Numerical Study On Self-Balancing Heating Of Main Power Builfingin Cold Regions

At present,the researched on the main power plant of the power plant are mostly concentrated on the ventilation in summer.However,the heating in winter is still a subject valuable research for the power plants in cold area.The main power plant of the power plant is divided into two parts,includes the turbine-room and the boiler-room.The turbine-room and the boiler-room are both the large space buildings,with a lot of internal heat dissipating equipment which are mostly concentrated in the bottom area and the central area of the work layer.In the heating duration of winter,it has been verified by theory and measurement that there will be obvious temperature stratification inside the main building,because of the thermal pressure in the workshop is concentrated in the upper part of the workshop.The temperature of the main plant floor and the working floor of the power plant may be unable to meet the heating demand in the cold area.In this paper,a scheme with the reversal of the roof fans which are using for summer is used to assist or provide heating in winter.The computational fluid mechanics method is used to simulate the heating effect,and the improvement scheme and the layout of equipment are put forward with the simulation results.First,according to the structure of real main power plant,the corresponding geometric model of the turbine room and boiler room has been set up.Structure grid and grid independence has been applied for meshing.The feasibility of the scheme is verified by the numerical simulation of the reversing of the roof fan and accident condition in the turbine-room,and the optimization scheme of the jet orifice is instead of direct jet of the roof fan by the simulation results.Finally,the simulation of turbinerooms with different specifications in different areas is simulated.The results show that the self-balanced heating scheme should not be used in 600 MW turbine-room when the outdoor temperature is above-20? in winter;and the self-balanced heating scheme can be adopted to reduce or replace the arrangement of the radiator in the steam engine room above 600 MW in the cold area.The numerical simulation of the high pressure roof fan reversing condition in the boiler-room indicates that this scheme is not applicable to the super depth building such as the boiler-room.The airflow relay type heating scheme is proposed and the numerical simulation of first or second layer fan pressure is carried out.The results show that the first layer fan with pressure of 20 Pa and the second layer fan of 100 Pa could be the best scheme for the uniform temperature field and velocity field on the bottom platform.