The main concept of combined cooling, heating and power (CCHP) generation systems, which produce three energy commodities simultaneously, is based on using absorption chillers fired by the waste heat from the engine instead of electricity for air conditioning or for any other cooling purpose where electricity could have been used. Proper selection and design of the heat recovery system plays an important and challenging role in achieving this goal. Minimum exergy destruction in the waste heat recovery process increases the thermal performance. This paper introduces the modulating flow cascade heat recovery system (CHRS) to improve the coefficient of performance (COP) of the absorption chiller at part load engine operation. Due to this novel feature, it is possible to obtain a percentage increase of over 13% in COP at 50% engine load compared to the conventional fixed flow waste heat recovery.