power per unit meaning in English

单机容量

The immersion electrical heater is chiefly applied in the direct contact mode of fluid heating . it features fast heat exchange and high thermal efficiency . it has the varieties of water heater , oil heater and gas heater . its heating element power density , i . e . the power per unit of heating area of the heating element , is an important parameter of the electrical heating element , which has a direct bearing on the performance and working life . the working out of the value is a highly specialized problem , being under the influence of many factors ( media flow rate , tempt , physical and chemical properties and direction in which the medium flows past the element etc )
浸入式电加热器主要用于直接对流体接触加热的场合，具有热交换快，热效率高等特点，分为水用加热器、油用加热器、气体用加热器，加热元件的功率密度：即电加热元件单位发热面积上的功率，它是电加热元件极重要的参数，直接影响加热器的使用性能及使用寿命，它的取值是一个非常专业的问题，受到许多因素的影响（如介质的流速、温度、物理和化学性质及介质流过加热元件的方向等等）。