Comparison of Technical, Economic, and Environmental Performance of Sewage Source Heat Pump Coupling with Micro-cogeneration System

学生名：徐　桐宇

研究テーマ：Comparison of Technical, Economic, and Environmental Performance of Sewage Source Heat Pump Coupling with Micro-cogeneration System

入学年月:2021.04

修了年月:2023.03

取得学位：修士（工学）

論文概要:The carbon reduction of building space heating and cooling technology has become an important way to achieve the goal of carbon neutrality in the world, among which heat pump and cogeneration system is one of the technical means of building carbon reduction. However, most research focus on the efficiency improvement of single system, ignoring the possibility of system joint operation. In the context of "two-carbon" strategy, natural gas power generation with low carbon, high efficiency, flexible and other characteristics will play an important role in the country's energy transition. Combined cycle is a typical comprehensive utilization of natural gas. It reduces energy consumption and improves economic and environmental benefits by using energy in steps. It has been widely used in recent years. For sewage source heat pump coupled micro cogeneration combined cycle units, scientific and reasonable load distribution of each unit is the internal requirements of enterprise development under the background of power marketization. The optimal load distribution of regional units is to determine the load borne by each unit according to the regional total load instruction and combined with the thermal characteristics of each unit, so as to minimize the total fuel consumption of regional units and maximize the economic benefits. The main research content of this paper is as follows: Firstly, three micro-cogeneration systems composed of gas turbines are determined based on the load characteristics of the hotel building. Secondly, different combined operation strategies of three groups of gas turbines are determined according to different load frequencies. Then TRNSYS software is used to build the original system and coupling system respectively. Finally, the economic performance, environmental performance and energy efficiency of the coupling system are determined. In this research, the operation feasibility of a sewage source heat pump coupled with micro-cogeneration system is studied based on a large hotel building. An economic operation strategy based on the load characteristics of domestic hot water is proposed and validated by simulation using TRNSYS software. It was found that the proposed system can reduce peak power usage by 66% throughout the year and reduce operating costs. The calculation shows that compared with a single sewage source heat pump system, the proposed system can reduce the operating cost by 402,300 CNY per year, and the payback period of the proposed system is 6 years under the current TOU electricity price, under different energy policy conditions, 71% of the proposed system's payback period is less than 20 years. Meanwhile, the emissions of SO2, NOX and CO2 are reduced by 73.5%, 73% and 68.4% respectively. The system has significant economic and environmental benefits, and this study can provide reference for energy supply system in cold regions.