DEVELOPMENT OF HIGH-TEMPERATURE HEAT EXCHANGER FOR HYDROGEN COMBUSTION TURBINE SYSTEM

摘要

New Rankine Cycle and Topping Regenerative Cycle shown in Fig. A-1 and Fig. A-2 are representative 500 MW power generation systems for a hydrogen combustion turbine (HCT). The energy efficiency based on HHV of these is expected to be over 60% because the inlet temperature of turbine can be increased to 1970 K. These systems comprise various heat exchangers. Especially, the development of high temperature heat exchanger dealing with the high temperature and pressure steam is very important to realize the hydrogen combustion turbine system. The high-temperature heat exchanger of New Rankine Cycle is a supercritical heat recovery steam generator operating at pressure of 36 MPa. This heat exchanger is heated by steam at temperature of 1390 K. On the other hand, Topping Regenerative Cycle has two high-temperature heat exchangers. One is a regenerator operating at pressure of 37 MPa. The other is a regenerator operating at pressure of 5 MPa. Both regenerators are heated by steam at temperature of 1030 K. The followings are the principal development subject of high-temperature heat exchanger. 1) Improving the heat transfer characteristics to achieve the compact heat exchanger. 2) Planning the heat exchanger structure suitable for the high thermal stress. To improve a heat transfer characteristic of the high-temperature heat exchangers, a parameter survey is conducted to optimize a tube arrangement and a fin configuration on tube outside and/or inside. The heat transfer areas are minimized through using the tubes with an extended heat transfer surface on the both sides of a tube. Structural integrity is also estimated by conducting a structural analysis for the critical parts of the high-temperature heat exchangers.