Analysis On Optimization Design And Thermodynamic Performance Of Solar Aided Power Generation System

Solar aided power generation (SAPG) systems are an advanced and comprehensive system for the sustainable utilization of energy. Sustainable development is importance to the human population, as rising energy demands create an energy shortage problem. SAPG is expected to contribute to solving the energy requirements of the human population, whilst being more environmentally sustainable than conventional coal-fired power stations. SAPG is based on the coal-fired thermal power unit design framework with the addition of an intelligently integrated system for the utilization of solar energy. Compared to conventional coal-fired power generation, SAPG allows for reduced use of fossil fuel. Therefore, by incorporating solar energy and thermal power units into a unified system this technology may fulfill the role of providing efficient, low cost, large-scale energy conservation and emissions reduction Subsequently, SAPG has broad prospects for application.Solar direct steam generating systems have issues with two-phase flow phenomena. Over time, this uneven distribution of heat flow density produces problems such as thermal stresses caused by variation in thermal collection. Therefore, expansion evaporative solar steam generating systems emerged as an alternative solution (and calculation models were developed for these systems). In expansion evaporative solar steam generating systems, the system pipe for liquid water or steam contains only single-phase flow, thus producing lower thermal stress and deformation than the two-phase flow pipelines. The single-phase flow is easier to control and has good stability.In this thesis, the systems engineering point of view is used to construct a model of the typical coal complementary composite power generation system based on the original frame structure. In the thermal power plant thermodynamic system, the composition of the power systems are defined based on three main aspects:auxiliary thermodynamic cycle, heat transfer components, and on the basis of system energy balance and mass balance. After a rigorous mathematical derivation, a matrix system which has one-to-one correspondence with the system structure is derived. This turns the complex analysis process into series of simple matrix operations. Matrix fill out clear rules, strong regularity. The model is reliable, as a good foundation is laid by the system of line heat load calculation and economic analysis. This method has been verified against the traditional method with an error of 0.1% found. As long as the structure of the composite power system is known then, according to the rules of this method, the equation of state can be written directly. This enables straight-forward analysis of different configurations of hybrid power system.For a hybrid SAPG system, the economic calculation is based on the constant solar irradiation intensity, and different solar steam introduction cases. These produce changes to the thermal performance of the hybridized coal-fired unit. In addition, the thesis delves into the ability of the regenerative system of the thermal power plant thermodynamic cycle to adapt to small disturbances by pressure changes in the group stage, inlet steam flux, power, thermal conversion rate, generating heat rate, coal consumption rate in solar steam input from the solar collector.The goal of the methods developed in this thesis are to strengthen the ability to make scientifically-based project decisions correctly, based on the technical and economic analysis, thereby reducing or avoiding risks after the hybrid solar-coal power generation system has implemented. Many solar energy integration modes of power plants generate only a small cost difference. To analyze this cost difference, the net present value rate and static investment payback period instead of the second segment extraction were confirmed as the best criteria in this work. The research results in this thesis provide reference for engineering applications of complementary hybrid power systems consisting of solar power and coal-fired units.