Investigation On Novel Externally Fired Humid Air Turbine System And Its Performance

On the basis of the theory of thermodynamics, improvement of the efficiency of energy utilization is the primary motivity of power systems. To research the energy transformation and utilization orderliness of the new proposed system is the main objective and content of this dissertation, as follows:About two thirds of the work output of the turbine is consumed by the compressor. Traditionally, every way of inter-cooling adopted in gas turbine decreases the work consumption of compressor in some degree. Through the spraying of water at the entrace of compressor, the air can be continuously cooled in compression so that the work consumption can be reduced greatly. In this complicated process, the air is cooled by the sensible and latent heat of water; at the same time, the water is vaporized, and the water vapor is also compressed. From the viewpoint of equilibrium thermodynamics, this dissertation establishes the stepless-cooling mathematic model, and investigates the corresponding orderliness and characteristics of the stepless-cooling gas turbine cycle.Furthermore, the new Externally Fired Humid Air Turbine (EFHAT) cycle has been proposed and its characteristics been investigated. The new proposed EHFAT cycle can make the latent heat be utilized effectively. Based on the principle of cascade utilization of energy and the methodology of system integration, a new orientation for the clean coal power generation system has been opened up. It is well known that the traditional EFHAT is the integration of the externally fired boiler and humid air turbine, in which various kinds of fuels can be used and the perfomance be improved. In particular, the temperature of clean humid air discharging to atmosphere is not limited by the dew point, and large amount of latent heat of water vapor in condensing will be released. How to utilize this latent heat will lead to different system conception, therefore, becoming the key point for the innovation of thermodynamic cycle system. This dissertation creatively proposed that the latent heat can be utilized to preheat thewater entering the saturator to improve its humidification ability. And on this basis, this dissertation has investigated and disclosed the elementary characteristics and orderliness of the new system.Additionally, the low-temperature heat utilization is the all-pervading problems confronted-by industries. The thermal efficiecy of traditional heat engine cycle with the low temperature is very low. Through system integration, this dissertation proposed the new system in which the low-temperature heat is introduced into the EFHAT system with latent heat utilization. In the new system, the insufficiency of low-temperature heat in EFHAT system can be offset; at the same time, the thermal efficiency of the low-temperature heat becomes higher than that of traditional low-temperature heat utilization in great degree. Therefore, the more reasonable cascade utilization of energy with different energy level is achieved. The novel EFHAT system integrated with low temperature heat utilization will be a new promising direction not only for the clean coal power generation system, but also for low-temperature heat utilization. This dissertation has studied and disclosed the elementary characteristics and orderliness of the new system. Furthermore, the solar energy as one kind of low-temperature heat is integrated into the new EFHAT system. This dissertation has also researched the characteristics and orderliness of this new integration system. The new way of solar energy utilization in integration with the EFHAT system is a new hybridization of solar energy and fossil fuel. Because its performance is superior to traditional ways of hybridizations about solar energy utilization under the same conditions, it is a promising direction for integration utilization of solar energy and clean use of coal.