Study On Heat Transfer Characteristics Of Nano - Organic Refrigerant Cu - R123

There is a very real problem of the ORC technology popularization, the heat transfer area is larger due to the low temperature heat driven, and that as a result of heat exchange equipment problem of huge volume and high cost of heat exchanger, these are to a certain extent hindered ORC technology popularization and application. Therefore strengthen the ORC hot side heat transfer process in the system, is one of the effective ways to solve this problem. At present the latest nanotechnology and material progress has been achieved the use of nano particle strengthening fluid heat transfer process is a very promising technology is in many improved heat transfer, So the paper using nanometer organic working medium as an organic Rankine’s cycle of cyclic working substance. From the hot end of nanometer organic laser strengthening ORC feasibility of heat transfer. Studied the nanometer organic medium base choice principle and method of preparation of nanometer organic working medium, and further analyses the nanometer organic working medium physical parameters. On the heat transfer experimental platform, the nanometer organic working medium heat transfer performance, for the application of nanometer organic substance in the ORC system to provide the experimental basis.(1) This article system elaborated the selection principle of nanometer organic base fluid substance. And choose R123 as nano organic base fluid substance. Using the "two-step" the preparation of the nanometer organic working medium Cu-R123. Components of Cu nanoparticles size range of 0.3～1.0% vol, R123 volume composition range of 97.9～99.6% vol, dispersant component size range of 0.1～1.1% vol.(2) Study the nanometer organic working medium stability analysis method. Visual method is used to analyze the preparation of the nanometer organic substance, found that its stable performance meet the test requirements. And further studies the main physical parameters of nanometer organic working medium, including the coefficient of thermal conductivity and viscosity. Of substance found organic coefficient of thermal conductivity and viscosity are increased with the increase of Cu nanoparticles volume fraction increased gradually. Including the coefficient of thermal conductivity of nano organic working medium of the coefficient of thermal conductivity increase is more significant than pure organic.(3) The nanometer organic working medium Cu-R123 experimental study heat transfer performance. First by pure working medium R123 to the calibration of test platform, its precision meet the test requirements. And further analyzes the nanometer organic working medium convective heat transfer performance are studied. Found the mass flow and dryness all influence the change of the convective heat transfer coefficient. When the dry degree of 0.5 nm organic variations in the convective heat transfer coefficient of working medium is the largest, and when the mass flow rate increases, the nanometer organic working medium of heat transfer coefficient increase amplitude decreases.