Research On The Key Problems Of River Water Source District Cooling And Heating System

With the operating of related project and emergence of problems, the research on river water source district heating and cooling heat pump is gradually increasing, and achieved certain results.But the research on contents and methords are not enough.Combined with the characteristics of river water source DHC,this paper do the research on river water intaking,re-pipelines and thermodynamic analysis.Firstly, collecting related factors of water intaking and establishing the river water source DHC index system based on the princeples and methords of establishing index system.After comprehensive comparison of various evaluation methords,this paper select the improved analytic hierarchy process(IAHP)to determine the weight of each index and use VIKOR multi attribute metrod to evaluating the pre-selecting water intaking solution.According to the basic princeples of loop network hydraulic Kirchoff first law and Kirchoff second law,exploring the performance of loop network from economic flow and reserve supply rate.Selecting the node of loop network after comprehensive evaluation EUAC and reserve supply rate with weighted sum approach method.Establishing the exergy and energy analysis model,and the calculation formule of unit cooling and heating exergyand energy.Study on the methord of initial investment and cost,using the EUAC integrate initial investment,energy cost,maintenance cost and residual value.Researching on the supply distance from exergy and energy perspective.Finally, taking Chongqing Jiangbei CBD as a case to test and verify the above research methods.Using VIKOR multi attribute metrod to evaluating water intaking ways,the results indicate that direct water intaking is best, Infiltration water intaking is better,and percolation water intaking is worst.Taking node of furthest from energy station and node near the load of 50%, calculating the economic flow,and EUAC,reserve supply rate of at economic flow of the two nodes. The comprehensive evaluation using weighted sum approach method shows that node of furthest from energy station is better than node near the load of 50%.The cooling exergy and energy prime,heating exergy and energy prime is calculated after the calculation of initial investment,operation cost,maintenance cost.At last this paper get the supply distance from the angle of exergy and energy.