Analysis of Heat Pump Application in Yinchuan - Groundwater

I. Brief Description of Regional Conditions 1. Brief Description of Meteorological Environment Yinchuan is a temperate continental continental plateau climate zone with arid climate, scarce rain and snow, abundant sunshine, strong evaporation, large winds, hot sum and short in summer and cold in winter The long, rapid changes in hot and cold, annual temperature difference, temperature difference, is a typical continental climate. July-September is the rainy season, accounting for 70-80% of annual rainfall, the average annual average rainfall of 218.6mm, the average annual evaporation of 1574 mm, the annual maximum temperature of about 36.5 ℃, July average temperature of about 24 ℃ Frozen starts in November each year and thaws in March the following year. (B) a brief description of regional geological conditions The site is located in the central Yinchuan plain, Himalayas Helan Mountain fold so that Erdos platform and relative rise, forming a "Yinchuan Graben." The graben is about 170km long and 50km wide and extends northeastward. The graben has been relatively active during the Neotectonic movement and has undergone many tectonic movements that lead to the development of faults with frequent seismogenic activities in history. The Yinchuan Graben has formed a vast lake basin from the Tertiary. The lake basin is a Cretaceous-Tertiary clastic sediment. Yinchuan plain formed on this basis. In Yinchuan plain, covering the Tertiary strata above the Quaternary sand and clay layer, the thickness of about 1600 meters. (III) Brief Introduction to Regional Hydrogeological Conditions Yinchuan Plain is a widely distributed hydrogeological unit body with multiple layers of confined water. In the geological structure zone of the basement strata, the hot mineral resources with higher salinity are present. Quaternary soil depth of 200 meters or more in the fine sand, fine sand layer rich in pressure bearing water, with the exception of the surface layer (60m above) for a slightly submersible submersible water, water quality slightly worse, The pressure in the other sand layers is plentiful and the quality of water is good. Groundwater recharge is mainly for the lateral supply of mountainous areas around the basin. Surface submersion is also recharged by atmospheric precipitation. However, due to the small amount of precipitation in the atmosphere, if the man-made mining capacity is large, the exploitation amount will be much larger than the recharge amount, which will inevitably cause the groundwater level to drop, However, due to the large area of ​​hydrogeological unit and thick aquifer, the groundwater level in the area will decline more slowly. Second, the site hydrogeological conditions (A) diving - micro-pressure water: the site was deposited in the depth of 9.0-11.0m fine sand, fine sand layer, the water depth of 3.0-6.0m, sand thickness 42.0-45.0m, in which there is a layer of 4.0-4.5m thick silty clay, the surface layer of fill and silty clay, the thickness of the venue within the larger changes, the water quality is unknown. (B) pressure water, buried deep in the depth of 75.0-76.0m clay layer below the fine sand layer, the sand is dense in a dense, uniform particle size, the depth of the buried water depth 12.5-13.5m, water permeability medium , Permeability coefficient 1-2m / d, aquifer thickness 25.0-28.0m. The thickness of the aquifer is less changed in the field area, water quality is better, low salinity of water. Third, water source heat pump technology well water usage Before 2005, Yinchuan region total water source heat pump project 19, according to the user, the 19 projects of well water can not be fully recharged or can not fully recharge. Therefore, the basic conclusion of the past in Yinchuan is that the water source heat pump technology is not applicable in Yinchuan. Otherwise it will cause waste of water resources. According to our actual experience in Ningxia Power Group office building project, the geological conditions of Yinchuan is more difficult to recharge, but not can not be recharged. Yinchuan is not suitable for common reclamation technology, but Yinchuan underground rich water resources will surely bring safe, high-efficiency and energy-saving for Yinchuan area if proper drilling technology is used and the system water consumption is reduced Air conditioning heating and cooling energy. We Ningxia Power Group office building project, the original plan to fight 5 wells, using 2 pumping 3 irrigation way. After using the SEAT technology, the last four wells were drilled, two for two and one for the recharge wells to achieve 100% well water recharge. Pumping wells per well pumping 80 tons / hour, recharge well recharge 80 tons / hour. The actual use of instructions as long as the technical processing is reasonable, Yinchuan underground well water recharge is guaranteed. Fourth, pumping test and reperfusion test results 1, pumping wells pumping test, September 11, 2005 started pumping, before pumping measured at rest water level (starting from the well nozzle) buried depth 73m, 15:13 pump to It stopped at 23:13 on September 12 and stopped at 7:13 on September 12. The steady water level was 29.40m and the water level dropped to 14.6m. At this moment, the water inflow was 60.0 m3 / h and the unit inflow was 5.62 m3 / hm. Pumping wells for the non-complete well, aquifer thickness 20.0m depth, filter length 18.0m, depth 53.0m-71.0 m. 2, pumping a combination of irrigation test, a total of two tests, the first test at 12 o'clock on September 12, 2005 to 12:00 on September 13, after 24 hours. The second test, from 10:00 on September 14 to 10:00 on September 17, lasted 72 hours. From No. 3 well to pump 59 m3 / h, No. 1 well continuous recharge. In the first pumping experiment, the fluctuating water level of the pumping well was 25.10 m and the water level was decreased to 14.6 m. At this moment, the moving water level of the reinjection well increased by 8.2 m and the water inflow from the pumping well was 5.73 m3 / h · m , While the recharge volume of recharge wells was 5.20 m3 / hm. In the second pumping-back-irrigation experiment, the pumping water level was 24.37m and the water level drop value was 10.11m. At this moment, the moving water level of the recharging well was 3.64m, increased by 10.07m and the pumping water volume per unit was 5.86m3 / hm, while the recharge volume of the recharge well is 5.85m3 / hm. The recharge efficiency of the recharge well is only 0.4% higher than that of the pumping well. V. CONCLUSIONS AND RECOMMENDATIONS 1. Through the experiment of pumping and recharging of wells No. 1 and No. 3, the No. 3 well, as a pumping well, has a pumping capacity of 5.2 m3 / h at a pumping rate of 60 m3 / h. When the well No. 1 (injection well) is in a natural state (no pressure), the single-well irrigation volume can meet 60m3 / h · m (affected by the recharge), and the unit recharge volume is 5.86-7.20m3 / h, can meet the requirements of the project. 2. The unit recharging capacity of the second recharging test is about 19% less than the unit recharging capacity of the first recharging test, which shows the importance of reinstating the recharging wells in the long-term use of air conditioning. 3, long-term operation, the system of recharging according to the limited pressure recharging method for device, recharge pressure limit at 0.1MPa, as long as the exhaust properly and regularly Yang Yang, is able to ensure long-term amount of 100% recharge.