scholarly journals Energy and environmental analysis of an open-loop ground-water heat pump system in an urban area

2010 ◽  
Vol 14 (3) ◽  
pp. 693-706 ◽  
Author(s):  
Giorgia Baccino ◽  
Russo Lo ◽  
Glenda Taddia ◽  
Vittorio Verda

In this paper a multidisciplinary methodology for analyzing the opportunities for exploitation of open-loop groundwater heat pump is proposed. The approach starts from a model for calculation of a time profile of thermal requirements (heat and domestic hot water). This curve is then coupled with a model of the control system in order to determine the heat pump operation, which includes its energy performances (primary energy consumption) as well as profiles of water discharge to the aquifer in terms of mass flow rate and temperature. Then the thermo-fluid dynamics of the aquifer is performed in order to determine the system impact on the environment as on possible other systems. The application to a case study in the Piedmont region, in Italy, is proposed. Energy analysis of the system shows that ground-water heat pumps constitute an interesting option in areas with small housing density, where there is not district heating. In comparison with typical heating/cooling systems, environmental benefits are related with reduction in global emissions. These benefits may be significantly enhanced using renewables as the primary energy source to produce electricity. The analysis also shows that possible issues related with the extension of the subsurface thermal plume may arise in the case of massive utilization of this technology.

2021 ◽  
Vol 13 (2) ◽  
pp. 983
Author(s):  
Mustapha Mukhtar ◽  
Bismark Ameyaw ◽  
Nasser Yimen ◽  
Quixin Zhang ◽  
Olusola Bamisile ◽  
...  

The world has not been able to achieve minimum greenhouse gas emissions in buildings’ energy consumptions because the energy and emissions optimization techniques have not been fully utilized. Thermal comfort is one of the most important issues for both residential and commercial buildings. Out of the 40% of global energy consumed by buildings, a large fraction is used to maintain their thermal comfort. In this study, a comprehensive review of the recent advancements in building energy conservation and efficiency application is presented based on existing high-quality research papers. Additionally, the retrofit of the heating/cooling and hot water system for an entire community in Cyprus is presented. This study aims to analyze the technical and environmental benefits of replacing existing electric heaters for hot water with heat pump water heating systems and the use of heat pump air conditioners for thermal comfort in place of the existing ordinary air conditioners for space heating and cooling. One administrative building, 86 apartments (including residential and commercial) buildings, and a restaurant building is retrofitted, and the feasibility of the project is determined based on three economic indicators, namely; simple payback period (SPP), internal rate of return (IRR), and net present value (NPV). The electrical energy required by the hot water systems and the heating/cooling system is reduced by 263,564 kWh/yr and 144,825 kWh/yr, respectively. Additionally, the retrofit project will reduce Cyprus’ CO2 emission by 121,592.8 kg yearly. The SPP, IRR, and NPV for the project show that the retrofit is economically feasible.


2019 ◽  
Vol 118 ◽  
pp. 03029
Author(s):  
Wei Dong ◽  
Yongcun Li

In present study, a novel heat pump named multi-functional heat pump systems for dishwashers is introduced. 45 oC hot water cycle and hot air cycle are provided by the single-stage heat pump cycle to complete the cleaning and drying process. Moreover, the high temperature water at 85 °C is provided by the two-stage heat pump cycle system to achieve the disinfection function, and the 26°C cold air is realized by the single-stage refrigeration cycle for rapid cooling. Thermodynamic analysis of multi-functional heat pump systems for dishwashers under four different operating conditions with R22 / R134a as working fluid was carried out. The results show that COP (coefficient of performance) of the system is above 3.2 under all four conditions, which meets the energy efficiency rating index. Comparing energy efficiency and environmental benefits and operating costs of multi-functional heat pump systems for dishwashers with the traditional electric heating dishwashers, these can be known that primary energy consumption, carbon dioxide emissions and operating cost of multifunctional heat pump dishwasher are 1.24 * 105kJ, 10.55kg and 21.70 Yuan respectively under the condition of per running energy consumption for 40kW·h, above three all lower than the traditional electric heating dishwasher.


2018 ◽  
Vol 77 (18) ◽  
Author(s):  
Stefano Lo Russo ◽  
Glenda Taddia ◽  
Paolo Dabove ◽  
Elena Cerino Abdin ◽  
Ambrogio Maria Manzino

Author(s):  
D. Birks ◽  
C. Adamson ◽  
M. G. Woods ◽  
G. Holmes

A case study documenting the development of a groundwater-fed district heat network in Colchester, UK, is presented. The performance of an open loop groundwater heating and cooling system (also known as a ground source heat pump (GSHP)) is a function of the performance of individual boreholes and interactions between the boreholes. When performance does not meet its design capacity or decreases with time, various measures can be undertaken to improve either the performance of individual wells or the performance of the system as a whole.Output from the first exploration borehole was less than expected, placing the business case for the development in jeopardy. Consequently, refinements to the remainder of the drilling programme were implemented including three to improve the performance of individual wells and two to improve performance of the system in its entirety. Results of these refinements are presented and may be used to inform the design of new open loop groundwater heat pump systems (GSHPs) and/or the rehabilitation of existing systems that have experienced diminished performance.Yields from three wells drilled using the reverse circulation method were more than double those drilled with the direct water flush method. A significant improvement in the performance of abstraction wells due to reinjection was observed. Specific capacity in abstraction wells increased by c. 40% due to reinjection, where the distance between abstraction and reinjection locations was 535–717 m. Allowing an excess pressure of up to 0.2 MPa in the reinjection boreholes meant that reinjection could be achieved with fewer wells.Outputs from abstraction wells were not increased by extending the depth of boreholes from 135 to 200 m or implementing additional acid treatments.


HortScience ◽  
1994 ◽  
Vol 29 (4) ◽  
pp. 249a-249
Author(s):  
Eric A. Lavoie ◽  
Damien de Halleux ◽  
André Gosselin ◽  
Jean-Claude Dufour

The main objective of this research was to produce a simulated model that permitted the evaluation of operating costs of commercial greenhouse tomato growers with respect to heating methods (hot air, hot water, radiant and heat pumps) and the use of artificial lighting for 1991 and 1992. This research showed that the main factors that negatively influence profitability were energy consumption during cold periods and the price of tomatoes during the summer season. The conventional hot water system consumed less energy than the heat pump system and produced marketable fruit yields similar to those from the heat pump system. The hot water system was generally more profitable in regards to energy consumption and productivity. Moreover, investment costs were less; therefore, this system gives best overall financial savings. As for radiant and hot air systems, their overall financial status falls between that of the hot water system and the heat pump. The radiant system proved to be more energy efficient that the hot air system, but the latter produced a higher marketable fruit yield over the 2-year study.


Geothermics ◽  
2021 ◽  
Vol 92 ◽  
pp. 102050
Author(s):  
Dongkyu Park ◽  
Eunhee Lee ◽  
Dugin Kaown ◽  
Seong-Sun Lee ◽  
Kang-Kun Lee

2016 ◽  
Author(s):  
Gabriel Agila ◽  
Guillermo Soriano

This research develops a detailed model for a Water to Water Heat Pump Water Heater (HPWH), operating for heating and cooling simultaneously, using two water storage tanks as thermal deposits. The primary function of the system is to produce useful heat for domestic hot water services according to the thermal requirements for an average household (two adults and one child) in the city of Quito, Ecuador. The purpose of the project is to analyze the technical and economic feasibility of implementing thermal storage and heat pump technology to provide efficient thermal services and reduce energy consumption; as well as environmental impacts associated with conventional systems for residential water heating. An energy simulation using TRNSYS 17 is carried to evaluate model operation for one year. The purpose of the simulation is to assess and quantifies the performance, energy consumption and potential savings of integrating heat pump systems with thermal energy storage technology, as well as determines the main parameter affecting the efficiency of the system. Finally, a comparative analysis based on annual energy consumption for different ways to produce hot water is conducted. Five alternatives were examined: (1) electric storage water heater; (2) gas fired water heater; (3) solar water heater; (4) air source heat pump water heater; and (5) a heat pump water heater integrated with thermal storage.


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