In the early nineteenth century, French scientist Sadi Karnot first proposed the "Carnot cycle" theory in a paper in 1824, which became the origin of heat pump technology. In 1852, the British scientist L. Kelvin proposed that the refrigeration device could be used for heating and the idea of a heat pump using the reverse Carnot cycle for heating. He was the first to propose a formal heat pump system, then called a "heat multiplier." After that, many scientists and engineers conducted a lot of research on heat pumps, and the research lasted for 80 years. In 1912, Zurich, Switzerland, successfully installed a heat pump equipment that used river water as a low-level heat source for heating. This was an early water source heat pump system and the first heat pump system in the world. The heat pump industry developed rapidly from the 1940s to the early 1950s. Household heat pumps and heat pumps for industrial buildings began to enter the market, and heat pumps entered the early stage of development. Since the 1970s, the heat pump industry has entered a golden age. Countries around the world have attached great importance to heat pump research. For example, the International Energy Agency and the European Community have formulated large-scale heat pump development plans. New heat pump technologies are emerging one after another, and the uses of heat pumps are also With continuous development, it is widely used in air conditioning and industrial fields, playing an important role in energy conservation and environmental protection. In the 21st century, with the emergence of the "energy crisis" and the sudden rise in fuel prices, the improved and developed heat pump has returned to the stage of history and has become the most valuable new energy technology due to its efficient recovery of heat energy from low-temperature environments, energy conservation and environmental protection. . The former International Thermal Energy Agency specifically established the International Heat Pump Center and established the Heat Pump Program to promote and coordinate the application and development of heat pump technology to countries around the world. The governments of the United States, Canada, Sweden, Germany, Japan, South Korea and other countries have issued special official guidelines to promote the social application of heat pump technology. Compared with the development of heat pumps in the world, the research work on heat pumps in China started about 20-30 years later. After the founding of New China, with the arrival of a new upsurge in industrial construction, heat pump technology began to be introduced into China. After entering the 21st century, factors such as the rapid urbanization of China's coastal areas, the growth of per capita GDP, the 2008 Beijing Olympics and the 2010 Shanghai World Expo have driven the development of China's air conditioning market, promoting the increasingly widespread application of heat pumps in China. The development of heat pumps is very rapid, and research on heat pump technology continues to innovate. Since the start of heat pumps in 2001, after five years of cultivation, China's heat pump industry has begun to move from the introduction period to the growth stage. The rapid development of the heat pump industry is due to the energy shortage, which makes the energy-saving advantages of heat pumps more and more obvious. On the other hand, it has a lot to do with the participation of various forces to promote technological innovation in the industry.