Experimental Study on Performance of Liquid–Gas Jet Pump with Square Nozzle

Abstract

An experimental study is conducted to investigate the effects of different operating parameters on the performance of liquid–gas jet pumps. A square nozzle with an area ratio of 2.25 is designed for the liquid–gas jet pump, and an experimental setup for the liquid–gas jet pump system is constructed. By varying parameters such as inlet flow rate, temperature, and inlet pressure, the variations in the pumping capacity and pumping ratio of the system are studied. The performance of liquid–gas jet pumps with square nozzles and traditional circular nozzles under the same working conditions was compared through experimental data. Explore the performance advantages and disadvantages of liquid–gas jet pumps with different shaped nozzles under the same working conditions. The experimental results indicate that as the inlet flow rate of the liquid–gas jet pump increases, the pumping capacity of the system increases, leading to an increase in the pumping ratio. The operational efficiency slightly decreases with a rise in the working water flow rate. The pumping ratio of the system increases with an increase in the inlet pressure, reaching a peak value of around 4.0 when the inlet valve is fully open. Inlet pressure significantly affects the efficiency of the liquid–gas jet pump, with the highest efficiency point achieved at Pa (inlet air pressure) = 60 kPa, reaching an operational efficiency of 42.48%. When Pa exceeds 70 kPa, the operational efficiency rapidly declines. Comparing the performance of square and circular nozzle liquid–gas jet pumps under the same operating conditions, the performance of the square nozzle liquid–gas jet pump outperforms that of the circular nozzle counterpart. The pumping system’s performance decreases continuously with an increase in the working liquid temperature; however, the decline in pumping performance becomes gradual after exceeding 40 °C. As the water level rises, both the pumping capacity and pumping ratio of the system increase. After the liquid level reaches 40 cm, the changes in the pumping system’s performance become less pronounced.