The Research And Application Of Thermoelectric Heat Pump With Thermal Energy Storage

The supply of thermal energy can not fulfil such a demand, in terms of the mismatch between energy supply and energy demands in quantity, location and time. In view of the efficiency of the energy utilization and energy-saving, a potential way is to use the heat pump with thermal energy storage, and it is of great practical interest in waste heat recovery, o? peak electricity storage and other fields.Traditional energy storage is passive process that cannot adjust the rate of heat charging and discharging. Thermoelectric systems do not require any compressor, expansion valves, absorbers, condensers or solution pumps, and moreover, they do not require working fluids employed in vapor-compression systems that are damaging to the environment. Based on the thermodynamic analysis on a thermoelectric heat pump system,a new active thermal storage system is introduced by means of integrating thermoelectric heat pump with latent heat storage in this paper. The work involved design and constrction of an active thermoelectric heat pump latent heat storage. The performance of the active latent heat storage was investigated under different work conditions. The experiment results show that the rate of the heat charging and discharging can be adjusted by changing the operating voltage of thermoelectric heat pump based on the time and the quantity of the waste heat when charging and the need of energy use when discharing. The higher the temperature of waste heat source is, the larger the coefficient of performance becomes. Under an operating voltage of 8V, the coefficient of performance decreases from 2.23 to 1.14 when the temperature of waste heat source decreases from 32℃to 18℃; The smaller the temperature of air is, the larger the coefficient of performance becomes when discharging process. Under an operating voltage of 4V and the temperature of air temperature is about 25℃, the coefficient of performance decreases from 5.6 to 3.2. Thermoelectric heat pump latent heat storage brings new ideas on waste recovery and off peak electricity storage, utilization of solar and other renewable energies.This paper also investigated the feasibility of heat recovery from exhaust by thermoelectric heat pump for water heating. Experiment verified that a thermoelectric heat pump system is more efficient than an electic heating decice, for its heating coefficient was always more than 1 when the temperature exhaust was higher than 26℃and the temperature of water was not higher than 46℃. On the base of the experiment data, a new kind of thermoelectric heat pump water heater for kitchens exhaust heat recovery was development by means of integrating thermoelectric heat pump with heat pipe heat sink. The higer the temperature of exhaust is, the larger the coefficient of performance becomes. Under an exhaust temperature of 33℃and operating voltage of 20V, performance tests illustrated that the new water heater can save more than 30% of the power consumption compared with that of conventional electric water heaters when the temperature of water increases from 28℃to 46℃. It is of great practical interest in building saving.