4 Matching Results

Search Results

Advanced search parameters have been applied.

Oxygen enrichment for open cycle magnetohydrodynamic power systems

Description: Efficient coal fired, open cycle MHD power generation systems require a combustion flame temperature of approximately 4600 F to provide adequate electrical conductivity in the MHD gas. To achieve this high flame temperature, either highly preheated combustion air or oxygen enrichment of combustion air preheated to a lower temperature is required. Since directly and separately fired high temperature air preheaters are not sufficiently advanced in development to ensure their reliable operation in near term MHD systems, oxygen enrichment may be the practical alternative for obtaining required flame temperatures in the near future. The work presented is a preliminary evaluation of economic and performance effects due to oxygen enrichment of combustion air in open cycle MHD power systems. Studies were initiated with a literature search and a comprehensive review of previous studies of oxygen enrichment in MHD systems. Summaries of these studies and their conclusions are contained in Appendix A. Using selected references from the literature as a starting point, sets of ground rules and assumptions were established for conducting an updated study with subsonic MHD channels. A NASA-developed computer code for modeling of the combustion products and establishing plasma properties was utilized, with slight modification, to prepare a base of thermal properties. Assuming Montana Rosebud coal and combustion air enriched with oxygen from 0 to 50% (by mass), a series of Mollier diagrams was prepared for the complete range of oxygen enriched cases (Appendix B). (WHK)
Date: June 1, 1979
Partner: UNT Libraries Government Documents Department

Key contributions in MHD power generation. Quarterly report, 1 June 1979-31 August 1979

Description: Activities during the third quarter of the contract period are reported in detail. The tasks reported on include: (1) investigation of electrical behavior in the vicinity of electrode and insulating walls; (2) studies of critical performance issues in the development of combustion disk generators; (3) development and testing of electrode modules, including studies of insulator properties; and (4) determination of coal combustion kinetics and ash behavior relevant to two-stage MHD combustors, and investigation of the mixing and flow aerodynamics of a high swirl geometry second stage.
Date: November 1, 1979
Creator: Louis, J F
Partner: UNT Libraries Government Documents Department

US/USSR cooperative program in open-cycle MHD electrical power gneration. Joint test report No. 2: tests in the U-25B facility; MHD generator test No. 3

Description: The third joint test with a Soviet U-25B MHD generator and a US superconducting magnet system (SCMS) was conducted in the Soviet U-25B Facility. The primary objectives of the 3rd test were: (1) to operate the facility and MHD channel over a wider range of test parameters, and (2) to study the performance of all components and systems of the flow train at increased mass flow rates of combustion products (up to 4 kg/s), at high magnetic-field induction (up to 5 T), and high values of the electrical field in the MHD generator. The third test has demonstrated that all components and systems of the U-25B facility performed reliably. The electric power generated by the MHD generaor reached a maximum of 575 kW during this test. The MHD generator was operated under electrical loading conditions for 9 hours, and the combustor for a total of approximately 14 hours. Very high Hall fields (2.1 kV/m) were produced in the MHD channel, with a total Hall voltage of 4.24 kV. A detailed description is given of (1) performance of all components and systems of the U-25B facility, (2) analysis of the thermal, gasdynamic, and electrical characteristics of the MHD generator, (3) results of plasma diagnostic studies, (4) studies of vibrational characteristics of the flow train, (5) fluctuation of electrodynamic and gasdynamic parameters, (6) interaction of the MHD generator with the superconducting magnet, and (7) an operational problem, which terminated the test.
Date: April 1, 1979
Creator: Tempelmeyer, K E & Sokolov, Y N
Partner: UNT Libraries Government Documents Department

Study of the U-25B MHD generator system in strong electric and magnetic fields

Description: The third and fourth tests of the U-25B facility have demonstrated that the MHD flow train has operated for over 50 h with little difficulty. Review of the data reveals no significant problems associated with vibration, stress, or fluctuation of the electrical and gasdynamic parameters of the system components. In Test 3, the MHD generator produced a maximum power of 575 kW, a maximum Hall voltage of 4240 V, and a maximum Hall field of 2100 V/m. Inverter loading characteristics indicated that the upstream portion of the channel operated at low conductivity compared to the two downstream sections. During Test 4, at a lower mass flow rate but with cesium seed and oxygen enrichment to 60%, a power level of about 400 kW was generated. Because of inadvertent water and air leakage into the combustion chamber, however, combustion temperatures were lower in Test 4 that anticipated. These factors had a detrimental effect on the generator performance. Analysis of the data obtained from Tests 3 and Test 4 illustrates that in order to increase the power of the U-25B channel, a number of steps should be taken to increase the effective plasma conductivity and channel mass flow. For example, increasing the mass flow rate to 5 kg/s and achieving a K/sub sigma/ of 0.7 to 0.8, a channel inlet temperature about 2950 K may produce an electrical power output up to 1.3 MW. Steps are being taken to increase the preheat temperature in the facility, as well as to eliminate all water and air leakage into the combustor and decrease other thermal losses in the combustor nozzle and generator.
Date: January 1, 1979
Creator: Iserov, A.D.; Maksimenko, V.I. & Maslennikov, G.I.
Partner: UNT Libraries Government Documents Department