the evaporator  1 , the heat dissipation bridge  303  is cooled by the evaporator  1 , thereby further cooling the cooling ring  302 , and then heat transfer occurs between the cooling ring  302  and the coil  300  to cool the electronic expansion valve  2 . In the present application, the cooling ring  302  and the heat dissipation bridge  303  function to transfer heat and fix the system structure. 
         [0075]    Thermal analysis validation is conducted as follows. 
         [0076]    In order to verify the actual using effect of the present application, a thermal analysis validation is conducted on the automobile air conditioner according to the embodiment of the present application shown in  FIG. 1 . The heat dissipation bridge and the cooling ring in each solution in the following experiments are parts made of aluminum alloy material. 
         [0077]    First Experiment: a comparison validation between the prior art and the embodiment of the present application shown in  FIG. 1   
         [0078]    The extreme heat-resistance temperature of the electronic expansion valve in this experiment is set as 120 degree Celsius, and other data are shown in Sheet 1. 
         [0000]    
       
         
               
             
               
               
             
           
               
                   
               
               
                 Sheet 1 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 Type of analysis 
                 Steady state thermal analysis 
               
               
                 Material 
                 Aluminum alloy 
               
               
                 Environment temperature 
                 120 degree Celsius 
               
               
                 Unit 
                 m 
               
               
                 Temperature of a heat 
                 2 degree Celsius 
               
               
                 exchanger 
                   
               
               
                 Heat quantity of the 
                 7 W 
               
               
                 electronic expansion valve 
                   
               
               
                 Load 
                 Convection: a vertical convective heat transfer 
               
               
                   
                 coefficient is 5.7 w/m 2 gk, and a horizontal 
               
               
                   
                 convective heat transfer coefficient is 6.15 
               
               
                   
                 w/m 2 gk 
               
               
                   
                 Thermal load: a surface temperature of the 
               
               
                   
                 evaporator is 2 degree Celsius 
               
               
                   
                 Internal heat source: 286720.734 w/m 3   
               
               
                   
               
             
          
         
       
     
         [0079]    A comparison experiment is conducted under the above experimental conditions, and according to the analysis result, the highest temperature of the electronic expansion valve in the prior art reaches around 218 degree Celsius when the evaporator is not provided for transmitting heat. And the temperature at the top of the coil of the electronic expansion valve is relatively higher, and the temperature at the bottom of the coil is relatively lower, the above situation is caused because heat generated by the coil in operation is absorbed from the bottom of the coil by the valve body, and there is no heat dissipation approach at the top of the coil. 
         [0080]    The analysis result shows that the solution in the embodiment of the present application shown in  FIG. 1  has a significant heat dissipation effect. The highest temperature of the electronic expansion valve is around 8 degree Celsius, the temperature field distribution of the valve body of the electronic expansion valve is even, and the temperature difference is about 0.5 degree Celsius, which will not affect the system operation. 
         [0081]    In the solution of the embodiment of the present application shown in  FIG. 1 , heat transfer may be controlled by designing and modifying dimensions of the heat dissipation bridge and the cooling ring. Main parameters influencing the heat transfer in the technical solution of the present application are a height of the cooling ring and a width of the heat dissipation bridge. As shown in  FIG. 10 , which is a top view of the bracket of the embodiment shown in  FIG. 1 , the heat dissipation bridge has a length a and a width b. As shown in  FIG. 11 , which is a rear view of the bracket of the embodiment shown in  FIG. 1 , the cooling ring is a height c. In the following solutions, the cooling ring is set to have the same thickness and diameter, the connecting plate is set to have the same dimension, a distance from a center of the cooling ring to the connecting plate is set be the same, and the same components in each solution has the same material. Thermal analysis validations are conducted, respectively, to analyze influences on the heat dissipation efficiency of the cooling ring caused by the width of the heat dissipation bridge and the height of the cooling ring. 
         [0082]    Second Experiment: a comparison validation is conducted with different widths of the heat dissipation bridge in the embodiment oft he present application shown in  FIG. 1 , wherein the cooling ring has the same dimension, and the height of the cooling ring is 0.015 m. The experimental condition is shown in Sheet 1 and Sheet 2. The width of the heat dissipation bridge in each solution is shown in Sheet 2. 
         [0000]    
       
         
               
             
               
               
               
             
               
               
               
             
           
               
                   
               
               
                 Sheet 2 
               
             
          
           
               
                   
                 Experiment solution 
                 The width of the heat dissipation bridge (m) 
               
               
                   
                   
               
             
          
           
               
                   
                 First Solution 
                 0.015 
               
               
                   
                 Second Solution 
                 0.02 
               
               
                   
                 Third Solution 
                 0.026 
               
               
                   
                 Fourth Solution 
                 0.032 
               
               
                   
                   
               
             
          
         
       
     
         [0083]    The experimental results of the four solutions are shown in  FIG. 12 . In the first solution, the width of the heat dissipation bridge is 0.015 m, and the maximum temperature of the cooling ring is about 8 degree Celsius, which may basically satisfy the cooling requirement of the electronic expansion valve. And as can be seen from  FIG. 12 , the maximum temperature of the cooling ring decreases as the width of the heat dissipation bridge increases. That is, the larger the width of the heat dissipation bridge, the better the cooling effect. 
         [0084]    Third Experiment: a comparison validation is conducted with different heights of the cooling ring in the embodiment of the present application shown in  FIG. 1 , wherein the heat dissipation bridge in each solution has the same dimension, and the width of the heat dissipation bridge is 0.015 m. The experimental condition is shown in Sheet 1 and Sheet 3. The height of the cooling ring in each solution is shown in  FIG. 3 . 
         [0000]    
       
         
               
             
               
               
               
             
               
               
               
             
           
               
                   
               
               
                 Sheet 3 
               
             
          
           
               
                   
                 Experiment solution 
                 the height of the cooling ring (m) 
               
               
                   
                   
               
             
          
           
               
                   
                 Fifth Solution 
                 0.015 
               
               
                   
                 Sixth Solution 
                 0.01 
               
               
                   
                 Seventh Solution 
                 0.005 
               
               
                   
                 Eighth Solution 
                 0.003 
               
               
                   
                   
               
             
          
         
       
     
         [0085]    The experimental results of the four solutions are shown in  FIG. 13 . In the eighth solution, the height of the cooling ring is 0.003 m, and the maximum temperature of the cooling ring is about 44 degree Celsius, which may basically satisfy the cooling requirement of the electronic expansion valve. As can be seen from  FIG. 13 , the maximum temperature of the cooling ring increases as the height of the cooling ring decreases. That is, the larger the height of the cooling ring, the better the cooling effect. 
         [0086]    As can be concluded from the above verification results, the automobile air-conditioning system in the present application may better solve the problem that the electronic expansion valve is difficult to meet the requirement for temperature resistance of the automobile environment. 
         [0087]    The embodiments described hereinabove are only exemplary embodiments of the present application. It should be noted that, for the person skilled in the art, many modifications and improvements may be made to the present application without departing from the principle of the present application. The protection scope of the present application is defined by the accompanying claims.