The Research On Indoor Temperature Control Technology Of Indoor DC Field In Large Space

In the projects of HVDC transmission,as the transmission voltage level is continuously improved,the indoor DC field gradually becomes the mainstream form.During the summer,the electrical equipment inside the indoor DC field emits a large amount of heat,causing the indoor air temperature to be too high,which is not conducive to the safe operation of the equipment.Therefore,it is necessary to adopt appropriate measures to eliminate the residual heat and to control the indoor temperature environment.In this paper,through the theoretical analysis of indoor environment control requirements and load characteristics of indoor DC field,the design analysis on two temperature control schemes of ventilation and air-conditioning has been conducted separately in the principle of energy-saving.And an indoor DC field is selected as an example to carry out the concrete scheme design.Because the indoor DC field belongs to the large space building,the indoor air distribution has a great influence on the control effect of room temperature and the energy consumption of the scheme.So,using CFD simulation software to simulate the indoor air flow field in different schemes,it can forecast the indoor temperature field and velocity vector,so as to provide data basis for scheme selection and optimization.For the air-conditioning scheme of indoor DC field,the impact to the air distribution which is caused by are air supply temperature,air supply amount,the scale of the opening.By choosing the uneven temperature coefficient,energy utilization coefficient and temperature safety guarantee coefficient as the evaluation indexes,the three factors’ comprehensive effect to the air distribution is analyzed by the way of orthogonal test method.Finally the three factors have the same influence on the above evaluation indexes,ranging from big to small: air supply temperature,air supply amount,the scale of the opening.,the higher air supply temperature,the smaller uneven temperature coefficient,and the higher energy utilization coefficient,and the lower temperature safety guarantee coefficient;the larger the air supply amount,the smaller uneven temperature coefficient,and the higher energy utilization coefficient,and the higher temperature safety guarantee coefficient.According to the results,the best air-conditioning air supply scheme is determined.Based on the optimal air conditioning air supply scheme,the design of two kinds of temperature control schemes is carried out in indoor DC field during the summer operation period.From indoor air distribution,in the most adverse operating condition solutions,when the ventilation scheme is used,the uneven temperature coefficient decreases by 30.09%,and the energy utilization coefficient increase by 30.44%,the temperature safety guarantee coefficient decreased by 40.02%,and the average temperature in the indoor control area increase by 1.3℃ and the highest temperature increased by 2.2℃;Compared with the operating energy consumption,during the whole summer operation,the total operating power consumption of the whole ventilation system decreased by 3.8 thousands kWh,and the energy saving rate is only 3%.