A discussion on advanced methods of energy conversion- Magnetohydrodynamic power generation - The prospects for closed cycle m .p.d power generation

The basic features of closed cycle m.p.d. systems are described, introducing the three main combination cycles (direct nuclear, indirect nuclear, indirect fired) which could be adopted for commercialpower stations. Because of the high temperatures and attendant problems associated with thermal ionization of the working gas plasma, emphasis is placed upon achieving non-equilibrium ionization. This phenomenon is generally applicable only in closed cycle systems employing certain gases as the working fluid: the basic theory and required operating parameters of several techniques for inducing non-equilibrium ionization are reviewed. Matching a heat source, whether based on combustion or nuclear energy, to the m.p.d. stage imposes a number of restrictions. Nuclear reactors to provide temperatures suitable for m.p.d. systems (perhaps up to 1800 °G) have yet to be developed, but design criteria can be formulated. Cycle studies to specify operating parameters (including temperature, pressure, associated steam cycle, etc.) are presented. The technical feasibility of an indirect fired heat exchanger is considered. Over-all system performance, development time scale and incentives are also examined. In the United Kingdom, experimental research and development towards closed cycle m.p.d. power generation is mainly in progress at International Research and Development Co. Ltd and at A.E.R.E., Harwell. Details of the programmes are given and achievements in terms of experimental data are presented. Finally, the prospects for closed cycle m.p.d. power generation are reviewed.