Performance of geothermal energy extraction in a horizontal well by using CO2 as the working fluid

Sun, Fengrui; Yao, Yuedong; Li, Guozhen; Li, Xiangfang

doi:10.1016/j.enconman.2018.06.092

Cited by 142 publications

(21 citation statements)

References 80 publications

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“…Nekså proposed that CO 2 is highly suitable for application of building heating . It has been used in a variety of applications like fire extinguisher, lasers, refrigeration, supercritical drying, domestic hot water, solar water heating, mobile air conditioning (MAC) and heating for vehicles, CO 2 heat pump with Phase Change Materials, and geothermal heat transfer fluid, and so on. Gullo et al investigated the efficiency of R404A and R744 systems.…”

Section: History Of Refrigerantsmentioning

confidence: 99%

Review of carbon dioxide (CO ₂ ) based heating and cooling technologies: Past, present, and future outlook

2019

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Summary Refrigerants bearing high global warming potential (GWP) and ozone depletion potential (ODP) were outlawed or facing time‐beared permission under the Montreal (1987), Kyoto (1997) protocols, F‐Gas law (2015), Paris Accord (2016), and recent Kigali Amendment to Montreal Protocol (2019). In order to modify followed by the paradigm shift of existing heating and cooling systems, American Society of Heating, Refrigeration, and Air‐Conditioning Engineers (ASHRAE) envisaged natural and synthetic refrigerants (Synrefs) are under investigation globally. Carbon dioxide (CO2) is a popular natural refrigerant (Natref) replacing Synrefs used in commercial heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems globally. A rampant rise is observed in markets of Asia (Japan and China), North America (the United States and Canada), the Australian continent, and Africa (South Africa) by reaching 20 000 CO2‐stores around the globe. The European markets are leading the utilization of CO2 in the heat pump, and refrigeration, CO2 based markets estimate 14% of the total food retail stores (400 m2). Japan is the second leading market of CO2 heat pump and refrigeration with more than 10 200 CO2 condensing units. CO2 transcritical systems have a share of more than 10% in only European market (large stores); however, their share is less than 10% of total stores in other major markets of the world. New pump and compressor‐driven transcritical CO2 systems integrate ejectors, condensers, and booster systems to reduce energy consumptions, enhance efficiency, efficacy, and coefficient of performance. This article reports a critical review of the CO2 based heating, cooling, and refrigeration system and presents updated literature along with barriers and challenges on commercial use of Natref‐based heating and cooling applications worldwide.

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Section: History Of Refrigerantsmentioning

confidence: 99%

Review of carbon dioxide (CO ₂ ) based heating and cooling technologies: Past, present, and future outlook

2019

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“…The temperature sensor, electronically controlled fuel injector, and exhaust gas analyzer are controlled by electronic control unit, and they operate interactively to adjust the amount of fuel depending on the time and to stabilize the combustion temperatures and thus the formation of NO x emissions. A comprehensive computational performance investigation has been carried out to investigate the variations of performance specifications depending on the variations of engine design and operating parameters by a finite‐time thermodynamics modeling . In the simulation, the performance parameters at the standard condition are determined as in Table .…”

Section: Theoretical Modelmentioning

confidence: 99%

“…A comprehensive computational performance investigation has been carried out to investigate the variations of performance specifications depending on the variations of engine design and operating parameters by a finite-time thermodynamics modeling. [68][69][70][71] In the simulation, the performance parameters at the standard condition are determined as in Table 1. The EFP (P ef ) and EFPD (P d ) are obtained as below 29,30,[72][73][74][75][76][77][78][79][80][81][82][83][84][85] :…”

Section: Theoretical Modelmentioning

confidence: 99%

Performance analysis of a novel eco‐friendly internal combustion engine cycle

Gonca

Şahi̇n

2019

Int J Energy Res

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Summary The Miller cycle applications have been performed to diminish NOx released from internal combustion engines (ICEs), in recent years. The Miller cycle provides decreased compression ratio and enhanced expansion ratio; hereby, maximum in‐cylinder combustion temperatures diminish, and NOx formations slow down remarkably. Another less‐known method is Takemura cycle application, which provides heat addition into engine cylinder at constant combustion temperatures. In this study, a novel cycle including the Miller cycle and the Takemura cycle has been developed by using novel numerical models and computing methods with seven processes and a novel way to decrease NOx emissions at higher levels compared with the single applications of known cycles. A comprehensive performance examination of the proposed cycle engine in terms of performance characteristics such as effective power (EFP), effective power density (EFPD), exergy destruction (X), exergy efficiency (ε), and ecological coefficient of performance (ECOP) has been conducted. The impacts of engine operating and design parameters on the performance characteristics have been computationally examined. Furthermore, irreversibilities depending on incomplete combustion loss (INCL), exhaust output loss (EXOL), heat transfer loss (HTRL), and friction loss (FRL) have been considered in the performance simulations. The minimum exergy destruction and maximum performance specifications have been observed with 30 of the compression ratio. Maximum effective power values have been obtained at range between 1 and 1.2 of equivalence ratio. The optimum range for exergy efficiency is between 0.8 and 1 of equivalence ratio. Increasing engine speed has provided enhancing effective power. However, an optimum range has been found for the exergy efficiency that is interval of 3000 to 4000 rpm. The results obtained can be assessed by researchers studying on modeling of the engine systems and designs.

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“…Fengrui et al observed that (a) the standard of choosing parameters for measuring the rate of geothermal production is dependent on whether or not the parameter can reflect the heat transfer or fluid temperature rise and (b) taking multiple factors such as mass injection and injection pressure, a model is developed for simulating CO 2 flow in the descending, horizontal, and ascending sections of a geothermal well. Finally, they suggested a series of works on establishing a simulation model to describe the heat mass transfer process of CO 2 in abandoned horizontal wellbores.…”

Section: Introductionmentioning

confidence: 99%

Analysis of effective thermal conductivity stability of geothermal heat exchanger according to ambient environmental conditions

You

Lee

2019

Int J Energy Res

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Summary At present, geothermal energy is a promising research area but still has numerous areas to be explored. The thermal performance verification of U‐shaped closed geothermal heat exchange was proposed to improve the effective thermal conductivity value applying initial ignoring time (IIT). To verify the thermal performance of the underground heat exchanger in the rock layer according to the surrounding environment and groundwater conditions, verifications were conducted for the amount of circulating water, amount of heat input, and groundwater conditions. The circulating fluid flow rate of the system, supply of water into the ground, and influence of the change of supplied heat source were analyzed. The effective heat conduction characteristics were analyzed using the linear heat source model and initial exclusion time. Therefore, in the thermal response test, the main error occurs according to the determined initial removal time, and the reliability of the effective thermal conductivity value is increased by applying IIT to reduce this error.

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Performance of geothermal energy extraction in a horizontal well by using CO2 as the working fluid

Cited by 142 publications

References 80 publications

Review of carbon dioxide (CO ₂ ) based heating and cooling technologies: Past, present, and future outlook

Review of carbon dioxide (CO ₂ ) based heating and cooling technologies: Past, present, and future outlook

Performance analysis of a novel eco‐friendly internal combustion engine cycle

Analysis of effective thermal conductivity stability of geothermal heat exchanger according to ambient environmental conditions

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Performance of geothermal energy extraction in a horizontal well by using CO2 as the working fluid

Cited by 142 publications

References 80 publications

Review of carbon dioxide (CO 2 ) based heating and cooling technologies: Past, present, and future outlook

Review of carbon dioxide (CO 2 ) based heating and cooling technologies: Past, present, and future outlook

Performance analysis of a novel eco‐friendly internal combustion engine cycle

Analysis of effective thermal conductivity stability of geothermal heat exchanger according to ambient environmental conditions

Contact Info

Product

Resources

About

Review of carbon dioxide (CO ₂ ) based heating and cooling technologies: Past, present, and future outlook

Review of carbon dioxide (CO ₂ ) based heating and cooling technologies: Past, present, and future outlook