Application of Central Liquid Cold and Heat Source Environmental System in Shanxi Province

Zhao Xiaoping 1 Xu Yongsheng 1 Fan Jian 2

(1. Shanxi Third Geological Engineering Survey Institute; 2. Shanxi Energy Industry Group Science and Technology Development Co., Ltd.

Abstract: Central liquid cold and heat source environmental system is a shallow geothermal energy (heat) development and utilization technology, which has been initially popularized and applied in Shanxi. Two pilot projects, one using reclaimed water from sewage purification plant and the other using shallow groundwater. Compared with the traditional coal-fired boiler heating mode, it has obvious advantages in energy saving, environmental protection, water saving and land saving.

The central liquid cold and heat source environmental system is a shallow geothermal energy (heat) development and utilization technology. The system takes water as the carrier, takes out the renewable low energy (10 ~ 15℃) in surface water (sewage, rivers and lakes) and shallow groundwater under the condition of closed circulation, and combines it with heat pump technology to form a complete set of devices, realizing the heating, cooling and domestic hot water supply of buildings.

Shanxi Energy Industry Group Co., Ltd. cooperated with Beijing Hengyuan Company to develop and popularize the project in Shanxi from September 2003. So far, two pilot projects, Shanxi Kewei Science and Technology Incubator Building and Taiyuan Senior Apartment, have been built by using surface water and groundwater respectively.

1 reclaimed water utilization project in Shanxi Kewei science and technology incubator building

Construction area of Shanxi Kewei Science and Technology Incubator Building 13000m2. Originally, two 880kW gas-fired direct-fired engines were used to provide heating and cooling for the building, and the operating cost in winter was about 8 yuan/m2 month. With the strong support of Taiyuan Science and Technology Bureau, the building was transformed into a central liquid cold and heat source environmental system, which provided cooling and heating for it. The water source was the reclaimed water from Yangjiabao Sewage Treatment Plant.

The project started in April 2004 and was completed at the end of June of the same year. In July, 1 was officially used to cool down. At present, it has run two cooling periods in summer and two heating periods in winter, and the operation effect is good. The room temperature is 20 ~ 22℃ in winter and 26℃ 2℃ in summer, which fully meets the design requirements. The operating cost in winter is 3.2 yuan/m2 month, saving about 60%.

2 Taiyuan City, the use of "single well pumping irrigation" technology for the elderly apartment project

Taiyuan Senior Apartment is located in the southwest corner of the intersection of Changzhi Road and Changfeng Street. It is an apartment building for the elderly built by Taiyuan Municipal Committee on Aging, with a building area of 13000m2. The main building was completed at the end of 2003.

In February 2004, Shanxi Energy Industry Company began to implement the supporting project of this technology for this building. Using "single well pumping and irrigation" technology, two water source wells are designed and constructed, with a design depth of 70m, a diameter of 800mm and a diameter of 500 mm. The water inflow of a single well is required to be greater than 60m3/h, and two main engines are equipped.

The construction of water source well is undertaken by Shanxi Third Geological Engineering Survey Institute. The well is located at 7m east of Ruichi Commercial Building on the north side of the apartment for the aged. 1 # water source well is located in the north, and 2 # water source well is located in the south. The distance between the two wells is 10m.

The geomorphic unit of water source well is located in Fenhe alluvial plain. The groundwater type is pore phreatic water of loose rocks, and the aquifer is mainly fine sand and medium coarse sand, with a thickness of about 40m. The buried depth of groundwater level is 1 1. 1m, and the recharge sources are mainly atmospheric precipitation and lateral runoff. The actual well depths are 9 1.0m and 90.8m respectively, the water level drop depth is 16.0 ~ 19.4m, and the water inflow of a single well is 82. 18m3/h and 8 1.42m3/h respectively. The water temperature is 15.0 ~ 17.5℃. The water quality is slightly poor, with the hydrochemical type of SO4 HCO3-mg Ca Na, pH value of 7. 15 ~ 7.2, salinity of 1954.2 ~ 2068.8 mg/L, and so42- ion content of 790.1~ 823.7 mg/L.

According to the comprehensive evaluation standard of boiler water quality, the total scale of boiler is 3316.95438+0 ~ 3,386.38+0 mg/L, which belongs to water with more scale. The hard scale coefficient is 0.34 ~ 0.36, which is medium sediment water; The foaming coefficient (f) is F)598.02~695.38, which belongs to foaming water; The corrosion coefficient is 1.9 1 ~ 2.52, which is corrosive water. As common boiler water, it must be treated before it can be used.

The supporting project was completed in July 2004, and it has the conditions for use. The project was operated in winter from June, 2004 1 65438+1October/KLOC-0 to March, 30, 2005, and it ran continuously for five months. The monitoring shows that the water level and quality of well water have not changed significantly except for a slight change in water temperature.

3 the significance of project promotion and use

Shanxi is a big energy province, with relatively rich mineral resources, especially coal resources, and an important energy and heavy chemical production base in China, but relatively poor water resources and land resources. In recent years, with the rapid development of social economy, people's material and cultural living standards have been greatly improved, but environmental pollution has become more and more serious. The application of central liquid cold and heat source environmental system technology has obvious advantages in energy saving, environmental protection, water saving and land saving compared with the heating mode that our province has long relied on coal-fired boilers for heating. Social, environmental and economic benefits can be achieved simultaneously.

3. 1 energy saving

According to scientific calculation and practice, if the temperature difference of water circulating at an hour 1 000 m3 in soil, sewage or rivers and lakes is about 6℃, the heat obtained per hour is 0.7MW, which is equivalent to the heating of an oil-fired boiler1ton of coal/hour, and can be used for the heating of ordinary buildings in Taiyuan 10000 m2 in winter. For every 0.7MW of heat obtained, about 0.2MW of electric energy needed to maintain the machine's own operation is subtracted, and the remaining 0.5MW comes from soil and sewage, which belongs to renewable low-order energy. Its efficiency ratio COP can reach 1∶4, which is far from that of electric boiler1∶ kloc-0/and coal-fired boiler 1∶0.6.

3.2 Environmental protection

According to the promotion of 654.38+100,000 m2, 80,000 tons of coal can be saved, 300,000 m3 of exhaust smoke can be reduced, 60,000 tons of particulate matter can be reduced, 2,250 tons of SO, 800 tons of NOX and 2654.38+0.2 million tons of CO can be reduced. The environmental protection effect is remarkable.

3.3 water saving

The system has a closed cycle and does not consume water itself. No cooling tower is needed, and in the process of refrigeration in summer, the evaporation of water vapor generated by using other central air conditioners is avoided, and the water saving effect is obvious.

3.4 Save land

The system can centralize or distribute the computer rooms, and can be located in the basement of the corner of the building, saving a lot of land occupied by heating equipment buildings and coal yards.

Most cities and populations in Shanxi are concentrated in Taiyuan, Datong, Xinzhou, Linfen, Yuncheng, Changzhi and Jincheng, seven great basin cities. The groundwater resources in the basin are relatively rich, the water level is generally shallow, and the water temperature is 2 ~ 3℃ higher than that in the mountainous area. The operation of the system does not require high water quality, and the local water source can basically meet the requirements. Urban land resources are in short supply, and the efficiency of saving land is more obvious. At the same time, the system will not produce high temperature and high pressure during operation, and will not burn any gas, solid and liquid fuel, which can greatly reduce the potential safety hazards such as fire and explosion.

4 problems in the project promotion

4. The popularization of1is not strong.

The traditional heating and cooling system has been used for a long time, and it is difficult to change and accept new technologies and processes. In addition, the awareness of environmental protection is not strong, and Shanxi is relatively rich in coal resources, which hinders the promotion of clean environmental protection projects.

4.2 The support and measures of government departments are backward.

(1) As the "single-well pumping and irrigation" device is a soil heat exchange device with water as the medium, it is not a water intake device, and the original well of well water is reinjected, so the single-well reinjection technology should not be included in the scope of water resource fee collection, just drilling wells for record and approval.

(2) As a standard heating and refrigeration system promulgated by the Ministry of Construction, all new buildings are given key support as recommended application technologies in the design approval process.

The central liquid cold and heat source environmental system adopts clean and renewable energy, with less one-time investment and economical operation cost, which solves the important problems of heating in winter, cooling in summer and ordinary domestic hot water in people's daily life. The application of this environmental system not only improves the living environment and quality of life, but also greatly relieves the environmental pollution caused by the use of unclean energy. Shanxi is a big energy province and also a province with serious pollution. Popularizing this technology can not only change the heating mode that only relies on coal-fired boilers for a long time, but also establish a number of green and energy-saving heating systems, which creates a new road for urban heating diversification and benefits Shanxi's clear water and blue sky project.