Heat exchanger and brayton cycle system based on solution to pinch point in thermodynamic cycle

Abstract

A heat exchanger based on solution to pinch point in a thermodynamic cycle includes a heat exchange core and a cover plate. The heat exchange core is sealed by the cover plate. Through coordinated structure of first and second flow channels and branch flow channels on alternately stacked cold side and hot side heat exchange plates, the heat exchanger of the present application improves heat exchange efficiency and avoids the adverse effects caused by pinch points. A Brayton cycle system including the heat exchanger is also provided.

What is claimed is: 
     
         1 . A heat exchanger based on a solution to a pinch point in a thermodynamic cycle, comprising:
 a heat exchange core, wherein the heat exchange core comprises a plurality of cold side heat exchange plates and a plurality of hot side heat exchange plates stacked alternately; a first surface of each cold side heat exchange plate defines a plurality of first flow channels by first partitions; a second surface, which faces the same direction as the first surface, of each hot side heat exchange plate defines a plurality of second flow channels by second partitions; the cold side heat exchange plates and/or the hot side heat exchange plates further comprise branch flow channels; the branch flow channels are disposed along flow paths of all the first flow channels and/or all the second flow channels, and are in fluid communication with all the first flow channels and/or all the second flow channels, to converge or split flows within the cold side heat exchange plates and/or the hot side heat exchange plates; and   a cover plate, configured to seal the heat exchange core.   
     
     
         2 . The heat exchanger according to  claim 1 , wherein the heat exchanger further comprises a heat exchange interface, the heat exchange interface comprises a cold side inlet, a cold side outlet, a hot side inlet, a hot side outlet and a branch port which are arranged on a side face of the heat exchange core, the cold side inlet and the cold side outlet are respectively connected to two ends of the second heat channels, the hot side inlet and hot side outlet are respectively connected to two ends of the second flow channels, the cold side inlet and the hot side inlet are respectively located on two opposite sides of the heat exchange core, the cold side outlet and the hot side outlet are respectively located on two opposite sides of the heat exchange core, and the branch port is connected to one end of the branch flow channels. 
     
     
         3 . The heat exchanger according to  claim 2 , wherein the branch ports are provided in pairs, and the branch flow channels transversely penetrate through all the first flow channels and/or all the second flow channels, with two ends of the branch flow channels are connected to respective branch ports. 
     
     
         4 . The heat exchanger according to  claim 3 , wherein each branch port is provided with a control valve to regulate flow entering the branch flow channel. 
     
     
         5 . The heat exchanger according to  claim 1 , wherein a plurality of the branch flow channels are arranged at preset intervals on each cold side heat exchange plate and/or each hot side heat exchange plate. 
     
     
         6 . The heat exchanger according to  claim 1 , wherein the partitions are a plurality of elongated grid plates arranged in parallel, and all the first flow channels and/or all the second flow channels are formed as continuous linear, zigzag, or meandering flow channels through the partitions. 
     
     
         7 . The heat exchanger according to  claim 1 , wherein the partitions are a plurality of regularly distributed fins, and all the first flow channels and/or all the second flow channels are formed as aligned and interconnected non-continuous flow channels through the partitions. 
     
     
         8 . A Brayton cycle system, comprising:
 a heat source;   a thermoelectric conversion unit;   a recuperating unit;   a cooling unit; and   a compression unit, wherein the heat source, the thermoelectric conversion unit, the recuperating unit, the cooling unit, and the compression unit are in communication sequentially, the recuperating unit and the cooling unit comprise the heat exchanger according to  claim 1 .   
     
     
         9 . The Brayton cycle system according to  claim 8 , wherein the compression unit comprises a main compressor and at least one re-compressor, an input end of the main compressor is connected to a hot side outlet of the cooling unit, an input end of the re-compressor is connected to a hot side outlet of the recuperating unit, an output end of the main compressor is connected to a cold side inlet of the recuperating unit, and an output end of the re-compressor is connected to a branch port of the recuperating unit. 
     
     
         10 . The Brayton cycle system according to  claim 9 , wherein the hot side outlet of the cooling unit and a cold side outlet of the recuperating unit each are provided with a temperature monitoring unit, the Brayton cycle system further comprises a measurement and control unit, the measurement and control unit is electrically connected to the control valve on each branch port and the temperature monitoring unit, and is configured to monitor the temperature at the hot side outlet of the cooling unit and the temperature at the cold side outlet of recuperating unit, and regulate a flow rate of a working fluid inside the cooling unit and the recuperating unit. 
     
     
         11 . The Brayton cycle system according to  claim 10 , wherein a working fluid of the Brayton cycle system is supercritical carbon dioxide, a pressure at the cold side inlet of the recuperating unit is 12 MPa to 25 MPa, the pressure at the hot side inlet of the recuperating unit is 7.38 MPa, and a temperature at the cold side inlet of the recuperating unit is greater than 50° C.