针对地铁车站侧向机械排烟系统中的烟气吸穿现象,本文在排烟口下沿加装排烟挡板以提高机械排烟效率.应用火灾模拟软件FDS数值模拟计算站台内烟气温度分布,排烟口的流场分布,压力损失增加量和排烟口CO体积浓度等,分析了排烟挡板的宽度和设置方式对机械排烟中烟气层吸穿的影响.研究表明,排烟挡板的设置有利于避免烟气吸穿现象的发生,改善机械排烟效果.排烟挡板宽度为0.6 m,角度为30° 时机械排烟效果最好.
Thermal comfort has become an important index to evaluate car performance. Accurate prediction of passenger thermal sensation is the key to evaluate thermal comfort of car. In this paper, the steady-state thermal environment of the car in summer was tested and the environment parameters of driver were measured. The Predicted Mean Vote（PMV） was calculated to predicted the whole thermal sensation of the driver. The sensitivity of parameters which influence PMV was analyzed quantitatively by Python. Finally, the PMV was corrected by thermal adaptability theory and compared with subjective thermal sensation vote. The results show that clothing insulation and activity level can significantly affect PMV, which need to be accurately measured in the test. The sensitivity of environmental parameters to PMV from high to low is air temperature, mean radiation temperature, air velocity and relative humidity,which provides a reference for the prediction of the driver’s thermal sensation. The PMV, which was corrected by expectaion fator, can predict the whole thermal sensation accurately.
In order to study the effect of heat pipe cooling turbine blades, a transient dynamic mesh model was used to simulate the rotation process of a turbine blade. Through the comparison of the temperature and the cooling efficiency coefficient at each position of the blade under different gas inlet temperatures, the analysis results show that the inlet temperature rises from 1500 K to 2000 K, and the temperature of the blade surface can always be kept below 1550 K,and the distribution of the blade surface temperature will be more uniform. But the overall cooling efficiency will decrease, and the temperature difference between the pressure side and the suction side will gradually increase in a small amount.
Aiming at the influence of different burial depths and different flow rates on the thermal interference of the soil around the buried pipe, a line heat source model of the vertical buried pipe heat exchanger is established. The effect of the buried pipe on the surrounding soil temperature was calculated and analyzed at four drilling depths of 40, 60, 80,and 100 m; and the impact of the buried pipe on the ground pipe at four flow rates of 0.75, 1.25, 1.75, and 2.25 m/s at each depth was studied. The effect of heat exchange and surrounding soil temperature. The results show that the buried depth of the buried pipe is negatively correlated with the soil heat-dry radius of the buried pipe, and the thermal action radius is within 6m at each buried depth. After the drilling depth reaches 80m, the effect of increasing the buried depth of the buried pipe on reducing the soil thermal interference radius is weakened. When the buried depth of the buried pipe is100, the thermal interference radius is the smallest, which is 2.3m. the inflow velocity of the buried pipe is positively correlated with the thermal interference radius of the buried pipe to the soil, and negatively correlated with the temperature difference between the inlet and outlet water. Under the burial depth of 80m, the change of flow velocity has the most obvious influence on the thermal interference radius of the buried pipe. Under the same burial depth and different flow rates, the flow rate is positively correlated with the heat transfer per unit depth and the total heat transfer.At different burial depths and the same flow rate, the flow rate is positively correlated with the total heat exchange, but negatively correlated with the heat exchange per unit depth.
TRNSYS software is used to build a system model, with the system life cycle economic cost as the objective function, and the Hooke-Jeeves algorithm is called to ensure that the indoor temperature reaches heating during the heating season. Under the premise of requirements, the four key parameters of hot water storage tank volume, solar collector area, biomass boiler rated thermal power, and solar collector inclination angle are optimized. The results show that the solar energy guarantee rate of the optimized combined system is 27.5%, the ratio of the water tank volume to the solar collector area is 101 L/m~2, best collector inclination angle is φ+18°（φ is the local latitude）, the biomass The rated thermal power of the boiler is 1.27 times the instantaneous maximum thermal load of the building during the heating period, and the economic cost of the optimized system life cycle is reduced by 17.8%. The influence of the rated heating power of the biomass boiler, the area of the solar collector, the volume of the hot water storage tank, and the inclination of the solar collector on the economic cost of the life cycle of the system is successively reduced. The research results can provide reference for the design and application of the combined system.
