EXPERIMENTAL STUDY ON INERT GAS MAGNETOHYDRODYNAMIC POWER GENERATION BY DETONATION-DRIVEN

As a special high-power pulse supply, magnetohydrodynamic (MHD) power generation device has many advantages, such as high efficiency, large capacity, and fast startup. The key to restrict the development of it is how to obtain the working gas with high conductivity. The driving capacity of detonation-driven is far beyond the conventional mode. It has unique advantages in providing high temperature and high conductivity gas. Applying the detonation-driven shock tube technology to MHD power generation is beneficial to breaking through the technical bottleneck, so an experimental study of inert gas MHD power generation based on detonation-driven shock tube was carried out. According to different ignition positions, detonation-driven shock tube can be divided into backward mode and forward mode. Backward detonation-driven mode can provide a long time and stable state of the gas, while forward detonation-driven mode has the advantage of producing high enthalpy gas. The test system is composed of detonation-driven shock tube, Laval nozzle, power channel, electromagnet, vacuum tank, load resistance and other measuring devices. In the test, plasma flow is generated by backward or forward detonation-driven shock tube. The inert gas is compressed to high temperature and high conductivity by shock wave, ionized into conductive plasma. The plasma accelerates to high speed inside the nozzle, then cut the magnetic induction line in linear shaped faraday-type generator to generate electricity. Under the condition of 0.9 T magnetic induction intensity, the stable output power at 3.5 Ω load reaches 1.9 kW by backward detonation-driven with a duration of 1.5 ms. With an external load of 35 mΩ, the generator can produce up to 212 kW for a short time within 0.3 ms by forward detonation-driven, and the power density is 0.2 GW/m³. The experiment successfully verified the feasibility of inert gas MHD power generation by detonation-driven shock tube. And it provides a new method for the application and development of high-power pulse supply.