Thermodynamic Simulation of CCP in Air-Cooled Heat Pump Unit with HFCs and CO₂Trans-Critical

The exergy analysis and finite time thermodynamic methods had been employed to analyze the compound condensation process (CCP). It was based on the air-cooling heat pump unit. The cooling capacity of the chiller unit is about 1 kW, and the work refrigerant is R22/R407C/R410A/CO2. The MATLAB/SIMULINK software was employed to build the simulation model. The thermodynamic simulation model is significant for the optimization of parameters of the unit, such as condensation and evaporation temperature and mass flow of the sanitary hot water and size of hot water storage tank. The COP of the CCP of R410A system is about 3% - 5% higher than the CCP of the R22 system, while CCP of the R407C system is a little lower than the CCP of R22 system. And the CCP of CO2 trans-critical system has advantage in the hot supply mode. The simulation method provided a theoretical reference for developing the production of CCP with substitute refrigerant R407C/R410A/CO2.

Research and Demonstration of Direct Air-Cooling System for 600-MW Fossil-Fired Power Plants

Given the distribution feature of resources such as coal and water, the requirements for the development of Chinese power industry, and the fact of monopoly by foreign companies, it is very necessary and significant to independently research and develop air-cooling technologies. Through experimental research, simulative calculation, process and equipment development, field tests and a demonstration project, the design and operation technologies for air-cooling system are grasped and relevant key equipment is developed. The results of the demonstration project show that the technical indicators for the air-cooling system have met or exceeded the design requirements. Part of the research results have been incorporated into the relevant national design standards. The technologies developed have been applied to more than 23 sets of thermal power units of or above 600 MW in China.

An Influencing Factor - Water-Filter Ratio on Heat Resistance of Condensate Polishing Filter Material in Water

In air-cooled condenser, high temperature condensing water m summer which approaching and exceed 60＊ C, which may result in filter materials degradation and release impurities. This paper discusses an influencing factor, water-filter ratio （soaking solution and filter quality ratio）, on leachable dissolution rate and filter material degradation rate m high temperature water. The UV absorption at 254nm （A254） and the exchange capacity ware measured after heat test as composite indicators. In addition, the Wends of A254 variation with heating time were measured in different water-filter ratio. The stability is probably due to the effect of water-filter ratio. This has been further borne out that, water-filter ratio increases, leachable concentration decreases exponentially and tends to a fLxed value.

Permitted emissions of major air pollutants from coal-fired power plants in China based on best available control technology

Based on the activity level and technical information of coal-fired power-generating units(CFPGU)obtained in China from 2011 to 2015,we,1)analyzed the time and spatial distribution of SO_(2) and NOx emission performance of CFPGUs in China;2)studied the impact of installed capacity,sulfur content of coal combustion,and unit operation starting time on CFPGUs’pollutant emission performance;and 3)proposed the SO_(2) and NOx emission performance standards for coal-fired power plants based on the best available control technology.Our results show that:1)the larger the capacity of a CFPGU,the higher the control level and the faster the improvement;2)the CFPGUs in the developed eastern regions had significantly lower SO_(2) and NOx emission performance values than those in other provinces due to better economic and technological development and higher environmental management levels;3)the SO_(2) and NOx emission performance of the Chinese thermal power industry was significantly affected by the single-unit capacity,coal sulfur content,and unit operation starting time;and 4)based on the achievability analysis of best available pollution control technology,we believe that the CFPGUs’SO_(2) emission performance reference values should be 0.34 g/kWh for active units in general areas,0.8 g/kWh for active units in high-sulfur coal areas,and 0.13 g/kWh for newly built units and active units in key areas.In addition,the NOx emission performance reference values should be 0.35 g/kWh for active units in general areas and 0.175 g/kWh for new units and active units in key areas.