Research On Heat Carrying Capacity And Thermal Diffusion Of Water In Lake-Water Source Heat Pump System

Sustainable development, energy conservation and environmental protection is the trend of the development of the world, the development and utilization of renewable clean energy is a key research subject at present stage. The surface water source heat pump technology is low heat source, the surface water is a kind of energy saving, high efficiency and environmental protection of green technology, has the very broad prospects for development. As the study unfolds, the surface water source heat pump air conditioning system development is very rapid. At the same time, the cooling water discharged into receiving waters in the process of system operation, can cause thermal pollution to water environment. Lakes, reservoirs, ponds and other water bodies as liquidity is weak, relatively more fragile ecological environment, the influence of the cooling water will be more obvious, severe cases may result in serious deterioration of water environment, aquatic organisms such as death consequences. And water temperature rise will also affect the operation of the unit system efficiency, reduce the energy of the system. So, in order to protect the water ecological environment, energy-saving and high efficiency of the heat pump unit operation, the system after the thermal diffusion of cooling water, lake body temperature field distribution, thus the research of load carrying capacity of water, has very important practical significance.Exampled by a certain lake water source heat pump engineering of Fuzhou as the research object, the thermal diffusion of cooling water, lake water source heat pump system is studied. Analysis of the application form and characteristics of lake water source heat pump system, the requirement of water quality and treatment methods. According to the weather and water conditions, project characteristics determine the boundary conditions of the water temperature model; Based on the principle of energy conservation, momentum conservation, in combination with kappa epsilon model and wall function method theory predominate established the thermal diffusion of cooling water, three dimensional numerical model of temperature distribution. To simplified the lake body model, the application software Gambit to meshing of the model, by using the Fluent software to simulate software runtime lake water temperature distribution of the system, the running stability of lake water source heat pump system, to simulate the temperature field distribution of the lake body temperature field are obtained.Simulation results it can be seen that drain depth have effects on the temperature distribution of cooling water heat diffusion. Drain more close to the surface of the water, more conducive to water cooling, over temperature range is smaller. Therefore port Settings should be close to the surface. Simulation results show that the over temperature areas concentrated in the small region near the port, so near the drain water measures, such as small fountain can effectively increase the disturbance of water and heat dissipation area, reduce the water temperature rise caused by cooling water. When the outlet flow increases, over-temperature region area will increase, so the drainage design should try to increase the number of each drain outfall to reduce traffic.