MODEL-BASED SIMULATION OF A SOLAR THERMAL HEAT PUMP HYBRID SYSTEM

Abstract

The pace at which the increase in urbanization and unprecedented increasing population growth do not commensurate with rising energy demand. This has led to energy shortage, and the consequence is quite dominant in hot water energy demanding applications that predominantly relies on energy for thermal comfort and domestic use. However, the reliance on fossil fuel to generate the needed energy has not only posed a colossal threat to the world climate but also has a significant direct impact on the inhabitants’ life expectancy. Residential building such as hotels, hostels, etc. and industrial sectors like chemical, brewery and food industries in Nigeria with the substantial requirement for heating often experience an increase in net annual energy demand and the existing infrastructure could not accommodate for the increase since the peak energy demand. However, the combination of heat pumps and solar components is a recent development and has great potential for improving the efficiency of the house and the hot water system. Hence, a solar thermal heat pump hybrid system (STHPHS) has been seen as an effective means of achieving an energy conservation measures to sustain zero-emission and also serves as alternative means to improve energy imbalance by reducing electricity charges through optimizing the operation of the heat pump, integrating the available solar energy and by shifting electricity consumption to the low-cost night-time tariffs. In this paper, the facility is based on a five-year-old on-campus field with 50m2 flat plate solar collector, which operated for a domestic hot water application and the working parameters were recorded during an entire year for periods of 10 minutes. This paper presents a novel mathematical model and simulation of solar-thermal heat pump hybrid system for energy conservation in a building. An ordinary differential equation (ODE) models are proposed for a wide sort of solar heating systems with a solar collector, a heat exchanger, a boiler tank, heat pump and pipes and to simulate dynamics accurately pipe sections were used for Solar Thermal Collectors (STC) and Heat Exchanger (HE). The hybrid system is modelled with MATLAB/Simulink computation environment and the yearly energy performance was simulated. The model was experimentally validated by comparing its results to the instant thermal collector temperatures and the hybrid system that were obtained from the experimental database. The result shows that the system coefficient of performance is higher than the conventional fossil fuel-based hot water-heating method and in terms of energy savings, the hybrid system is optimally economical.