Driven by the “dual carbon” goal, my country has strengthened the prevention and control of air pollution, optimized the structure of energy utilization, promoted clean heating in rural areas, and made energy consumption more clean and diversified. Since entering the “14th Five-Year Plan” period, the quality and efficiency of coal consumption have been optimized, and cleaner energy is gradually replacing coal.
Clean heating is advancing in depth. In winter, heating methods have a profound impact on air quality. At present, my country continues to build a long-term mechanism for scattered coal management, and promotes clean heating in depth.
So, what is clean energy heating?
- What is clean energy heating?
Clean heating is to use clean energy and use it to use high-efficiency machines to achieve the purpose of heating. At present, it mainly involves natural gas, electric energy, geothermal, biomass, solar energy, industrial waste heat, combined heat and power, clean coal combustion, nuclear energy and other energy varieties.
Among them, electric energy plays an important role in clean heating. On the one hand, it can be directly converted into thermal energy for heating; heating needs.
At present, my country is actively building a new type of power system with new energy as the main body. Renewable clean energy represented by hydropower, wind power, and photovoltaics has been vigorously developed, and the heating mode has changed from “coal-fired” to “wind-solar” heat. The major changes have effectively alleviated the difficulty of wind power grid-connected operation during the winter heating period when the power load is low, promoted the clean utilization of energy in cities and towns, and reduced environmental pollution caused by inefficient combustion of fossil energy.
- What are the common clean energy heating methods in daily life? What are the advantages?
2.1 Electric heating.
“Coal to electricity” is one of the typical measures to use clean energy for heating. Electric heating is a high-quality, comfortable and environmentally friendly heating method that converts clean electric energy into heat energy. After long-term practical application, it has been proved that it has many incomparable advantages over other heating methods, and has been recognized by more and more users around the world. and accept.
In electric heating, in addition to traditional hydropower, photovoltaic power generation heating and wind power heating technology and projects are getting more and more applications as the technology becomes more mature and popularized.
2.1.1 Photovoltaic power generation for heating
During the heating season, the photovoltaic power generation system converts light energy into electrical energy during the day, drives electric heating equipment for heating, and realizes self-use; at night, the heating system can make full use of peak and valley electricity prices, and is equipped with an intelligent control system to further reduce residents’ heating costs. In the non-heating season, after the photovoltaic is connected to the grid, in addition to the basic domestic electricity consumption, the excess electricity can also be sold to the grid to increase additional income. At the same time, photovoltaic heating has good adaptability and can be applied in any area. It does not require complicated pipelines and circulation systems, and is easy to control. There are no problems such as pipeline scaling and freezing in winter. The construction and operation and maintenance are simple, and the equipment has a long service life.
2.1.1 Wind power heating
Wind power heating means that the supply and demand of electricity is difficult to balance for a while, the wind that could be used for power generation cannot be used for a while, and it is a pity to discard the “excess wind”, and the electricity generated by it is used for heat production and heating engineering application measures. In the process of wind power heating, more wind is not redundant than the power grid, and more heat production is realized through the power grid. Therefore, there is an intermediate medium between wind power and heat supply—the power grid. Therefore, wind power heating is essentially electric heating, and the power grid is always the basic role to absorb wind power, guide heating load, and balance power supply and demand.
From the perspective of the whole process of power generation, transmission, and heat production and heating, wind power heating weakens the random intermittency of wind power generation, and the heating system can realize energy storage and use in the form of heat storage, thereby reducing the impact of wind power on Grid adaptability requirements. On the other hand, the thermal load of heating can be arranged according to the requirements of the power grid, and the output can be smoothed with the help of heat storage facilities, so as to make a capacity contribution to reduce the peak-valley difference of the power grid and peak-shaving and valley-filling.
3.1 is an air energy (source) heat pump.
As a kind of heat pump technology, it enjoys the reputation of “porter of natural energy”, and has multiple advantages such as low cost of use, easy operation, good heating effect, safety and cleanliness. Its working principle is: use a small amount of electric energy to drive the compressor to run, compress the air like a pump to increase the temperature of the air, and then use the medium to conduct heat energy to realize energy transfer.
4.1 Solar heating system.
That is, the solar collector is used to collect solar radiation and convert it into heat energy. The liquid is used as the heat transfer medium and water is used as the heat storage medium. The heat is sent to the room for heating through the cooling parts. Box, connecting pipeline, auxiliary heat source, heat dissipation components and control system.
5.1 Water source heat pump.
Shallow water sources on the earth’s surface (generally within 1000 meters), such as groundwater, surface rivers, lakes and oceans, absorb considerable radiant energy from the sun entering the earth, and the temperature of the water sources is generally very stable. The working principle of water source heat pump technology is: through the input of a small amount of high-grade energy (such as electric energy), the heat energy of the low-temperature level can be transferred to the high-temperature level. The water body is used as the heat source of the heat pump heating in winter and the cold source of the air conditioner in summer, that is, the heat in the building is “taken” in summer and released into the water body. Because the temperature of the water source is low, it can efficiently take away the heat to achieve summer cooling. The purpose of cooling the building’s interior: in winter, the water source heat pump unit “extracts” heat energy from the water source and sends it to the building for heating.
6.1 LNG natural gas heating.
Natural gas heating refers to the use of natural gas as fuel, the use of denitrified gas boilers, gas cogeneration, etc. for centralized heating, and gas heat pumps, wall-hung boilers, etc. for decentralized heating.
6.1.1 Gas boilers. For gas-fired boilers, the heat generated by the combustion of natural gas is directly used for heating, which is the simplest way of heating. In terms of scale, this heating method includes domestic gas furnaces for a family, small gas boilers for a building or a community, and regional gas boilers for heating a large area.
6.1.2 Gas cogeneration of heat and power. For pure thermal power generation systems, generally only a small part of the energy in the fuel is converted into electricity, and the power generation efficiency is only about 30%, while most of the energy in the fuel forms waste heat and is discharged to the atmosphere. The combined heat and power system uses this part of waste heat for heating while generating electricity, so that the energy utilization efficiency of combined heat and power can reach more than 80%. Due to the cascade utilization of energy, it is an advanced heating form than gas boilers. The indicators for evaluating the energy utilization efficiency of cogeneration systems mainly include heat-to-power ratio and power generation efficiency.
- What are the typical demonstration projects (landed projects) of clean energy heating?
In recent years, Energy China has promoted the design, construction and operation of a series of projects around the clean energy heating system, and created a series of “model projects”.
(1) Lingqiu Wind Power Heating Demonstration Project
The 400,000-kilowatt wind power heating demonstration project in Lingqiu County, Datong City, Shanxi Province is a key project that stimulates demand-side consumption of green power to cut peaks and fill valleys of the power grid. The project is located in Lingqiu County, Datong City, Shanxi Province, with a planned total investment of 3.5 billion yuan and a total installed wind power capacity of 400,000 kilowatts. The project plans to install 193 wind turbines, with an average annual power generation of nearly 1 billion kwh, which can meet the short-term needs of Lingqiu County. 225,000 square meters, and the long-term heating demand of 800,000 square meters will directly benefit 5,513 people relocated for poverty alleviation in Lingqiu County.
After the completion of the project, while continuously providing energy output, it will not produce smoke, sulfur dioxide, waste water, waste residue and other emissions, and will not consume non-renewable energy such as coal. It is a response to the country’s call for sustainable energy development and environmental protection. key demonstration projects.
(2) Hongdong 1×30 MW Biomass Cogeneration Project
Hongdong 1×30 MW Biomass Cogeneration Project is located in Hongdong County, Linfen City, Shanxi Province. After the project is put into operation, it will burn 308,200 tons of biomass annually, generate 245 million kWh of electricity, and supply 287,000 GJ of heat annually. . The commissioning of the project has effectively solved the problems of the prohibition of crop straw burning in the surrounding areas and the central heating around Hongdong County, reduced the emission of harmful substances such as carbon dioxide, nitrogen oxides, and sulfides, effectively promoted the healthy development of the local economy, and improved the happiness index of the masses , to help rural revitalization.
(3) Wuzhai 1×30 MW Biomass Cogeneration EPC Project
Wuzhai 1×30 MW Biomass Cogeneration EPC Project is located in Wuzhai County, Xinzhou City, Shanxi Province. After the project is put into operation, it will consume about 300,000 tons of local agricultural and forestry waste annually, provide clean electricity of 210 million kWh/year, and provide heat The volume is 672,000 gigajoules per year, which can save 92,000 tons of standard coal and reduce the emission of carbon dioxide, nitrogen oxides, and sulfides. The collected straw can generate more than 60 million yuan for local farmers, indirectly drive more than 1,000 local jobs, and add new resources to rural revitalization. kinetic energy.
- What is the application prospect of clean energy heating?
Heating is the largest energy consumption field, and heating accounts for about 50% of the global final energy consumption. With the increasing demand for natural gas imports in my country, the high premium in the international natural gas market has become increasingly prominent. With the background of the “dual carbon” goal, it is imperative to develop renewable and clean energy for heating.
According to the “2022 Global Renewable Energy Report” released by the international organization “21st Century Renewable Energy Network” in June this year, the global renewable energy investment in 2021 will be 365.9 billion US dollars, an increase of 27% compared with 2019; the newly installed capacity of wind power will be 102 million kilowatts , the cumulative installed capacity is 845 million kilowatts; the new installed capacity of photovoltaic power generation is 175 million kilowatts, and the cumulative installed capacity is 942 million kilowatts; in 2021, the global wind power and photovoltaic power generation will account for more than 10% of the total power generation for the first time (only 2% 10 years ago) . As a local supply of energy, wind power has played a certain role in alleviating the shortage of energy and power supply and rising prices in many areas in the past year.
In October 2021, the Ministry of Ecology and Environment issued the “Plan for Comprehensive Control of Air Pollution in Key Areas 2021-2022 Autumn and Winter”, which clearly pointed out that in accordance with the principle of “determining reforms based on gas, determining demand based on supply, establishing first and then destroying, and no establishment and no destruction” In principle, under the premise of ensuring warmth for the winter, resources will be concentrated to promote clean heating in units of districts, counties or towns. According to data released by the Ministry of Ecology and Environment, before the heating season in 2021, Beijing, Hebei, Shanxi, Shandong, Henan, and Shaanxi have completed the replacement of 20,000 households, 790,000 households, 810,000 households, 1.65 million households, and 50,000 households respectively. , 350,000 households. This year, the pace will be further accelerated.
Looking forward to the future, with the rapid advancement of zero-carbon governance policies in various countries around the world, my country will continue to accelerate the realization of large-scale construction of renewable energy, increase efforts to develop energy storage and heat storage industries, and promote zero-carbon transformation of energy storage, heat storage, and clean heating systems , The “hot land” of clean energy heating is bound to have great potential and great achievements.
