Performance Of Chemical Heat Pump Research Articles

Performance analysis of Isopropanol–Acetone–Hydrogen chemical heat pump

The performance of an Isopropanol–Acetone–Hydrogen (IAH) chemical heat pump system is investigated in terms of enthalpy efficiency (COP) and exergy efficiency, in which the exothermic and endothermic reactions take place in the gas phase. The increase of reflux ratio, temperature of endothermic reaction and temperature of exothermic reaction reduces the performance of the heat pump when the other operating parameters remain unchanged. However, the performance of the IAH chemical heat pump improves with the increase of the ratio of molar quantity of hydrogen to that of acetone in the entry of exothermic reactor and the number of heat transfer units of regenerator. Generally, a better performance of the chemical heat pump corresponds to a larger number of trays in the distillation column. The performance of the system can be improved significantly after multi-parameter optimization design. The coefficient of performance (COP) pays more attention to the heat released from the exothermic reactor, while the exergy efficiency takes into consideration of both heat released from the exothermic reactor and temperature of exothermic reaction.

Performance analysis of solar-assisted chemical heat-pump dryer

A solar-assisted chemical heat-pump dryer has been designed, fabricated and tested. The performance of the system has been studied under the meteorological conditions of Malaysia. The system consists of four main components: solar collector (evacuated tubes type), storage tank, solid–gas chemical heat pump unit and dryer chamber. A solid–gas chemical heat pump unit consists of reactor, condenser and evaporator. The reaction used in this study (CaCl2–NH 3). A simulation has been developed, and the predicted results are compared with those obtained from experiments. The maximum efficiency for evacuated tubes solar collector of 80% has been predicted against the maximum experiment of 74%. The maximum values of solar fraction from the simulation and experiment are 0.795 and 0.713, respectively, whereas the coefficient of performance of chemical heat pump (COP h ) maximum values 2.2 and 2 are obtained from simulation and experiments, respectively. The results show that any reduction of energy at condenser as a result of the decrease in solar radiation will decrease the coefficient of performance of chemical heat pump as well as decrease the efficiency of drying.

An experimental analysis of solar-assisted chemical heat pump dryer

The performance of a solar-assisted chemical heat pump dryer has been studied under the meteorological conditions of Malaysia. The system consists of four mean components: solar collector (evacuated tubes type), storage tank, solid--gas chemical heat pump (CHP) unit and dryer chamber. A solid--gas CHP unit consists of a reactor, condenser and evaporator. The reaction (CaCl 2 --NH 3 ) has been used in this study. A series of experiments have been performed on the system under varied conditions for two days. The maximum values of solar fraction from the experiments on clear and cloudy days are 0.713 and 0.322, respectively; whereas the coefficient of performance of CHP (COP-super-h) maximum values of 2 and 1.42 are obtained from the experiments on clear and cloudy days, respectively. The total system energy output from the experiment on a clear day is 51 kWh against 25 kWh on a cloudy day. Any reduction of energy at the condenser as a result of decrease in solar radiation will decrease the coefficient of performance as well as the efficiency of drying. Copyright The Author 2009. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org, Oxford University Press.

Review of Recent Patents on Chemical Heat Pump

The concerns of energy consumption and environmental pollution urge researchers to work on the development of clean energy and the utilization of waste energy. Sorts of novel technologies were developed and the achievements were patented. Among these patents, chemical heat pump system, is one important topic. It utilizes the transformation between potential energy and thermal power energy to realize the performance of heat pumping and refrigeration. The thermal-potential tansformation reversible reaction in chemical heat pump mainly includes liquid-gas absorption, solid-gas reaction and solid adsorption. According to the characteristic of transformation reaction, chemical heat pump is classified into mono-variant system and di-variant system. The mono-variant system includes solid-gas reaction system and liquid-gas reaction system, etc, the di-variant system is also known as solid adsorption system. In this paper, novel technology on chemical heat pump system and its components was surveyed and typical patents were introduced. With the achievements disclosed in these critical patents, the performance of chemical heat pump could be significantly improved.