The Development And Thermodynamic Analysis Of Thermoelectric Heat Pump Water Heater

Thermoelectric effects, discovered in the raid-upper terra of the 19lh century, had been less applied in practical projects during more than 100 years after its discovery because of its inefficiency, but the discovery of materials with high thermoelectric properties made thermoelectric effects be applied in practical projects in 1950' s, which involved many fields, such as national defense, industry, agriculture, medicine, commerce, daily lives and so on. Although its efficiency is still lower than that of the other refrigeration techniques, thermoelectric refrigeration can' t be substituted in some conditions, for examples of small refrigeration capacity and some special projects, because it possesses some distinctive traits, such as no pollution, long life, simple construction, controllable features and so on.On the analysis of fundamental principle of thermoelectric refrigeration, the steady state mathematical model of the thermoelectric system was founded, and, on the basis of the model, the thermal parameters of the thermoelectric apparatus were calculated, -and the theoretical analysis, on the relations between the performances of thermoelectric apparatus and factors, as follows: the properties of its heat exchangers, the temperature difference between heat sink and heat source and the module' s effective system figure of merit, was conducted, which founded the theoretical basis for the calculation on the development of thermoelectric devices and the surveying of its performances according to temperature difference between heat sink and heat source. Performances analysis pointed out that thermoelectric refrigeration depend on some conditions, for examples, temperature difference and the properties of heat exchangers, especially depend on the properties of heat exchangers on the hot side.A thermoelectric heat pump instantaneous water heater was originally developed. All of performances parameters of the sample machine come up toor exceed the standards that state required for instantaneous water heaters. The output of surveying under standard conditions displayed that, in the comparison with the other sorts of water heaters, it can save energy by 50% or so, because its heating performance factor reached 2.0 or so, that is to say, its heating output ratio is 200% or so. The successful development of thermoelectric water heater opens a new field of heating device with large power, which is hoped to bring a revolution in the aspects of high power utilization ratio and safety protection of electrical water heaters, and to bring new ideas on the method of building energy conservation, waste heat recovering and the utilization of other sorts of energy in low temperature. On the basis of the analysis of building energy consumption and the feasibility of waste heat recovering, taking middle or high-grade hotels for example, the methods exploration of waste heat recovering have been conducted by the means of thermoelectric heat pump apparatus, and it is showed that the latent capacity of energy conservation is very large if we can utilize thermoelectric heat pump apparatus to recovery the waste "hot" or "cold" energy in air displacing or to heat water for daily use by means of recovering the waste energy in cooling water of refrigerant compressor unit and waste energy in dally waste water, which, at the same time, achieve the double goal of energy saving and environment protection by means of removing the "heat" pollution in environment.