Influence of water temperature variation on hydraulic performance of hot water circulating pump

In order to research the hydraulic performance of hot water circulating pump, the type 200YRB-50 hot water circulating pump was analyzed. The whole flow field of the pump was modeled with Pro/E. The pump whole flow field model was meshed with Meshing. Whole flow field have been numerical calculated at 8 different temperatures and 9 different operating conditions with CFX. Hydraulic performance parameters such as head, efficiency and power, have been calculated through post-processing. Hydraulic performance curves at different temperatures have been drawn. The results show that, water temperature variation has no effect on impeller theoretical head with infinite blades H_t∞, impeller theoretical head with finite blades H_t, and impeller head H_i; Volute hydraulic loss ΔhV decreases significantly with the increase of water temperature; hot water circulating pump head H will increase at high temperature; Pump hydraulic loss Δh, impeller ring leakage Δq, and disk friction loss P_m3 decrease with the water temperature increasing; Hydraulic efficiency ηh, volumetric efficiency ηV, and mechanical efficiency ηm increase with the water temperature increasing, so the pump total efficiency also increases; Hydraulic power P_w is proportional to liquid density, so hydraulic power P_w and shaft power P of the hot water circulating pump decrease with the increase of water temperature.