Investigation of a mixed effect absorption chiller powered by jacket water and exhaust gas waste heat of internal combustion engine

• Jacket water and exhaust gas waste heat of ICE is used to power a mixed effect AC.
• Considering thermodynamic constraints, SPT of LG1 is 77 °C or lower.
• The mixed effect degree depends on the heating source proportion.
• For a 16 kW ICE, cooling output can reach 34.4 kW with COP of 0.96.
• CCHP system performance can be obviously improved by using mixed effect AC.

CCHP (combined cooling heating and power) system based on ICE (internal combustion engine) has been widely used. A key issue is to efficiently recover the jacket water and exhaust gas waste heat for refrigeration. In this work, a mixed effect absorption chiller (AC), which couples single effect and double effect processes together, is investigated to recover these two kinds of waste heat simultaneously. The high pressure generator is powered by exhaust gas while one low pressure generator is powered by jacket water waste heat. Thermodynamic characteristics and off-design performance are simulated. Considering thermodynamic constraints, the start point temperature in low pressure generator should be 77°Cor lower. For a 16 kW ICE, the cooling output can reach 34.4 kW with COP of 0.96 and exergy efficiency of 0.186. Comparing with double effect or single effect AC, it can make a better use of different waste heat in CCHP system.