Research On District Heating System Using Petrochemical Industrial Low-grade Waste Heat

With the growth of the heating load year by year,air pollution and heating shortage has become increasingly prominent.Thus,looking for clean and cheap heating source shall be important.As one of China's top five highest energy consumption enterprises,petrochemical enterprises suffers from low-temperature excess heat emissions.Energy saving and emission reduction is difficult because of technology constraints for these corporates.Recycling these heat waste for providing heating can benefit both in improving efficiency and easing the contradiction between heating supply and demand in this country.This paper focus on the research of the reuse of low temperature excess heat for cooling water i n petrochemical enterprises.Firstly,the preliminary application of thermoelectric synergy technology is analyzed,the selection principle of storage technology and the economic influencing factors are analyzed.At the same time,the heating process of two kinds of low temperature waste heat heating system and the technical process of thermoelectric coordination are also analyzed.Secondly,the heating energy consumption of two kinds of low-temperature waste heat heating system is studied theoretically.The concept of equivalent heating coefficient is put forward,and the law of equivalent heating coefficient variation of taking heat,transmission and distribution,heat station,peaking and heat pump system and the total heating system are analyzed.And the influence of the peak-to-peak ratio and the heating distance on the heating performance of the heating system were studied.The size of the heating performance of the two systems was compared with the heating performance of the two heating systems.It can be seen from the research results that the effect of peaking ratio on the heating performance of the system is small,and the heating coefficient of the heat pump system in the two kinds of low temperature waste heat heating system is more than 3.4,which is better than that of coal heating when the heating distance is less than 50 km.What is more,this paper also conducted research of how these two systems influenced in economic field.The research process takes the unit cost as the objective function,analyzing the aspects of peak-to-peak ratio,heating distance,heating area and heat storage rate.From the theoretical research results we can see that in the economic heating distance,low-temperature heating system economy is better than the medium-temperature heating system.In addition,the design of low temperature waste heat heating for a petrochemical enterprise is carried out,and the temperature and peak load ratio of the system are analyzed.The heating costs of different heat storage system are calculated.Compared with the no thermal storage system,the greater the heat storage rate of the regenerative system,the better its economy.