Analysis of Heat Pump Application in Yinchuan

First, a brief description of the regional conditions (A) a brief description of meteorological environment

Yinchuan is a moderate temperate arid continental plateau climate zone, climate arid, scarce rain and snow, full sunshine, strong evaporation, wind and more sand, summer hot and short, cold and long in winter, hot and cold changes rapidly, annual temperature difference, daily temperature difference Large, 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 â„ƒ, July average temperature of about 24 â„ƒ Frozen starts in November each year and thaws in March the following year.

(B) a brief description of regional geological conditions

The site area is located in the middle of Yinchuan Plain, and the Himalayas movement makes Helan Mountain fold and Erdos Platform rise relatively, forming "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.

Yinchuan plain is a vast distribution of hydrogeological units, bearing multiple layers of confined water. In the geological structure zone of the basement strata, there is a hot mineral resource with a high salinity.

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 submersibles are 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 extraction volume will be much larger than the recharge volume, which will inevitably cause the groundwater level to drop. However, due to the large area of â€‹â€‹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
Prior to 2005, there were 19 water source heat pump projects in Yinchuan. According to the users, the well water in these 19 projects can not be fully recharged or completely irrigated. 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, the pumping wells pumping test, September 11, 2005 began pumping, measured before pumping water at rest (starting from the well nozzle) buried depth 73m, 15:13 pump to 23:13 stable until September At 7.13 on the 12th, the pump was stopped and the steady water depth was 29.40m. The water level dropped to 14.6m. At this time, the water inflow was 60.0 m3 / h and the unit inflow was 5.62 m3 / hm.

Pumping wells for the incomplete wells, thick aquifers

Degree of 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 dropped 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 Â· 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 Suggestions
1, Through the pumping and recharging tests of wells No. 1 and No. 3, it shows that No. 3 well is a pumping well, and when the pumping volume is 60m3 / h, the water inflow rate per unit is 5.2m3 / hm. When the well No. 1 (injection well) is in a natural state (not pressurized), the single-well irrigation volume can meet 60m3 / h Â· m (affected by the recharge) with a unit recharge of 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 of 0.1MPa, as long as the exhaust properly and regularly Yang Yang, is able to ensure long-term volume recharging 100%.