scholarly journals Geoexchanger System for Buildings Heating and Cooling

Geothermal heat pumps (GSHPs), or direct expansion (DX) ground source heat pumps, are a highly efficient renewable energy technology, which uses the earth, groundwater or surface water as a heat source when operating in heating mode or as a heat sink when operating in a cooling mode. It is receiving increasing interest because of its potential to reduce primary energy consumption and thus reduce emissions of the greenhouse gases (GHGs). The main concept of this technology is that it utilises the lower temperature of the ground (approximately <32°C), which remains relatively stable throughout the year, to provide space heating, cooling and domestic hot water inside the building area. The main goal of this study is to stimulate the uptake of the GSHPs. Recent attempts to stimulate alternative energy sources for heating and cooling of buildings has emphasised the utilisation of the ambient energy from ground source and other renewable energy sources. The purpose of this study, however, is to examine the means of reduction of energy consumption in buildings, identify GSHPs as an environmental friendly technology able to provide efficient utilisation of energy in the buildings sector, promote using GSHPs applications as an optimum means of heating and cooling, and to present typical applications and recent advances of the DX GSHPs. The study highlighted the potential energy saving that could be achieved through the use of ground energy sources. It also focuses on the optimisation and improvement of the operation conditions of the heat cycle and performance of the DX GSHP. It is concluded that the direct expansion of the GSHP, combined with the ground heat exchanger in foundation piles and the seasonal thermal energy storage from solar thermal collectors, is extendable to more comprehensive applications.

2019 ◽  
Vol 3 (2) ◽  

In the recent attempts to stimulate alternative energy sources for heating and cooling of buildings, emphasise has been put on utilisation of the ambient energy from ground source heat pump systems (GSHPs) and other renewable energy sources. Exploitation of renewable energy sources and particularly ground heat in buildings can significantly contribute towards reducing dependency on fossil fuels. The study was carried out at the Energy Research Institute (ERI), between September 2016 and November 2017. This paper highlights the potential energy saving that could be achieved through use of ground energy source. The main concept of this technology is that it uses the lower temperature of the ground (approximately <32°C), which remains relatively stable throughout the year, to provide space heating, cooling and domestic hot water inside the building area. The purpose of this study, however, is to examine the means of reducing of energy consumption in buildings, identifying GSHPs as an environmental friendly technology able to provide efficient utilisation of energy in the buildings sector, promoting the use of GSHPs applications as an optimum means of heating and cooling, and presenting typical applications and recent advances of the DX GSHPs. It is concluded that the direct expansion of GSHP are extendable to more comprehensive applications combined with the ground heat exchanger in foundation piles and the seasonal thermal energy storage from solar thermal collectors. This study highlights the energy problem and the possible saving that can be achieved through the use of the GSHP systems. This article discusses the principle of the ground source energy, varieties of GSHPs, and various developments.


2013 ◽  
pp. 261-278
Author(s):  
Abdeen Mustafa Omer

In the recent attempts to stimulate alternative energy sources for heating and cooling of buildings, emphasis has been put on utilisation of the ambient energy from ground source and other renewable energy sources. Exploitation of renewable energy sources and particularly ground heat in buildings can significantly contribute towards reducing dependency on fossil fuels. This paper highlights the potential energy saving that could be achieved through use of ground energy source. It also focuses on the optimisation and improvement of the operation conditions of the heat cycles and performances of the DX GSHP. It is concluded that the direct expansion of GSHP are extendable to more comprehensive applications combined with the ground heat exchanger in foundation piles and the seasonal thermal energy storage from solar thermal collectors. This article discusses the principle of the ground source energy, varieties of GSHPs, and various developments.


2012 ◽  
Vol 1 (2) ◽  
pp. 41-58 ◽  
Author(s):  
Abdeen Mustafa Omer

In the recent attempts to stimulate alternative energy sources for heating and cooling of buildings, emphasis has been put on utilisation of the ambient energy from ground source and other renewable energy sources. Exploitation of renewable energy sources and particularly ground heat in buildings can significantly contribute towards reducing dependency on fossil fuels. This paper highlights the potential energy saving that could be achieved through use of ground energy source. It also focuses on the optimisation and improvement of the operation conditions of the heat cycles and performances of the DX GSHP. It is concluded that the direct expansion of GSHP are extendable to more comprehensive applications combined with the ground heat exchanger in foundation piles and the seasonal thermal energy storage from solar thermal collectors. This article discusses the principle of the ground source energy, varieties of GSHPs, and various developments.


Author(s):  
Birol I. Kilkis

Effective utilization of low-enthalpy energy resources in heating, ventilating, and air-conditioning (HVAC) of sustainable buildings require a careful optimization to assure the most economical coupling of HVAC systems with low-enthalpy energy resources. In one of the two separate prior studies an optimization algorithm for the optimal coupling of heat pumps and radiant panel heating and cooling systems was developed. In the second prior study an optimization algorithm for driving ground source heat pumps with wind turbines was developed. In this study these two algorithms were combined for a compound utilization of alternative energy resources. This paper describes the optimization algorithms, emphasizes their importance in achieving a cost effective combined application, and discusses the results obtained from the examples given.


Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2971
Author(s):  
Rok Koželj ◽  
Eneja Osterman ◽  
Fabrizio Leonforte ◽  
Claudio Del Pero ◽  
Alessandro Miglioli ◽  
...  

When considering the deployment of renewable energy sources in systems, the challenge of their utilization comes from their time instability when a mismatch between production and demand occurs. With the integration of thermal storages into systems that utilize renewable energy sources, such mismatch can be evened out. The use of phase-change materials (PCMs) as thermal storage has a theoretical advantage over the sensible one because of their high latent heat that is released or accumulated during the phase-change process. Therefore, the present paper is a review of latent thermal storages in hydronic systems for heating, cooling and domestic hot water in buildings. The work aims to offer an overview on applications of latent thermal storages coupled with heat pumps and solar collectors. The review shows that phase-change materials improve the release of heat from thermal storage and can supply heat or cold at a desired temperature level for longer time periods. The PCM review ends with the results from one of the Horizon2020 research projects, where indirect electrical storage in the form of thermal storage is considered. The review is a technological outline of the current state-of-the-art technology that could serve as a knowledge base for the practical implementation of latent thermal storages. The paper ends with an overview of energy storage maturity and the objectives from different roadmaps of European bodies.


2020 ◽  
Author(s):  
Eric Wagner ◽  
Benjamin McDaniel ◽  
Dragoljub Kosanovic

Ground-source heat pump (GSHP) systems have been implemented at large scales on several university campuses to provide heating and cooling. In this study, we test the idea that a GSHP system, as a replacement for an existing Combined Heat and Power (CHP) heating system coupled with conventional cooling systems, could reduce CO2 emissions, and provide a cost benefit to a university campus. We use the existing recorded annual heating and cooling loads supplied by the current system and an established technique of modeling the heat pumps and borehole heat exchangers (BHEs) using a TRNSYS model. The GSHP system is modeled to follow the parameters of industry standards and sized to provide an optimal balance of capital and operating costs. Results show that despite a decrease in heating and cooling energy usage and CO2 emissions are achieved, a significant increase in electric demand and purchased electricity result in an overall cost increase. These results highlight the need for thermal energy storage, onsite distributed energy resources and/or demand response in cases where electric heat pumps are used to help mitigate electric demand during peak periods.


Author(s):  
Abdeen Mustafa Omer

The move towards a low-carbon world, driven partly by climate science and partly by the business opportunities it offers, will need the promotion of environmentally friendly alternatives, if an acceptable stabilisation level of atmospheric carbon dioxide is to be achieved. This chapter presents a comprehensive review of energy sources, and the development of sustainable technologies to explore these energy sources. It also includes potential renewable energy technologies, efficient energy systems, energy savings techniques and other mitigation measures necessary to reduce climate changes. The chapter concludes with the technical status of the ground source heat pumps (GSHP) technologies. The purpose of this study, however, is to examine the means of reduction of energy consumption in buildings, identify GSHPs as an environmental friendly technology able to provide efficient utilisation of energy in the buildings sector.


2020 ◽  
Vol 165 ◽  
pp. 01013
Author(s):  
Linfeng Wang ◽  
Kai Zhang ◽  
Nan Xu ◽  
Jingyan Wang ◽  
Danyang Zhang ◽  
...  

With the depletion of fossil energy and the popularity of renewable energy, a comprehensive energy system with the goal of improving system energy efficiency and consuming renewable energy is booming. Based on the combined heat, power, and heat generation, this paper builds a comprehensive energy system operation optimization model in conjunction with ground source heat pumps. It aims to find the optimal operation strategy based on the actual situation of the park’s load, equipment capacity, and energy prices. Using the linear programming method, a mathematical model with the best economic efficiency of the integrated energy system is established, the optimal operation strategy for a typical day is analyzed, and the annual operation is simulated. Finally, it compares with conventional energy supply methods and analyzes the contribution to the consumption of renewable energy.


Energies ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2496 ◽  
Author(s):  
Laura Carnieletto ◽  
Borja Badenes ◽  
Marco Belliardi ◽  
Adriana Bernardi ◽  
Samantha Graci ◽  
...  

The design of ground source heat pumps is a fundamental step to ensure the high energy efficiency of heat pump systems throughout their operating years. To enhance the diffusion of ground source heat pump systems, two different tools are developed in the H2020 research project named, “Cheap GSHPs”: A design tool and a decision support system. In both cases, the energy demand of the buildings may not be calculated by the user. The main input data, to evaluate the size of the borehole heat exchangers, is the building energy demand. This paper presents a methodology to correlate energy demand, building typologies, and climatic conditions for different types of residential buildings. Rather than envelope properties, three insulation levels have been considered in different climatic conditions to set up a database of energy profiles. Analyzing European climatic test reference years, 23 locations have been considered. For each location, the overall energy and the mean hourly monthly energy profiles for heating and cooling have been calculated. Pre-calculated profiles are needed to size generation systems and, in particular, ground source heat pumps. For this reason, correlations based on the degree days for heating and cooling demand have been found in order to generalize the results for different buildings. These correlations depend on the Köppen–Geiger climate scale.


2021 ◽  
Author(s):  
Ying Lam E. Law ◽  
Seth B. Dworkin

Ground source heat pumps (GSHPs) are an environmentally friendly alternative to conventional heating and cooling systems because of their high efficiency and low greenhouse gas emissions. The ground acts as a heat sink/source for the excess/required heat inside a building for cooling and heating modes, respectively. However, imbalance in heating and cooling needs can change ground temperature over the operating duration. This increase/decrease in ground temperature lowers system efficiency and causes the ground to foul—failing to accept or provide more heat. In order to ensure that GSHPs can operate to their designed conditions, thermal modelling is required to simulate the ground temperature during system operation. In addition, the borehole field layout can have a major impact on ground temperature. In this study, four buildings were studied—a hospital, fast-food restaurant, residence, and school, each with varying borehole configurations. Boreholes were modeled in a soil volume using finite-element methods and heating and cooling fluxes were applied to the borehole walls to simulate the GSHP operation. 20 years of operation were modelled for each building for 2x2, 4x4, and 2x8 borehole configurations. Results indicate that the borehole separation distance of 6 m, recommended by ASHRAE, is not always sufficient to prevent borehole thermal interactions. Benefits of using a 2x8 configuration as opposed to a 4x4 configuration, which can be observed because of the larger perimeter it provides for heat to dissipate to surrounding soil were quantified. This study indicates that it is important to carefully consider ground temperature during the operation of a GSHP. Borehole separation distances, layout, and hybridization should be studied to alleviate ground fouling problems.


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