Chapter 9 - Solar-Assisted Heat Pumps

Abstract

This chapter presents the operation principle of a heat pump (HP), discusses the vapor-compression-based HP systems, and describes the thermodynamic cycle and the calculation, as well as operation regimes of a vapor-compression HP with electro-compressor. The calculation of greenhouse gas (GHG) emissions of HPs and energy and economic performance criteria that allow for implementing an HP in a heating/cooling system is considered. A detailed description of the HP types and ground-source HP (GSHP) development is presented and important information on the selection of the heat source and HP systems are discussed. Additionally, other approach is to integrate the solar thermal system on the source side of the HP so that the solar thermal energy is either the sole heat source for the HP or provides supplementary heat. Additionally, the operation principle and calculation of the thermodynamic cycle for a solar-assisted absorption HP are also briefly analyzed. Finally, analytical and experimental studies are performed on a direct-expansion solar-assisted heat pump (DX-SAHP) water heating system. The effects of various parameters, including solar radiation, ambient air temperature, collector area, storage volume and speed of compressor, are been investigated on the thermal performance of the DX-SAHP system. A novel heating, ventilating and air-conditioning system consisting of a solar-assisted absorption ground-coupled HP is also described, and some of the influence parameters on its energy efficiency is analyzed. A model of the experimental installation is developed using the TRNSYS software and validated with experimental results obtained in the installation for its cooling-mode operation.