On July 7, 2020, the project of 'high and low temperature simulation test device for a certain type of nozzle oil source pump' designed and manufactured by our company for a certain unit of China Aviation Development Co., Ltd. passed the final acceptance at the customer's site. The project innovatively adopts liquid nitrogen cooling and heat exchange technology to realize high-precision low-temperature fuel temperature control, and the temperature control accuracy can reach 100% ± 1℃。 Compared with the conventional compressor refrigeration mode, the liquid nitrogen refrigeration mode has the advantages of low construction cost and strong refrigeration capacity. Our company has obtained the utility model patent certificate of this technology.