Micro-channel refrigerating evaporator and freeze-drying system using evaporator

Abstract

A micro-channel refrigerating evaporator and a freeze-drying system using the evaporator. The micro-channel refrigerating evaporator comprises a rectangular flat tube structure, wherein the flat tube structure is arranged in a surrounding manner in the lengthwise direction thereof; first micro-channel structures, which are parallel to each other in a circumferential direction, are arranged in the flat tube structure. By means of using a rectangular metal flat tube structure and arrangement of the micro-channel structures in the middle thereof, the flat tube structure is completely attached to a surrounding drying box, such that no hollow structure is disposed in the middle, the coverage area is thus increased to the maximum extent and the heat exchange efficiency is improved.

1 . A micro-channel refrigerating evaporator, characterized in that,
 comprising a rectangular flat tube structure, the flat tube structure is encircled along its length, the flat tube structure is provided with a plurality of first micro-channel structures circumferentially parallel;   the flat tube structure is connected at one end to a width-extending first liquid inlet collector tube and at the other end to a width-extending first liquid outlet collector tube;   the first inlet collector, the first outlet collector and the first micro-channel structure are interconnected;   the first liquid inlet collector tube, the first liquid outlet collector tube are connected to a flow inlet and a flow outlet, respectively.   
     
     
         2 . The micro-channel refrigerating evaporator according to  claim 1 , characterized in that the center point of the micro-channel structure is closer to the inner wall side of the flat tube structure after it is surrounded. 
     
     
         3 . The micro-channel refrigerating evaporator according to  claim 2 , characterized in that the distance of the inner wall side of the flat tube structure from the boundary of the micro-channel structure is set to be the micro-channel wall thickness, and the micro-channel wall thickness is valued at between 0.3 mm and 5 mm, preferably between 0.3 mm and 1 mm. 
     
     
         4 . The micro-channel refrigerating evaporator according to  claim 1 , characterized in that the first micro-channel structure is provided with an enhanced-flow structure on the inner wall. 
     
     
         5 . The micro-channel refrigerating evaporator according to  claim 4 , characterized in that the enhanced-flow structure comprises one or more protruding sheets distributed in the first micro-channel structure. 
     
     
         6 . The micro-channel refrigerating evaporator according to  claim 5 , characterized in that the first micro-channel structure has a rectangular cross-section, with protruding sheets being provided at four vertices and extending towards the center of the rectangle. 
     
     
         7 . The micro-channel refrigerating evaporator according to  claim 4 , characterized in that the enhanced-flow structure causes the inner wall of the first micro-channel structure to have a mesh-like recessed structure. 
     
     
         8 . The micro-channel refrigerating evaporator according to  claim 1 , characterized in that each of the first micro-channel structures parallel to each other is provided with a control valve on the side near the first liquid outlet collector tube. 
     
     
         9 . The micro-channel refrigerating evaporator according to  claim 8 , characterized in that there is a linkage function among the control valves; refrigerant flows sequentially from the first liquid inlet collector tube into the parallel first micro-channel structures, during which all control valves remain closed; a pressure sensor installed on the control valve at the end of the last first micro-channel structure, once the pressure sensor detects the flow of refrigerant, all control valves are opened to allow refrigerant circulation. 
     
     
         10 . The micro-channel refrigerating evaporator according to  claim 1 , characterized in that the flat tube structure is divided into multiple uniform segments in the direction of its first liquid inlet collector tube and the first liquid outlet collector tube, and the first liquid inlet collector tube and the first liquid outlet collector tube are provided with collector partition plates which are spaced apart, and the collector partition plates are disposed at the same position as the segmentation of the flat tube structure is located, so that a series path is formed between the first liquid inlet collector tube, the first micro-channel structure and the first liquid outlet collector tube. 
     
     
         11 . The micro-channel refrigerating evaporator according to  claim 10 , characterized in that three segments of the flat tube structure are connected in parallel as an integral channel and in series to the next set of three segmented channels, and so on. 
     
     
         12 . The micro-channel refrigerating evaporator according to  claim 10 , characterized in that,
 the flat tube structure is provided with a second liquid inlet collector tube on one side perpendicular to the first inlet collector, and the flat tube structure is provided with a second liquid outlet collector tube on the other side perpendicular to the first inlet collector;   the flat tube structure is provided with a plurality of second micro-channel structures longitudinally parallel to each other, the second micro-channel structure interconnects the second liquid inlet collector tube and the second liquid outlet collector tube;   the first inlet collector pipe and the second inlet collector pipe share the flow inlet;   the first outlet collector and the second outlet collector share the flow outlet;   the first micro-channel structure and the second micro-channel structure are staggered from each other.   
     
     
         13 . The micro-channel refrigerating evaporator according to  claim 1 , characterized in that the first liquid inlet collector tube is provided with a first securing lug, and the first liquid outlet collector tube is provided with a matching second securing lug; and a hoop is internally threaded between the first securing lug and the second securing lug. 
     
     
         14 . A freeze-drying system, characterized in that, comprising a micro-channel refrigerating evaporator as described in  claim 1 , a compressor, a drying chamber, a vacuum device, a heating device; the micro-channel refrigerating evaporator is set up around the side wall of the drying chamber; the vacuum device and the bottom of the drying chamber are connected to each other; the heating device is set up in the interior of the drying chamber, and the compressor is connected to the micro-channel refrigerating evaporator. 
     
     
         15 . The freeze-drying system according to  claim 14 , characterized in that the compressor is selected as an air-cooled compressor and is connected to the other side of the micro-channel refrigerating evaporator away from the drying chamber, so that the whole freeze-drying system has a positive polygonal layout of the device. 
     
     
         16 . The freeze-drying system according to  claim 14 , characterized in that the drying chamber is in the form of a cylinder and the flat tube structure is made of aluminum.