Numerical Study of Heat Transfer in Trefoil Buried Cable with Fluidized Thermal Backfill and Laying Parameter Optimization

<table class="figure-group"><tr class="fig-image" id="a"><td><object data="https://static-preview.hindawi.com/articles/mpe/volume-2019/4741871/figures/4741871.fig.009a.svgz" name="4741871.fig.009a" type="image/svg+xml"></object></td></tr><tr class="fig-caption"><td><b>(a) </b>Flat-type FTB buried cables (<svg height="11.8174pt" id="M87" style="vertical-align:-3.1815pt" version="1.1" viewbox="-0.0498162 -8.6359 27.011 11.8174" width="27.011pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M686 28C612 35 607 44 591 112C563 234 541 360 519 489L489 666L457 658L147 121C100 40 89 36 24 28L17 0H240L250 28C168 34 159 41 190 101L262 237H482C495 180 503 137 510 91C517 47 514 35 441 28L433 0H677L686 28ZM475 280H285L429 541H431L475 280Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,10.244,3.132)"><path d="M502 500C497 551 492 613 491 650H43V617C122 612 130 606 130 521V129C130 45 122 38 41 33V0H319V33C227 38 217 45 217 129V305H319C411 305 413 295 427 225H461V421H427C414 357 411 348 319 348H217V580C217 609 219 612 250 612H330C401 612 423 605 439 578C452 557 458 539 467 496L502 500Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,15.158,3.132)"><path d="M601 496C596 555 591 627 591 675H567C551 656 544 650 516 650H120C91 650 79 651 64 675H41C38 619 34 555 29 492H63C75 537 83 566 96 582C110 604 128 612 207 612H272V126C272 46 264 38 170 33V0H464V33C368 38 359 48 359 126V612H430C502 612 520 605 535 582C547 566 556 541 567 492L601 496Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,20.873,3.132)"><path d="M384 354C435 370 515 408 515 502C515 549 494 593 459 616C426 639 384 650 308 650H45V618C127 613 130 606 130 524V127C130 45 125 38 37 33V0H262C342 0 409 12 461 40C521 73 558 124 558 192C558 295 481 336 384 352V354ZM217 365V556C217 587 221 597 229 604C238 611 261 615 288 615C382 615 421 558 421 490C421 406 374 365 266 365H217ZM217 327H264C384 327 457 284 457 183C457 80 383 38 301 38C235 38 217 55 217 127V327Z"></path></g></svg> = 0.560 m<sup>2</sup>)</td></tr><tr class="fig-image" id="b"><td><object data="https://static-preview.hindawi.com/articles/mpe/volume-2019/4741871/figures/4741871.fig.009b.svgz" name="4741871.fig.009b" type="image/svg+xml"></object></td></tr><tr class="fig-caption"><td><b>(b) </b>Parabolic-type FTB buried cables (<svg height="11.8174pt" id="M88" style="vertical-align:-3.1815pt" version="1.1" viewbox="-0.0498162 -8.6359 27.011 11.8174" width="27.011pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M686 28C612 35 607 44 591 112C563 234 541 360 519 489L489 666L457 658L147 121C100 40 89 36 24 28L17 0H240L250 28C168 34 159 41 190 101L262 237H482C495 180 503 137 510 91C517 47 514 35 441 28L433 0H677L686 28ZM475 280H285L429 541H431L475 280Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,10.244,3.132)"><path d="M502 500C497 551 492 613 491 650H43V617C122 612 130 606 130 521V129C130 45 122 38 41 33V0H319V33C227 38 217 45 217 129V305H319C411 305 413 295 427 225H461V421H427C414 357 411 348 319 348H217V580C217 609 219 612 250 612H330C401 612 423 605 439 578C452 557 458 539 467 496L502 500Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,15.158,3.132)"><path d="M601 496C596 555 591 627 591 675H567C551 656 544 650 516 650H120C91 650 79 651 64 675H41C38 619 34 555 29 492H63C75 537 83 566 96 582C110 604 128 612 207 612H272V126C272 46 264 38 170 33V0H464V33C368 38 359 48 359 126V612H430C502 612 520 605 535 582C547 566 556 541 567 492L601 496Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,20.873,3.132)"><path d="M384 354C435 370 515 408 515 502C515 549 494 593 459 616C426 639 384 650 308 650H45V618C127 613 130 606 130 524V127C130 45 125 38 37 33V0H262C342 0 409 12 461 40C521 73 558 124 558 192C558 295 481 336 384 352V354ZM217 365V556C217 587 221 597 229 604C238 611 261 615 288 615C382 615 421 558 421 490C421 406 374 365 266 365H217ZM217 327H264C384 327 457 284 457 183C457 80 383 38 301 38C235 38 217 55 217 127V327Z"></path></g></svg> = 0.351 m<sup>2</sup>)</td></tr></table>

<div>Temperature distributions in flat-type FTB and parabolic-type FTB trefoil buried cables. (<svg height="8.68572pt" id="M84" style="vertical-align:-0.0498209pt" version="1.1" viewbox="-0.0498162 -8.6359 5.68448 8.68572" width="5.68448pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M405 650H141L135 622C222 616 230 610 215 535L133 116C118 41 113 33 29 28L23 0H289L295 28C209 33 205 40 219 116L298 535C312 609 317 616 399 622L405 650Z"></path></g></svg> = 1500 A). (a) Flat-type FTB buried cables (<svg height="11.8174pt" id="M85" style="vertical-align:-3.1815pt" version="1.1" viewbox="-0.0498162 -8.6359 27.011 11.8174" width="27.011pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M686 28C612 35 607 44 591 112C563 234 541 360 519 489L489 666L457 658L147 121C100 40 89 36 24 28L17 0H240L250 28C168 34 159 41 190 101L262 237H482C495 180 503 137 510 91C517 47 514 35 441 28L433 0H677L686 28ZM475 280H285L429 541H431L475 280Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,10.244,3.132)"><path d="M502 500C497 551 492 613 491 650H43V617C122 612 130 606 130 521V129C130 45 122 38 41 33V0H319V33C227 38 217 45 217 129V305H319C411 305 413 295 427 225H461V421H427C414 357 411 348 319 348H217V580C217 609 219 612 250 612H330C401 612 423 605 439 578C452 557 458 539 467 496L502 500Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,15.158,3.132)"><path d="M601 496C596 555 591 627 591 675H567C551 656 544 650 516 650H120C91 650 79 651 64 675H41C38 619 34 555 29 492H63C75 537 83 566 96 582C110 604 128 612 207 612H272V126C272 46 264 38 170 33V0H464V33C368 38 359 48 359 126V612H430C502 612 520 605 535 582C547 566 556 541 567 492L601 496Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,20.873,3.132)"><path d="M384 354C435 370 515 408 515 502C515 549 494 593 459 616C426 639 384 650 308 650H45V618C127 613 130 606 130 524V127C130 45 125 38 37 33V0H262C342 0 409 12 461 40C521 73 558 124 558 192C558 295 481 336 384 352V354ZM217 365V556C217 587 221 597 229 604C238 611 261 615 288 615C382 615 421 558 421 490C421 406 374 365 266 365H217ZM217 327H264C384 327 457 284 457 183C457 80 383 38 301 38C235 38 217 55 217 127V327Z"></path></g></svg> = 0.560 m<sup>2</sup>). (b) Parabolic-type FTB buried cables. (<svg height="11.8174pt" id="M86" style="vertical-align:-3.1815pt" version="1.1" viewbox="-0.0498162 -8.6359 27.011 11.8174" width="27.011pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M686 28C612 35 607 44 591 112C563 234 541 360 519 489L489 666L457 658L147 121C100 40 89 36 24 28L17 0H240L250 28C168 34 159 41 190 101L262 237H482C495 180 503 137 510 91C517 47 514 35 441 28L433 0H677L686 28ZM475 280H285L429 541H431L475 280Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,10.244,3.132)"><path d="M502 500C497 551 492 613 491 650H43V617C122 612 130 606 130 521V129C130 45 122 38 41 33V0H319V33C227 38 217 45 217 129V305H319C411 305 413 295 427 225H461V421H427C414 357 411 348 319 348H217V580C217 609 219 612 250 612H330C401 612 423 605 439 578C452 557 458 539 467 496L502 500Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,15.158,3.132)"><path d="M601 496C596 555 591 627 591 675H567C551 656 544 650 516 650H120C91 650 79 651 64 675H41C38 619 34 555 29 492H63C75 537 83 566 96 582C110 604 128 612 207 612H272V126C272 46 264 38 170 33V0H464V33C368 38 359 48 359 126V612H430C502 612 520 605 535 582C547 566 556 541 567 492L601 496Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,20.873,3.132)"><path d="M384 354C435 370 515 408 515 502C515 549 494 593 459 616C426 639 384 650 308 650H45V618C127 613 130 606 130 524V127C130 45 125 38 37 33V0H262C342 0 409 12 461 40C521 73 558 124 558 192C558 295 481 336 384 352V354ZM217 365V556C217 587 221 597 229 604C238 611 261 615 288 615C382 615 421 558 421 490C421 406 374 365 266 365H217ZM217 327H264C384 327 457 284 457 183C457 80 383 38 301 38C235 38 217 55 217 127V327Z"></path></g></svg> = 0.351 m<sup>2</sup>).</div>

Mathematical Problems in Engineering

fig9

Figure 9

Figure 9: Numerical Study of Heat Transfer in Trefoil Buried Cable with Fluidized Thermal Backfill and Laying Parameter Optimization 