Study On Comprehensive Cascade Utilization And Reuse Of Deep Geothermal Water

Energy pinch and environmental pollution are major problems the world facing today,which give rise to the attention of the people all over the world.Therefore,the development of new green sustainable energy is the key of the national development,the development and utilization of deep geothermal water resources have great potential.When we use the new energy and new technology,saving energy and improving energy utilization are very important.This paper is combined with a practical geothermal water project in Taiyuan,Shanxi Province as an actual case,the plan of the project——Study on Comprehensive Cascade Utilization and Reuse of Deep Geothermal Water,analyzing the scheme advantages in economy and environmental protection.Besides,this paper uses the bath tail water contained mineral as raw water of gray-water project,using the method of analytic hierarchy process and grey correlation structure as a coupling model,relying on the MATLAB software to calculate and optimize the optimal process,then carries on the water balance design and economic analysis.This paper not only can enrich building energy-saving research,but also provide important references for the deep geothermal water exploitation and utilization projects in the future.In this paper,the main conclusions are as the following:?1?The power consumption in deep geothermal water heating system is 509.27 tce,the power consumption in living hot water supply system is 247.95tce,which are both minimum in the common heating system and hot water supply system,corresponding to reduce emissions of SO₂,CO₂,NO_x,and dust,the effect of energy conservation and emissions reduction is remarkable.?2?In the view of financial analysis,in the calculation period,annual profit of the project can reach 2.1385 million yuan;The value of after-tax financial internal rate of return is 15.51%,which is greater than the benchmark yield8%;Financial net present value of investment is 6.6066 million yuan,which is greater than zero;The static payback time and dynamic investment payback period are respectively 5.52 years and 7.53 years,which are smaller than benchmark payback period—10 years;The break-even point of the project is 38.05%,which is smaller than 70%.These data above show that the scheme possesses strong profitability,financial viability and anti-risk capability.?3?As to the optimization of water reuse treatment processes,according to the results of existing research results and expert consultation,this paper uses the analytic hierarchy process?AHP?to establish the evaluation index system of recycled water system,from the four aspects,such as economic,water quality,technology and management,builds ten indicators,then according to the AHP method to calculate the weights of each index.Finally,Using grey correlation method of quantitative analysis to determine the single factor correlation,and calculate the comprehensive correlation degree,the largest correlation is the optimal technology.This method avoids the disadvantages of relying too much on weight in AHP and parity with weight in grey correlation method,minimizing the influence of subjective factors in the process of optimization.?4?Through the design and calculation of water balance,it is concluded that the adjustment measures of water balance,and provide a reference for the design of water balance in the future.?5?The economic analysis of the gray-water project is used the benefits-cost analysis,and the benefit-cost ratio B/C=1.09>1,which indicates that the project can be accepted,with economic rationality.