Experimental Research on the Cavitation Suppression in the Water Hydraulic Throttle Valve

Abstract

A water hydraulic throttle valve is often used to control the water flow in piping systems. When the water flows through the valve port, cavitation occurs frequently because of the high pressure drop across the valve. The cavitation can lead to wear, vibration and noise. To solve the problem, a modified throttle valve with a drainage device is proposed to suppress the cavitation. A contrasting test was conducted to analyze the effect of drainage device on the cavitation suppression. For evaluating the influence of inlet pressure and outlet pressure on the ability of the drainage device to suppress cavitation, the power spectrum density (PSD), normalized intensity, and cavitation suppression coefficient (CSC) of dynamic pressure are introduced. The results indicate that adopting the drainage device is a feasible method to suppress cavitation. In addition, the inlet pressure and outlet pressure have a great influence on the capacity for cavitation suppression of the drainage device (CCSDD) by changing the intensity of cavitation. When the inlet pressure is at 4.0 MPa, the cavitation is generated and the CCSDD is weak. With increasing inlet pressure, the intensity of cavitation and CCSDD is gradually enhanced. But when the inlet pressure increases to 7.0 MPa, the cavitation is saturated and the cavitation suppression by the drainage device begins to decrease. On the other hand, the effect of cavitation suppression decreases significantly when the outlet pressure increases from 1.4 MPa to 3.8 MPa.

New Advances of Cavitation Instabilities

“…In addition, in the case of the cavitating jet in air at optimum conditions, the wavy pattern of the low-speed water jet was observed, as shown in Figure 1b [34,35,37,38]. The frequency of the wavy pattern is equal to the shedding frequency of the cloud [35]. Even for the cavitating jet in air, unsteady behavior is very important.…”

“…In water In air Normally, a cavitating jet is produced by injecting a high-speed water jet into a water-filled chamber, as mentioned above. To apply a cavitating jet for components and/or plants which cannot be put in the chamber, Soyama developed a cavitating jet in air by injecting a high-speed water jet into a low-speed water jet, which was injected into air without the water-filled chamber using a concentric nozzle [33][34][35][36]. A typical cavitating jet in air by injecting a high-speed water jet into a low-speed water jet is shown in Figure 1b.…”

“…Cavitation clouds are also observed in the water column of low-speed water jets of cavitating jets in air, as shown in Figure 1b. Even though the cavitating jet was in air, cloud shedding was observed [35,37,38]. In addition, in the case of the cavitating jet in air at optimum conditions, the wavy pattern of the low-speed water jet was observed, as shown in Figure 1b [34,35,37,38].…”

“…Even though the cavitating jet was in air, cloud shedding was observed [35,37,38]. In addition, in the case of the cavitating jet in air at optimum conditions, the wavy pattern of the low-speed water jet was observed, as shown in Figure 1b [34,35,37,38]. The frequency of the wavy pattern is equal to the shedding frequency of the cloud [35].…”

Numerical Investigation of Methodologies for Cavitation Suppression Inside Globe Valves

“…Xu et al [34] performed structure optimization of the valve port in a relief valve to reduce cavitation intensity. Shi et al [35] utilized a drainage device to suppress the cavitation in a throttle valve, and cavitation intensity could be reduced with appropriate inlet and outlet pressure. Lee et al [36] optimized the structure of the bottom plug in a To suppress or prevent the occurrence of cavitation, valve structure optimization, adding outlet pressure, or adding stage/anti-cavitation trims is inevitable.…”