Thermohydraulic Analysis of Ground as a Heat Source for Heat Pumps Using Vertical Pipes

1996 ◽  
Vol 118 (4) ◽  
pp. 300-305 ◽  
Author(s):  
M. T. Kangas
Keyword(s):  
Computer Simulation ◽  
Heat Source ◽  
Heat Pump ◽  
Thermal Energy ◽  
System Performance ◽  
Thermal Effects ◽  
Heat Pumps ◽  
The Other ◽  
Heat Extraction ◽  
Energy Potential

In this study, the use of the ground as the heat source for a heat pump was studied by computer simulation. The heat extraction system consisted of vertical pipes drilled into the ground where groundwater was present. Along with available thermal energy, potential environmental effects, such as freezing and thermal pollution, were examined. It was found that the presence of groundwater enhances system performance by decreasing the possibility of freezing but, on the other hand, increases the range of thermal effects in the ground. The temperature of the ground as well as extraction arrangements also have a significant effect on system performance.

Peak-Shaving Ratio Analysis of the Natural Gas Combined Heat and Power Plant With Distributed Peak-Shaving Heat Pumps

2017 ◽  
Author(s):  
Xiling Zhao ◽  
Xiaoyin Wang ◽  
Tao Sun
Keyword(s):  
Natural Gas ◽  
Heat Source ◽  
Heat Pump ◽  
Gas Turbines ◽  
Heat Load ◽  
Operating Cost ◽  
Heat Pumps ◽  
Optimized Design ◽  
Peak Shaving ◽  
Gas Price

Distributed peak-shaving heat pump technology is to use a heat pump to adjust the heat on the secondary network in a substation, with features of low initial investment, flexible adjustment, and high operating cost. The paper takes an example for the system that uses two 9F class gas turbines (back pressure steam) as the basic heat source and a distributed heat pump in the substation as the peak-shaving heat source. The peak-shaving ratio is defined as the ratio of the designed peak-shaving heat load and the designed total heat load. The economic annual cost is taken as a goal, and the optimal peak-shaving ratio of the system is investigated. The influence of natural gas price, electricity price, and transportation distance are also analyzed. It can provide the reference for the optimized design and operation of the system.

scholarly journals Prospect for the using of heat pumps for heating of buildings in enterprise

2020 ◽  
Author(s):  
Z. Sirkо ◽  
◽  
V. Korenda ◽  
I. Vyshnyakov ◽  
O. Protasov ◽  
...  
Keyword(s):  
Water Supply ◽  
Heat Pump ◽  
Thermal Energy ◽  
Alternative Energy ◽  
Thermodynamic Cycle ◽  
Heat Pumps ◽  
The State ◽  
Hot Water ◽  
Alternative Energy Sources ◽  
Hot Water Supply

Heat pump - a device for transferring thermal energy from a source of low potential thermal energy to a consumer with a higher temperature. The thermodynamic cycle of a heat pump is similar to a refrigerating machine. Depending on the principle of operation, heat pumps are divided into compression and absorption. The most commonly used compression heat pumps. In recent years, numerous publications on the use of heat pump technology in heating and hot water supply facilities of various spheres - from individual homes to residential neighborhoods have appeared in various media. The authors of the publication have many years of experience in joint scientific and technical cooperation with leading technical universities and industrial organizations in the field of development and practical use of heat pump technology. The authors analyze the possibilities of introducing heat pumps at enterprises and organizations of the State Reserve System of Ukraine. It has been shown that the amount of expenses in comparison with central heating or operation of gas and electric boilers of similar power is several times smaller. It is noted that the implementation of heat pumps is a promising direction in the use of alternative energy sources to meet the heating, ventilation and hot water supply needs of buildings. The payback period from the introduction of heat pumps at enterprises is 4-9 years, depending on the location of the object and the type of source of low-temperature heat. The article meets the requirements of the State Tax Code of Ukraine and can be recommended for publication.

scholarly journals Complex Heat Pump Operational Mode Identification and Comparison for Use in Electric Vehicles

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2000 ◽  
Author(s):  
James Jeffs ◽  
Andrew McGordon ◽  
Alessandro Picarelli ◽  
Simon Robinson ◽  
Yashraj Tripathy ◽  
...  
Keyword(s):  
Ambient Temperature ◽  
Heat Pump ◽  
Electric Vehicles ◽  
Heat Pumps ◽  
Heat Extraction ◽  
Storage Device ◽  
Thermal Source ◽  
Operational Mode ◽  
Mode Identification ◽  
Thermal Sources

Previous research has focused on the use of heat pumps in electric vehicles, with the focus on recuperating heat from, normally, ambient and one thermal source on the vehicle. Here 5 potential thermal sources on a vehicle have been identified and thorough testing on the benefit of each source has been performed. The results presented suggest the motor, a thermal storage device, and cabin exhaust extraction should be used >80% of the time according to the scenarios tested, while battery heating and transmission heat extraction should be used subject to conditions on the ambient temperature and drive cycle.

Analysis of Regional Suitability of the Ground-Coupled Heat Pump Based on the Shallow Ground Thermal Balance

2009 ◽  
Author(s):  
Yuefen Gao ◽  
Songling Wang ◽  
Guoqiang Zhang
Keyword(s):  
Heat Source ◽  
Heat Pump ◽  
Heat Pumps ◽  
Scientific Application ◽  
Term Operation ◽  
Ground Heat Exchangers ◽  
Ground Coupled Heat Pumps ◽  
Ground Coupled Heat Pump ◽  
Consistent Performance ◽  
Source And Sink

Ground-coupled heat pump systems use the ground as a heat source and sink either with vertical or horizontal ground heat exchangers (GHXs) to supply heating in winter and cooling in summer. The ground heat source and sink has a near constant temperature, which is well suited to ground-coupled heat pumps, giving them consistent performance, regardless of the outdoor temperature. However, when the heat extracted from and rejected to the ground has great imbalance, the ground temperature will deviate from the original temperature with a long term operation. The deviation can reduce GHX performance greatly. As China has vast territory with variety climate, the annual cooling loads and heating loads are different at different places. And the imbalance between the extracted heat and the rejected heat also varies at different places. Therefore, it is necessary to analysis the regional suitability of the ground-coupled heat pump systems. The imbalance between the extracted heat and the rejected heat is analyzed by taking several typical cities in different climates. The new concepts of the Imbalance Ratio and the Extracted Heat to Rejected Heat Ratio are introduced as the weight factors to measure the imbalance in the ground. The values of the Imbalance Ratio and those of the Extracted Heat to the Rejected Heat Ratio are calculated. The optimum range of the Imbalance Ratio is recommended based on the vast investigation of the ground-coupled heat pumps. Some supplemental systems are put forward to supply heat in winter or to reject heat in summer at the places existing serious heat imbalance. The study is very meaningful to the scientific application of the ground-coupled heat pump systems in China.

scholarly journals Finite element modeling of geothermal source of heat pump in long-term operation

2020 ◽  
Vol 154 ◽  
pp. 04003
Author(s):  
Elżbieta Hałaj
Keyword(s):  
Finite Element ◽  
Heat Source ◽  
Heat Pump ◽  
Heat Exchangers ◽  
Transport Model ◽  
Heat Pumps ◽  
Initial Temperature Distribution ◽  
Term Operation ◽  
Borehole Heat Exchangers

Heat pumps become more and more popular heat source. They can be an alternative choice for obsolete coal fired boilers which are emissive and not ecological. During heat pump installation designing process, especially for heat pumps with higher heating capacity (for example those suppling larger buildings), a simulation of heat balance of ground heat source must be provided. A 3D heat transport model and groundwater flow in the geothermal heat source for heat pump (GSHP) installation was developed in FEFLOW according to Finite Element Modelling Method. The model consists of 25 borehole heat exchangers, arranged with spacing recommended by heat pump branch guidelines. The model consists of both a homogeneous, non-layered domain and a layered domain, which reflected differences in thermal properties of the ground and hydrogeological factors. The initial temperature distribution in the ground was simulating according to conditions typical for Europe in steady state heat flow. Optimal mesh refinement for nodes around borehole heat exchangers were calculated according to Nillert method. The aim of this work is to present influence of geological, hydrogeological factors and borehole arrangement in the energy balance and long term sustainability of the ground source. The thermal changes in the subsurface have been determined for a long term operation (30 years of operation period). Some thermal energy storage applications have also been considered.

Analysis of Ground Massif Temperatures with Slinky Horizontal Heat Exchanger

2015 ◽  
Vol 752-753 ◽  
pp. 1035-1039 ◽  
Author(s):  
Michaela Šeďová ◽  
Pavel Neuberger ◽  
Radomír Adamovský
Keyword(s):  
Heat Exchanger ◽  
Heat Source ◽  
Heat Pump ◽  
Cold Water ◽  
Heat Energy ◽  
Burial Depth ◽  
Heating Season ◽  
Energy Potential ◽  
The Difference ◽  
Subsurface Temperatures

The article is describing a ground massif with a Slinky heat exchanger as a heat source for a heat pump, which is used for cold water warming and a heating of an administration building. The object of the research is to analyse the influence of the heat exchanger on the ground massif temperature while extracting heat energy at the beginning and during the heating season 2012 - 2013, as well as beyond it. Based on executed measurements the process of the ground massif temperatures near the exchanger is described. Also described is temperature process of the ground massif on a reference lot in a burial depth of the heat exchanger, and also subsurface temperatures in a depth of 0.2 m. The energy potential of the ground massif was evaluated using the difference of temperatures of the ground massif in the area of the Slinky heat exchanger at the beginning and at the end of the heating season.

scholarly journals An Overview of Geothermal Energy Production in Germencik, Turkey

2020 ◽  
Author(s):  
Kaan Yamanturk ◽  
Cihan Dogruoz
Keyword(s):  
Renewable Energy ◽  
Geothermal Energy ◽  
Critical Role ◽  
Heat Pumps ◽  
The Other ◽  
Energy Resources ◽  
Coefficient Of Performance ◽  
Energy Potential ◽  
West Side ◽  
Computer Aided

As it is known, the utilization and production of renewable energy resources are very important in recent years. Due to its geological structural formations, Turkey has a serious geothermal energy potential as a renewable energy resource comparing with the other countries. West side of Turkey has also a critical role to use the geothermal energy resources. In these fields, geothermal is mostly used in electricity generation, greenhouse heating and locational requirements. The components while producing the geothermal water from wells such as heating pumps, re-injection pipes and other equipment are also significant. In this study, coefficient of performance (COP) utilizing in heat pumps has been investigated and the new approach to find out the parameter has been identified. Based on COP equation, the formula of COP has been re-coded on Dev C++ compiler by using C++ computer language in order to focus on the importance of computer aided applications in geothermal energy sector. There are no more studies showing the COP with C++ codes in literature. On the other hand, Germencik region, in the west side of Turkey, has been evaluated and the production processes by Guris Construction and Engineering Co. Inc. have been explained in the study. Moreover, the potential of Turkey has also been mentioned in this study. The aim of the study is to examine the Germencik region geothermal energy potential and to improve the coefficient of performance by using C++ in heat pumps. The result of this study shows us the Germencik region has an important potential and the computer aided technologies can also be adapted easily into the processes while producing geothermal energy.

scholarly journals Recovery and Utilization of Low-Grade Waste Heat in the Oil-Refining Industry Using Heat Engines and Heat Pumps: An International Technoeconomic Comparison

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2560 ◽  
Author(s):  
Nikunj Gangar ◽  
Sandro Macchietto ◽  
Christos N. Markides
Keyword(s):  
Heat Source ◽  
Thermal Energy ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Oil Refining ◽  
Low Grade ◽  
Energy Prices ◽  
Steam Generation ◽  
Electricity Prices ◽  
Oil Refineries

We assess the technoeconomic feasibility of onsite electricity and steam generation from recovered low-grade thermal energy in oil refineries using organic Rankine cycle (ORC) engines and mechanical vapour compression (MVC) heat pumps in various countries. The efficiencies of 34 ORC and 20 MVC current commercial systems are regressed against modified theoretical models. The resulting theoretical relations predict the thermal efficiency of commercial ORC engines within 4–5% and the coefficient of performance (COP) of commercial MVC heat pumps within 10–15%, on average. Using these models, the economic viability of ORC engines and MVC heat pumps is then assessed for 19 refinery streams as a function of heat source and sink temperatures, and the available stream thermal energy, for gas and electricity prices in selected countries. Results show that: (i) conversion to electrical power with ORC engines is, in general, economically feasible for heat-source temperatures >70 °C, however with high sensitivity to energy prices; and (ii) steam generation in MVC heat pumps, even more sensitive to energy prices, is in some cases not economical under any conditions—it is only viable with high gas/low electricity prices, for large heat sources (>2 MW) and higher temperatures (>140 °C). In countries and conditions with positive economics, payback periods down to two years are found for both technologies.

scholarly journals Flexibility Estimation of Residential Heat Pumps under Heat Demand Uncertainty

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5709
Author(s):  
Zhengjie You ◽  
Michel Zade ◽  
Babu Kumaran Kumaran Nalini ◽  
Peter Tzscheutschler
Keyword(s):  
Energy Storage ◽  
Heat Pump ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Heat Pumps ◽  
Hot Water ◽  
Maximum Temperature ◽  
Heat Demand ◽  
Residential Units ◽  
The Impact

With the increasing penetration of intermittent renewable energy generation, there is a growing demand to use the inherent flexibility within buildings to absorb renewable related disruptions. Heat pumps play a particularly important role, as they account for a high share of electricity consumption in residential units. The most common way of quantifying the flexibility is by considering the response of the building or the household appliances to external penalty signals. However, this approach neither accounts for the use cases of flexibility trading nor considers its impact on the prosumer comfort, when the heat pump should cover the stochastic domestic hot water (DHW) consumption. Therefore, in this paper, a new approach to quantifying the flexibility potential of residential heat pumps is proposed. This methodology enables the prosumers themselves to generate and submit the operating plan of the heat pump to the system operator and trade the alternative operating plans of the heat pump on the flexibility market. In addition, the impact of the flexibility provision on the prosumer comfort is investigated by calculating the warm water temperature drops in the thermal energy storage given heat demand forecast errors. The results show that the approach with constant capacity reservation in the thermal energy storage provides the best solution, with an average of 2.5 min unsatisfactory time per day and a maximum temperature drop of 2.3∘C.

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