Experimental Study on Characteristics for CNG Electronic Pressure Regulator

The aim was to develop a new generation of electronic pressure regulator that can continuously vary the rail pressure in front of the injectors. The new pressure regulator can react on different pressure requirements in the CNG rail. The focus was on the functional optimization and size reduction. The proportional valve, which is a solenoid valve, is controlled by a PWM signal. Duty cycle 0 % means a closed valve, while 100 % means the proportional valve is fully open. The pressure regulation is divided into two stages. The first stage is mechanical regulation from a tank pressure of 0.2 to 26 MPa to a constant middle pressure of 2 MPa. The different type regulators was labeled as 1) A sample and 2) B sample. Through the bench experiment, the stroke characteristic of supply voltage, heat exchange effect on the low pressure side depending on cooling water capacity and cross-section area, the mass flow of different inlet pressure and rail pressure, and behavior in the regulator were evaluated and compared.