Development of Low Temperature Waste Heat Driven Advanced Adsorption Refrigeration System

在3.5 kW额定容量的两级高级硅胶-水吸附制冷机上进行了实验，以确定运行条件（水温和水质量流量）对制冷量和COP的影响。热水、冷却水和冷冻水的标准工作温度分别为55℃、30℃和14℃。换热流体入口和出口的实验温度分布表明，400s后，热水和冷却水温度接近各自的进口温度。因此，我们选择标准吸附/解吸循环时间为420 s。然而，在整个循环中，冷冻水温度持续低于进口温度，这意味着仍然有冷却能量产生。通过在50 ~ 64℃范围内改变热水温度，研究其对制冷量和COP的影响。当入口热水温度从50℃上升到6℃时，冷却能力增加，冷却水温度为30℃。这是因为随着驱动源温度的升高，制冷剂解吸量增加，制冷剂循环量增加。随着热水温度的变化，COP峰值在55 ~ 58℃之间，表明该温度范围是冷水机组有效运行的理想温度范围。对不同散热器温度下的制冷量和COP变化进行了实验研究。冷却水温度越低，制冷量和COP越高。这种趋势反映了这样一个事实，即较低的吸附温度导致大量的制冷剂被吸附。冷冻水温度变化的实验结果表明，随着冷冻水入口温度的升高，制冷量和COP呈线性增加。但输送的冷冻水温度也随着冷冻水入口温度的升高而升高。对不同流量的热水、冷却水和冷冻水的制冷量和COP变化进行了实验研究。实验数据表明，在研究范围内，随着热流量、冷流量和冷冻水流量的增加，制冷量稳步增加。COP的制冷量也有类似的变化趋势。实验结果表明，先进的两级冷水机适用于低温热源（~ 55℃）作为驱动源，冷却源为30℃。使用两级冷水机组克服了在这样一个小的再生温度升程（驱动源和汇之间的温差）下运行循环所固有的技术困难。少

Experiments were conducted on a 3.5 kW rated capacity two-stage, advanced silica gel-water adsorption chiller to determine the influence of operating conditions (water temperatures and water mass flow rates) on cooling capacity and COP. The standard operating temperatures for hot, cooling and chilled water are respectively taken as 55℃, 30℃ and14℃. Experimental temperature profiles of the heat transfer fluid inlets and outlets showed that after 400 s, the hot and the cooling water temperatures approach their respective inlet temperatures. This led us to select the standard adsorption/desorption cycle time as 420 s. The chilled water temperature, however, continues to be lower than the inlet temperature in the whole cycle, which means that there is still cooling energy production. Experiments were performed by varying hot water temperatures between 50 and 64℃ to determine its effect on cooling capacity and COP. Cooling capacity rises as the inlet hot water temperature rises from 50 to 6 … More 0℃ with a cooling water at 30℃. This is because the amount of refrigerant circulation increases due to increased refrigerant desorption with higher driving source temperatures. With hot water temperature variation, the COP peaks between 55 and 58℃ shows that this temperature range is ideal for the chiller to operate effectively. Experiments were conducted on cooling capacity and COP variations with various heat sink temperatures. Both cooling capacity and COP increase with lower cooling water temperatures. This tendency reflects the facts that lower adsorption temperature result in larger amounts of refrigerant being adsorbed. Experimental results for chilled water temperature variations showed that cooling capacity and COP increase linearly with increasing chilled water inlet temperatures. But the delivered chilled water temperature also increases with increasing chilled water inlet temperatures. Experiments were also performed on cooling capacity and COP variations with various flow rates of hot water, cooling water and chilled water. Experimental data indicate that cooling capacity increases steadily with the increase of hot, cooling and chilled water flow rates in the range studied. COP also has the similar tendency of cooling capacity. From the experimental evidence it can be concluded that the advanced two-stage chiller is well suited to utilize low-temperature thermal heat (〜55℃) as the driving source with a cooling source of 30℃. The technological difficulty inherent in operating a cycle with such a small regenerating temperature lift (temperature difference between driving source and sink) is overcome by use of a two-stage chiller. Less