Patent Publication Number: US-2010122544-A1

Title: Micro-channel heat exchanger for carbon dioxide refrigerant, fluid distributer thereof and method of fabricating heat exchanger

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This non-provisional application claims priority under 35 U.S.C. § 119(a) on Patent Application No(s). 097144429 filed in Taiwan, R.O.C. on Nov. 17, 2008 the entire contents of which are hereby incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     The present invention relates to an apparatus of a micro-channel heat exchanger module and a method of fabricating the same, and more particularly to a micro-channel heat exchanger module capable of condensing a high pressure gaseous working fluid to the liquid working fluid, a working fluid distributor thereof, and a method of fabricating the micro-channel heat exchanger module. 
     2. Related Art 
     Recently, people internationally pay attention to global ecologic protection and energy saving and carbon reduction topics. Based on the attention on the environmental protection topics, including Montreal Protocol and Kyoto Protocol, countries in the world have practiced in controlling compound refrigerant containing halide and greenhouse gas emission, and at the same time shown the international decision of protecting the global ecology and the environment. Therefore, in the refrigerating and air conditioning field, the application of the natural refrigerant becomes an important topic. 
     Currently, among alternative refrigerant being internationally developed and popularized, a carbon dioxide refrigerant is a natural refrigerant having a development potential. This is because that, the carbon dioxide refrigerant satisfies the environmental protection concept, in addition, the carbon dioxide refrigerant is obtained from nature and is refined, such that as compared with conventional chlorofluorocarbon compound or the alternative refrigerant, the carbon dioxide refrigerant has an advantage of low cost (the price is roughly one tenth of the price of the conventional chlorofluorocarbon compound or the alternative refrigerant or lower). Further, as compared with the conventional refrigerant or other alternative refrigerants, the carbon dioxide refrigerant has the advantages of being environmental friendly, secure, efficient, and having better heat pump characteristics. Moreover, a critical temperature of the carbon dioxide refrigerant quite approaches the normal temperature (approximately 31.1° C.), during a compression process, the carbon dioxide refrigerant quite easily enters a supercritical state, and a density thereof is several times higher than that of the conventional refrigerant, such that when the carbon dioxide is used as the working refrigerant, for the design disposition of the system and the tube module, the equivalent heat transfer capacity may be reached with smaller volume or specification capacity. In addition, a working pressure of the carbon dioxide refrigerant is extremely high, such that a micro-channel heat transfer tube module structure must be adopted, so as to obtain the preferred structural strength and the heat transfer capability. Based on the above reasons, it becomes one of the important researching directions in the refrigerating and air conditioning field for the academic circles or the industrial circles how to further understand the heat conductive characteristics of the carbon dioxide refrigerant in the supercritical state and the related techniques of the commercial application of the carbon dioxide refrigerant. 
       FIG. 1  is a schematic view of a conventional refrigerating cycle; whose condenser adopting the working refrigerant. Referring to  FIG. 1 , a condenser  500  includes a refrigerant inlet tube  510 , a plurality of heat transfer tube module  520 , and a refrigerant outlet tube (not shown). The heat transfer tube module  520  communicates the refrigerant inlet tube  510  with the refrigerant outlet tube. Therefore, the gaseous working refrigerant enters the heat transfer tube module  520  through the refrigerant inlet tube  510 , and is condensed to the liquid working refrigerant in the heat transfer tube module  520 . The condensed working refrigerant flows to the element of a next refrigerating cycle through the refrigerant outlet tube (not shown). 
     Generally, for a conventional method of fabricating the condenser  500 , a part of a tube wall of the refrigerant inlet tube  510  is squeezed inward by punching, and a part of the tube wall is damaged, so as to form a plurality of openings  512 . Then, the heat transfer tube modules  520  are inserted with the refrigerant inlet tube  510  through the openings  512 , and the heat transfer tube modules  520  are fixed with the refrigerant inlet tube  510  by brazing. 
     However, the condenser  500  has the problems as follows on operation. 
     In a refrigerating cycle which use the carbon dioxide as the working refrigerant, the working pressure of the working refrigerant is quite high (about 90-120 kg/cm 2 ), and the designer must consider the volume of the condenser on design, such that; usually the heat transfer tube module  520  of the condenser  500  adopt thin tubes having a tube diameter of small than below 1.0 mm. In this manner, when the heat transfer tube module  520  and the refrigerant inlet tube  510  are brazed, the solder  530  in a melted state is infiltrated to an end surface  522  of the heat transfer tube module  520  along a slit between the heat transfer tube module  520  and the refrigerant inlet tube  510  by reason of a capillary action. The tube diameter of the heat transfer tube module  520  is quite small, such that the solder  530  in the melted state infiltrated to the end surface  522  is absorbed in the heat transfer tube module  520  by reason of the capillary action, such that the channel of the heat transfer tube module  520  is obstructed. 
     In addition, based on the above structure, the heat transfer tube modules  520  are inserted with the refrigerant inlet tube  510 , such that end portions of the heat transfer tube modules  520  are raised inward from the tube wall of the refrigerant inlet tube  510 , in this manner, usually it becomes the barrier or the obstruction to the flow of refrigerant. 
     In addition, in the prior art, a front end inlet and a back end outlet of the refrigerant inlet tube  510  are usually connected by a penetrating channel. In the structure, for the refrigerant flowing from the main channel to each heat transfer tube module  520 , by reason of the pressure drop of the tube line, the flows of the refrigerant flowing to the heat transfer tube module  520  located on the front end and the back end of the refrigerant inlet tube  510  are not uniform and generate a difference, thereby seriously resulting in abnormal problems of non-uniform heat transfer distribution of the whole heat exchanger and consequently reduced the heat transfer capability. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention is directed to a working fluid distributor and a micro-channel heat exchanger module with a modified structure, thereby preventing problems such as a refrigerant flow distribution of working fluid in a channel and soldering obstruction in a channel during the process of fabricating the heat exchanger. 
     The present invention is further directed to a method of fabricating a micro-channel heat exchanger module, thereby preventing the problem that heat transfer tube are obstructed by solder during a brazing process. 
     The present invention provides a working fluid distributor, which is respectively connected to a compressor, an expansion device, and a heat transfer tube module. The working fluid distributor includes a block. The block has a working fluid inlet channel, a working fluid outlet channel, a working fluid distribution chamber, a plurality of working fluid outlet openings, and a plurality of working fluid inlet openings. The working fluid inlet channel is connected to one of a compressor and an expansion device. The working fluid distribution chamber communicates with the working fluid inlet channel and the working fluid outlet channel. The working fluid outlet openings communicate the working fluid distribution chamber with the heat sink. The working fluid inlet openings communicate the working fluid outlet channel with the heat sink. The working fluid outlet channel communicates with the other one of the compressor and the expansion device. 
     The micro-channel heat exchanger module of the present invention is respectively connected to a compressor and an expansion device. The micro-channel heat exchanger module includes a heat transfer tube module and a block. The block has a working fluid inlet channel, a working fluid outlet channel, a working fluid distribution chamber, a plurality of working fluid outlet openings, and a plurality of working fluid inlet openings. The working fluid inlet channel is connected to one of a compressor and an expansion device. The working fluid distribution chamber communicates with the working fluid inlet channel. The working fluid outlet openings communicate the working fluid distribution chamber with the heat sink. The working fluid inlet openings communicate the working fluid outlet channel with the heat sink. The working fluid outlet channel communicates with the other one of the compressor and the expansion device. According to a preferred embodiment of the present invention, the heat transfer tube module includes a plurality of heat transfer tube module. Each heat transfer tube module has a first end and a second end. The first end communicates with a corresponding working fluid outlet opening, and the second end communicates with a corresponding working fluid inlet opening. Preferably, an extending direction of the first end is vertical to an extending direction of the working fluid inlet channel. In addition, an extending direction of the second end is vertical to an extending direction of the working fluid outlet channel. 
     According to a preferred embodiment of the present invention, the working fluid distributor is a distributor of carbon dioxide refrigerant. 
     According to a preferred embodiment of the present invention, the micro-channel heat exchanger module is a micro-channel heat exchanger module of carbon dioxide refrigerant. 
     According to a preferred embodiment of the present invention, the working fluid distribution chamber has a chamber bottom surface. The working fluid outlet opening is located on the chamber bottom surface. The first end of the heat transfer tube module is inserted to the block from the working fluid outlet opening, and the first end is not raised to the working fluid distribution chamber from the chamber bottom surface. 
     According to a preferred embodiment of the present invention, the working fluid outlet channel has a channel bottom surface. The working fluid outlet is located on the channel bottom surface. The second end is inserted to the block from the working fluid inlet opening, and the second end is not raised to the working fluid outlet channel from the channel bottom surface. 
     According to a preferred embodiment of the present invention, the block includes a plurality of sub blocks, each sub block has a working fluid inlet channel section, a working fluid outlet channel section, the working fluid distribution chamber, the working fluid outlet openings, and the working fluid inlet openings. The working fluid distribution chamber communicates with the working fluid inlet channel section. The working fluid inlet openings communicate with the working fluid outlet channel section. The working fluid inlet channel section defines a part of the working fluid inlet channel. The working fluid outlet channel section defines a part of the working fluid outlet channel. 
     According to a preferred embodiment of the present invention, the sub block further includes a male connector and a female connector. The male connector of the sub block is jointed with the female connector of another sub block. Preferably, the male connector communicates with one of the working fluid inlet channel section and the working fluid outlet channel section. In addition, the female connector also communicates with one of the working fluid inlet channel section and the working fluid outlet channel section. 
     The method of fabricating the micro-channel heat exchanger module of the present invention includes the steps as follows. Firstly, an object to be processed is provided, and the object to be processed has a working fluid inlet channel, a working fluid outlet channel, a working fluid distribution chamber, a plurality of working fluid openings, and a plurality of soldering openings. The working fluid distribution chamber communicates with the working fluid inlet channel. The working fluid distribution chamber has a chamber bottom surface. The working fluid openings are located on the bottom surface, a part of the working fluid openings communicate with the working fluid distribution chamber, and the remaining working fluid openings communicate with the working fluid outlet channel. The soldering openings communicate the working fluid distribution chamber with an external environment, and the soldering openings are located on chamber top surface of the working fluid distribution chamber. Next, a plurality of heat transfer tube module and a plurality of stopping blocks are provided, and a solder resist process is performed on the stopping blocks. Then, an end portion of the heat sink tubes communicates with the working fluid outlet channel, and the other end portion of the heat transfer tube module is inserted to the corresponding working fluid outlet opening, the other end portion is not raised to the working fluid distribution chamber from the chamber bottom surface, and the stopping blocks are inserted to the working fluid distribution chamber through the soldering openings, such that a surface of the stopping blocks leans against an end surface of the end portion of the heat transfer tube module. 
     Then, a soldering process is performed, so as to fix the heat transfer tube module on the object to be processed. Next, the stopping blocks are removed. Finally, the soldering openings are sealed. 
     According to a preferred embodiment of the present invention, the soldering step is a brazing procedure. 
     According to a preferred embodiment of the present invention, the method of fabricating the heat transfer tube module further includes forming a flange with a profile corresponding to the end portion of the heat transfer tube module on the end surface of the stopping block. When the stopping block contacts with the end portion of the heat transfer tube module, the flange surrounds an outer surface of the end portion. 
     According to a preferred embodiment of the present invention, the step of performing the solder resist process on the stopping blocks includes performing a carbonizing process on the surfaces of the stopping blocks. 
     The efficacies of the present invention are as follows. The block of the present invention has the design of the working fluid distribution chamber. Before entering the plurality of working fluid outlet openings from the working fluid inlet channel, the working fluid firstly flows through the working fluid distribution chamber and being directed and distributed, such that through the design of the present invention, the flow of the working fluid becomes more uniform and smoother. In addition, the end portion of the heat transfer tube module of the present invention is not raised to the working fluid distribution chamber from the chamber bottom surface. Therefore, as compared with the prior art, when the working fluid enters the heat sink tube from the working fluid outlet channel, the end portion of the heat transfer tube module does not obstruct the flow of the working fluid. Therefore, the design of the heat transfer tube module of the present invention enables the flow of the working fluid much smoother. 
     Further, in the method of fabricating the heat transfer tube module of the present invention, before the soldering process is performed, an anti-soldered stopping block is placed on the end surface of the heat transfer tube module, such that during the soldering process, the solder in a melted state will not enter the channel of the heat transfer tube module under the effect of a capillary action. Therefore, the present invention may effectively prevent the heat transfer tube module from being obstructed by the solder. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will become more fully understood from the detailed description given herein below for illustration only, and thus are not limitative of the present invention, and wherein: 
         FIG. 1  is a schematic view of a conventional refrigerating cycle condenser adopting a working refrigerant; 
         FIG. 2  is a schematic view of a working fluid distributor according to an embodiment of the present invention; 
         FIG. 3  is a schematic sectional view of  FIG. 2 ; 
         FIG. 4  is a schematic view of a sub block used to form a block; 
         FIG. 5  is a schematic sectional view of  FIG. 4 ; 
         FIG. 6  is a schematic view of a micro-channel heat exchanger module having the block according to an embodiment of the present invention; 
         FIG. 7  is a schematic partial enlarged view of  FIG. 6 ; 
         FIG. 8  is a schematic sectional view relative to a first end of a heat transfer tube module of  FIG. 6 ; 
         FIG. 9  is a schematic sectional view relative to a second end of the heat transfer tube module of  FIG. 6 ; 
         FIGS. 10A to 10C  are schematic flow charts of fabricating the micro-channel heat exchanger module according to an embodiment of the present invention; 
         FIG. 11A  is a schematic longitudinal sectional view of  FIG. 10A ; 
         FIG. 11B  is a schematic cross-sectional view of  FIG. 10A ; and 
         FIG. 12  is a schematic sectional view of  FIG. 10C . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 2  is a schematic view of a working fluid distributor according to an embodiment of the present invention, and  FIG. 3  is a schematic sectional view of  FIG. 2 . Referring to  FIGS. 2 and 3 , a working fluid distributor  100  includes a block  110 . The block  110  has a working fluid inlet channel  112 , a working fluid outlet channel  114 , a working fluid distribution chamber  116 , and a plurality of working fluid openings, in which the working fluid openings are distributed into a plurality of working fluid outlet openings  118   a  and a plurality of working fluid inlet openings  118   b  according to flowing paths of a working fluid. The working fluid inlet channel  112  is used to receive the working fluid from a compressor or an expansion device, and the working fluid may be a carbon dioxide refrigerant or other types of refrigerants. The working fluid distribution chamber  116  communicates with the working fluid inlet channel  112 . The working fluid outlet openings  118   a  communicate the working fluid distribution chamber  116  with a heat transfer tube module (not shown), the working fluid inlet openings  118   b  communicate the working fluid outlet channel  114  with the heat transfer tube module (not shown), and a connection manner between the heat transfer tube module (not shown) and the block  110  is described in detail below. The working fluid outlet channel  114  is used to outlet the working fluid from the block  110  to the other one of the compressor and the expansion device. In other words, when the working fluid inlet channel  112  is used to receive the working fluid from the compressor, the working fluid outlet channel  114  is used to outlet the working fluid from the block  110  to the expansion device. When the working fluid inlet channel  112  is used to receive the working fluid from the expansion device, the working fluid outlet channel  114  is used to outlet the working fluid from the block  110  to the compressor. 
     Generally, a size of the working fluid distributor is determined according to a flow of the working fluid, a heat conduction amount of the heat exchanger, or other design conditions. For ease of fabrication, the block  110  of this embodiment may be composed of a plurality of sub blocks  110 ′ ( FIG. 4 ). 
     Referring to  FIGS. 4 and 5 ,  FIG. 4  is a schematic view of the sub block  110 ′ used to form the block  110 , and  FIG. 5  is a schematic sectional view of  FIG. 4 . The sub block  110 ′ has a working fluid inlet channel section  112 ′, a working fluid outlet channel section  114 ′, the working fluid distribution chamber  116 , the plurality of working fluid outlet openings  118   a , and the plurality of working fluid inlet openings  118   b . The working fluid distribution chamber  116  communicates with the working fluid inlet channel section  112 ′. The working fluid outlet openings  118   a  communicate with the working fluid distribution chamber  116 . The working fluid inlet openings  118   b  communicate with the working fluid outlet channel section  114 ′. The working fluid inlet channel section  112 ′ is used to define a part of the working fluid inlet channel  112  ( FIG. 3 ), and the working fluid outlet channel section  114 ′ is used to define a part of the working fluid outlet channel  114  ( FIG. 3 ). Based on the design of the sub block  110 ′, in this embodiment, through modularization, the plurality of sub blocks  110 ′ is fabricated, and then the plurality of sub blocks  110 ′ is combined to form the block  110  with a preset size. In other words, the length of the working fluid inlet channel  112  and the working fluid outlet channel  114  of the block  110  are respectively defined by the working fluid inlet channel sections  112 ′ and the working fluid outlet channel sections  114 ′ of the sub blocks  110 ′. 
     Preferably, in order to more conveniently and firmly assemble the sub blocks  110 ′, in this embodiment, at least one male connector  119   a  is formed on one side of the sub block  110 ′ and at least one female connector  119   b  is formed on the other side of the sub block  110 ′. In this manner, the male connector  119   a  of the sub block  110 ′ is inserted to the female connector  119   b  of another sub block  110 ′, so as to quickly joint the two sub blocks  110 ′. 
     Preferably, the male connector  119   a  has a through hole, and the male connector  119   a  communicates with one of the working fluid inlet channel section  112 ′ and the working fluid outlet channel section  114 ′ on one side of the sub block  110 ′. In addition, the female connector  119   b  also communicates with one of the working fluid inlet channel section  112 ′ and the working fluid outlet channel section  114 ′ on the other side of the sub block  110 . Therefore, during the assembly process, in this embodiment, the working fluid inlet channel section  112 ′ and the working fluid outlet channel section  114 ′ of one sub block  110 ′ may be quickly and accurately aligned with the working fluid inlet channel section  112 ′ and the working fluid outlet channel section  114 ′ of another sub block  110 ′ respectively, so as to define the working fluid inlet channel  112  through the working fluid inlet channel sections  112 ′, and define the working fluid outlet channel  114  through the working fluid outlet channel sections  114 ′. 
       FIG. 6  is a schematic view of a heat transfer tube module  210  having the block  110  according to an embodiment of the present invention, and  FIG. 7  is a schematic partial enlarged view of  FIG. 6 . Referring to  FIGS. 3 ,  6 , and  7 , based on the structure of the block  110 , the present invention further provides a micro-channel heat exchanger module  300 , which includes a heat transfer tube module  200  and a block  110 . The block  110  communicates with the heat transfer tube module  200 , such that the working fluid from the compressor enters the heat transfer tube module  200  through the block  110 , and the working fluid may perform the heat exchanger with the external air in heat sink fins of the heat transfer tube module  200 , so as to dissipate the heat delivered by the working fluid. The working fluid may be the carbon dioxide refrigerant or other types of refrigerants. Then, the working fluid after the heat exchanger enters the element of a next channel from the heat transfer tube module  200  through the block  110 . The combination of the heat transfer tube module  200  and the block  110  is described in detail as follows. 
     The heat transfer tube module  200  includes a plurality of heat transfer tube module  210 , and each of the heat transfer tube module  210  has a first end  212  and a second end  214 . The first end  212  communicates with the working fluid outlet openings  118   a , and the second end  214  communicates with the working fluid inlet openings  118   b . In this embodiment, an extending direction of the first end  212  is vertical to an extending direction of the working fluid inlet channel  112  (see  FIG. 3 ). In addition, an extending direction of the second end  214  is vertical to an extending direction of the working fluid outlet channel  114  (see  FIG. 3 ). In this manner, the working fluid may enter the first end  212  from the working fluid distribution chamber  116  (see  FIG. 3 ), and then the working fluid dissipates the heat to the external environment in the heat transfer tube module  210 . Then, the working fluid after heat dissipation enters the working fluid outlet channel  114  through the second end  214 . In addition, in order to improve the heat dissipation performance of the heat transfer tube module  210 , in other embodiments of the present invention, a plurality of heat sink fins may be disposed on the heat transfer tube module  210 . As the technique of improving the heat conduction performance of the heat transfer tube module  210  is quite mature, the detailed description is not given here. 
     Accordingly, in addition to the design of the working fluid distribution chamber  116 , in this embodiment, the relative position of the first end  212  of the heat transfer tube module  210  and the working fluid distribution chamber  116  (Referring to  FIG. 3 ) may be adjusted to improve the smoothness of the flow of the working fluid. Referring to  FIG. 8 , a schematic sectional view relative to the first end  212  of  FIG. 6  is shown. The working fluid distribution chamber  116  has a chamber bottom surface  116   a . The first end  212  of the heat transfer tube module  210  is inserted to the block  110  through the working fluid outlet opening  118   a . It should be noted that in order to make the working fluid smoothly flow from the working fluid distribution chamber  116  to the heat transfer tube bank  210 , the first end  212  of the heat transfer tube module  210  is not raised to the working fluid distribution chamber  116  from the chamber bottom surface  116   a , that is, a height of the end surface of the first end  212  may be lower than or equal to a height of the chamber bottom surface  116   a . As compared with the prior art, the design effectively prevents the first end  212  of the heat transfer tube module  210  from obstructing the channel of the working fluid, such that the design improves the smoothness of the flow of the working fluid. 
     Referring to  FIG. 9 , a schematic sectional view relative to the second end  214  of  FIG. 6  is shown. Similarly, the similar design of the relative position of the first end  212  and the working fluid distribution chamber  116  may be adopted between the second end  214  of the heat transfer tube module  210  and the working fluid outlet channel  114 . In order to improve the smoothness of the working fluid flow, in this embodiment, the relative position of the second end  214  of the heat transfer tube module  210  and the working fluid outlet channel  114  may be adjusted. The working fluid outlet channel  114  has a channel bottom surface  114   a . The second end  214  of the heat transfer tube module  210  is inserted to the block  110  through the working fluid inlet opening  118   b . It should be noted that in order to make the working fluid smoothly flow from the heat transfer tube module  210  to the working fluid outlet channel  114 , the second end  214  of the heat transfer tube module  210  is not raised to the working fluid outlet channel  114  from the through chamber bottom surface  116   a , that is, a height of the end surface of the second end  214  is lower than or equal to a height of the channel bottom surface  114   a.    
     The method of fabricating the micro-channel heat exchanger module  300  is described in detail as follows.  FIGS. 10A to 10C  are schematic flow charts of fabricating the micro-channel heat exchanger module  300  according to an embodiment of the present invention. Referring to  FIG. 10A , firstly an object to be processed  100 ′ is provided. Referring to  FIGS. 11A and 11B ,  FIG. 11A  is a schematic longitudinal sectional view of  FIG. 10A , and  FIG. 11B  is a schematic cross-sectional view of  FIG. 10A . The structure of the object to be processed  100 ′ is similar to that of the block  110 . The object to be processed  100 ′ has a working fluid inlet channel  112 , a working fluid outlet channel  114 , a working fluid distribution chamber  116 , and a plurality of working fluid openings. Being different from the block  110 , the object to be processed  100 ′ further has a plurality of soldering openings  101 . The working fluid distribution chamber  116  communicates with the working fluid inlet channel  112 . The working fluid distribution chamber  116  has a chamber bottom surface  116   a . The working fluid openings are located on the chamber bottom surface  116   a . A part of the working fluid openings communicate with the working fluid distribution chamber  116 , and the remaining working fluid openings communicate with the working fluid outlet channel  114 . The soldering openings  101  communicate the working fluid distribution chamber  116  with the external environment, and the soldering openings  101  are located on a chamber top surface  116   b  of the working fluid distribution chamber  116  opposite to the chamber bottom surface  116   a.    
     Referring to  FIG. 10B , next, a plurality of stopping blocks  410  is provided, and a solder resist process (for example, a carbonizing process) is performed on surfaces of the stopping blocks  410 . In this embodiment, the stopping blocks  410  are formed on a plate body plate body  420 , so as to form a stopping block module  400 . In this manner, during the fabricating flow, in this embodiment, the position of the plurality of stopping blocks  410  may be moved at the same time by operating the stopping block module  400 . 
     Referring to  FIGS. 10C and 12 ,  FIG. 12  is a schematic sectional view of  FIG. 10C . Next, the stopping block module  400  is disposed on the block  110 , such that each stopping block  410  is inserted to the block  110  through the soldering opening  101 , and the end portion of each stopping block  410  is inserted to the corresponding working fluid outlet opening  118   a . Next, a plurality of heat transfer tube module  210  is provided. The first end  212  of each heat transfer tube module  210  is inserted to the block  110  through the working fluid outlet opening  118   a , and each first end  212  contacts with the corresponding stopping block  410 . Preferably, the end surface of each stopping block  410  has a flange  412  corresponding to the first end  212  of the heat transfer tube module  210 , and when the stopping block  410  contacts with the first end  212  of the heat transfer tube module  210 , the flange  412  surrounds an outer surface of the first end  212 . 
     Similarly, in this embodiment, each stopping block  410  is inserted to the block  110  through the soldering opening  101  by using the similar method, and the end portion of each stopping block  410  is inserted to the corresponding working fluid inlet opening  118   b . Then, the second end  214  of each heat transfer tube module  210  is inserted to the block  110  through the working fluid inlet opening  118   b , and each second end  214  contacts with the corresponding stopping block  410 . 
     Next, for example, the heat transfer tube module  210  is soldered to the object to be processed  100 ′ by brazing. The solder resist process is performed on the surfaces of the stopping blocks  410 , such that during brazing, the solder will not enter the contacting surfaces of the first ends  212  and the stopping blocks  410  under the effect of the capillary action. Then, the stopping block module  400  is moved, so as to remove the stopping blocks  410  from the block  110 . Next, the soldering openings  101  are sealed, so as to form the micro-channel heat exchanger module  300  as shown in  FIG. 6 . 
     To sum up, the present invention has the working fluid distribution chamber connected between the working fluid inlet channel and the working fluid outlet opening, such that as compared with the prior art, the working fluid of the present invention flows to each heat transfer tube module  210  much smoother and more uniform. In addition, the end of the heat transfer tube module inserted to the working fluid outlet opening is not raised to the working fluid distribution chamber, and the other end of the heat transfer tube module inserted to the working fluid inlet opening is not raised to the working fluid outlet channel, such that as compared with the prior art, the design may further improve the smoothness of the flow of the working fluid. Further, the present invention adopts the design of the stopping block, such that by appropriately controlling a depth of the stopping block inserted to each working fluid opening, during the fabrication of the micro-channel heat exchanger module, in the present invention, each end portion of the heat transfer tube module may be inserted to the working fluid opening, and the relative position of each end portion of the heat transfer tube module and the block is quickly positioned.