Study Of Under Water Exchanger About The Low Side Of Surface Water Source Heat Pump

This paper first according to the principle of the design of the heat exchanger and relevant documents to calculate the heat exchange coil length of the experiments; Then refer to a lot of knowledge about the theory and application of the surface water source heat pump system, and then analyzed the factors that influence the heating of surface water source heat pump water heat exchange coil, on the basis of this, experiment proposed the research purpose and method of the surface water source heat pump system of underwater heat exchange coil, and then map the experiment principle, set up the surface water source heat pump testing bench of the experimental study of underwater heat exchanger low side.Through a series of experimental research, this paper draws the following conclusion: in each row of the number of heat transfer, the level of four rows of heat transfer is better;the increase the vertical spacing of surface water source heat pump underwater heat exchange coil is beneficial to increase of the heat transfer;the heat transfer of the surface water source heat pump water heat exchange coil increases with the increase of surface water flow;with the tube medium flow rate increases,the heat transfer of the surface water source heat pump water heat exchange coil increases.When surface water flow rate is far less than that of medium velocity, the influence on the heat exchange coil heat transfer of the change of surface water flow velocity of surface water source heat pump less than the change of the coil heat pipe flow;whether how many rows of the level of heat exchange coil, no matter the vertical spacing of heat exchange coil size, heat exchange coil resistance loss under various flow almost the same,the resistance loss of four rows of pipe a little smaller than others. But different with general resistance loss situation,the resistance losses of heat exchange coil under various flow will not be different from the rise of temperature of tube heat exchange medium, in contrast, when temperature is higher, the resistance loss will be increased slightly; to calculate the pressure loss for coil can use Mr Hughes formula to calculate the frictional resistance coefficient, and then combined with darcy formula to calculatethe theoretical results, and then multiplied by 1.05~1.10 correction coefficient;in winter heating conditions, the underwater heat exchange coil heat transfer number of surface water source heat pump system will decrease as the media emperature increased that the medium into the coil; Cooling conditions in the summer, the underwater heat exchange coil heat transfer number of surface water source heat pump system will increase as the media emperature increased that the medium into the coil; when surface water velocity is very small(for example, the experiment of 0.0045 m/s), the change of surface water flow will not caused by larger changes of heat exchange coil heat transfer number. The change of the heat exchange coil medium flow rate, as well as the medium into the coil inlet temperature changes can cause heat exchange coil heat transfer in great changes;the related theory of surface water source heat pump water heat exchange coil heat transfer calculation method with the actual situation of the same change trend.Therefore, can be calculated, using the theory and then carries on the corresponding revision.