Model And Experimental Investigation On Diffusion Absorption Heat Pump

Ammoniar diffusion absorption heat pump system structure is simple without moving parts, that can be directly drived with gas,waste heat or solar. Its performance study has important meaning.This research mainly concentrated on the following four aspects:The first , through the experimental method, it researches the relationship between bubble pump hoisting load VL and quantity of steam VG . By using data regression method, it concludes the relation model between VL and VG : VL=0.0205 +0.0691: The correlation is R2=0.9707. Combined with ammonia - water model and based on mass conservation, energy conservation, diffusion absorption heat pump system constructed thermal model.The second, by setting up the water-cooled experiment platform and the system thermal model, the effect of input power, filling concentration, absorbent temperature, Filling pressure and condensing temperature on the system refrigeration and heating performance in certain conditions is researched. The results show that: the optimal input power of prototype is 240W when the coefficient of performance is 0.253 and the heating coefficient is 1.19. Filling concentration is greatly influenced by the absorbing temperature. When the absorbing temperature is 36℃,45℃,51℃,the most appropriate concentration respectively is 0.40 g/g, 0.35 g/g ,0.28 g/g. When the hydrocarbon-charging pressure promote from 1.8MPa to 2.4MPa, the start time of prototype increased 39.3%. Studies indicate that there exists a critical absorbent temperature and the promoting of it has little effect on performance. When the filling concentration is 0.30 g/g or 0.40 g/g, the critical absorbent temperature is about 45℃.When the condensate temperature increases, the system efficiency decreases. Refrigerating capacity drops 10W, 16% declines, when the condensate temperature rose from 47℃to 53℃.The third, in the four XCD-120 diffusion absorption heat pump refrigerator of practical application with same structure, this thesis makes a study on the parameter's influence on the system in different environment; In the district with the mean annual temperature under 20℃, the optimal filling concentration, input power, and pressure is 0.35,120W,1.6MPa respectively. In the district with the mean annual temperature between 20℃～25℃, the optimal filling concentration, input power, and pressure is 0.30,150W, 2.0 MPa respectively; while in the district with the temperature above 30℃, the optimal filling concentration, input power, and pressure is 0.25,150W,2.2 MPa. The fourth, a diffusion absorption heat pump refrigerator with 1200W was designed and manufactured. A preliminary research was also be made to analyze its heating performance in terms of experiment. The result exhibits that the heating efficiency is 1.05~1.11 when the input power is between 750W~1500W.