Heat pumps using

Technology exists to recover heat from processes operating at all temperatures, from regenerators on high-temperature plant to heat pumps using low-temperature effluent as a heat source. The problem in many cases is to find a use for the heat recovered. The best solution is to recycle the heat within the same plant, as the supply will always be matched to the demand. An alternative is to use the heat recovered in associated plant (for example, the heat recovered from a melting furnace can be used to dry feedstock for the furnace). 

Space savings arising from the smaller size of boiler and cooling tower is offset by the addition of central heat pump. Use of fan coil units at the zone level is not expected to result in space savings because of larger requirement of air flow arising from lower temperature difference across the heating coil. 

Figure 19 depicts a water-loop heat pump system where the cooling tower and boiler have been replaced with a ground heat exchanger. This is the most common configuration of ground source heat pump used in commercial buildings. 

Chemical heat pump uses chemical reaction for thermal energy storage and conversion. The heat pump operation is based on reaction equilibrium relationship, and has two operation modes. Figure 221 shows equilibrium relationship of chemical heat pump cycle for Mg0/H20 system at (a) heat amplification and cooling mode and (b) heat transformation mode [26], Figure 222 shows... 

An ideal heat pump uses ammonia as the working fluid. The saturation temperature of the refrigerant in the evaporator is 22°F and in the condenser it is 98°F. The refrigerant is circulated at the rate of 0.051 Ibm/sec. Determine the compressor power required, heating load, and COP of the heat pump. 

High-temperature chemical heat pump using hydrogen-absorbing alloys Energy conversion efficiency... 

FIG. 13-75 Heat pumps transfer heat from the top to the bottom of the column, (a) External fluid heat pump, (h) Heat pump using column overhead, (c) Heat pump using column bottoms. 

Fig. 11.14. Process flow sheet of cyclohexane/benzene heat pump using hydrogen permeable membranes Rdit and R/rdehydrogenation and hydrogenation reactors C, compressors T, turbine HE, heat exchangers CHE, counter-current heat exchangers P, liquid pump M, hydrogen membranes. Reproduced from Cacciola et al. [133] with permission.

For a heat pump used in the central heating system, the refrigerant has to assess by selfdeclaration. 

AIR COIL - Coil on some types of heat pumps used either as an evaporator or a condenser. 

K. Kldcker, E.L. Schmidt, F. Steimle, A drying heat pump using carbon dioxide as working fluid, Drying Technology, 20(8) 1659-1671, (2002). 

Both absorption and adsorption are inhibited in their intensification potential by heat and mass transfer limitations. The method applied in Rotex above has been successful in intensifying the absorption cycle, but the adsorption refiigerator or heat pump uses a solid and a gas as working media and active enhancement of the solid can be difficult. 

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