| Ganhe pumping station which being built is the biggest underground pumping station in Asia. Underground pumping station is similar to underground hydropower station, their main plant were deeply buried underground. Affected by "warm in winter and cool in summer" characteristic of the soil isothermal layer, the cooling and heating load of underground plant is smaller than the similar ground buildings. Because the sun can’t irradiate underground plants, the distributed moisture of building envelope can’t easily evaporate and the underground plants are closed, the underground plants are usually more humid. There is also a sensible difference between underground pumping station plant and underground hydropower plant. The heating load is smaller in the interior plant of underground pumping station.So it need a very small amount of wind to exclude the waste heat.If outdoor weather condition is appropriate, ventilation can be used to improve the thermal and humidity environment of plant by reasonable airflow organization. This can reduce the time to use air-conditioning system and achieve the purpose of saving energy and reducing consumption. Based on this purpose, the numerical simulation and model experiment methods would be used to study the ventilation and air conditioning system design of underground plant in Ganhe pumping station.Firstly, the underground plants’air distribution of Ganhe pumping station are verified and optimized by numerical simulation software in this thesis. Then under different air supply parameters and pumping unit operation conditions, the thermal and humidity environmental conditions of plant would be simulated.The simulation results show that the air distribution of Ganhe pumping station which motor layer supply air via ceiling tuyere, other layers supply air via clip wall pipe is rational and feasible. When ceiling air supply outlet velocity of the motor layer is8-10m/s, the work area velocity of each layer in main workshop meet relevant code requirements, and the air distribution is more reasonable. While the ceiling supply air velocity of motor layer increased to12m/s, the work area velocity of motor layer will against code requirements. In the case of all pump units are turned on and the motor layer uses dew-point supply air which temperature is20-24℃, the average temperature and humidity of each layer’s work area in main workshop can meet relevant code requirements. But the lower temperature of supply air will lead to condensation in some areas of pump layer where the relative humidity is larger. When supply air temperature exceeds24℃, the temperature of some work area in main plant will against the code requirements.The model experiment in this thesis used the optimized air supply plan of simulation. Eight tuyeres are decorated at the top of the motor layer’s unit segment. The experiment model was builded in the scale of1:10.When the velocity of motor layer’s supply air outlet is3.62m/s in model, and the corresponding velocity of motor layer’s supply air outlet is10.3m/s in prototype. The model experiment results also show that the temperature of each layers’work area in Ganhe pumping station can meet the code requirements under these conditions:the ceiling supply air velocity of motor layer is about lOm/s, the supply air temperature is about23℃, and all pump units are turned on. This also verified numerical simulation results. The temperature distribution of motor layer workspace is uniform, the maximum standard deviation value of each measuring points’restore temperature don’t exceed0.1in every model experiment. The model experiment results are reliable and reproducible, the maximum restored average temperature standard deviation of each layer workspaces are less than0.04.This thesis verified the air distribution of Ganhe underground pumping station was reasonably practicable, and the results of this research can provide a reference for ventilation and air conditioning system design of similar underground pumping station in the future. |
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