The purpose of the work is the development of environmentally friendly technology of heat recovery from condensation of water vapor at a constant partial pressure of the outgoing flue gases in contact heat exchangers with a passive nozzle at thermal power plants running on natural gas, and the use of solar heaters in the block structure of an absorption refrigerating machine. Using contact heat exchangers can reduce greenhouse gas emissions. Greenhouse gas is harmful to the environment. Using solar heaters can improve the efficiency of the Li-Br absorption refrigerating machine. Ways to improve the efficiency of industrial enterprises are different. One of the main ways is to use renewable energy for heat recovery. In addition, the use of renewable energy sources reduces emissions of harmful greenhouse gases into the atmosphere.