Vapour compression heat pump is driven using electrical energy or shaft power as input energy, while the energy input to the absorption, adsorption and ejector type heat pumps is in the form of heat. This heat can be obtained by direct burning of fuel or by recovering heat from various waste heat sources.Safe, service free and reliable integration of MU_HPs depends to a great extent on the heat exchangers used to transfer heating and cooling effect from the refrigerant in the MU_HP and the process fluids/utility streams. Several challenges, with respect to reliability of operation, durability of the equipment, meeting the constraints of space, weight and cost, have restricted tapping into these opportunities.

Patented technologies, like the Tube-Tube Heat Exchanger (TT_HE), Rane and Tandale (2002), for heat recovery and exchange using a reliable vented double wall construction, and Multi-Utility Heat Pump (MU_HP), Rane and Das Gupta (2003) are some examples of technologies which have opened up the possibilities to encash the above listed opportunities. Proper application engineering is essential to ensure success in saving initial and/or operating cost while simultaneously being environment friendly.

This article presents some such opportunities for co-and tri-generating various cold and hot utilities using Tube-Tube Heat Exchangers (TT_HE) and Multi-Utility Heat Pumps (MU_HP) developed at Heat Pump Laboratory in IIT Bombay (HPL_IITB). Techno-economic benefits of these MU_HPs deployed in commercial and industrial applications are discussed.