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Pneumatic Systems
Published in Anton H. Hehn, Fluid Power Troubleshooting, 1995
In order to control or regulate the air pressure downstream of the receiver tank, a pressure regulator is utilized. A pressure regulator is a pressure-reducing valve and consists of a valve body with inlet and outlet connections, and a moving member which controls the size of the opening between the inlet and outlet. It is a normally open valve, which means that air is normally allowed to flow freely through the unit. With the regulator connected after the receiver tank, air from the receiver flows freely through the valve to a point downstream of the outlet connection. When pressure in the outlet of the regulator increases, it is transmitted through a pilot passage to a piston or diaphragm area which is opposed by a spring. The area over which the pilot pressure signal acts is rather large, which makes the unit responsive to the outlet pressure fluctuations. When the controlled (regulated) pressure nears the preset force level, the piston or diaphragm moves upward, allowing the poppet or spool to move toward its seat, thereby controlling the flow (increasing the resistance). The poppet or spool blocks flow once it seats and does not allow pressure to continue building downstream. In this way, air at a controlled pressure is made available to an actuator.
Effect of number of the nozzle and cold mass fraction on the performance of counter flow vortex tube using the computational fluid dynamic analysis
Published in International Journal of Ambient Energy, 2022
Experiments were conducted with three sets of inlet nozzles to validate the CFD model. Figure 16 shows the schematic diagram and photograph of the experimental set-up. The compressor was run for 20 min to get steady-state condition at 8 bar. Then the gate valve was slowly opened. The air enters into the vortex tube after passing through the pressure regulator and rotameter where the inlet volume flow rate was measured. The volume flow rate at the cold end was measured by another rotameter. The temperature at inlet, cold end and hot end were measured using ‘T’ type thermocouples at different pressures by adjusting the pressure regulator at different positions of the control valve. Figure 17 shows the different types of number of nozzles in brass materials. Figures 18Figure 19.–20 show the variation of experimental and CFD cold outlet temperature with inlet pressure. It is observed that experiential and CFD values of cold air temperature are closer, which suggests that the present CFD model is good enough to study the performance of the vortex tube.
Predicting the performance and emission characteristics of a Mahua oil-hydrogen dual fuel engine using artificial neural networks
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2020
Karthic s. v., Senthil Kumar Masimalai
Kirloskar engine model AV-1 was used for experimentation. Engine specifications are tabulated in Table 2 whereas the schematic diagram of the test engine setup can be seen in Figure 1. The engine was then modified to run on dual fuel mode incorporating hydrogen supply system, which comprises of hydrogen cylinder, control valve and pressure regulator. Since hydrogen being highly inflammable, flame arrestor was used to apprehend the backfire propagation. Mahua oil was directly injected into engine cylinder through conventional mechanical injector. Accuracy and uncertainties of the measurement instruments that were used for testing purposes are tabulated in Table 3. Initially the experiments were conducted with diesel and Mahua oil to get baseline readings for 0.7, 1.4, 2.1, 2.8 and 3.7 engine loads. Then, the dual fuel operation was performed by varying hydrogen flow rate from 0 to 5 LPM at a rate of 0.5 LPM and constant flow of pilot Mahua oil. Finally, a computational model was developed using ANN to predict various performance and emission parameters of hydrogen dual fuel engine.
Effect of injection parameters on the hydrogen enriched dual-fuel CRDI diesel engine
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2023
The hydrogen supply line consists of a cylinder, pressure regulator, hydrogen flow meter, flame arrester, flow control valve, and flame trapper. The intake manifold receives a constant stream of hydrogen, which mixes with the air to create a uniform atmosphere inside the cylinder. With the aid of the pressure regulator, the high-pressure hydrogen held in the cylinder may be safely delivered to the engine cylinder at a much lower pressure of around 2 bar. A hydrogen flow control valve and a flow meter serve to maintain a hydrogen flow rate of 7 to 10 lpm.The flame arrester is installed in the flow line to prevent any backfire. Figure 4 represents the real time images of the hydrogen supply line.