Active energy-saving of buildings and comprehensive emission reduction of buildings - Observation on the development of ultra low energy buildings in multiple p

Source: China Construction News Network

Summer insulation and winter insulation, compared to ordinary buildings, ultra-low energy buildings have a longer service life and lower energy consumption requirements.

Why should we develop ultra-low energy buildings? Data shows that nearly 50% of the country's carbon emissions come from the full life cycle energy consumption of buildings, and ultra-low energy buildings are one of the directions for the future development of energy conservation and emission reduction in the construction industry, and an important way to achieve the goal of "carbon peaking and carbon neutrality".

Innovating technological means to achieve healthy development

In the Sino German Eco tech Town Industrial Park in Harbin, Heilongjiang Province, the red wall building is particularly eye-catching. It is worth noting that the thickness of the walls and exterior windows here is about twice that of ordinary residential buildings. "These buildings are like 'Vacuum flask'. They are insulated in summer and winter, and their energy consumption is still low." The relevant person in charge of the park said that the overall park is an ultra-low energy consumption building. The external insulation material of the building is 250 mm graphite polystyrene board, and the local application of "STP vacuum insulation board" high-performance insulation material has a good thermal insulation coefficient. At the same time, high-performance door and window systems are used to solve the problems of houses not being insulated in summer and not being insulated in winter, as well as high energy consumption. In addition to the good thermal insulation performance of the building itself, Graphene Heating film is used for auxiliary heating in cold winter, and the heat conversion rate of Heating film is as high as 99%.

Harbin Housing and Urban Rural Development Bureau recently issued the Implementation Plan of Harbin for Promoting the Development of Ultra low Energy Consumption Building Industry, which proposed that by 2025, the city's ultra-low energy consumption building industry will form a good development pattern with significantly improved scientific and technological innovation ability, increasingly improved industrial chain, and constantly expanding industrial scale, create a number of domestic first-class ultra-low energy consumption building demonstration projects, and become the core area of industry city integration development in the province. The total industrial chain output value of the ultra-low energy construction, manufacturing, operation and maintenance, and service industries in the city has reached over 58 billion yuan, and the construction area of new and renovated ultra-low energy building projects has reached 5.8 million square meters. Among them, in 2023, the industrial chain output value will be 10 billion yuan, with a new construction area of 1 million square meters; In 2024, the industrial chain output value will be 15 billion yuan, with a new construction area of 1.5 million square meters; In 2025, the industrial chain output value will be 32 billion yuan, with a new construction area of 2 million square meters and a total of 1.2 million square meters of building renovation projects.

Provide financial subsidies to solve industry problems

Entering the Yuelai Art Museum in Chongqing, although it is adjacent to the city road, there is almost no noise inside the museum. It is understood that this water droplet shaped building, with an area of less than 10000 square meters, integrates over 120 energy-saving "black technologies".

The venue has adopted facilities such as LOW-E three-layer double insulated glass, which has strengthened the air tightness of the building. The relevant person in charge introduced that one of the main reasons why traditional houses are not energy-saving is due to poor sealing and fast indoor and outdoor heat exchange. Passive doors and windows such as three-layer double insulated glass have characteristics such as insulation, insulation, and sound insulation, and indoor temperature, humidity, and other indicators are relatively constant. The dome of the building is equipped with over a hundred pieces of thermally dimmable glass, which can automatically switch between transparent glass and frosted glass based on the intensity of sunlight, reducing sunlight radiation; A solar photovoltaic power generation system is installed between the garage ceiling and the grass; Adding light conduits inside the building can introduce natural light into the interior, achieving the lighting effect of a 40 watt fluorescent lamp.

In addition, the underground Ground source heat pump of the building can use water and Geothermal energy for cold and heat exchange. In winter, the heat in the ground energy is "taken out" for indoor heating; In summer, the indoor heat is released into the earth, achieving "warm winter and cool summer".

Previously, the Chongqing Municipal Commission of Housing and Urban Rural Development issued a notice on doing a good job in the city's green building and energy conservation work in 2023, requiring each district and county to cultivate no less than one demonstration project of ultra-low energy consumption buildings this year, but the construction cost has become a major challenge. To this end, Chongqing has issued special financial subsidies and green finance preferential policies. For zero energy consumption buildings, near zero energy consumption buildings, and ultra-low energy consumption building demonstration projects that apply for subsidies, subsidies of 200 yuan/square meter, 120 yuan/square meter, and 80 yuan/square meter will be given according to the demonstration area, and green finance services will be provided.

Take effective measures to make good use of green energy

The "Implementation Plan for Carbon Peak in Urban and Rural Construction" issued last year proposed that the renewable energy substitution rate for urban buildings should reach 8% by 2025. Building solar photovoltaic integration, solar hot water systems, air source electric heat pump technology, and various waste heat utilization measures are all optional measures.

Near the Xixi National Wetland Park in Hangzhou, Zhejiang Province, there is a low-carbon building - Zheneng Group Comprehensive Energy Production Scheduling Research and Development Center. It is reported that the total construction area of the project is 136900 square meters, utilizing the space of the building to produce green energy and building a smart energy control platform to improve utilization efficiency. After being put into operation, it can save about 1106 tons of standard coal annually, reduce carbon dioxide emissions by about 1891 tons, sulfur dioxide by about 22 tons, and dust by about 11 tons. In this building, about 2400 square meters of "Cadmium telluride film" solar panels with different light transmittance are laid on the roof, Ground source heat pump is laid in the underground space of the green belt of the building, and micro wind power generation system and air source heat pump system are arranged on the roof of the podium building. The clean and green energy produced by ourselves exceeds 30% of the total energy consumption.

The project makes full use of natural gas and solar energy, forms complementary coupling with renewable energy such as wind energy, Geothermal energy, air energy and municipal power supply, and then configures corresponding energy storage systems to maximize the substitution of green energy for traditional thermal power.

In Junsheng Plaza, Xuzhou City, Jiangsu Province, the roof is a photovoltaic integration project, which is equipped with a solar photovoltaic power generation system and a solar hot water system, totaling 264 square meters. In addition, a solar hot water system has been installed, with a total of 160 sets of solar collectors and a collection area of 460.8 square meters. As large energy users, the application of solar domestic hot water and solar photovoltaic power generation in these large public buildings greatly reduces building energy consumption.

Improving the utilization rate of renewable energy during the use of buildings has become an important measure to reduce carbon emissions. Xuzhou City proposed that this year it will focus on optimizing the energy structure of green buildings, promote the integrated application of renewable energy in new buildings, encourage existing buildings to install renewable energy application systems, and increase the proportion of renewable energy applications in new industrial plants and new public buildings. Promote the comprehensive utilization of solar energy, shallow Geothermal energy, biomass energy, heat pump and other renewable energy in buildings according to local conditions, actively explore the application of "light storage, direct and flexible" technology in buildings, and promote the demonstration and application of distributed solar photovoltaic buildings. Promote the comprehensive electrification of new public buildings, eliminate direct combustion of coal and other materials at building terminals, encourage the use of renewable energy to achieve building heating (cooling), cooking, and hot water supply, and improve the electrification level of building terminals.