scholarly journals Geothermal source heat pump performance for a greenhouse heating system: an experimental study

2016 ◽  
Vol 47 (3) ◽  
pp. 164-170 ◽  
Author(s):  
Alexandros Sotirios Anifantis ◽  
Simone Pascuzzi ◽  
Giacomo Scarascia-Mugnozza
Keyword(s):  
Experimental Data ◽  
Heat Pump ◽  
Energy Demand ◽  
Thermal Conditions ◽  
Heating System ◽  
Coefficient Of Performance ◽  
Working Fluid ◽  
Geothermal Heat ◽  
Pump Performance ◽  
Heating Energy Demand

Greenhouses play a significant function in the modern agriculture economy even if require great amount of energy for heating systems. An interesting solution to alleviate the energy costs and environmental problems may be represented by the use of geothermal energy. The aim of this paper, based on measured experimental data, such as the inside greenhouse temperature and the heat pump performance (input and output temperatures of the working fluid, electric consumption), was the evaluation of the suitability of low enthalpy geothermal heat sources for agricultural needs such as greenhouses heating. The study was carried out at the experimental farm of the University of Bari, where a greenhouse was arranged with a heating system connected to a ground-source heat pump (GSHP), which had to cover the thermal energy request. The experimental results of this survey highlight the capability of the geothermal heat source to ensue thermal conditions suitable for cultivation in greenhouses even if the compressor inside the heat pump have operated continuously in a fluctuating state without ever reaching the steady condition. Probably, to increase the performance of the heat pump and then its coefficient of performance within GSHP systems for heating greenhouses, it is important to analyse and maximise the power conductivity of the greenhouse heating system, before to design an expensive borehole ground exchanger. Nevertheless, according to the experimental data obtained, the GSHP systems are effective, efficient and environmental friendly and may be useful to supply the heating energy demand of greenhouses.

The design of a seasonal heat storage system with a geothermal heat pump for a residential building in Tehran

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Akbar Alidadi Shamsabadi ◽  
Mehdi Jahangiri ◽  
Tayebeh Rezaei ◽  
Rouhollah Yadollahi Farsani ◽  
Ali Seryani ◽  
...  
Keyword(s):  
Heat Pump ◽  
Heating System ◽  
Coefficient Of Performance ◽  
Maximum Temperature ◽  
Software Environment ◽  
Geothermal Heat ◽  
Pump System ◽  
Matlab Software ◽  
Content Type ◽  
Heat Pump System

Purpose In this study, a solar water heating system along with a seasonal thermal energy storage and a heat pump is designed for a villa with an area of 192 m2 in Tehran, the capital of Iran. Design/methodology/approach According to the material and the area of the residential space, the required heating of the building was calculated manually and then the thermodynamic analysis of the system and simulation was done in MATLAB software. Finally, regarding the waste of system, an efficient solar heating system, providing all the required energy to heat the building, was obtained. Findings The surface area of the solar collector is equal to 46 m2, the capacity of the tank is about 2,850 m3, insulation thickness stands at 55 cm and the coefficient of performance in required heat pump is accounted to about 9.02. Also, according to the assessments, the maximum level of received energy by the collector in this system occurs at a maximum temperature of 68ºC. Originality/value To the best of the authors’ knowledge, in the present work, for the first time, using mathematical modeling and analyzing of the first and second laws of thermodynamics, as well as using of computational code in MATLAB software environment, the solar-assisted ground source heat pump system is simulated in a residential unit located in Tehran.

Experience With a Solar Heating ATES System for a University Building

1994 ◽  
Vol 116 (2) ◽  
pp. 88-93 ◽  
Author(s):  
E. Hahne ◽  
M. Hornberger
Keyword(s):  
Solar Energy ◽  
Heat Pump ◽  
Waste Heat ◽  
Heating System ◽  
Solar Heating ◽  
Coefficient Of Performance ◽  
Solar Collectors ◽  
Power Station ◽  
Heat Demand ◽  
Heat Store

At Stuttgart University, a solar heating system for an office building with laboratories and lecture rooms was installed in 1985. It consists of 211 m2 of unglazed solar collectors, a 1050 m3 water-flooded pebble bed heat store, and a heat pump. Heat can be supplied to the store from the solar collectors or from a power station (as waste heat). The whole system has worked successfully for five years under varied strategies. In the first two heating periods, the heating strategy was aimed to collect as much solar energy as possible. Thus, about 60 percent of the heat demand could be covered by solar energy; but the yearly heat pump coefficient of performance (COP) was only around 2.76. With an improved heat pump, a monthly COP of 3.6 was obtained. Heat losses from the storage amounted to about 20 percent.

scholarly journals The thermal behavior of a novel wall radiator panel coupled with horizontal ground source heat pump heating system: improve indoor environment to reduce the airborne transmission of infectious diseases

2020 ◽  
Vol 5 ◽  
pp. 11
Author(s):  
Sabrin Korichi ◽  
Bachir Bouchekima ◽  
Nabiha Naili ◽  
Messaouda Azzouzi
Keyword(s):  
Infectious Diseases ◽  
Thermal Comfort ◽  
Heat Pump ◽  
Heating System ◽  
The Novel ◽  
Ground Source Heat Pump ◽  
Radiation Heating ◽  
Geothermal Heat ◽  
Ground Source ◽  
Geothermal Heat Pump

Motivated by the rapid spread of the novel pandemic disease (COVID-19) that swept the most countries in the world, a new radiation heating system consists of wall radiator panel system connected to a reversible geothermal heat pump (GHP) coupled with horizontal ground heat exchanger (HGHX) was proposed as fast and permanent solution to the risks of the dispersion of airborne infectious diseases in air-conditioned enclosed spaces. An experimental system was installed and tested in the laboratory of thermal process of Research and Technology Center of Energy (CRTEn), Tunisia, in order to achieve the two main goals of this work: developing a new radiation heating system with quick and inexpensive implementation while ensuring high efficiency and environment-friendly performance for the entire system. The results obtained show that it is feasible to use the novel RPHs as heat rejecter of the horizontal ground source heat pump system (HGSHPs) for heating buildings with limited surface land areas epically those located in the Mediterranean regions such as Tunisia, the average performance coefficients of the geothermal heat pump COPhp and the overall system COPsys are found to be 6.3 and 3, respectively. The thermal comfort analysis indicates that there is only a small vertical temperature fluctuation in the test room that would not produce any negative effect on thermal comfort.

scholarly journals A Domestic Solar/Heat Pump Heating System Incorporating Latent and Stratified Thermal Storage

2008 ◽  
Author(s):  
Christoph Trinkl ◽  
Wilfried Zo¨rner ◽  
Vic Hanby
Keyword(s):  
Latent Heat ◽  
Heat Pump ◽  
Solar Collector ◽  
Energy Demand ◽  
Heat Storage ◽  
Thermal Storage ◽  
Heating System ◽  
System Control ◽  
Latent Heat Storage ◽  
Solar Heat

Both solar and heat pump heating systems are innovative technologies for sustaining ecological heat generation. They are gaining more and more importance due to the accelerating pace of climate change and the rising cost of limited fossil resources. Against this background, a heating system combining solar thermal collectors, heat pump, stratified thermal storage and water/ice latent heat storage has been investigated. The major advantages of the proposed solar/heat pump heating system are considered to be its flexible application (suitable for new and existing buildings because of acceptable space demand) as well as the improvement of solar fraction (extended solar collector utilisation time, enhanced collector efficiency), i.e. the reduction of electric energy demand for the heat pump. In order to investigate and optimise the heating system, a dynamic system simulation model was developed. On this basis, a fundamental control strategy was derived for the overall coordination of the heating system with particular regard to the performance of the two storage tanks. In a simulation study, a fundamental investigation of the heating system configuration was carried out and optimisation derived for the system control as well as the selection of components and their dimensioning. The influence of different parameters on the system performance was identified, where the collector area and the latent heat storage volume were found to be the predominant parameters for system dimensioning. For a modern one-family house, a solar collector area of 30m2 and a latent heat store volume of 12.5m3 are proposed. In this configuration, the heating system reaches a seasonal performance factor of 4.6, meaning that 78% of the building’s and users’ heat demand are delivered by solar energy. The results show that the solar/heat pump heating system can give an acceptable performance using up-to-date components in a state-of-the-art building.

scholarly journals Frosting Phenomenon and Frost-Free Technology of Outdoor Air Heat Exchanger for an Air-Source Heat Pump System in China: An Analysis and Review

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2642 ◽  
Author(s):  
Yi Zhang ◽  
Guanmin Zhang ◽  
Aiqun Zhang ◽  
Yinhan Jin ◽  
Ruirui Ru ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Heat Pump ◽  
Operating Cost ◽  
Heating System ◽  
Coefficient Of Performance ◽  
Outdoor Air ◽  
Pump System ◽  
Heat Pump System ◽  
Reduce Operating Cost ◽  
Air Source Heat Pump

Frost layer on the outdoor air heat exchanger surface in an air-source heat pump (ASHP) can decrease the system coefficient of performance (COP). Although the common defrosting and anti-frosting methods can improve the COP, the periodic defrosting not only reduces the system energy efficiency but also deteriorates the indoor environment. To solve these problems, it is necessary to clearly understand the frosting phenomenon and to achieve the system frost-free operation. This paper focused firstly on the analyses of frosting pathways and frosting maps. Followed by summarizing the characteristics of frost-free technologies. And then the performances of two types of frost-free ASHP (FFASHP) systems were reviewed, and the exergy and economic analysis of a FFASHP heating system were carried out. Finally, the existing problems related to the FFASHP technologies were proposed. Results show that the existing frosting maps need to be further improved. The FFASHP systems can not only achieve continuous frost-free operation but reduce operating cost. And the total COP of the FFASHP heating system is approximately 30–64% higher than that of the conventional ASHP system under the same frosting conditions. However, the investment cost of the FFASHP system increases, and its reliability also needs further field test in a wider frosting environment. In the future, combined with a new frosting map, the control strategy for the FFASHP system should be optimized.

scholarly journals Validation of black-box performance models for a water-to-water heat pump operating under steady state and dynamic loads

2019 ◽  
Vol 111 ◽  
pp. 01068
Author(s):  
Elena Fuentes ◽  
Jaume Salom
Keyword(s):  
Steady State ◽  
Heat Pump ◽  
Thermal Power ◽  
Energy Performance ◽  
Heat Pumps ◽  
Black Box ◽  
Coefficient Of Performance ◽  
Performance Models ◽  
Pump Performance ◽  
Transient Phases

The use of simple mathematical models for describing the behaviour of heat pumps is important for assessing the energy performance of this equipment when installed in buildings. However, because of their simplicity, commonly used simple models, may not be able to fully account for the dynamic performance of heat pumps during transient phases. In this study, different performance black box models for an on-off water-to-water heat pump are validated by comparison with laboratory experimental results at steady state and dynamic cycling conditions. The models range from the solution based on the interpolation on the heat pump performance map to the detailed dynamic solution that combines correlations for the quasi-steady state operation and activation functions to model the transient phases. The output temperatures, electrical and thermal power and coefficient of performance from simulations were compared with experimental data from a water-to-water heat pump of 40.5 kW nominal heating capacity operating under cycling conditions. After validation with experiments, annual energy performance simulations of a tertiary building provided with a heat pump were conducted. These simulations quantifying the uncertainty expected when using heat pump performance models in simulation environments for estimating their annual energy performance.

scholarly journals Experimental and Numerical Study on Energy Piles with Phase Change Materials

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4699 ◽  
Author(s):  
M. M. Mousa ◽  
A. M. Bayomy ◽  
M. Z. Saghir
Keyword(s):  
Phase Change ◽  
Heat Pump ◽  
Flow Rate ◽  
Phase Change Materials ◽  
Numerical Study ◽  
Coefficient Of Performance ◽  
Working Fluid ◽  
Numerical Predictions ◽  
Energy Piles ◽  
Discharging Capacity

Phase change materials (PCM) utilization in energy storage systems represents a point of interest and attraction for the researchers to reduce greenhouse gas emissions. PCM have been used widely on the interior or exterior walls of the building application to optimize the energy consumption during heating and cooling periods. Meanwhile, ground source heat pump (GSHP) gained its popularity because of the high coefficient of performance (COP) and low running cost of the system. However, GSHP system requires a stand-by heat pump during peak loads. This study will present a new concept of energy piles that used PCM in the form of enclosed tube containers. A lab-scaled foundation pile was developed to examine the performance of the present energy pile, where three layers of insulation replaced the underground soil to focus on the effect of PCM. The investigation was conducted experimentally and numerically on two identical piles with and without PCM. Moreover, a flow rate parametric study was conducted to study the effect of the working fluid flow rate on the amount of energy stored and released at each model. Finally, a comprehensive Computational fluid dynamic (CFD) model was developed and compared with the experimental results. There was a good agreement between the experimental measurements and the numerical predictions. The results revealed that the presence of PCM inside the piles increased not only the charging and discharging capacity but also the storage efficiency of the piles. It was found that PCM enhances the thermal response of the concrete during cooling and heating processes. Although increasing the flow rate increased charging and discharging capacity, the percentage of energy stored/released was insignificant compared to the flow rate increasing percentage.

scholarly journals Thermodynamic analysis on an instantaneous water heating system of shower wastewater source heat pump

2017 ◽  
Vol 8 (3) ◽  
pp. 404-411 ◽  
Author(s):  
Yuguo Wu ◽  
Yake Jiang ◽  
Bo Gao ◽  
Zhigang Liu ◽  
Jing Liu
Keyword(s):  
Heat Transfer ◽  
Energy Consumption ◽  
Heat Pump ◽  
Water Reuse ◽  
Heating System ◽  
Water Systems ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Heat Transfer Area ◽  
Discharge Pressure

Abstract Water reuse and desalination systems are energy intensive processes, and their increasing use is leading energy consumption within water systems to be an increasingly important issue. Shower wastewater contains large amounts of heat, so there is an opportunity to recover energy from shower water to offset energy consumption elsewhere in water systems. This paper found ways to increase the output of hot water and lower the energy consumption by establishing a thermodynamic model of an instantaneous wastewater source heat pump. The system proved to be very effective, the heating COP (coefficient of performance) can reach 3.3 even in the winter. Under the conditions of limited heat transfer area, reducing the suction pressure of a compressor is a more feasible way to increase the hot water output to meet the needs of users rather than increasing the discharge pressure. Besides, increasing the heat transfer area of the evaporator is a more effective option. When the heat transfer area of evaporator varies from 0.5 to 1.0 square meters, a notable change is that the heating COP increases from 3.283 to 3.936. The heating COP in a system with a recuperator can reach 5.672, almost double that compared to the original systems.

Comparing the Energetic and Exergetic Performances of a Building Heated by Solar Energy and Ground-Source (Geothermal) Heat Pump

2011 ◽  
Vol 347-353 ◽  
pp. 1801-1805
Author(s):  
Arif Hepbasli ◽  
Mustafa Tolga Balta ◽  
Zeyad Alsuhaibani
Keyword(s):  
Heat Pump ◽  
Heating System ◽  
Building Envelope ◽  
Geothermal Heat ◽  
Pump System ◽  
Sustainability Index ◽  
Dead State ◽  
Ground Source ◽  
Energy And Exergy ◽  
Geothermal Heat Pump

In this study, we considered a building, which had a volume of 336 m3 and a floor area of 120 m2, with indoor and outdoor air temperatures of 20 oC and 0 oC, respectively. For heating this building, we selected two options, namely (i) a ground-source (geothermal) heat pump system (Case 1), and (ii) a solar collector heating system (Case 2). We employed both energy and exergy analysis methods to assess their performances and compare them through energy and exergy efficiencies and sustainability index. We also investigated energy and exergy flows for this building and illustrated from the primary energy transformation through the heat production system and a distribution system to a heating system, and from there, via the indoor air, across the building envelope to the surrounding air. We calculated that the total exergy efficiencies for Cases 1 and 2 were 4.7%, and 26.1% while sustainability index values for both cases were 1.049 and 1.353 at a reference (dead) state temperature of 0 oC, respectively.

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