The purpose of this research is to solve the complex long-distance and high-lift water supply engineering accident water hammer protection problem. Taking the Zhaojinzhuang water supply project as an example, based on the method of characteristics (MOC), the water hammer of the pumping station under the combined action of a water hammer relief valve, hydraulic-control butterfly valve, air vessel, air valve, and other water hammer protection measures is numerically simulated and calculated, and the effectiveness of the range method is analyzed, to ensure a waterproof hammer in pump stop accidents. The results show that the main factors affecting the effect of water hammer protection under the two-stage valve-closing parameters of the hydraulic-control butterfly valve are the fast-closing angle and the slow-closing time. The arrangement of the air vessel behind the pump can effectively increase the minimum water hammer pressure in the climbing section, and with the increase of the volume of the air vessel, the pump reverse speed and the maximum positive pressure increase slightly, but the overall water hammer protection effect is better. With the increase of the moment of inertia of the motor, the maximum positive pressure and minimum negative pressure of the pipeline still do not meet the requirements of the specification, and the modification cost is relatively large. The combination of the one-stage hydraulic-control butterfly valve, the air valve, the air vessel, and the water hammer relief valve can effectively reduce the volume of the air vessel. Under the optimal method, the maximum positive pressure head is 236.61 m, and the minimum negative pressure head is −3.18 m. Compared with the original method, the maximum positive pressure head is increased by 1.18%, the minimum negative pressure head is reduced by 95.78%, the maximum reverse speed of the pump is reduced by 100%, and the maximum reverse flow of the pump is reduced by 70.27%, meeting the requirements of water hammer protection. This is a safe and economical protection method.

To investigate the variation laws of various hydraulic parameters and internal fluid flow patterns of eccentric semi-ball valves under different boundary conditions, the DPM model was used to numerically simulate the eccentric semi-ball valve based on Fluent 2021 R1 software. The flow velocity, pressure distribution, and erosion wear rate on the valve wall were simulated under different combinations of opening, inlet flow velocity, and sediment concentration conditions, and hydraulic parameters such as drag coefficient, flow coefficient, and cavitation coefficient were calculated. The results show that as the opening of the eccentric semi-ball valve increases, the valve drag coefficient decreases, the flow coefficient increases, the cavitation coefficient increases, and the degree of cavitation decreases. The flow velocity in the high-velocity zone at both ends of the valve plate decreases, and the gradient of water flow velocity passing through the valve decreases. The area of the low-velocity zone at the rear of the valve plate decreases, and the vortex phenomenon gradually weakens; as the sediment content in the water increases, the valve drag coefficient increases, the flow coefficient decreases, and the cavitation coefficient first increases and then decreases. The maximum flow velocity of the pipeline decreases faster and faster, causing an increase in pressure gradient in the flow area and drastic changes. This results in higher pressure on the pipe wall near the valve plate, especially a significant increase in negative pressure; As the inlet flow rate increases, the valve drag coefficient decreases, the flow coefficient increases, and the cavitation coefficient gradually decreases. The flow velocity of the water passing through the valve increases, and the low-pressure area downstream of the valve plate increases. The pressure gradient at both ends of the valve port increases significantly from small to large, and the positive pressure upstream of the valve plate gradually increases. The force of the water flow on the valve plate is large, causing friction between the valve stem and the valve body, which is not conducive to long-term operation. With the increase in inlet flow rate, the maximum wear amount and wear range of the valve plate have significantly increased, and erosion wear is mainly distributed in point blocks at the edge of the valve plate. This study can provide certain references and solutions for the key technology research of eccentric semi-ball valves and assess the performance indicators of the operation being maintained.

To investigate the causes of water leakage in the waterproof hammer air valve and its impact on sustainable water resource management, the DN100 waterproof hammer air valve was taken as the research object. By using the overset grid solution method of ANSYS Fluent 2021 R1 software, the flow field simulation of the waterproof hammer air valve was carried out. The transient action during the ascent phase of the key structural component floating ball, and the velocity and pressure distribution of the flow field inside the air valve are analyzed. The results showed that by giving different inlet flow velocities, the normal flow velocity range for the floating ball to float up was below 35 m/s and above 50 m/s. When the inlet flow velocity was between 35 m/s and 50 m/s, the growth rate of the pressure difference above and below the floating ball increased from 1.48% to 5.79% and then decreased to 0.4%. The floating ball would not be able to float up due to excessive outlet pressure above, which would cause the DN100 waterproof hammer air valve to leak water and fail to provide water hammer protection. When the inlet flow rate is 5 m/s, the velocity and pressure inside the valve body increase with time during the upward movement of the floating ball inside the waterproof hammer air valve and tend to stabilize at 400 ms. Through the generated pressure and velocity cloud maps, it can be observed that the location of maximum pressure is at the bottom of the buoy, directly below the floating ball, and at the narrow channels on both sides of the outflow domain. The location of the maximum velocity is at the small inlet of the bottom of the buoy. When the inlet speed of the valve is constant, a large amount of water flow is blocked by the floating ball, reducing the flow velocity and forming partial backflow below the floating ball, with an obvious vortex phenomenon. A small portion of the water flow passes through the air valve at a high velocity from both ends of the channel, and the water flow below the floating ball is in an extremely unstable state under the impact of high-speed water flow, resulting in a large gradient of water flow velocity passing through the valve. The research results not only help to improve the operational efficiency of water resource management systems but also reduce unnecessary water resource waste, thereby supporting the goal of sustainable water resource management.