Experimental study of thermal performance of the backfill material around underground power cable under steady and cyclic thermal loading

Ahmad, Shahbaz; Rizvi, Zarghaam Haider; Khan, Mohammad Arsalan; Jamal, Anwar; Wuttke, Frank

doi:10.1016/j.matpr.2019.06.404

Cited by 14 publications

(9 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The large latent heat absorption and clear diminishing of temperature variations during phase transformation are essential for alleviating the impact of UPCSs on the soil temperature field. Furthermore, the intermittent operation of UPCSs on a regular daily schedule facilitates the operation and recovery of the PCM phase process for each cycle, which is very important for long-term stable system operation [ 30 , 31 ]. However, existing studies on cable backfill materials have mostly focused on increasing the thermal conductivity, such that there have been no significant improvements in either the heat accumulation or the heat capacity of these materials.…”

Section: Introductionmentioning

confidence: 99%

Heat Storage of Paraffin-Based Composite Phase Change Materials and Their Temperature Regulation of Underground Power Cable Systems

Xie

Huang

et al. 2021

Materials

View full text Add to dashboard Cite

Excessive heat accumulation in backfill materials causes thermal fatigue damage in underground power cable systems that significantly affects the cable carrying capacity. To improve the thermal conditions of the system, two types of composite phase change materials (CPCMs) were prepared by incorporating paraffin into porous ceramsite (CS)/expanded graphite (EG) in this study. EG and CS can carry 90 and 40 wt.% paraffin, respectively. The phase change temperature of paraffin/CS and paraffin/EG CPCMs was approximately 65 °C, and the corresponding latent heats were 63.38 J/g and 156.4 J/g, respectively. Furthermore, the temperature regulation by CPCMs was evaluated experimentally by designing a setup to simulate the underground power cable system. The reduction in the maximum temperature of the backfill materials with paraffin/CS CPCM and paraffin/EG CPCM was approximately 7.1 °C and 17.1 °C, respectively, compared to reference samples. A similar conclusion was drawn from the heat flux curves. Therefore, the prepared CPCMs could significantly alleviate temperature fluctuations, where the paraffin/EG CPCM provided better temperature regulation than paraffin/CS CPCM. Both materials have potential applications for use in backfill materials for underground power cable systems.

show abstract

Section: Introductionmentioning

confidence: 99%

Heat Storage of Paraffin-Based Composite Phase Change Materials and Their Temperature Regulation of Underground Power Cable Systems

Xie

Huang

et al. 2021

Materials

View full text Add to dashboard Cite

show abstract

“…Despite its advantages, i.e., low unit price, availability on the market, and adequate mechanical properties, it does not ensure the thermal stability of the cable line operation in the long-term period. After a few months of the thermal load caused by the line operation, its thermal conductivity drops significantly (Ahmad et al 2019). What is more, the manufacturing of Portland cement caused a considerable Fig.…”

Section: Introductionmentioning

confidence: 99%

Analysis of an application possibility of geopolymer materials as thermal backfill for underground power cable system

Ocłoń

Cisek

Matysiak

2020

Clean Techn Environ Policy

View full text Add to dashboard Cite

The circular economy is a closed cycle that allows one to reuse the industrial waste, as well as minimize the energy and resources losses during the production process. This paper presents an innovative idea of the application of a geopolymer cable backfill for underground power cable system installation. The closed cycle, in this case, is formulated as follows: the primary resource is the waste from the combustion of fossil fuels, i.e., fly ash that is utilized to form the geopolymer matrix. The geopolymer then is used as thermal backfill in underground power cable systems. Utilization of combustion by-products in the form of a geopolymer is a highly profitable solution since landfill waste disposal, in this case, generates considerable costs for the electrical energy producers. In typical applications, geopolymers are used as insulators. By adding individual components, the thermal conductivity of 2.0 W/(m K), higher than of typical thermal backfills (Fluidized Thermal Backfill), which value is close to 1.5 W/(m K), is reached. What is very important, geopolymers can absorb water better than typical sand–cement mixtures. As a result, a high thermal conductivity with the temperature increase is maintained. The application of geopolymers as thermal backfills has the potential to improve the flexibility of underground power cable systems, as well as to minimize the material costs of installation. The case study is presented to show the economic benefits of using the combustion by-products as a geopolymer thermal backfill. The finite element method model of an underground power cable system is developed, and optimization of backfill dimensions is provided to minimize the material costs using the geopolymer thermal backfill and to maximize the underground power cable system performance. The main result of this paper is that the application of geopolymers leads to a decrease in underground power cable system costs, compared to traditional backfill (sand–cement mixture). The reason is the higher value of thermal conductivity, which allows selecting a cable with a smaller cross-sectional area. Also, the environmental benefits of geopolymer application for cable bedding are discussed. Graphic abstract

show abstract

“…In the study of Ahmad et al [21] a single electrical heater was used to examine dry soil and the designed backfill performance. Several cycles of 12 h heating and cooling were performed in order to investigate the nature and characteristics of the proposed backfill.…”

Section: Introductionmentioning

confidence: 99%

“…Several cycles of 12 h heating and cooling were performed in order to investigate the nature and characteristics of the proposed backfill. The test stand presented in [21] was a modification of the experimental setup proposed by Moya et al [22]. This paper presents an experimental validation of the numerical model of heat transfer in an underground power cable system.…”

Section: Introductionmentioning

confidence: 99%

Experimental Validation of a Heat Transfer Model in Underground Power Cable Systems

et al. 2020

View full text Add to dashboard Cite

This paper presents the laboratory test stand that is used for experimental validation of underground power cable system models. Determination of temperature distribution in the vicinity of the cable is the main goal of the study. The paper considers a system of three power cables, situated in the in-line arrangement, and buried in sand. Three electrical heaters of special construction are used in order to simulate the heat flux that is generated in the power cables during their operation. The test stand is designed to be placed in a thermoclimatic chamber, which allows testing the system in various thermal conditions when the ambient temperature changes by 20 °C to 30 °C. Numerical computations of the steady-state temperature fields are performed using the finite element method.

show abstract

Experimental study of thermal performance of the backfill material around underground power cable under steady and cyclic thermal loading

Cited by 14 publications

References 15 publications

Heat Storage of Paraffin-Based Composite Phase Change Materials and Their Temperature Regulation of Underground Power Cable Systems

Heat Storage of Paraffin-Based Composite Phase Change Materials and Their Temperature Regulation of Underground Power Cable Systems

Analysis of an application possibility of geopolymer materials as thermal backfill for underground power cable system

Experimental Validation of a Heat Transfer Model in Underground Power Cable Systems

Contact Info

Product

Resources

About