Integrated solar-assisted heat pumps for water heating coupled to gas burners; control criteria for dynamic operation

Abstract

A direct expansion integrated solar assisted heat pump (ISAHP) is compared to a traditional flat plate solar panel for low temperature (45 °C) water heating applications. The (simulated) comparison is accomplished assuming both the devices are energy supplemented with an auxiliary standard gas burner, to provide the typical heat duty of a four-member family. Literature dynamical models of the systems involved have been used to calculate the main performance figures in a context of actual climatic conditions and typical stochastic user demand.The paper highlights new heat pump control concepts, needed when maximum energy savings are the main goal of the apparatus for given user demand. Simulations confirm the high collector efficiency of the ISAHP when its panel/evaporator works at temperature close to the ambient one. The device, with respect to a flat plate solar water heater, shows a doubled performance, so that it can do the same task just using an unglazed panel with roughly half of the surface.

Operational performance of a novel heat pump assisted solar façade loop-heat-pipe water heating system

“…Guoying et al [29] and Chow et al [30] reported numerical and theoretical investigations of solar assisted heat pump in their literatures. An ISAHP for water heating coupled to gas burners was reported by Scarpa et al [31] to perform a better performance of free energy use and obtain high COP values up to 8. Gang et al [32] performed an experimental study of PV-SAHP system, and obtained PV-SAHP COP of 9.0, a conventional SAHP COP of 6.3 an PV efficiency of 13.2%.…”

Cooperative Optimization of A Refrigeration System with A Water-Cooled Chiller and Air-Cooled Heat Pump by Coupling BPNN and PSO

“…In this paper, 144 samples were sampled, of which 83.3% (120) were used for BP model training, and the remaining 16.7% (24) were used to test the effectiveness of the model. The early stop is used to select the number of iterations that produce the minimum mean square error in training and testing.…”

“…In terms of comfort in air-conditioned environments, Kapalo et al [23] studied the interdependence between air parameters (air temperature, relative humidity, CO2 concentration) in airconditioned rooms. In terms of coupling with other cold and heat sources, Scarpa et al [24] analyzed the characteristics of the direct expansion solar combined air-cooled heat pump system and concluded that the dual heat source system has higher performance efficiency than the single heat source system. Wang et al [25] designed a solar-assisted air-cooled heat pump unit, and the simulation results show that its performance is better than that without solar-assisted air-cooled heat pump, which effectively improves the COP of the unit.…”

Performance Analysis of a Hybrid District Heating System: a Case Study of a Small Town in Croatia

“…Blake et al [33] showed that a hybrid DHS that consists of a heat pump and a CHP unit offers significant reductions in fuel consumption and operational costs. Scarpa et al [34] analysed the performance of a hybrid DHS composed of a heat pump and a gas boiler. A hybrid DHS composed of heat pumps and a thermal storage was analysed in research done by Pardo et al [35].…”