Optimum Study Of Circulating Cooling Water System With Multistage Intermediate Cooling Water Mains

Circulating cooling water system has great potential of large water-saving,energy-saving potential in industrial applications.At present,the research on circulating cooling water is mainly focused on the water saving or energy saving and cooling tower model of circulating water system.This article combines the previous research results,and it is proposed to set up multistage intermediate cooling water mains to optimize the circulating cooling water system.And on this basis,it established the cooling water system model which considered a water cooler,cooling tower and other devices.Then the optimal design of the circulating cooling water system was determined.The main contents of this paper are as follows:First of all,through the comparison and analysis of the water cooler network optimization method of the current circulating cooling water system,this paper put forward to the method of optimizing the circulating cooling water of the multistage intermediate cooling water mains,based on the analysis of the water pinch point.This method can obviously improve the cooling tower water temperature and reduce the amount of circulating cooling water.In this paper,the design steps of the water cooler network with multistage intermediate cooling water mains were summarized,and the example shows that the method can reduce the circulating water by 60% with setting the intermediate cooling water mains,and prove the effectiveness of the method.In addition,this paper established the mathematical model based on the sum of the operating cost and the equipment cost.The equipment cost mainly considered the equipment investment of the cooling tower and the cost of the water cooler equipment represented by the heat transfer area.The operating cost is mainly considered the cost of running the circulating pump during the operation of the system,the cost of fresh water and the cost of dosing.The nonlinear programming method was used to solve the problem.And the basis of the study of the tower water temperature on the objective function of the law,to determine the best out of the tower water temperature,made thesystem the total cost of running a year the least.Finally,this paper used an annual output of 150,000 tons TDI part of the plant as an engineering example to optimize the system structure and operating parameters.(1)After the optimization,the water cooler network adopted the structure of the secondary intermediate cooling water mains,the circulating water is reduced by 81.3%.(2)After optimization,the performance of the cooling tower had been improved.The cooling rate of the cooling water inlet and outlet increased by 387.3%,the cooling limit was reduced by 60%,and the efficiency coefficient of the cooling tower was increased by61%.(3)After optimization,the optimum outlet temperature of the system was 27?,which is lower than that of the previous optimized 3?,and the cooling efficiency was increased by 30%.At this time,although the system equipment costs increased by30.2%,the operating costs decreased by 81.3%,the total cost reduced by 73.3%.