自然对流磁制冷工作原理及影响因素试验研究

Experimental research on operation theory and impact factors of natural convective magnetic refrigeration

试验研究了自然对流磁制冷样机工作原理的可行性以及换热过程的影响因素。试验在环境温度和压力下进行,试验件是背面粘有锰铜加热丝的铝板。通过调节加热丝上的电压,调节热流量,来模拟磁制冷样机中工质的磁化过程。制冷工质相当于多个竖直矩形窄通道构成的圆环。试验件间隙分别为1.5、2.5、5和10 mm,宽为40 mm,高为50 mm。试验结果表明:板间距的大小对换热性能有很大影响,较小的板间距能很好的提高换热性能;板高与板间距之比对换热性能也有较大影响,较大的板高-板间距比可以得到较大的传热系数;自然对流磁制冷样机的工作原理是可行的。

Feasibility of the operation theory and impact factors of the heat transfer process for a natural convection typed magnetic refrigeration prototype were studied experimentally. The experiments were carried out at ambient temperature and pressure. The test part consisted of two aluminum plates with manganin heating wires stuck at back sides. The magnetic refrigerant magnetization of the magnetic refrigeration proto- type was simulated through adjusting the heating voltages of heating wires, corresponding to adjust the heat flux. The magnetic refrigerant corresponds to an annulus that consists of many numbers of vertical narrow rectangular channels. The dimensions of the four channels investigated were 50 mm in height, 40 mm in width and 1.5 mm, 2.5 mm, 5 mm and 10 mm in the gap depth respectively. The experiment results show that the gap depth and the height-gap ratio have significant effect on heat transfer performance, also indicate that the operation theory of the natural convective magnetic refrigeration prototype is feasible.