What is the current situation of building energy conservation promotion in Wuhan?

In GB50 189-2005 "Design Standard for Energy Efficiency of Public Buildings", the Committee of Plastic Doors and Windows listed the thermal performance of the envelope as a mandatory provision according to the building climate zoning of the city where the building is located, which must be strictly implemented. The following are the performance requirements for building external windows (including transparent curtain walls) in the mandatory provisions.

I. heat transfer coefficient k

The area ratio of climate zoning representing the shape coefficient of window wall is ≤0.3, and the heat transfer coefficient KW/(m2? k)0.3 & lt； Shape coefficient ≤0.4 Heat transfer coefficient KW/(m2? k)

Helen, Bogetu, Yichun, Huma, Hailar, Manzhouli, Qiqihar, Fujin, Harbin, Mudanjiang, Karamay, Jiamusi and Anda area ratio of window to wall ≤0.2 ≤3.0 ≤2.7.

0.2< area ratio of window to wall ≤0.3 ≤2.8 ≤2.5

0.3< area ratio of window to wall ≤0.4 ≤2.5 ≤2.2

0.4< area ratio of window to wall ≤0.5 ≤2.0 ≤ 1.7

0.5< area ratio of window to wall ≤0.7 ≤ 1.7 ≤ 1.5.

Cold regions B Changchun, Urumqi, Yanji, Tongliao, Tonghua, Siping, Hohhot, Fushun, Dachaidan, Shenyang, Datong, Benxi, Fuxin, Hami, Anshan, Zhangjiakou, Jiuquan, Yining, Turpan, Xining, Yinchuan and Dandong area ratio of window to wall ≤0.2 ≤3.2 ≤2.8.

0.2< area ratio of window to wall ≤0.3 ≤2.9 ≤2.5

0.3< area ratio of window to wall ≤0.4 ≤2.6 ≤2.2

0.4< area ratio of window to wall ≤0.5 ≤2. 1 ≤ 1.8.

0.5< area ratio of window to wall ≤0.7 ≤ 1.8 ≤ 1.6.

Lanzhou, Taiyuan, Tangshan, Aba, Kashgar, Beijing, Tianjin, Dalian, Yangquan, Pingliang, Shijiazhuang, Dezhou, Jincheng, Tianshui, Xi 'an, Lhasa, Kangding, Jinan, Qingdao, Anyang, Zhengzhou, Luoyang, Baoji and Xuzhou area ratio of window to wall ≤0.2 ≤3.5 ≤3.0.

0.2 < area ratio of window to wall ≤0.3 ≤3.0 ≤2.5.

0.3< area ratio of window to wall ≤0.4 ≤2.7 ≤2.3

0.4 < area ratio of window to wall ≤0.5 ≤2.3 ≤2.0.

0.5< area ratio of window to wall ≤0.7 ≤2.0 ≤ 1.8

Nanjing, Bengbu, Yancheng, Nantong, Hefei, Anqing, Jiujiang, Wuhan, Huangshi, Yueyang, Hanzhong, Ankang, Shanghai, Hangzhou, Ningbo, Yichang, Changsha, Nanchang, Zhuzhou, Yongzhou, Ganzhou, Shaoguan, Guilin, Chongqing, Daxian, Wanzhou, Fuling, Nanchong, Yibin and Chengdu.

0.2< area ratio of window to wall ≤0.3 ≤3.5.

0.3< area ratio of window to wall ≤0.4 ≤3.0

0.4< area ratio of window to wall ≤0.5 ≤2.8

0.5< area ratio of window to wall ≤0.7 ≤2.5

Fuzhou, Putian, Longyan, Meizhou, Xingning, Yingde, Hechi, Liuzhou, Hezhou, Quanzhou, Xiamen, Guangzhou, Shenzhen, Zhanjiang, Shantou, Haikou, Nanning, Beihai and Wuzhou area ratio of window to wall ≤0.2 ≤6.5.

0.2< area ratio of window to wall ≤0.3 ≤4.7

0.3< area ratio of window to wall ≤0.4 ≤3.5.

0.4< area ratio of window to wall ≤0.5 ≤3.0

0.5< area ratio of window to wall ≤0.7 ≤3.0.

Second, the shading coefficient SC

Climate zoning indicates that the shape number of window-wall system area ratio of one-way exterior windows (including transparent curtain wall) in the city is ≤0.3, and the shading coefficient SC (east, south, west/north) is 0.3.

Lanzhou, Taiyuan, Tangshan, Aba, Kashgar, Beijing, Tianjin, Dalian, Yangquan, Pingliang, Shijiazhuang, Dezhou, Jincheng, Tianshui, Xi, Lhasa, Kangding, Jinan, Qingdao, Anyang, Zhengzhou, Luoyang, Baoji, Xuzhou, area ratio of window to wall ≤ 0.2-

0.2 < area ratio of window to wall ≤ 0.3—

0.3< area ratio of window to wall ≤ 0.4 ≤ 0.70/-≤ 0.70/-

0.4< area ratio of window to wall ≤ 0.5 ≤ 0.60/-≤ 0.60/-

0.5< area ratio of window to wall ≤ 0.7 ≤ 0.50/-≤ 0.50/-

Nanjing, Bengbu, Yancheng, Nantong, Hefei, Anqing, Jiujiang, Wuhan, Huangshi, Yueyang, Hanzhong, Ankang, Shanghai, Hangzhou, Ningbo, Yichang, Changsha, Nanchang, Zhuzhou, Yongzhou, Ganzhou, Shaoguan, Guilin, Chongqing, Daxian, Wanzhou, Fuling, Nanchong, Yibin and Chengdu.

0.2< area ratio of window to wall ≤0.3 ≤0.55/—

0.3< area ratio of window to wall ≤0.4 ≤0.50/0.60.

0.4 < area ratio of window to wall ≤0.5 ≤0.45/0.55.

0.5< area ratio of window to wall ≤0.7 ≤0.40/0.50.

Fuzhou, Putian, Longyan, Meizhou, Xingning, Yingde, Hechi, Liuzhou, Hezhou, Quanzhou, Xiamen, Guangzhou, Shenzhen, Zhanjiang, Shantou, Haikou, Nanning, Beihai and Wuzhou area ratio of window to wall ≤ 0.2-

0.2< area ratio of window to wall ≤0.3 ≤0.50/0.60.

0.3< area ratio of window to wall ≤0.4 ≤0.45/0.55.

0.4 < area ratio of window to wall ≤0.5 ≤0.40/0.50.

0.5< area ratio of window to wall ≤0.7 ≤0.35/0.45.

Note: When there is external shading, shading coefficient = glass shading coefficient × external shading coefficient; Without external shading, shading coefficient = glass shading coefficient.

Some thoughts on building energy saving

1 overview

Energy statistics in developed countries are based on four sectors: industry, transportation, residents and commerce. So it is easy to get building energy consumption data, that is, the sum of residential and commercial energy consumption. Its building energy consumption generally accounts for about one-third of the total energy consumption in China. For example, in the United States, building energy consumption accounted for 35% of the total energy consumption in the United States in 2000. However, China's energy statistics model is different from that of developed countries, which is divided into industries, agriculture, construction, transportation, posts and telecommunications, wholesale and retail, daily consumption and other departments. If the energy consumption of the last three departments is regarded as building energy consumption, the proportion of building energy consumption in China's total energy consumption has been around 20% for many years. 20.4% in 2000. China Ministry of Construction announced that the proportion of building energy consumption in 2000 was 27.6%. The figures of the Ministry of Construction include the energy consumption of the building materials industry, which is actually a generalized building energy consumption. In addition, there are several versions of the scale diagram.

Secondly, in many buildings, the energy consumption of each part is indistinguishable. For example, it is generally believed that the energy consumption of air conditioning and heating in public buildings accounts for the largest proportion of the total energy consumption. In fact, this conclusion is not supported by the actual data of China. Because the energy consumption measurement of domestic buildings is very rough, generally only water chillers have separate meters, and the energy consumption of air conditioning terminal devices and conveying systems cannot be distinguished from other power equipment and lighting. In industrial buildings, the energy consumption of air conditioners and other building equipment is traditionally included in the production energy consumption. The author once quoted the survey results of energy consumption ratio of all parts of the office building obtained by the Japanese Building Environment and Energy Conservation Department. However, after being repeatedly quoted by many articles, this data was misinformed and became "the energy consumption ratio of office buildings in Shanghai", and even entered some formal research reports and documents.

In the case of unclear basic data and energy consumption, it is difficult to properly determine the goal of building energy saving (for example, the energy saving rate based on a certain time node), and it is also difficult to properly allocate the energy saving rate of each part (for example, how much the envelope, lighting and air conditioning should bear in the total energy saving rate).

Figure 1 Annual Energy Consumption Distribution of a High-rise Office Building

Figure 1 is the annual total energy consumption curve of a high-rise office building in Shanghai. It can be found that the energy consumption curve of figure 1 has two lowest points, which appear in April and 1 1 respectively. These two months are the most pleasant time in Shanghai. Generally speaking, buildings need neither heating nor cooling. Take the average energy consumption of these two months and draw a horizontal line (dotted line in Figure 2- 17). It can be considered that the area surrounded by the curve above the horizontal line is the energy consumed by heating and air conditioning in the building; The rectangular area below the horizontal line is the energy consumed by lighting and other power equipment (such as elevators).

Therefore, the energy consumption of lighting, sockets, elevators and other equipment can be regarded as stable energy consumption. Although the days in winter are short and the nights in summer are long, there are some differences in the time people use lighting, but from the perspective of the annual energy consumption of modern commercial buildings, this difference is not obvious. The energy consumption of heating and air conditioning is changeable and unstable, not only with the climate zone, but also with the building type, shape, structure and use, even today and tomorrow will be different. This brings complexity and diversity to the building energy-saving work, but it is also the part with the greatest energy-saving potential in the building.

In the United States, building energy consumption statistics are carried out by the government, while in Japan, they are completed by professional societies and academic groups. However, in China, there is no large-scale investigation on building energy consumption as in developed countries such as the United States and Japan. Therefore, it is impossible for most energy-saving policy makers and researchers engaged in building energy conservation to understand the building energy consumption of a country or a city like developed countries. Due to the lack of necessary measurement means, the energy consumption of various parts of the building managed by many building property managers is countless. Therefore, building energy conservation must begin with measurement.

2 structural energy saving and air conditioning system energy saving

Taking energy-saving measures of envelope structure is the basis of building energy-saving. Because China's building energy efficiency starts from heating residential buildings, it is undoubtedly the right decision to consider strengthening the thermal insulation of the envelope structure first. From the management point of view, it is easy to make a limited index for the envelope and evaluate it. But the key to building energy saving is the efficiency of air conditioning heating system, and the ultimate energy saving should also be reflected from air conditioning heating system. After the wall reform, the northern region has developed into a hot spot of reform. If there is no regulating valve and heat metering, the better the insulation of the envelope, the more heat may be wasted.

Fig. 2 Total cooling load of air conditioning in different windows.

Annual total load (MWh) under different wall heat transfer coefficients.

In intermittent air-conditioned buildings, the room temperature rises after the air conditioner is turned off. When the outdoor air temperature is lower than the room temperature, the starting load of the air conditioner can be reduced the next day through the reverse heat transfer of the envelope structure. Therefore, the better the thermal insulation of the envelope, the greater the heat storage and the greater the air conditioning load (see Figure 2).

For public buildings, the load formed by the envelope accounts for a small proportion of the total load, so the energy-saving potential of the envelope is limited.

As can be seen from Figure 3, the heat transfer coefficient of the wall is reduced by 40%, and the maximum energy saving rate is 8. 1% (Harbin) and the minimum is 2.8% (Guangzhou). It can be seen that the important link of energy saving in public buildings is to reduce the internal load and internal heat. For example, reducing the lighting load under the premise of ensuring the illumination can not only reduce the lighting power consumption, but also reduce the air conditioning load, which can be described as killing two birds with one stone.

3 energy saving and ieq

After SARS, people's awareness of health and self-protection increased, which put forward higher requirements for ieq.

More than 80% of AHU in public buildings in big cities in China has only one-stage coarse filtration, and some even have only one filter screen. According to ASHRAE standard 62-200 1, a dust filter or purifier with a minimum efficiency report value of not less than 6 should be added at the front end of cooling coils or its treatment equipment with wet surface. European standards also require AHU filters to meet F7 standards. In other words, it needs two stages: coarse filtration and medium filtration. The resistance of the whole wind system is at least 200Pa higher than it is now. Suppose a 3600m3/h air conditioning box, running all year round, will increase the power consumption of 2500kWh.

In addition, the fresh air volume of air conditioning in many buildings did not meet the requirements of the specification. Moreover, after SARS, some owners of new buildings put forward requirements for excessive fresh air volume. Fresh air load accounts for 20 ~ 30% of air conditioning load, and increasing fresh air volume means increasing energy consumption.

In public buildings, ieq directly affects users' comfort, health and work efficiency. For building managers, this is "open source". Building energy saving is to reduce operating costs, which is "throttling". Open source and throttling should complement each other.

Therefore, building energy-saving work should take indoor environment as the bottom line. On the one hand, building energy conservation must not be at the expense of ieq; On the other hand, unreasonable environmental consumption behavior (such as too low ambient temperature in summer, too high ambient temperature in winter, too large fresh air volume, opening windows when using air conditioning, etc.). ), that is, unreasonable energy use, should be changed.

To solve the contradiction between energy saving and ieq, many new technologies or the integration of original technologies can be adopted. For example, independent fresh air system (DOAS), radiant ceiling+displacement air supply system, dehumidification air conditioning system, etc.

4 save energy and electricity

During the high temperature in the summer of 2003, the severe power shortage in China 19 provinces and cities and the blackout accidents in some parts of the United States and Canada sounded the alarm for us. The application of electric air conditioning is related to the safety of power grid, and attention should be paid to energy saving at the same time.

Some energy-saving technologies may reduce the annual building energy consumption, but they do not save electricity. This is the case, for example, with the envelope insulation discussed in Section 2 of this paper. In the traditional energy structure of air conditioning, electricity is used for refrigeration in summer and primary energy is used for heating in winter. For heating-oriented areas, strengthening the insulation of the envelope can reduce the annual energy consumption (such as Harbin); However, in the cold supply area, the total energy saving effect of strengthening the insulation of the envelope is limited, which will increase the energy (electricity) consumption of air conditioning.

Some technologies may consume a little more energy, but they can use clean energy, which is beneficial to environmental protection. For example, gas-fired direct-fired engines have always been regarded by many people as "saving electricity but not energy" in China. However, direct-fired engines do not use CFC and HCFC refrigerants, and burning natural gas has little impact on the environment and low greenhouse gas emissions, so it is regarded as a green technology by all countries in the world. Using low-peak gas in summer to stabilize peak power load can achieve electrical "win-win".

Some technologies may not save energy at the micro level, but they are energy-saving at the macro level. For example, in ice storage air conditioning, when ice is made by electricity at night, the COP value of refrigeration unit decreases. On the user side, if there is no reasonable peak-valley price difference, ice storage air conditioning is neither energy-saving nor expensive. However, on the power generation side, the use of a large number of ice storage air conditioners fills the low power load at night, which makes the generator set always in a high incidence and full power state, and the coal consumption of power generation decreases. Compared with 40% partial load, 300,000 kW generator set can save energy 15.7%. At the same time, the utilization rate of power generation equipment is improved. The average annual load rate of electric power in developed countries is 66.6%, and that of power generation equipment in China is 1999, reaching the lowest value of 50%. After that, it increased year by year, reaching 54.8% in 2002. Compared with developed countries, there is still a big gap.

Therefore, building energy conservation needs to be balanced in energy, environment, economy, technology and other aspects, which should become a basic quality of building energy conservation workers.