Algorithms of controlling water discharge for maintaining water level in absorber by using pressure regulator

The article considers the problems of regulating the seawater level in the absorber for removing carbon dioxide from a hydrogen mixture. Decreasing or increasing the water level in the absorber lead to its low operation efficiency, the pressure in the absorber being constant in various modes of operation. The feed valve’s main function is to maintain the necessary water level. There has been given a functional diagram of the channel controlling the feed valve from the pressure regulator with a task signal adjusted by the water level in the absorber. Analysis of changing twelve parameters of the absorber under typical operating modes with the external water pressure of 0.5 and 1.6 MPa was conducted by using the LabVIEW software. The results obtained confirmed the possibility of using the control method to maintain the water level in the absorber within the specified limits. Regulating the water level in the absorber with the correction of the pressure setting signal to the pressure regulator by signals from the limiting regulators of the upper and lower water levels in the absorber is also examined. It is recommended to adjust the signal of the set pressure value, according to the level changes beyond the limits by increasing or decreasing it depending on the level going beyond the upper or lower permissible limits for increasing the duration and accuracy of maintaining the assigned pressure in the absorber. The duration of maintaining the assigned pressure in the absorber has been referred as to be increased by changing the design characteristics of the absorber: increasing the water volume in the absorber tank, increasing the range of permissible changes of the water level.