Research On Special Subjects Of “code For The Design Of Evaporative Cooling Ventilation And Air-conditioning System In Power Plant”

With the rapid development of China’s power industry, energy efficient and environmentally friendly has become a new concept in power plant construction. in the premise of ensuring safe and reliable operation of process equipment, the use of natural ventilation,evaporative cooling and other natural cold source technology is the key measures of energy-saving. Evaporative ventilation and air conditioning technology is an efficient and environmentally friendly way of ventilation and air conditioning systems in power plants and nuclear electrical equipment rooms, centralized control rooms and electronic equipment rooms. Make such renewable energy, energy-efficient air-conditioning refrigeration method healthy and orderly development, we must take the road of industrial application. During the process of promote the industrialization, standardize feasible evaporative cooling air conditioning system design is particularly important, especially national standards, specifications, atlas and industry standards.Electric Power Planning &Engineering Institute applied for a code, named ―Code for the design of evaporative cooling ventilation and air conditioning system in power plant‖. The National Energy Board put this code in the 2012 annual electricity industry standard project planning and design preparation schedule. The main topic of this paper according to the requirements and provisions of the outline, study and analyze four basic themes: evaporative cooling outdoor design calculation parameters, evaporative cooling design parameters and operating modes partition, direct evaporative cooling thermal calculation and equipment selection, indirect evaporative cooling thermal calculation and equipment selection.The main factors(1) The outdoor design calculation parameters of building location are important in the process of design and calculation, outdoor air wet bulb temperature difference is the main factor of the cooling efficiency of evaporative cooling. Based on the function features of buildings in power plant and the outdoor design parameters in the codes, determine reasonable outdoor design parameters for evaporative ventilation and air conditioning system in power plant. By comparing different weather databases, use the typical meteorological year hourly weather data for parameters statistic. Get the data not guaranteed 50 h wet bulb temperature and the average dry bulb temperature in the same time about 31 cities. Initial air state points include five groups, analysis the outlet air temperature and drop of temperature by the direct evaporative cooling. In the end, outdoor design parameters for evaporative ventilation system are summer ventilation outside design temperature and relative humidity, outdoor design parameters for evaporative air conditioning system are not guaranteed 50 h wet bulb temperature and the average dry bulb temperature. The initial idea of the evaporative cooling ventilation systems and air conditioning systems outdoor design calculations parameters are put forward.(2) Our country’s dominion is very vast, climatic conditions vary widely. The effect of evaporative cooling also varies by region. According to the outdoor design parameters and the indoor air temperature of the project location, designers can easy to determine its specific form in this partitions and evaporative cooling systems. Research and analysis on the point of scholars home and abroad, rules of the current national standards, the partition index of ventilation systems and air conditioning systems and evaporative cooling system forms of vary partitions are determined.(3) Padding direct evaporative cooling system and spraying direct evaporative cooling system are main forms of direct evaporative cooling. Based on mature thermal calculation methods of direct evaporative cooling, sorting out the easy to use design parameters. Some problems during process of design that need attention, the selection principles and requirements of air handling equipment are proposed.(4) Thermal calculation method of indirect evaporative cooling is also mature, sorting out the important thermal performance parameters. The most commonly used form of indirect evaporative coolers are mainly plate-fin type, tube type, etc. According to the project site conditions and design requirements make the right choice of equipment regulations.