Industrial waste heat and renewable energy research
DATE:2024-06-20 16:42:22
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Heating, especially in the northern part of China, is an important livelihood protection. According to Tsinghua University Building Energy Efficiency Research Center estimates that in 2021, the northern heating area of 16.2 billion m2, the operation of carbon emissions of 490 million tons, accounting for 22% of the total CO2 emissions related to the operation of the building (2.2 billion tons), therefore, reducing the carbon emissions of the heating system in the country's "dual-carbon" strategy has a pivotal role. To realize low-carbon or even zero-carbon operation of the heating system, the following requirements should be met:
(1) Prioritize energy saving. Energy saving can reduce carbon emissions from the root, in line with the CPC Central Committee and the State Council "on the complete and accurate implementation of the new development concept to do a good job of carbon peak carbon and the work of the opinions" (hereinafter referred to as "Opinions") in the "adhere to the energy-saving priority of energy development strategy" related to the spirit. By strengthening the heat preservation performance of buildings and pipeline networks, the heat demand of buildings and the heat loss of pipeline networks can be reduced; by strengthening the fine tuning of source-network-end, the uneven heat loss of buildings can be reduced, and the degree of over-heating of heat sources in the initial and final stages of heat supply can be reduced.
(2) Fully explore low-carbon or zero-carbon heat sources, thereby eliminating high-carbon emission heat sources. The Opinion lists low-carbon or zero-carbon heat sources such as cogeneration, industrial waste heat, nuclear waste heat, biomass energy and geothermal energy. Considering the resource endowment and the difficulty of collection, cogeneration, industrial waste heat, nuclear waste heat and other heat sources are expected to meet most of the heat demand as the basic heat source. As a result of large-scale new energy grid, making coal-fired power generation as the main basic power supply fully involved in the depth of power peak, especially in the "three northern regions" wind power, photovoltaic installed capacity is huge, abandoned wind, abandoned the light problem is more prominent, the requirements of the northern region heating unit must be from "to heat the electricity "The way to change to" electricity to set heat "" heat and power decoupling ". Therefore, in the future, small, over-service, or do not have the conditions for the transformation of the cogeneration unit will be gradually phased out, to participate in the depth of the power peaking cogeneration unit is also required to do as much as possible to recycle waste heat. Process industries (such as iron and steel smelting, non-ferrous metal smelting, cement manufacturing, etc.) emit a large amount of low-grade industrial waste heat along with the production of industrial products, which can be recycled and utilized in centralized heat supply systems. With the gradual elimination of backward production capacity in the future, the remaining production capacity will be more centralized, making the waste heat resources also more centralized and stable, increasing the reliability of waste heat heating.
(3) Reduce the return water temperature, thus improving the utilization rate of waste heat and the economy of long-distance transmission and distribution. Cogeneration, industrial waste heat and nuclear waste heat are far away from the center of the heating load, and long-distance heat transfer will be common in the future, so the long-distance heat transfer technology centered on reducing the return water temperature will be widely used.
(4) Appropriate utilization of heat storage technology. Short-cycle (days or shorter cycle) heat storage can be applied in the scenarios such as thermal electrolysis coupling; long-cycle (monthly or quarterly cycle or even longer cycle) heat storage can be applied in the scenarios such as non-heating season waste heat storage and heating season waste heat peaking.
In the future, with the increasing demand for heat supply, by lowering the return water temperature of the primary network in a phased and orderly manner and by constructing cross-seasonal heat storage facilities, it will be possible to realize zero-carbon heat supply by relying solely on industrial waste heat, spent steam waste heat and a small amount of extracted steam heat of power plants operated in conjunction with "cogeneration", as well as the heat from cross-seasonal heat storage.
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(1) Prioritize energy saving. Energy saving can reduce carbon emissions from the root, in line with the CPC Central Committee and the State Council "on the complete and accurate implementation of the new development concept to do a good job of carbon peak carbon and the work of the opinions" (hereinafter referred to as "Opinions") in the "adhere to the energy-saving priority of energy development strategy" related to the spirit. By strengthening the heat preservation performance of buildings and pipeline networks, the heat demand of buildings and the heat loss of pipeline networks can be reduced; by strengthening the fine tuning of source-network-end, the uneven heat loss of buildings can be reduced, and the degree of over-heating of heat sources in the initial and final stages of heat supply can be reduced.
(2) Fully explore low-carbon or zero-carbon heat sources, thereby eliminating high-carbon emission heat sources. The Opinion lists low-carbon or zero-carbon heat sources such as cogeneration, industrial waste heat, nuclear waste heat, biomass energy and geothermal energy. Considering the resource endowment and the difficulty of collection, cogeneration, industrial waste heat, nuclear waste heat and other heat sources are expected to meet most of the heat demand as the basic heat source. As a result of large-scale new energy grid, making coal-fired power generation as the main basic power supply fully involved in the depth of power peak, especially in the "three northern regions" wind power, photovoltaic installed capacity is huge, abandoned wind, abandoned the light problem is more prominent, the requirements of the northern region heating unit must be from "to heat the electricity "The way to change to" electricity to set heat "" heat and power decoupling ". Therefore, in the future, small, over-service, or do not have the conditions for the transformation of the cogeneration unit will be gradually phased out, to participate in the depth of the power peaking cogeneration unit is also required to do as much as possible to recycle waste heat. Process industries (such as iron and steel smelting, non-ferrous metal smelting, cement manufacturing, etc.) emit a large amount of low-grade industrial waste heat along with the production of industrial products, which can be recycled and utilized in centralized heat supply systems. With the gradual elimination of backward production capacity in the future, the remaining production capacity will be more centralized, making the waste heat resources also more centralized and stable, increasing the reliability of waste heat heating.
(3) Reduce the return water temperature, thus improving the utilization rate of waste heat and the economy of long-distance transmission and distribution. Cogeneration, industrial waste heat and nuclear waste heat are far away from the center of the heating load, and long-distance heat transfer will be common in the future, so the long-distance heat transfer technology centered on reducing the return water temperature will be widely used.
(4) Appropriate utilization of heat storage technology. Short-cycle (days or shorter cycle) heat storage can be applied in the scenarios such as thermal electrolysis coupling; long-cycle (monthly or quarterly cycle or even longer cycle) heat storage can be applied in the scenarios such as non-heating season waste heat storage and heating season waste heat peaking.
In the future, with the increasing demand for heat supply, by lowering the return water temperature of the primary network in a phased and orderly manner and by constructing cross-seasonal heat storage facilities, it will be possible to realize zero-carbon heat supply by relying solely on industrial waste heat, spent steam waste heat and a small amount of extracted steam heat of power plants operated in conjunction with "cogeneration", as well as the heat from cross-seasonal heat storage.