The “dual carbon” goal is a huge opportunity and challenge for my country’s energy development. To achieve carbon neutrality, it is necessary to promote energy transformation and promote the transformation of the energy system from carbon-based energy based on fossil energy to zero-carbon energy based on renewable energy. The low-grade energy in the environmental medium and waste heat provides high-grade heat energy that can be used. For each energy consumed by the heat pump, it can obtain three times or more heat, which greatly improves the utilization efficiency of energy. Energy efficient and clean energy products. In addition, the use of heat pump technology for heat recovery and the use of different technologies to make full use of waste heat sources can effectively save a lot of energy resources for the country. Heat pumps can not only take into account summer cooling and winter heating and hot water production, but also play a role in many fields of the national economy such as industrial and agricultural production, national defense construction, and have great application potential.

Air source heat pump

The application of heat pump unit The heat pump unit is an air conditioner that uses water/soil/air/industrial waste heat/sewage as the heat source for heat pump heating. The heat source can be surface water such as rivers and lakes, as well as groundwater and soil. As an energy-saving and environmentally friendly solution, heat pump will definitely play its due positive role and make more contributions to the country’s environmental protection and people’s livelihood security. In terms of industrial production, a large number of light industrial production, including textiles, food, leather, etc., use heat pump units to replace coal-fired boilers in industrial production, which can effectively achieve low-carbon production.

Drying links in the industrial sector, where heat pumps can also generate the required heat. Such as drying of agricultural and sideline products, rapid drying of ink for color printing, etc. Using a heat pump as a heat source improves the process control accuracy, environmental cleanliness and product quality, and its operating cost is close to that of a coal-fired boiler, and its comprehensive economic benefits are better than coal-fired. There are also some meat processing plants that can recover the waste heat from the cold storage, and then raise the temperature through a heat pump to prepare hot water and steam for production; food processing plants can extract the exhaust heat from the product cooling process, use the heat pump to heat up, and prepare production steam; There are also printing and dyeing industries, textile industries, tanning industries, paper industries, pharmaceutical industries, etc. that may use heat pumps to extract heat from the exhausted hot humid air or hot water to prepare and produce higher-temperature heat. In the application of building energy, the heat demand for heating in northern urban buildings in winter is about 5 billion GJ per year. At present, it is mainly provided by coal-fired gas cogeneration and coal-fired boilers (accounting for about 80%), and various Gas boilers and electric heat pumps (accounting for about 5%). With the development of urbanization and the rapid increase in heating load, the application of electric heat pumps still has a lot of room for growth.

At the same time, heat pumps can also provide heating sources for areas that cannot be reached by central heating, especially in the south of the Yangtze River, where heating is only needed for two or three months a year, which is not suitable for building a huge central heating network. Heat pumps are the solution. One of the best ways to heat up in winter. In particular, the continuous improvement of building thermal insulation performance requires less and less heat, and central heating may not be economical. Electric heat pump distributed heating can give play to its advantages. In scattered low-density buildings in rural areas, it is most suitable to use ground source heat pumps for heating in a “part-time, part-space” approach.

Domestic hot water preparation

Domestic hot water is generally around 50 degrees Celsius, which is the scope of application of electric heat pumps. When the COP value (how much heat is increased by one degree of electric energy through the heat pump) is equal to 3, the electricity price is 0.90 yuan/kWh, and its energy cost is lower than that of a gas water heater with a gas cost of 3 yuan/standard cubic meter.

Water (ground) source heat pump has the characteristics of high energy efficiency and stable operation. For units with different heat sources such as groundwater, surface water and soil, there are different advantages and disadvantages.

1) Surface water source heat pumps Surface water source heat pumps are generally only suitable for occasions close to water sources. Surface water source heat pumps can be divided into sea water sources, rivers and lakes water sources, etc. according to different water sources. As far as seawater source heat pumps are concerned, seawater is relatively corrosive, the heat exchanger needs to use special materials, and the seawater source is generally far away from the use occasion, so the problem of long-distance transportation needs to be solved. For river and lake water source heat pumps, according to the “Water Law of the People’s Republic of China” and the “Urban Water Management Regulations” in various places, it is required to call for water approval and charge for water use. Some places charge twice for the extraction and discharge of water sources, resulting in high water charges. , so that the energy saving cost of the water source heat pump operation is insufficient to increase the water cost. The promotion of water source heat pumps requires the government to adjust the policy on the use of surface water source heat pumps from the perspective of sustainable development, considering all aspects of energy, environmental protection and resources, and to re-determine how to manage and charge water sources; at the same time, the application of water source heat pumps in rivers and lakes also involves planning , municipal, waterway, maritime and other departments, involving many approval links, it is necessary to establish a corresponding coordination and linkage mechanism in order to promote its further development.

2) Groundwater source heat pump For groundwater type water source heat pump, a large amount of groundwater needs to be exploited in a concentrated manner. Generally, the groundwater is buried in a large depth and the cost of water extraction is high. At the same time, the groundwater needs to be prevented from being polluted and the ground subsidence caused by the decline of the groundwater level during the utilization process. Recharge technology also has the following shortcomings and problems: recharge is closely related to geological conditions, and it is difficult and expensive to construct suitable recharge wells; recharge pressure is high; groundwater pollution and recharge fluid leakage to the surface; production well chemical change in nature, etc. At present, the use of groundwater is strictly controlled by the state. For example, Beijing has successively issued policies such as the Measures for the Implementation of the Water Law of the People’s Republic of China in Beijing and the Regulations on the Prevention and Control of Water Pollution in Beijing, which strictly restrict the exploitation and use of groundwater.

3) Sewage source heat pump In recent years, the development of sewage source heat pump has also made great progress in China. The water temperature of the sewage source is suitable for the heat pump, but the composition of the sewage is complex, and the problem of dirty and blocked heat exchangers needs to be solved, and the system is easy to breed bacteria, which requires long-term monitoring. The sewage source heat pump room also needs to meet the sanitary and epidemic prevention requirements. 4) Soil source heat pump For the buried pipe type soil source heat pump, heating is mainly used in the northern region, and there is a long-term thermal imbalance problem of the soil source heat pump. The heat output in winter is greater than the heat output, which will lead to a long-term continuous drop in soil temperature. , resulting in system performance degradation or even inoperability. At present, the measures taken for thermal imbalance are mainly to supplement heat by reducing heat extraction or auxiliary equipment, such as boiler supplementary heat, solar supplementary heat and air source heat pump supplementary heat. In addition, the buried pipe method needs to take up a lot of space. Before formulating the system plan, it is necessary to conduct a geological survey of the project to ensure that there is enough space for the laying of the buried pipe. At the same time, the high initial investment cost of the soil source heat pump should also be considered. The problem.

As an emerging product category in the refrigeration and air-conditioning industry, heat pumps have been used more and more in places such as replacing traditional coal-fired heating through the strong support and incentives of the state and local governments in recent years. According to the current experience of heat pump application, according to the various needs of users for heating, hot water supply and refrigeration and air conditioning, combined with building characteristics, climate environment changes, and the energy saving and environmental protection advantages of heat pumps, comprehensive transformation and management of systems and terminals are carried out to provide suitable The comprehensive technical solutions have great energy saving value and potential. In the future, the road to clean heating requires overall planning and management, selecting renewable energy as the heat source of the heat pump according to local conditions, attaching importance to and promoting the comprehensive utilization of various energy sources, and integrating air, sewage, seawater, rivers and lakes, and waste heat. It can be combined with waste heat and solar energy to overcome the shortcomings of a single heat source, so as to fully improve the comprehensive integration efficiency of heating and cooling, and achieve the best energy-saving benefits.