The thermal masses of components influence the performance of many adsorption heat pump systems. However, typically when experimental adsorption systems are reported, data on thermal mass are missing or incomplete. This work provides original measurements of the thermal masses for experimental sorption heat exchanger hardware. Much of this hardware was previously reported in the literature, but without detailed thermal mass data. The data reported in this work are the first values reported in the literature to thoroughly account for all thermal masses, including heat transfer fluid. The impact of thermal mass on system performance is also discussed, with detailed calculation left for future work. The degree to which heat transfer fluid contributes to overall effective thermal mass is also discussed, with detailed calculation left for future work. This work provides a framework for future reporting of experimental thermal masses. The utilization of this framework will enrich the data available for model validation and provide a more thorough accounting of adsorption heat pumps.
•Simple unified equation works for diverse single-effect sorption heat pump types.•Efficiency differences among configuration types can be readily traced to root source.•Dead mass is defined in a utilizable way, with separate terms for design-related and inherent mass.•Configuration and working pair selection are made for resorption residential space heating.
Gas-driven sorption heat pumps (GDSHP) show significant potential to reduce primary energy use, associated emissions and energy costs for space heating and domestic hot water production in residential applications. This study considered a bivalent heating system consisting of a sorption heat pump and a condensing boiler, and focuses on the optimal heating capacity of each of these components relative to each other. Two bivalent systems were considered: one based on a solid chemisorption cycle (GDSHPA), and one based on a resorption cycle (GDSHPB). Simulations of year-round space heating loads for two single-family houses, one in New York and the other Minnesota, were carried out and the seasonal gas coefficient of performance (SGCOP) calculated. The sorption heat pump's design heating capacity as a fraction of the bivalent system's total heating capacity was varied from 0 to 100%. Results show that SGCOP was effectively constant for sorption heat pump design capacity greater than 41% of the peak bivalent GDSHPA design capacity in Minnesota, and 32% for GDSHPB. In New York, these values were 42% and 34% for GDSHPA and GDSHPB respectively. The payback period was also evaluated based on postulated sorption heat pump component costs. The fastest payback was achieved with sorption heat pump design capacity between 22 and 44%.
Sorption heat pumps are employed in various heat-driven cooling and heat pumping applications. These heat pumps may be driven by solar energy, natural gas, biogas, geothermal energy or waste heat. ...
Gas-driven sorption heat pumps (GDSHPs) exhibit possibilities in the reduction of energy use and environmental impact of heating systems that utilise natural gas. By utilising renewable thermal ene ...
Exploiting solar energy technology for both heating and cooling purposes has the potential of meeting an appreciable portion of the energy demand in buildings throughout the year. By developing an ...
Given the environmental benefits of utilizing free thermal energy sources, such as waste heat and solar energy for cooling purposes, many developments have come about in thermally driven cooling. However, there are still some barriers to the general commercialization and market penetration of such technologies that are associated with system and installation costs, complexity, and maintenance. In efforts to overcome these limitations, a novel absorption heat pump module has been developed and tested. The module comprises a fully encapsulated sorption tube containing hygroscopic salt sorbent and water as a refrigerant, sealed under vacuum, and within which there are no moving parts. The absorption module consists of two main components, one that alternately functions as an absorber or generator and other that alternates between the roles of evaporator and condenser. The module therefore operates cyclically between a cooling delivery phase and a regeneration phase. Each module has a significant energy storage capacity with cooling delivery phases ranging from 6-10 h in length with temperature lifts between 16 degrees C and 25 degrees C. The modules are optimized for integration directly into a solar thermal collector, for roof or facade installation, for daytime regeneration and night-time cooling delivery. Collector integrated modules would be completely modular maintenance-free absorption heat pumps with similar installation requirements to standard solar thermal collectors. This article describes the test method and performance characteristics of the individual absorption modules.
Currently the use of solar energy for heating and cooling isn’t widespread. In order to reduce primary energy consumption in the built environment along with improving the thermal performance of the current building stock, retrofit solutions are required to utilise renewable energy. Using solar energy to reduce primary energy consumption is seen as a possible solution. With the precipitous fall in the prices of crystalline solar photovoltaic modules, utilising this technology to reduce electrical energy consumption for cooling is an attractive solution. Recently, a sorption module integrated collector has been developed in order to improve cost-effectiveness and simplify solar thermal heating and cooling systems. A techno-economic analysis has been performed to evaluate solar photovoltaic cooling and solar thermal cooling systems for residential renewable energy retrofit. The analysis is based on potential energy and cost savings according to simulated heating and cooling loads under climatic conditions of Madrid, Spain. Simplified models were used to determine heating and cooling demands and the solar energy contribution to heating and cooling loads. Additionally, given the sorption collector's unique capacity to store solar energy thermally and provide cooling at night an analysis has been carried out to identify the combined benefit of solar-assisted heating and cooling via photovoltaics during the day and solar sorption at night. For system sizes between 5m2 and 20m2 solar fractions between 16% and 64% could be achieved which translated to annual energy cost savings between €153 to €615.
An enhanced-modularity thermally driven chemical heat pump was conceptualised as a second generation product for various heating and cooling applications with special emphasis on solar applications. The typical characteristics of the absorption heat pump were studied and the key performance parameters were selected for further investigation. An experimental test rig was constructed to allow for the testing of each component’s performance characteristics with special attention being paid to the ability to interchange components to test various configurations as well as to the facilitation of standardised relatively rapid testing. The heat transfer coefficient of the condenser/evaporator was found to be between 260 and 300 W/m2-°C during evaporation and between 130 and 170 W/m2-°C during condensation. Salt type has major impact on the system’s cooling power and cooling energy with the LiBr and water sorption pair having a 62% higher cooling/heating power than LiCl with the same matrix type and thickness. Matrix types and sorption pairs were compared with regards to the principal parameters of power and energy density with results ranging from 60 to 163 Wh/litre. The final section of the study tackled the theoretical foundation behind the system processes with modelling and simulation of the processes and comparison with the experimental data. The model makes the foundation of the continuous development of a more detailed and accurate physical model to enhance the design and optimisation process of the system.