A Study About Turbine-driven Pump Applied In Surface Water Heat Pump System

The shortage of energy has become a bottle neck of economy development for many countries worldwide recently. Thus it is an imperative to make use of environmental friendly as well as sustainable techniques in the field of HVAC. Surface water heat pump has become representative in this sort of techniques. The open loop system of surface water heat pump is an operation mode in which pumps are used to carry water from lake, river or sea directly to the plate heat exchangers. The pumps have to provide energy to overcome gravitational potential energy besides energy loss along the pipe owing to such an operation mode. Given these characteristics in surface water heat pump, it is possible to employ turbine to recover the gravitational potential energy of the water. Thus the objective of this paper is to develop a turbine-driven pump and to make use of it in the surface water heat pump system to reduce energy consumption and increase the energy efficiency of the whole system.After the process of design of turbine-driven pump, the analysis of the performance curves, and more importantly the performance in different seasons and under partial load, have been carried out in this paper. Secondly, computational fluid dynamics technology have been introduced to carry out the analysis of different types of spiral casings and draft tubs in order to decide which type is more appropriate applied in the system.A theoretical type of turbine-driven pump has been developed on the basis of a surface water heat pump system in Chongqing Tiandi project. The design process is based on traditional design process of turbine-driven pump normally applied in agriculture. The performance curves have been developed according to the performance curves of the pump and the turbine selected in the design process. Performance of the turbine-driven pump under different circumstance has been discussed later based on the performance curves developed, thus working out the operation strategies. Spiral casings with both rectangle cross-section and circle cross-section and two types of draft tubes have been developed. After the analysis of the characteristics of flow passage with the aid of computational fluid dynamics, both suitable spiral casing and draft tube has been selected. Variance has been introduced to evaluate the homogeneity of the velocities in the outlet of spiral casing, while the velocity curve and pressure curve has been used to determine the performance of draft tube. The possible future research focuses were revealed in the end of this dissertation, including the effect of design parameters on the performance of the turbine-driven pump to fit to the application, the computational fluid dynamics analysis of the full flow passage of the turbine-driven pump and the installation site.