What is the cold chain, the meaning of refrigeration and the history of refrigerant development

What is the cold chain

Food is one of the material bases on which human society depends for survival. In industrialized and urbanized countries and regions, the production of food materials such as agriculture, forestry, animal husbandry and fishery and food consumption such as catering are separated in space and time.cold chain In order to improve production efficiency, prevent the spread of epidemics, and protect the environment, agriculture, forestry, animal husbandry and fisheries production are mostly carried out in specific areas far away from cities. However, their production tends to fluctuate due to factors such as biological growth patterns, while food consumption, such as catering, is concentrated in urban areas, and its consumption is constantly changing due to factors such as living habits. Therefore, the spatial and temporal separation of production such as agriculture, forestry, animal husbandry and fishery and food consumption such as catering requires that food must be stored and transported, and the spatial and temporal dislocation is solved through storage and transportation.

Cold chain is a way to keep food at a suitable temperature throughout the process from the place of production to the place of consumption. The life metabolic activities of fruits and vegetables after harvest,cold warehouse and the physiological and biochemical reactions of meat, poultry and aquatic products after slaughter are all closely related to temperature. Appropriate temperature can make the life of fruits and vegetables metabolic activity down to the normal minimum level, thus greatly extending its shelf life. Cooling of meat, poultry and aquatic products not only controls the ripening process, but also mitigates microbial hazards. The freezing of meat, poultry and aquatic products can completely inhibit the harm of microorganisms, as the shelf life of food products up to several months or even years. Therefore, the cold chain is an important production method for industrialized and urbanized countries and regions to integrate the production of agriculture, forestry, animal husbandry and fishery, etc. with food and beverage consumption. The whole cold chain is the basic condition to guarantee food safety and quality, and its role for industrialized and urbanized countries and regions is not fundamentally different from that of transportation, communication and other infrastructures. And bear the cold chain within the processing, storage and distribution of cold storage facilities is the node of the cold chain, the cold chain of all production activities need to rely on cold storage facilities to carry out.

Meaning of Refrigeration

Refrigeration refers to the process of artificially bringing an object or a space in nature to a temperature lower than the ambient temperature and maintaining it at that temperature. According to the principle of liquid vaporization refrigeration, the use of liquid phase change when the latent heat of vaporization to achieve refrigeration can be divided into vapor compression refrigeration, vapor absorption refrigeration, vapor injection refrigeration, vapor adsorption refrigeration four refrigeration methods.

Refrigerant development history

The refrigerant in the vapor refrigerator draws heat from a low-temperature heat source, vaporizes at a low temperature, and then condenses at a high temperature, discharging heat to a high-temperature heat source. Therefore, only substances that can gasify and condense within the operating temperature range can be used as refrigerants. With the development of science and technology, the types of refrigerants are increasing. Early refrigerants were mainly ammonia and Freon (CFCs), but Freon has now been banned due to its damaging effect on the ozone layer. Currently, commonly used refrigerants include hydrofluorocarbons (HFCs), hydrofluoroolefins (HFOs), and others. These refrigerants have a low greenhouse effect potential and have a low impact on the environment. In the future, as the requirements for environmental protection become higher and higher, the research and development of refrigerants will also develop in a more environmentally friendly direction.

To sum up, the cold chain is an important production method for industrialized and urbanized countries and regions to integrate the production of agriculture, forestry, animal husbandry and fishery, etc. with catering consumption, and the whole cold chain is the basic condition to guarantee food safety and quality. Refrigeration is the process of making an object or space reach a temperature lower than the surrounding environment and maintaining this temperature through artificial methods. The development of refrigerants has gone through a number of stages, from ammonia and Freon in the early days to hydrofluorocarbons (HFCs) and hydrofluoroolefins (HFOs) nowadays, with an ever-increasing variety of types and a decreasing impact on the environment. In the future, as the requirements for environmental protection continue to increase, the research and development of refrigerants will also develop in a more environmentally friendly direction.

cold chain Refrigeration Refrigerant development history

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