internal heat generation

例句：

1. 1. Themachine generates heat internally during operation.
   这台机器在运行过程中会产生内部热量。
2. 2.The process of generating internal heat is essential for the operation of the engine.
   产生内部热量的过程对于发动机的运行至关重要。
3. 3.The company's internal heat generation has been reduced by 20% compared to last year.
   与去年相比，该公司的内部热产生量减少了20%。