A New Method for Continuous Charging of Spacecraft Fuel Elements Under Conditions of Long-term Space Flight

Abstract

Any flight control of a spacecraft (SC) depends on electricity on board. With the help of electricity, all its instruments and equipment (propulsion system, controls, communication systems, instrument complex, heating, etc.) function on board of the spacecraft. The power supply system (PSS) of a spacecraft is a critical system that ensures its life. The main base of the spacecraft power supply system is a system that generates direct electric current. This is determined by the fact that most of the sources that can be used on board are direct current sources. At present, the primary source is a source that converts any energy (chemical, light, nuclear) into electrical energy, and which must ensure the work of astronauts during the entire flight. Today, three sources have found their practical application that convert chemical energy directly into electrical energy with a fairly high efficiency (about 70%): galvanic cells, batteries and fuel cells taken from the Earth. The most developed are fuel cells, which use hydrogen and oxygen as "fuel and oxygen". A fuel cell is a device that directly converts chemical energy into electrical energy for forming water and generating heat. Two important advantages of fuel cells over electric batteries are: (i)Functioning until full use of fuel (fuel and oxidizer - hydrogen and oxygen), coming from an external source; (ii)The fuel cell does not need to be recharged during operation. Under space flight conditions, hydrogen and oxygen are constantly supplied to the fuel cells from tanks, filled on Earth with liquid hydrogen and oxygen. Under weightlessness conditions, hydrogen and oxygen gases and, accordingly, liquid hydrogen and liquid oxygen in the supercritical state are separated in the tanks, which forced the designers to install a special impeller for mixing oxygen. This drastically complicated fuel cell continuous supplying by hydrogen and oxygen and is unsafe (accident during flight of Apollo 13). The article presents the developed method and electrolyzer for the continuous supply by hydrogen and oxygen of fuel cells in space flight conditions directly from a specially designed conical electrolyzer, operating on the basis of obtaining separately concentrated gas-liquid mixtures: negatively charged electrolytic hydrogen bubbles + water, formed in the near-anode zone throughout anode length; positively charged electrolytic oxygen bubbles + water, formed in the near-cathode zone along the entire length of the cathode during electrolysis, due to the electrostatic attraction of opposite charge mixtures and voltage on the grid anode and cathode. The conical shape of the developed electrolyzer and its outlets under microgravity conditions allows for the separate discharge of two gas-liquid mixtures into different ampoules, equipped with static separators, generating separately hydrogen and oxygen in a continuous mode. The developed method and electrolyzer make it possible to continuously supply by hydrogen and oxygen of fuel cells in a safe and cost-effective way.