Study Of The Heating Operation Mode Of The HVAC System With Direct-Fired LiBr Chillers Assisted By Solar Energy

Coal is dominat in energy structure of china, but the proportion of petroleum and natural gas in china are much lower than the world level. Increasing the proportion of natural gas in energy structure will play an important role in the energy structure adjustment, solving the problems of energy security and the environment protecting, and the sustained development of economy and society. So the direct-fired lithium bromide absorption chiller-heater is widespred used in air conditioning system. But the resource of natural gas in china is not rich. Making things worse is that the price of the natural gas continues increasing. Based on these problems, the economical efficiency of the direct-fired LiBr absorption chiller-heater is oppugned. And moreover, building energy consumption has a high proportion of energy consumed for heating. Solar energy is a clean and recycled energy and solar heating is widespread used both at home and abroad. So how to combine the direct-fired LiBr absorption chiller-heater with the solar heating for heating in winter season, how about the operation status and economical status of this kind of system, and these questions are worth researching. This paper is trying to give a reform scheme for the direct-fired LiBr absorption chiller-heater air conditioning system which serves the NO. 3 and NO. 4 College building in DongHua University, and the old HVAC system will be combine with solar collector system. This paper will research the economical efficiency and feasibility of this kind of reform project.Based on investigation and analysis, the write gives six kinds of reform schemes for the old system. Because the heating load is a dominant factor which will affect the equipments choosing, the operation status and the economical efficiency of the system. So based on Typical Meteorological Year weather data, this paper gets hourly heating load of the NO. 3 and NO. 4 College building in heating season by Energyplus. With the different kinds of reform schemes, a mathematical modeling and a program are developed. Then some conclusions are got through simulating and analysis: the series system is better than parallel system in stability and energy saving efficiency. This kind of system can get a 40 percent solar friction, and this value demonstrates this kind of system has a good energy saving efficiency. But under the current economic conditions, this kind of refom system can not get a good economical efficiency. At last by sensitivity analysis, this paper gets some critical value, and with these values, the six kinds of reform systems will performance a good economical efficiency.Through simulating and analysis, these reform systems performance a good energy saving efficiency but a worse economical efficiency. But as the price of the natural gas continuing rising, as the technology of making solar collector continuing improving and its price continuing dropping, the reform systems will performance a better technicality and economical efficiency. So even without the government assisting, market competitiveness of the reform systems are worth looking forward to the future.