Experimental Investigation of Water Level Control System of Liquid-Gas Separator in The Fuel Cell

Water is one of the products of the interaction between hydrogen and oxygen in a fuel cell. The presence of this product can reduce the fuel cell performance and cause problems in its operation. The purpose of this study is to introduce a water level control system preventing the loss of reactant gases, such as hydrogen and oxygen, by improving the process of water separation from these gases. Therefore, unused gases are returned to the fuel cell, resulting in a reduction in the cost of using reactant gases to generate electricity. In this paper focuses on the performance of the water level control system in terms of fuel cell specifications and construction constraints. The system consists of a mechanical unit and a control unit and is based on various reactive gases. Effective parameters for controlling the discharge valve, such as the length of the connection path, the sensor angle, the time lags, have been investigated. The path length check showed that if the path length being too high, the pressure changes oscillate, failing to establish a pressure condition for time, and the system loses its performance. The sensor angle only affects on , somehow reaches its maximum by placing the sensor at a 90-degree angle. In addition, according to the tests performed, time between 0.3 and 0.5 seconds is recommended for . Finally, in order to control the water level control system automatically, relations are proposed based on the fuel cell pressure. Overall, the control algorithm showed the correct performance.