If you are learning about refrigeration engineering in 7th semester of your B-Tech so here I have attached a lecture notes PDF which has complete module to learn. This is full pdf including 85 pages with all basic concepts, examples, diagrams and definition etc. I hope you will find the pdf helpful.

UNIT-IMODULE-IAirRefrigeration Cycles

MODULE-IICompound VapourCompressionRefrigeration Systems

MODULE-IIIREFRIGERANTS

UNIT-IIMODULE-IVAIR – CONDITIONINGPSYCHOMETRY