Experimental Study on Circulation Cooling in Novel Diaphragm Compressor

To promote the development of hydrogen fuel cells, this paper designs a new diaphragm compressor that features diaphragm head wrap-around cooling. A plurality of the first cooling flow channels are provided inside the upper diaphragm head of the diaphragm compressor, which are arranged vertically to each other in the plane with the air inlet pipe and exhaust pipe. The air inlet pipe and exhaust pipe are located between the first cooling flow channels, wherein the first cooling flow channels include a plurality of cooling pipelines, and the cooling pipeline is arranged in an asterisk pattern. The second cooling channel is provided at the end of the lower diaphragm head near the oil chamber side with a cooling line arrangement similar to that of the first cooling line; thus, the diaphragm compressor can be fully cooled inside the diaphragm head. By building a new diaphragm head wrap-around cooling diaphragm compressor test bench, its performance is tested, and the effects of the pressure ratio, inlet gas temperature, and cooling effect of the wrap-around cooling line with the cooling medium temperature change law are analyzed. The test results show that the isentropic and volumetric efficiencies of the diaphragm compressor decrease with the increase in the pressure ratio, and the highest isentropic and volumetric efficiencies can reach 65% and 64%; under the condition of a certain pressure ratio, the exhaust temperature increases with the increase in the inlet gas temperature, and in the case of a similar inlet gas temperature, the higher the pressure ratio the higher the exhaust temperature. The cooling effect of the wrap-around cooling line is more significant under the condition of a large pressure ratio, and the highest can be reduced by 184.5 ℃.