Numerical Simulation of Soil Thermal Response Test with Thermal-dissipation Corrected Model

Ma, Ling; Gao, Zhiyou; Wang, Yongzhen; Sun, Yu; Zhao, Jianlin; Feng, Ning

doi:10.1016/j.egypro.2017.12.719

Cited by 4 publications

(4 citation statements)

References 3 publications

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“…In-situ measurements by thermal response test (TRT) are the dominant common approach to determine these values and the borehole thermal resistance. The TRT methodology is injecting/extracting a constant rate of heat energy at a constant fluid flow rate inside BHX, and the inlet and outlet fluid temperature is recorded for continuous 48 hours [5][6][7][8][9]. The Infinite Line Source Model (ILSM) is the typical model to calculate and predict the soil properties; the LSM in an infinite homogenous medium, borehole and grouting is not accounted for in the ILS but is added through the borehole resistance term [10].…”

Section: Introductionmentioning

confidence: 99%

The Effect of Groundwater Flow on the Thermal Performance of a Novel Borehole Heat Exchanger for Ground Source Heat Pump Systems: Small Scale Experiments and Numerical Simulation

et al. 2020

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New small-scale experiments are carried out to study the effect of groundwater flow on the thermal performance of water ground heat exchangers for ground source heat pump systems. Four heat exchanger configurations are investigated; single U-tube with circular cross-section (SUC), single U-tube with an oval cross-section (SUO), single U-tube with circular cross-section and single spacer with circular cross-section (SUC + SSC) and single U-tube with an oval cross-section and single spacer with circular cross-section (SUO + SSC). The soil temperature distributions along the horizontal and vertical axis are measured and recorded simultaneously with measuring the electrical energy injected into the fluid, and the borehole wall temperature is measured as well; consequently, the borehole thermal resistance (Rb) is calculated. Moreover, two dimensional and steady-state CFD simulations are validated against the experimental measurements at the groundwater velocity of 1000 m/year with an average error of 3%. Under saturated conditions without groundwater flow effect; using a spacer with SUC decreases the Rb by 13% from 0.15 m·K/W to 0.13 m·K/W, also using a spacer with the SUO decreases the Rb by 9% from 0.11 m·K/W to 0.1 m·K/W. In addition, the oval cross-section with spacer SUO + SSC decreases the Rb by 33% compared with SUC. Under the effect of groundwater flow of 1000 m/year; Rb of the SUC, SUO, SUC + SSC and SUO + SSC cases decrease by 15.5%, 12.3%, 6.1% and 4%, respectively, compared with the saturated condition.

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Section: Introductionmentioning

confidence: 99%

The Effect of Groundwater Flow on the Thermal Performance of a Novel Borehole Heat Exchanger for Ground Source Heat Pump Systems: Small Scale Experiments and Numerical Simulation

et al. 2020

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“…In general, the research evaluating indoor thermal comfort is carried out by direct survey of the observation location (Santoso, 2012), using thermal technology (Kyriaki et al, 2015). Intended to determine the accuracy of the temperature parameters observed (Ma et al, 2017). Everyone expect to live in a thermal environment where they feel comfortable.…”

Section: Introductionmentioning

confidence: 99%

Analysis of Indoor Thermal Comfort of Room Space in the International Standard Hotel Building

Sahid

Rahim

Hamzah

et al. 2019

ASSRJ

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The objective of this study was to analyze the indoor thermal comfort of room space international standard hotel buildings. The sample of the study was guests staying at five international standard hotels. The total sample were 1,092 people from five international standard hotels then sampling through Slovin formula of 10% to determine the number of respondents as many as 92 respondents. Primary data was collected through survey and questionnaires. Data was analyzed with software regarding air temperature of international standard hotel rooms both indoor and outdoor has fulfilled the prerequisites of ASHRAE, Thermal Environmental Conditions for Human Occupancy (Standard 55-66).Indoor air temperature of the five hotels observed was between 28.85 °C to 29.54 °C, with the air temperature approaching the comfort zone ranging from 20.5 °C to 27.1 °C. The outdoor air temperature of international standard hotel room space observed is on average range between 28.42 °C to 40.52 °C, with a standard deviation ranging from 0.01 to 0.44. The maximum value is between 28.45 °C to 41.41 °C and a minimum value is 28.40 °C to 39.87 °C. Solar radiation on international standard hotel building observed is in an average range between 32.79 watts / m 2 to 769.75 watts / m 2 , with a standard deviation ranging from 0.95 to 285.43 watts / m 2. The maximum value is between 36.37 to 918.97 watts / m 2 and a minimum value is between 30.08 to 715.63 watts / m 2. Solar radiation has a major influence in changing the indoor thermal comfort temperature in hotel rooms.

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“…A retirada de amostras do campo para posterior análise em laboratório, através do ensaio da sonda-agulha, apresenta custos elevados e problemas operacionais. Como alternativa, há a execução de ensaios in situ do tipo TRT, que oferecem resultados representativos dos parâmetros térmicos de solos (LHENDUP et al, 2014;MA et al, 2017).…”

Section: Ensaio Teste Resposta Térmica (Trt)unclassified

“…A eficiência do conjunto também aumenta com o número de circuitos de tubos em "U". O autor acredita que o programa numérico desenvolveu satisfatoriamente os cenários analisados, uma vez que os resultados experimentais e numéricos de temperatura do fluido na saída (Tout) dos tubos de PEAD foi inferior a 0,5 ᵒ C Ma et al (2017). realizaram um ensaio TRT por furo trocador de calor de diâmetro 0,15 m e comprimento 117 m em um solo arenoso da região de Binzhou, na província de Shandong, China.…”

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Análise do comportamento térmico de estacas geotérmicas em solo arenoso.

Almeida¹

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The search for sustainable renewable energy matrices has motivated the use of geothermal piles to take advantage of deep building foundation structures to, in tropical climate countries, dissipate heat from building to soil layers. Heating with geothermal piles is a technique widely used by European countries, where severe winters make spending on heating system mandatory. The geothermal pile system is coupled to the Ground Source Heat Pump (GSHP) assembly and is based on the circulation of a fluid through a closed circuit of pipes connected to the pile and to the heat pump. The present work aims to study the thermal behaviour of geothermal piles in a saturated sandy soil using numerical simulations to identify the variables of greatest interest to the project. The numerical model was developed with the ANSYS CFX version 19.2 program, a high performance CFD (Computational Fluid Dynamics) tool. Data from a Thermal Response Test (TRT) test carried out at the Polytechnic School of the University of São Paulo were used to calibrate the numerical model. In the steady state simulations, the variables studied were: diameter and length of piles; thermal conductivity of soil, concrete and pipe; degree of soil saturation; system inlet temperature; and circulating fluid velocity. Fluid inlet temperature, pile diameter and pile length are the variables that cause the greatest increases in the total heat transfer rates. However, the variables pile length and pile diameter do not really affect the thermal efficiency of the system, as normalized heat transfer rates showed unimportant variation. Regarding the heat transfer rates per unit of parameter, the most relevant variables are contact resistance, degree of saturation and thermal conductivity of the concrete.

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Numerical Simulation of Soil Thermal Response Test with Thermal-dissipation Corrected Model

Cited by 4 publications

References 3 publications

The Effect of Groundwater Flow on the Thermal Performance of a Novel Borehole Heat Exchanger for Ground Source Heat Pump Systems: Small Scale Experiments and Numerical Simulation

The Effect of Groundwater Flow on the Thermal Performance of a Novel Borehole Heat Exchanger for Ground Source Heat Pump Systems: Small Scale Experiments and Numerical Simulation

Analysis of Indoor Thermal Comfort of Room Space in the International Standard Hotel Building

Análise do comportamento térmico de estacas geotérmicas em solo arenoso.

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