"Refrigeration" is the use of certain methods, in a certain period of time, so that an object or space to achieve a lower temperature than the surrounding environmental media, and maintained at a given temperature range. Here the so-called environmental media, is the nature of the air and water. In order to make an object or space to achieve or maintain a certain low temperature, a certain method must be used to continuously remove the object or space heat, and this heat is transferred to the external environment. Such heat "transfer" process is "refrigeration process", referred to as according to the development of refrigeration technology, refrigeration means there are two kinds of: one is the use of nature's natural cold source of refrigeration; the other is "artificial refrigeration ". At present, "artificial refrigeration" is the rapid development and is widely used.
Natural cold source has winter storage of natural ice or deep well water. The use of natural ice melting heat and lower than the ground temperature of the deep well water heat absorption, can make the object or space cooling, in order to realize the "refrigeration". Natural ice has the advantage of the largest storage, inexpensive, is the ancient world's earliest countries to adopt the cold source. China as early as in the "Poetry - You Feng" in the "two days chiseling ice rushing, three days in the Lingyin" record, and in the "Summer Fugue" also recorded "accumulation of ice in the house in Youkan, the gas fly knot and for the book of the poem". These are examples of how our ancestors used ice to refrigerate food and prevent heatstroke, illustrating the long history of utilizing natural cold sources to achieve refrigeration in China. Due to the use of natural cold source by the region, season and ice storage conditions, and the use of natural cold source is subject to the limitations of the refrigeration temperature range, it is difficult to meet the requirements of large refrigeration and, therefore, with the development and progress of artificial refrigeration technology, the natural cold source refrigeration is gradually for the artificial system, supermarkets, air-curtain cabinets
Refrigeration in the petrochemical industry in the production process, but also plays an important role. Natural gas and LPG liquefaction and gas separation processes are inseparable from refrigeration technology. Refrigeration technology is used in soil freezing, for mining and tunneling project excavation to provide safety assurance and good economic benefits.
The application of refrigeration technology promotes the production and development of health care and pharmaceutical products. Medical effects of certain diseases. Low temperature for the preservation of biological organs, transplantation to provide ding guarantee. The development of cryobiology and bioengineering. Low-temperature medical treatment effectively improves the
Low-temperature technology application more promote
Refrigeration technology is widely used in air conditioning, effectively improve the process of various industrial production, enriching the people's life, tourism and cultural and recreational activities. The rapid development of refrigeration and air-conditioning technology and widely used, bit more and more energy consumption, therefore, refrigeration, air-conditioning energy saving, waste heat utilization and recovery, to carry out the "secondary energy" research, the development of solar energy, wind energy, geothermal heat, etc., has become the world's countries in the development of refrigeration, air-conditioning technology, an important research topic. Research topics.
Refrigeration and air-conditioning technology, the two independent and closely related disciplines, with industrial development and scientific and technological progress will be greater application and popularization. Refrigeration and air-conditioning technology, will be in various fields of the national economy [such as national defense, delivery of cold instead.
Nowadays, artificial refrigeration can be realized than the natural cold source refrigeration lower temperature, and have a wide range of temperature regulation. In order to facilitate the use of international artificial refrigeration can be achieved by the low temperature for the temperature zone: the temperature is higher than 120K (153 ℃) temperature zone called freezing temperature zone, this temperature zone is widely used in cold storage of food and air conditioning, etc., the main method of refrigeration is the use of refrigeration mass