Study on the Performance of a Ground Source Heat Pump System Assisted by Solar Thermal Storage

Abstract

Abstract:A ground source heat pump system (GSHPS) utilizes a relatively stable underground temperature to achieve energy-saving for heating and cooling in buildings. However, continuous long-term operation will reduce the soil temperature in winter, resulting in a decline in system performance. In this research, in order to improve the system performance of a GSHPS, a ground heat pump system integrated with solar thermal storage was developed. This solar-assisted ground heat pump system (SAGHPS) can both maintain the balance of the soil temperature effectively and achieve higher system performance than the conventional system. In this paper, in order to examine the characteristics of the system, a dynamic simulation was conducted under various conditions. The results of our case study provide specific operation data such as heat exchange rate, heat source temperature, and heat pump COP. As a result, the heat pump COP of SAGHPS was 4.7%, 9.3% higher than that of the GSHPS.

Research on a Household Dual Heat Source Heat Pump Water Heater with Preheater Based on ASPEN PLUS

“…called a "heat sink". Various forms of heat pump (HP) technology have been gradually popularized in recent years, such as air source heat pump (ASHP) technology (extracting heat from air), wastewater source heat pump (WSHP) technology (extracting heat from wastewater), ground source heat pump (GSHP) technology (extracting heat from ground) [3] and underground water source heat pump (UWSHP) technology (extracting heat from underground water) [4]. Among all these heat pump technologies, ASHP and WSHP technologies play an important role [5].…”

Seasonal Thermal-Energy Storage: A Critical Review on BTES Systems, Modeling, and System Design for Higher System Efficiency

“…BTES is a prevalent choice of seasonal storage because of its universal applicability, not limited to specific formations as with ATES and GWTES [30,32,33,36,46,48]. However, variations in climate can impact the performance of BTES systems [79]. Limitations of BTES include the comparatively large amount of heat loss compared to insulated water tank or gravel tank systems [30,56].…”

“…The higher temperature of the systems ensure the longevity and efficiency of the BTES and GSHP system in colder climates [47,89]. Nam et al find that GSHP systems coupled with solar thermal energy can maintain better soil temperature balances to perform at higher COPs over the lifetime of the system [79]. Sliwa and Rosen summarize a number of natural and artificial heat regeneration options for BTES alternative to solar thermal coupling [90].…”

Effect of an Off-Peak Ground Pre-Cool Control Strategy on Hybrid Ground-Source Heat Pump Systems

“…The GSHP system transient COP response as a function of cycle time is estimated for experimental data presented by Alzahrani (2013). Utilizing the numerically generated data presented by Nam et al (2015), a set of linear correlations were generated and used to predict the bore-field's response to pre-cooling and resulting impact on GSHP cooling output/COP. The developed numerical model simulates two physical responses to the presence of a pre-cooled bore-field, an increase in the rate of heat rejection to the ground during cooling operation (increase in cooling output) and an increase in the GSHP system COP (reduced compressor compensation).…”

“…This technique employs a solar thermal collector to heat the ground-loop working fluid, which is circulated through a bore-field to pre-heat the surrounding soil prior to a dwelling requiring heat. The literature suggests significant improvements in solar assistant geo-exchange system efficiency, resulting in a 28.1% increase in bore-field heat excahnge rates and 8.74% to 9.3% increase in the coefficient of performance (COP) (Nam et al 2015;Verma and Murugesan 2014).…”