We know that all biological processes are affected by temperature. Low temperature inhibits the reproduction of yeast and mold in food, and the human body is also very sensitive to temperature. In modern society, refrigeration technology has penetrated into almost every production technology and scientific research field, which has played a great role in improving the quality of human life. In life, refrigeration is widely used in food cold processing, refrigeration, refrigerated transportation, adaptive air conditioning, artificial skating rink in sports and so on. In industrial production, the necessary constant temperature and humidity environment is provided for the production environment, materials are treated at low temperature, and the interference fit between parts is carried out by using low temperature. In agriculture and animal husbandry, the seeds of crops are treated at low temperature; In building engineering, the excavation of earthwork in frozen soil is realized by refrigeration; Modern medicine is also inseparable from refrigeration, cryopreservation of bone marrow and peripheral blood stem cells, and hypothermia anesthesia during surgery. Refrigeration technology also plays an important role in the research and development of frontier scientific fields such as microelectronics, new materials, space development and biotechnology. It can be said that the progress of modern technology is accompanied by the development of refrigeration technology.

Technology is the labor skill, skill, experience and knowledge developed in the course of human history. It includes hardware and software in human technical activities, and it is the sum total of human activities to transform nature and create artificial nature. Theoretically speaking, technology belongs to the practical field of social material wealth and material wealth creation, and it is the materialized form of labor skills, production experience and scientific knowledge. The use of tools essentially changes the relationship between man and nature and determines the production structure and development mode of human beings. Technology is an important part of social productive forces, and technological progress has promoted human development. Since entering the industrial age, science and technology have created a highly developed material civilization. With the rise of the new scientific and technological revolution, production tools have developed from electrification to automation and intelligence, which has greatly expanded the scope of labor objects and greatly improved the cultural and technical level of workers. Technological progress has brought great convenience to human production and life, and profoundly changed human appearance and people's lifestyle. As a modern person, it is no longer a dream to live in a space with four seasons like spring, eat cold food and enjoy the taste of summer. The developed communication makes distance no longer an obstacle to communication. In this case, the earth has become a global village, and the voices of chickens and dogs are heard. This is the embodiment of the infiltration of science and technology into human life. Among them, the development of refrigeration technology has a particularly important impact on human beings.

2 refrigeration technology and its negative effects

2. 1 technology and human beings

In the interaction between man and nature and society, man is in a dominant position, subject to nature and society, and affects nature and society at the same time. The influence of human beings on nature is basically manifested in two aspects: on the one hand, it exerts a positive and constructive influence on nature, makes rational use of natural conditions, and creates a new artificial nature or artificial ecosystem that is more suitable for human life; On the other hand, technology also has a negative and destructive impact on nature, which makes the original "natural balance" out of balance. The survival and development of human society is based on the support and restriction of natural system on human activities. The subject of technological activities is human, and the object is nature and society. Technology has a clear practical purpose, and it is the intermediary for human beings to carry out production activities, cultural activities and social activities. As an intermediary, technological activities will inevitably lead to positive and negative consequences. As early as two centuries ago, the philosopher Engels warned us, "Don't be too intoxicated with our victory over nature." Every time such a victory, nature will retaliate against us. Every victory did achieve our expected results in the first step, but it produced completely different and unexpected effects in the second and third steps, and the first result was often cancelled. "With the advancement of industrialization, urbanization and modernization, the changes and destruction of human activities on the ecological environment are also deepening, which eventually leads to the deterioration of the global ecological environment. The 20th century is an era of rapid development of science and technology. However, the technological revolution in the 20th century did not solve the social contradictions pointed out by Marx and Engels, but also formed some outstanding new social contradictions and social problems such as population, ecological environment, resources and energy, and the disparity between the rich and the poor.

2.2 Development and harm of refrigeration technology

The same is true of refrigeration technology, which brings great convenience to human production and life. It not only benefits human beings, but also brings profound disasters to the natural environment on which human beings depend. Historically, the first stage of refrigeration technology development (from 1830 to 1930) mainly used NH3, HCS, CO2 and air as refrigerants. Some of these refrigerants are toxic, some are flammable and some are inefficient. They have been used for a hundred years. When CFCS and chlorofluorocarbons (CFCs) appear, they are safe. The first major turning point was achieved, and it entered the second stage of refrigeration technology development (from 1930 to 1990). Freon is mainly used as refrigerant. After 60 years of use, it was found that these refrigerants destroyed the ozone layer. As we all know, the "ozone layer" of the earth's atmosphere is like a filter and an umbrella, which keeps the harmful part of solar radiation out of the atmosphere. In fact, it can be said that after the formation of the ozone layer, life will survive, continue and develop on the earth, and the ozone layer is the "protective umbrella" of the surface biological system. However, in recent years, the destruction of the ozone layer has been increasing. According to the latest survey by the World Meteorological Organization, the "ozone hole" over Antarctica has reached 2 1 10,000 square kilometers, which is larger than the area of two China. Ozone depletion in some areas of the equator has exceeded 20%. Last summer, ozone in parts of northern Europe even decreased by 40%. The ozone over the Qinghai-Tibet Plateau, known as the "roof of the world", is decreasing at a rate of 2.7% per 10/0 in recent years, and has become the third ozone hole in the atmosphere. The reduction of ozone content in the ozone layer is equivalent to opening a skylight over the earth, allowing a large number of ultraviolet rays to shine on the surface without being blocked. The result will seriously destroy the basic structure of animals and plants, reduce the biological yield, lead to abnormal changes in climate and ecological environment, and especially cause great damage to human health. If the ozone layer disappears, the ecological environment on the earth will be restored to that of 450 million years ago, and tens of millions of terrestrial creatures, including humans, will face extinction. Some people even think that when the amount of ozone in the ozone layer is reduced to 1/5 of the normal amount, it will be the critical point of life death on earth. What is the cause of the ozone hole? Scientific research shows that some chemicals such as bromochlorofluoroalkane discharged into the atmosphere by human activities enter the ozone layer and react with ozone, resulting in ozone loss, which is directly related to the development of refrigeration technology. Since 1930s, a series of freon refrigerants adapted to different working temperature ranges have almost swept the refrigeration field, which greatly promoted the development of refrigeration and air conditioning technology. It is estimated that a chlorine atom can destroy 104 ~ 105 ozone molecules, and the destructive power of bromine atom is 30 ~ 60 times that of chlorine atom. Moreover, chlorine atoms and bromine atoms also have a synergistic effect, that is, when they exist at the same time, the ability to destroy ozone is greater than their simple addition. In other words, freon, which is widely used in refrigerators and air conditioners, is the chief culprit of "ozone hole". The development of refrigeration technology at this stage shows that technology can not only enhance people's ability, but also change human nature and destroy people's living environment. Refrigeration technology, like smelting and chemical technology, has the dual functions of benefiting human beings and destroying human environment.

2.3 the negative impact of technological development

Contemporary technological revolution is forming new productive forces, new modes of production, new ways of market exchange, new industrial structure and employment institutions, new ways of property possession and hierarchical structure, and new power and organizational management structure. The positive and negative effects of technology are objective and inevitable. Humans have thoughts, spirits and languages that no other living thing has. They have created rich material civilization with their intelligence, and they must also respond to the negative effects brought by technology. Holland, an American postmodernist scholar, pointed out: "Modern dreams have bypassed a strange circle. In this circle, the modern scientific progress was originally intended to liberate itself, but it has dangerously lost its foundation in the earth, in human society, in tradition and, more importantly, in religious mystery. Its energy has shifted from creation to destruction. The myth of progress leads to unexpected adverse consequences. " Although the development of science and technology is indispensable to solve the "global problems" and the dilemma of contemporary human development, we should also see the side effects of the development of science and technology and the possible limitations of science and technology in solving "global problems".

3 control the negative impact of refrigeration technology

It is impossible to completely eliminate the negative effects of science and technology. The only thing we can do is to try our best to avoid and suppress its negative effects in scientific and technological activities. Ozone layer destruction and global climate change are the main environmental problems facing the world today. When scientists' research convincingly revealed that freon widely used in refrigeration technology caused serious depletion of the ozone layer, the action of "mending the sky" was very rapid. 1985, that is, 1 1 After Monlina and Rowland put forward the mechanism of atomic ozone depletion, that is, the year when the Antarctic ozone hole was discovered, the Vienna Convention for the Protection of the Ozone Layer was initiated by the United Nations Environment Programme, which established a series of principles and policies to control the destruction of the ozone layer for the first time in the world. 1987, the Montreal protocol, an important historical document for protecting the atmospheric ozone layer, was adopted. In the Protocol, the types of controlled substances for ozone layer protection and the phase-out schedule are specified. It is required that the global freon be reduced by half by 2000, and the control measures for the production, consumption, import and export of freon substances have been formulated. As further scientific research shows that the situation of ozone depletion in the atmosphere is more severe, 1990 adopted the London Amendment to the Montreal Protocol. The Copenhagen Amendment was adopted in 1992, which expanded the categories of controlled substances again. The timetable for complete elimination has been advanced again and again. China will also phase out freon F 1 1 in 20 10/. However, even if we make such efforts to make up the "ozone hole" above our heads, it is difficult to remove ozone-depleting substances from the atmosphere. It is predicted that the concentration of chlorine atoms in the stratosphere will fall below the critical level around 2050 through the Copenhagen Amendment. By then, the "ozone hole" above us is expected to begin to recover. From here we can clearly see that technology is a double-edged sword. Humans gradually realize that the value standard of technology lies not only in whether it is practical and what economic benefits it brings, but also in its negative effects. However, is it because of the negative effects of technological progress that human beings must deny technological progress and degenerate into primitive and ancient production and life? Shouldn't we return to the era of grain storage described in The Book of Songs: July in the Wind, "………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………… This negative view of avoiding the world obviously does not conform to the nature and development law of human exploration. In fact, when the refrigerants used in the second stage of refrigeration technology development were included in the elimination schedule, refrigeration technology entered the third development stage (from 1990 to now) and entered a period dominated by HFCS. The research on the development and practical process of a new generation of alternative refrigerants with environmental protection, high efficiency, energy saving and emission reduction is being stepped up. Humans should not only be able to use, dominate, transform and control nature through technical means, but also adapt and coordinate nature through technical activities to reduce or avoid the damage to nature.

4 conclusion

The utilization and transformation of nature by human beings through technical means will inevitably change the original balance of nature. The problem is that human beings should correctly understand the positive and negative effects of their own activities on nature, and provide scientific, predictable and controllable human behavior that adapts to the laws of nature, so that the consequences will be conducive to coordinating the relationship between man and nature and making nature better benefit mankind. Marxism believes in the power of technology and that mankind can overcome all kinds of difficulties and get rid of difficulties by relying on science and technology. The ability of human beings to seek development is infinite. However, the exertion and development of scientific and technological strength should be carried out under a certain mode of production and influenced and restricted by economic and social systems. Therefore, the development of contemporary science and technology must follow the unified purpose of "humanism" as Marx said, so as to truly overcome the negative effects of technological development and give full play to the positive effects of technological development. The development of refrigeration technology and ozone layer protection is a typical example of technological progress and global cooperation in modern history. Its technological progress and cooperation mechanism to control the consequences of technological progress will also become human wealth, providing valuable reference experience for solving other major problems.

Reference [1] Zhao Jinglai: A Summary of Research on Frontiers of Philosophy in 1990s, Tianjin Academy of Social Sciences Press, September 2002, p. 38.

[2] Wang Bing Dai Zhengnong: A Course of Dialectics of Nature, Southeast University Press.

[3] Chen Guobang: Latest cryogenic refrigeration technology, Machinery Industry Press, 2003.