Shanghai Jiao Tong University is abbreviated as "Shanghai Jiao Tong University". It is located in Shanghai. It is a key university directly under the Ministry of Education of my country. It is one of the higher education institutions with a long history in my country and is well-known all over the world. As of the end of 2018, the school consists of 6 campuses and 30 colleges. / Directly affiliated departments, composed of 31 research institutes and other institutions.
The Refrigeration and Cryogenic Engineering Discipline of Shanghai Jiaotong University was established in 1956. It is one of the oldest refrigeration disciplines in my country’s universities, especially in energy utilization and environmental control in refrigeration and air conditioning, simulation optimization control, automation, and indoor air quality, food freezing and Refrigeration research, and other directions have distinct research directions, and the institute has determined new academic directions such as the digital design of refrigeration and air-conditioning electromechanical products, low-temperature superconductivity and low-temperature heat transfer, and refrigeration and air-conditioning system engineering.
In 2017, a technical expert from the Institute of Refrigeration and Cryogenic Engineering of Shanghai Jiaotong University, due to the scientific research needs of the cryogenic refrigeration laboratory, it is necessary to reduce the -40 degree alcohol and other media to -45 degree to provide a low-temperature environment in the refrigeration test to facilitate various low-temperature Engineering test.
Kaydeli chiller plays an extremely important role in refrigeration equipment in this low-temperature project. If a single-stage compression refrigeration cycle is used, it can only produce a temperature of -25 degrees to -35 degrees, which cannot meet the target low-temperature requirements. Therefore, the custom technicians of Kaideli Refrigerator adopt the cascade low-temperature refrigeration scheme.
The cascade refrigerator is composed of two independent compression refrigeration cycles to synthesize a binary cascade refrigeration system, which is divided into two cycles of high temperature and low temperature, and the middle is connected by a condensation evaporator, that is, the condenser in the low-temperature cycle is in the high-temperature cycle Evaporator. The high-temperature stage of the system uses R22/R404A as the working fluid, and the low-temperature stage uses R23 as the working fluid. The working process is as follows:
1. High-temperature circulation system (left):
In the high-temperature cycle, the refrigerant that enters the evaporative condenser absorbs heat and is vaporized, passes through the compressor in the high-temperature zone, becomes high-pressure refrigerant vapor, then enters the condenser through the oil-liquid separator, condenses into a high-pressure liquid, and then passes through the filter and expands. The valve transforms into low-pressure and low-temperature steam, continues to absorb the heat of the evaporative condenser, re-vaporizes, and enters the next refrigeration cycle.
2. Low-temperature circulation system (right):
In the low-temperature cycle, the heat of the refrigerant in the condensing evaporator is absorbed and taken away by the high-temperature cycle, and the gas refrigerant is converted into a high-pressure liquid, throttling and reducing the pressure through a filter and an expansion valve, and entering the low-temperature evaporator. Heat exchange (to produce the required cooling capacity), and then converted to low-pressure steam, sucked into the low-temperature compressor, compressed into high-pressure steam, and re-enter the condensing evaporator to continue the refrigeration cycle.
In the Kaydeli low-temperature cascade refrigeration solution, the equipment is composed of branded accessories, the German "Bitzer" compressor, the American Aike refrigeration accessories, and the French Schneider electric control equipment; the evaporator and condenser are made of stainless steel.
In order to ensure the good operation of the equipment, the equipment is equipped with high and low-voltage switches, motor overload protection, phase loss, reverse phase protection, safety valves, and other protection devices to ensure that the equipment is safe and reliable under abnormal working conditions.
The practice has proved that the design of the Kadeli low-temperature cascade chiller has stable low-temperature refrigeration performance, stable operation, and low noise, and is completely suitable for use by the Institute of Refrigeration and Cryogenic Engineering of Shanghai Jiaotong University. It provides a stable low-temperature environment for related experiments of refrigeration and cryogenic engineering, promotes the academic research and application of corresponding refrigeration disciplines at Shanghai Jiaotong University, and to a certain extent promotes the knowledge innovation and development of China's refrigeration and air-conditioning industry.
In terms of chiller R&D and design, Kedli has a professional chiller R&D team, which can produce customized special chillers, chillers, and low-temperature chillers for enterprises. It is unique in energy saving and environmental protection and has successfully won various domestic and foreign refrigeration industries. Honor, and maintain close cooperation with more than 2,000 domestic enterprises and scientific research institutes, and have made due contributions to promoting industrial development and social progress.
