专业英语课程作业.docVIP

专业英语（2）课程作业 组长：无 小组成员：徐海龙（热能091班 33号），文增岩（热能092班34号），洪育免（热能091班35号），张泽林（热能092班 32号），林旭丹（热能092班33号），廖禄辉（热能092班34号）， 张泽林：P42-P45 3.2 PLOTTING THE REFRIGERANT 绘制制冷循环 A graphic picture of the refrigerant cycle may be plotted on a pressure/enthalpy diagram. Enthalpy describes how much heat a substance contains from some starting point. Many people refer to enthalpy as total heat .This is not an absolutely accurate state. It is a convenient statement because it is the total heat from a starting point. Refer to Figure 1-13, the heat/temperature graph for water. We used 0癋 as the starting point of heat for water, knowing that you can really remove more heat from the water(ice) and lower the Ttemperature below 0癋. We described the process as the amount of heat added starting at 0癋. This heat is called enthalpy. A similar diagram is available for all refrigerants; it is 制冷called a pressure /diagram and is used to pot the refrigerant cycle in a complete loop, Figure3-41.The pressure/enthalpy diagram plots pressure on the left hand column and enthalpy or total heat on the bottom of the diagram. The enthalpy readings start at -40癋. saturated liquid with a heat content of 0 Btu/lb. Readings below -40癋 saturated liquid show as minus values. Notice, e temperature corresponds to pressure and is plotted on the inside of the chart along the left and right of the horseshoe-shaped curve. 一个形象的制冷循环可以绘制在一张压焓图表上。焓表示物质含有热量的多少。很多人将焓定义为全热。这是一个不完全准确的说法。之所以有这种随意的规定是因为全热是从一个温度开始点算起。在水的温度图表上我们可以查阅1-13度。我们把0摄氏度作为水温的起点，当水或冰的温度低于0摄氏度时候就会放出热量。我们可以描述从开始0摄氏度升温的全部过程。这个热量称为焓。一个相似的图表可以适用于所有的制冷循环；这个称为压焓图可以绘制制冷循环为一个完整循环，图3—41压焓图上的纵坐标上表示压力，横坐标上表示全热或焓。 在压焓图上，焓从-40°开始描绘。饱和液体含有0背光链路或磅。低于-40°的饱和液体出现不足的价值。值得注意的是，在图表上从左边到右边温度随着压力呈现驼峰型曲线的形状。 The horseshoe-shaped curve is the saturation curve with the temperature corresponding to the absolute pressure. Anytime a plot falls on this curve, the refrigerant is saturated with heat. There are two saturation curves: the one on the left is the saturated liquid curve. If