scholarly journals Performance of Hybrid Single Well Enhanced Geothermal System and Solar Energy for Buildings Heating

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2473
Author(s):  
Yujiang He ◽  
Xianbiao Bu
Keyword(s):  
Solar Energy ◽  
Service Life ◽  
Heating System ◽  
Hydrothermal Systems ◽  
Geothermal System ◽  
Heat Output ◽  
Enhanced Geothermal System ◽  
Geothermal Heat ◽  
Hybrid Heating ◽  
Single Well

The energy reserves in hot dry rock and hydrothermal systems are abundant in China, however, the developed resources are far below the potential estimates due to immature technology of enhanced geothermal system (EGS) and scattered resources of hydrothermal systems. To circumvent these problems and reduce the thermal resistance of rocks, here a shallow depth enhanced geothermal system (SDEGS) is proposed, which can be implemented by fracturing the hydrothermal system. We find that, the service life for SDEGS is 14 years with heat output of 4521.1 kW. To extend service life, the hybrid SDEGS and solar energy heating system is proposed with 10,000 m2 solar collectors installed to store heat into geothermal reservoir. The service life of the hybrid heating system is 35 years with geothermal heat output of 4653.78 kW. The novelty of the present work is that the hybrid heating system can solve the unstable and discontinuous problems of solar energy without building additional back-up sources or seasonal storage equipment, and the geothermal thermal output can be adjusted easily to meet the demand of building thermal loads varying with outside temperature.

scholarly journals Performance Analysis of Single-Well Enhanced Geothermal System for Building Heating

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Haijun Liang ◽  
Xiaofeng Guo ◽  
Tao Gao ◽  
Lingbao Wang ◽  
Xianbiao Bu
Keyword(s):  
Volume Flow Rate ◽  
Water Reservoir ◽  
Hot Water ◽  
Heat Extraction ◽  
Geothermal System ◽  
Enhanced Geothermal System ◽  
Artificial Reservoir ◽  
Reservoir Volume ◽  
Thermal Output ◽  
Single Well

Deep borehole heat exchanger (DBHE) technology does not depend on the existence of hot water reservoir and can be used in various regions. However, the heat extraction from DBHE can hardly be improved due to poor thermal conductivity of rocks. Here, a single-well enhanced geothermal system (SWEGS) is proposed, which has a larger heat-exchange area of artificial reservoir created by fracturing hydrothermal technology. We find that, due to heat convection between rocks and fluid, the extracted thermal output for SWEGS is 4772.73 kW, which is 10.64 times of that of DBHE. By changing the injection water temperature, volume flow rate, and artificial reservoir volume, it is easy to adjust the extracted thermal output to meet the requirement of building thermal loads varying with outdoor air temperature. Understanding these will enable us to better apply SWEGS technology and solve the fog and haze problem easily and efficiently.

scholarly journals The impact of ETC/PCM solar energy storage on the energy performance of a building

2019 ◽  
Vol 116 ◽  
pp. 00073
Author(s):  
Robert Sekret ◽  
Piotr Feliński
Keyword(s):  
Solar Energy ◽  
Surface Area ◽  
Solar Collector ◽  
Heating Surface ◽  
Heating System ◽  
Energy Performance ◽  
Primary Energy ◽  
Heat Output ◽  
Solar Fraction ◽  
The Impact

The main goal of this investigation was to increase the solar fraction and reduce the demand for non-renewable primary energy in a building heating system. Thermal performance of the prototype evacuated tube solar collector/storage integrated with a PCM (ETC/PCM) was analyzed. Technical grade paraffin with onset melting point of 51.24°C was used as a PCM. It has been shown that the highest solar energy fraction in the building heating system was obtained with a thermal load of 40 W·m-2 and the highest the surface area of ETC/PCM aperture in relation to the heating surface area value of 0.2. Lowering the heating system parameters from 45/35°C to 35/25°C allowed for an increase in heat output from solar energy in the range from 2.71% to 5.44%. The largest increase in the solar fraction was in the range of the ratio of the surface area of the solar collector ETC/PCM aperture to the area of the heated building from 0.03 to 0.07. In summary, obtained results indicated that the proposed solution allowed reduction of non-renewable primary energy demand in conceptual heating system from 6% to 27% depending on the heat load of the building and the aperture area of the ETC/PCM.

Impact of Component Selection and Operation on Thermal Ratings of Drain-Back Solar Water Heaters

1992 ◽  
Vol 114 (4) ◽  
pp. 219-226 ◽  
Author(s):  
J. H. Davidson ◽  
W. T. Carlson ◽  
W. S. Duff
Keyword(s):  
Solar Energy ◽  
Flow Rate ◽  
Storage Tank ◽  
Heating System ◽  
Heat Output ◽  
Drop Tube ◽  
Recirculation Flow ◽  
Water Heaters ◽  
Industry Standards ◽  
Tank Design

A half-factorial, two-level experimental design is used to determine the effects of changes in collector area, storage tank volume, collector flow rate, recirculation flow rate, and storage tank design on thermal rating of a solar drain-back water heating system. Experimental ratings are determined in accordance with the Solar Rating and Certification Corporation guidelines. Storage tank design is varied by using a stratification manifold in place of the standard drop tube. Variations in other component sizes and operating factors are based on current industry standards. Statistical analyses indicate that a change in collector area accounts for nearly 90 percent of the variation in heat output. Doubling collector area from 2.78 m2 to 5.56 m2 increases delivered solar energy by 31 percent. Use of a stratification manifold increases the delivery of solar energy by six percent. Doubling collector flow rate from 0.057 to 0.114 1/s increases solar output by approximately three percent; however, the increase in pumping energy outweighs the benefits of increasing collector flow rate. The effects of recirculation flow rate and tank volume are obscured by experimental error.

scholarly journals Effect of a Heating System Using a Ground Source Geothermal Heat Pump on Production Performance, Energy-Saving and Housing Environment of Pigs

Animals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2075
Author(s):  
Hong Seok Mun ◽  
Muhammad Ammar Dilawar ◽  
Myeong Gil Jeong ◽  
Dhanushka Rathnayake ◽  
Jun Sung Won ◽  
...  
Keyword(s):  
Heat Pump ◽  
Heating System ◽  
Production Performance ◽  
Conventional Heating ◽  
Geothermal System ◽  
Outlet Temperature ◽  
Geothermal Heat ◽  
Housing Environment ◽  
Ground Source ◽  
Geothermal Heat Pump

This study examined the effects of a heating system using a ground source geothermal heat pump (GHP). A GHP was installed in a pig house, and a comparative analysis was performed between the GHP and the control (conventional heating system) in terms of the production performance, housing environment, noxious gas emissions, electricity consumption, and economics. The geothermal system performance index, such as the coefficient of performance (COP), inlet, and outlet temperature, were also evaluated. The outflow temperature during each period (weaning, growing, and finishing) was significantly higher than the inflow temperature in all three components of the GHP system. Similarly, the average internal temperature of the GHP-connected pig house was increased (p < 0.05) during each period. The carbon dioxide (CO2) concentration, electricity usage, and cost of electricity during the 16-week experimental period were reduced significantly in the GHP system relative to the control. The concentrations of ammonia (NH3) during the growing and finishing period and the concentrations of formaldehyde during the weaning phase were also lower in the GHP-installed pig house (p < 0.05). These results indicate that the GHP system can be used as an environmentally friendly renewable energy source in pig houses for sustainable pig production without harming the growth performance.

The radiator-enhanced geothermal system: Benefits of emulating a natural hydrothermal system

2016 ◽  
Vol 4 (4) ◽  
pp. SR35-SR48
Author(s):  
Markus Hilpert ◽  
Bruce D. Marsh ◽  
Peter Geiser
Keyword(s):  
Hydrothermal System ◽  
Cold Water ◽  
Combustion Engine ◽  
Wall Rock ◽  
Hydrothermal Systems ◽  
Hot Water ◽  
Geothermal System ◽  
Enhanced Geothermal System ◽  
Surrounding Water ◽  
Water Saturated

We have developed a novel enhanced geothermal system (EGS) called radiator EGS (RAD-EGS). This system attempts to emulate naturally occurring hydrothermal systems by creating a vertically oriented heat exchanger or vane in the deep subsurface, mimicking a radiator in an internal combustion engine. Water is injected at the bottom of the vane and produced on the top. We propose to build the RAD-EGS in hot sedimentary aquifers (HSAs) with high-permeability vane(s) created in the plane defined by [Formula: see text] and [Formula: see text] (vertical). We have evaluated 3D heat-transfer simulations to better understand the fluid and heat flows that may occur in RAD-EGSs. The simulations account for subsurface heterogeneity including the presence of underlying basement rock, an overlying confining layer, and an ambient hydraulic gradient, which causes background groundwater flow. Our simulations indicate that our induced upward flow in the vane significantly prolongs the lifetime of RAD-EGS when compared with downward flow because hydraulic short circuiting is avoided. Within the vane, convection may occur, and its onset is analyzed in terms of a characteristic Rayleigh number. A critical aspect of RAD-EGS, therefore, is that thermal recharge does not rely solely on heat conduction from the surrounding wall rock, which is typical for EGS built in hot dry rock (HDR). Instead, recharge is also due to heat advection through the surrounding water-saturated aquifer, substantially prolonging the lifetime of the thermal reservoir. Moreover, fluid losses as typical for EGS built in HDR do not occur. It is also possible that cold water injected at the bottom of the vane may sink into deeper rock layers, which displaces hot water from the surrounding aquifer into the RAD-EGS. We suggest that mimicking a natural hydrothermal system is a successful EGS strategy via RAD-EGS.

scholarly journals USE OF SOLAR ENERGY HEAT IN ANIMAL BREEDING BUILDINGS

2019 ◽  
Vol 9 (3) ◽  
pp. 56-62
Author(s):  
Elena V. CHIRKOVA
Keyword(s):  
Solar Energy ◽  
Heat Release ◽  
Heat Loss ◽  
Heat Load ◽  
Critical Level ◽  
Heating System ◽  
Solar Heating ◽  
Heat Output ◽  
Outdoor Temperature ◽  
Livestock Buildings

The article discusses the possibility of using solar air collectors for heating livestock buildings. The disposable amount of solar energy in the Samara region is determined during the winter months when the outdoor temperature drops below the critical level, at which biological heat release from animals does not compensate for heat loss through outdoor fences, and a defi cit of heat in the premises for their maintenance begins. The calculation of the heat output of the solar heating system and the degree of substitution of the required heat load is given using the example of a cowhouse. Based on the calculations performed, the feasibility of using the heat of solar energy in livestock buildings is estimated. Recommendations are given on the place of installation of solar collectors on the cowhouse.

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