The promotion of heat engine to human civilization and its influence on living environment

The invention and application of steam engine technology triggered the industrial revolution in the18th century. Since then, the large-scale production of machines has gradually replaced the handicraft production mode, and the production efficiency has been improved ten times and one hundred times. The fineness and precision of product quality make handmade products far behind, reaching an almost perfect level. In the more than one hundred years after the invention of the steam engine, great productivity has been formed and extremely brilliant achievements have been established. However, with the development of the times and the progress of science and technology, the steam engine has insurmountable shortcomings (heavy, low thermal efficiency, insecurity and so on). ) urges people to develop new power devices. Therefore, with the continuous improvement of the steam engine, under the guidance of scientific theories such as thermodynamics, a new type of heat engine-internal combustion engine was born. As a prerequisite for the emergence of internal combustion engines, of course, it is the reform of fuel. /kloc-at the end of 0/8, the Englishman Murdoch (1754- 1839) discovered that in the process of refining coke from coal, gas was produced at the same time. Soon, this combustible gas was used for lighting in some European countries at the beginning of19th century. 1859, Delecque, USA (18 19- 1880) successfully drilled oil with a drill bit, and by the 1970s, oil production had entered an industrialized period. The invention of the internal combustion engine became possible only when gasoline and oil were fully supplied. The French Renault (1822- 1900) invented the first two-stroke gas engine, and later the Germans Otto (1832- 189 1) and Daimler (1834-/) Later, steam turbines and gas turbines appeared. The improvement, development and application of this series of internal combustion engines have promoted the development of transportation. Later, modern means of transportation such as cars, ships and planes appeared.

But the second law of thermodynamics tells us that it is impossible for a heat engine to achieve the efficiency of 100%, and the heat engine must release heat. So in today's massive use of fossil fuels, what impact will a large amount of exhaust gas enter the atmosphere have on the living environment of human beings?

1, "colorless killer"-carbon monoxide

Carbon monoxide is a colorless and odorless toxic gas, which is produced in fossil fuels. When the content of carbon monoxide in the air exceeds 10 parts per million, it can poison people; When the content exceeds 1%, it can cause death within two minutes. More seriously, carbon monoxide can generally exist in the atmosphere for 4 ~ 6 months, with strong accumulation.

At present, carbon monoxide that pollutes the atmosphere mainly comes from automobile exhaust. It is estimated that the amount of carbon monoxide released into the atmosphere every year in the world is about 200 million tons. Especially in big cities with many cars and busy traffic, 70 ~ 80% of carbon monoxide in the air comes from the tail gas emitted by motor vehicles. In new york, USA, 1926, a carbon monoxide poisoning incident occurred among traffic policemen and drivers.

2. Greenhouse gas-carbon dioxide

According to reports, "global warming may have caused 654.38 million deaths in the past three years, and may lead to mass migration, disease, poverty and even war". This is precisely due to the greenhouse effect caused by the increase of carbon dioxide in the atmosphere. The normal concentration of carbon dioxide in the atmosphere is as important as oxygen. However, carbon dioxide is also called greenhouse gas because of its strong absorption of long-wave radiation. When the content of carbon dioxide in the atmosphere increases, it is like forming a thicker and thicker glass wall over the earth. It allows the short-wave radiation from the sun to pass through smoothly, but absorbs the thermal radiation from the surface and radiates it to the ground again, resulting in the continuous increase of the surface temperature and the greenhouse effect.

After entering the industrial society, with the development of science and technology and economic growth, human beings consume a lot of fossil fuels, resulting in a sharp increase in the amount of carbon dioxide discharged into the atmosphere. According to scientific experiments, the content of carbon dioxide in the atmosphere was only 270mg/kg in the first half of 1978, increased to 330mg/kg in 1986, and reached 345mg/kg in 1986. At present, it has reached the highest level in 20 million years, and it is still growing at an annual rate of 0.4%. Scientists predict that if people do not take decisive and necessary measures, by 2030 ~ 2050, the carbon dioxide content in the atmosphere will increase by 1 times compared with that during the industrial revolution, and the global average temperature may rise by 1.5 ~ 4.5℃.

The first effect of global warming is to melt global glaciers and frozen soil, leading to sea level rise. According to scientists' prediction, if greenhouse gases continue to be released according to the current situation, it is predicted that by the end of 2 1 century, the sea level may rise by more than 1m, and 50% ~ 80% of coastal marshes and islands may be submerged. This will directly threaten the survival of residents living in these areas, who account for about 1/3 of the world population. Secondly, climate warming has a great influence on the living environment of living things. According to research and observation, climate warming below 65438 0℃ will cause significant changes in the distribution of animals and plants. Therefore, if the future global climate is as predicted by scientists, many species will become extinct because they can't adapt or lose their living environment. At the same time, because of the biological chain, it will also trigger a chain reaction. Scientists speculate that due to the extinction of a bird, 90 species of insects, 335 species of plants, 12 species of fish and 0.5 species of mammals will be extinct one after another. Biodiversity is a precious wealth endowed by nature and the material basis for human survival. The extinction of living things will pose a great threat to the survival of mankind. Third, the climate change caused by the greenhouse effect will have a direct and indirect impact on human health. The direct impact is caused by temperature difference, breathing and more natural disasters. Indirect effects are caused by the variation and spread of parasites and disease vectors.

3. Death in the air-acid rain

After burning fossil fuels, acid gases such as sulfur oxides and nitrogen oxides will enter the atmosphere. When the atmosphere contains more sulfur and nitrogen oxides, these substances will dissolve or adhere to raindrops, and then fall to the ground, forming acid rain with PH less than 5.6.

Acid rain is a serious pollutant and a manifestation of air pollution. Acid rain can stay in the air for a long time and is very harmful. Mainly in three aspects.

First, acid rain destroys forests. Acid rain reduced some trace elements in the soil. Resulting in poor soil. Acid rain destroys the stomata of plants, makes plants lose their balanced photosynthesis, reduces the disease resistance of trees, and finally leads to the death of large forests. At present, 5% of the forests in northern Italy have disappeared due to acid rain, and14 of nearly 300 million trees in Switzerland have died due to acid rain, and 654,380+10,000 hectares of evergreen forests in Central Europe have been destroyed due to acid rain pollution. The economic loss caused by acid rain in Europe is as high as $30 billion.

Second, acid rain causes lake acidification. Acidification of water quality inhibits the activities of microorganisms, and the decomposition of organic matter in water leads to the continuous accumulation of solid waste in water, which destroys the circulation of aquatic ecosystem and affects the animal community in lakes. Acid rain has turned many lively and beautiful lakes into "lakes of death". There are no fish swimming in the water and no waterfowl flying on the water. Today,15,000 of Sweden's 90,000 lakes are "dying out". More than 4,000 lakes in Ontario, Canada have all been acidified, and almost all fish have disappeared.

Third, acid rain has caused serious erosion to buildings. Acid rain falling on the surface of buildings reacts with calcium carbonate to produce calcium sulfate. This process can be deepened, leading to the delamination and peeling of building stone. This erosion has caused different degrees of damage to cultural relics and historic sites around the world. In the past 40 years, the loss of precious cultural relics caused by acid rain pollution in Athens has exceeded the sum of the past 400 years. The world-famous Egyptian pyramids and the Sphinx have been eroded by acid rain since the 20th century. The reliefs on the steps, railings and pillars of the Hall of Supreme Harmony in the Forbidden City in China and Beijing are now blurred. The Dutch government pays millions of Dutch guilders every year to repair corroded ancient buildings and monuments.

Fourth, the harm of acid rain to people. Acid rain can not only directly stimulate people's eyes, respiratory tract, skin and other parts, but also indirectly cause more serious harm to human body. Toxic metals in river water, such as mercury and lead, are introduced into the food chain due to acid rain, which is harmful to human health. Children have diarrhea due to drinking acidified water. Some scientists once thought that acid rain would lead to a large increase in patients with cancer, kidney disease and birth defects.

What is even more worrying is that acid rain is a pollutant that transcends national boundaries, and it can be transported to areas beyond 1000km or even further with the atmosphere. Therefore, the problem of acid rain is no longer a local environmental problem. Especially in industrialized countries, nitrogen oxides emitted by automobiles account for 50% of the total emissions, and they are "exporters" of acid rain to neighboring countries. At present, China's sulfur dioxide emissions are about180,000 tons. Southwest and South China have formed the third largest acid rain area in the world, and there is a tendency to spread to Central China, East China and North China.

4. photochemical smog

In a big city with a large number of cars, pungent light blue smoke often appears over the city in summer and early autumn. This unusual smog makes people's eyes red, cough, dizziness and nausea. Long-term injury will lead to diseases such as decreased lung function. This is the secondary pollutant-photochemical smog produced by automobile exhaust.

A large number of hydrocarbons and nitrogen oxides in automobile exhaust will produce a series of complex photochemical reactions under strong sunlight, generating ozone and other compounds. These compounds and water vapor will produce secondary pollutants, that is, photochemical smog. The formation of photochemical smog includes not only the chemical oxidation process, but also the diffusion and transportation of pollutants. The photochemical smog in the city can spread to the area of 100 ~ 700 km. Therefore, photochemical smog pollution is not only a problem in the city, but also around the city.

There are about 6,543.8 billion cars in the United States, and the exhaust gas emitted by cars is the biggest pollution source, and photochemical smog has appeared in major cities. In Mexico City, in order to protect children from smog, schools were closed for a whole month.

5. Lead pollution

Lead is a toxic element that has serious harm to human body. Long-term large-scale contact will cause harm to the central nervous system, kidney, reproductive system and immune system. It can cause convulsions, coma and even death. Children whose blood lead content is higher than 100μg/ 1 are lead poisoning patients, which will lead to mental retardation and low IQ. The main reason for the high lead content in children is the lead in the air. Because of the large proportion of lead, it is unevenly distributed in the atmosphere. The closer to the ground, the greater the lead content in the air. Children live under the breathing zone of adults, so children inhale more lead than adults and suffer more harm.

A series of studies show that about 86% of lead compounds drifting in the air come from automobile exhaust, so automobile exhaust is the main cause of lead pollution.

The above are just five aspects that the exhaust pollution of heat engines is harmful, but we have seen an indisputable fact: while bringing convenience to human beings, heat engines are also like a pollution source that destroys the living environment of human beings and erodes the supporting structure of life on earth. Alvin toffler once warned: "In this process, we are eager to get direct economic benefits from technology. We have turned the environment into a combustible product of nature and society. " Indeed, this century has witnessed the most serious destruction of natural resources and environment since the beginning of human society. In addition, the problem of air pollution around the world is getting worse. To this end, we should realize that the earth's atmosphere is not a bottomless pit where human beings can dispose of wastes indefinitely. If human beings want to survive on the earth, the only planet in the solar system that can provide a living environment, they must change the values of anthropocentrism and the way of making a living with economic growth as the sole goal. Create new technological forms and develop new energy and ecological technologies. While giving full play to the positive role of science and technology, we should overcome the negative impact of the development of science and technology. Fundamentally change the disharmonious relationship between man and science and technology, man and nature, combine economic growth with the long-term development of human civilization, and make our human civilization move in a more rational and reasonable direction.