在直埋敷設(shè)的設(shè)計和施工必須真正了解加熱管分為直埋敷設(shè)和直埋敷設(shè)無擴張，兩種方法都有各自的特點和兩個方法，設(shè)計一個合理的選擇和建設(shè)直埋保溫管的工作原理的應(yīng)用是的，可靠的經(jīng)濟。
In the design and construction of direct buried laying must really understand the heating pipe is divided into direct buried laying and direct buried laying without expansion, both methods have their own characteristics and two methods, design a reasonable choice and construction of the working principle of the direct buried insulation pipe is safe, reliable and economical.
直埋保溫管道敷設(shè)有補償：通過自然補償和補償器（如方形補償器和波紋管補償器），將熱應(yīng)力降更低。直埋敷設(shè)沒有補償，這僅僅意味著對管道的熱量沒有補償，而是熱應(yīng)力吸收。
Direct buried insulation pipe laying has compensation: through natural compensation and compensators (such as square compensators and bellows compensators), the thermal stress is minimized. There is no compensation for direct embedding, which simply means that there is no compensation for the heat in the pipeline, but thermal stress absorption.
直埋直埋保溫管無需補償安裝、安裝，熱管先固定到一定溫度后，再進(jìn)行固定管焊接，當(dāng)管道回溫（低溫）時，管道在拉伸應(yīng)力作用下提前進(jìn)行。當(dāng)通過熱管工作時，隨著溫度的升高，管道應(yīng)力為零，在繼續(xù)升溫時，壓縮應(yīng)力增大，當(dāng)溫度達(dá)到工作溫度時，管道的壓縮應(yīng)力、熱應(yīng)力仍小于許用應(yīng)力。這樣，管道就可以在不補償設(shè)備的情況下工作。
There is no need to compensate the installation and installation of the directly buried and directly buried insulation pipe. After the heat pipe is fixed to a certain temperature, the fixed pipe is welded. When the pipe returns to temperature (low temperature), the pipe is carried out in advance under the action of tensile stress. When working through the heat pipe, the pipe stress is zero as the temperature increases. When the temperature continues to rise, the compressive stress increases. When the temperature reaches the working temperature, the compressive stress and thermal stress of the pipe are still less than the allowable stress. In this way, the pipeline can work without compensating the equipment.
第四強度理論中要求預(yù)熱管道施工的補償方法，在施工中會非常麻煩，在國內(nèi)外也有許多工程實踐，理論計算可靠，能保證。近年來，在的北京煤制氣的熱設(shè)計院的分類進(jìn)行了分析，并對第三強度理論的方法和應(yīng)力的應(yīng)用。該方法充分發(fā)揮了鋼的塑性潛力，施工方便，不預(yù)熱。
The fourth strength theory requires the compensation method of preheating pipeline construction, which will be very troublesome in the construction. There are also many engineering practices at home and abroad. The theoretical calculation is reliable and can guarantee the safety. In recent years, the classification of the thermal design institute of coal gasification in Beijing, China has been analyzed and the application of the third strength theory method and stress. The method gives full play to the plastic potential of steel, which is convenient for construction and not preheating.
兩不同埋深的考慮因素：直埋安裝部署，嵌入深度來確定補償，只考慮不會破壞管道的穩(wěn)定性可能是由于地面荷載，從經(jīng)濟方面考慮，施工方便，方法等要埋在直埋補償盡可能淺。上覆巖層的厚度應(yīng)大于0.6米，不論管徑大小。
Two different burial depth considerations: direct burial installation and deployment, embedding depth to determine the compensation, only considering that the stability of the pipeline will not be damaged may be due to the ground load, from the economic perspective, construction convenience, methods to be buried in direct burial compensation as shallow as possible. The thickness of the overlying strata shall be greater than 0.6 m, regardless of pipe diameter.
當(dāng)直埋無補償，考慮穩(wěn)定性的管道埋深要求，一般覆土厚度、埋藏深度、穩(wěn)定性，比有補償直埋敷設(shè)時使用無預(yù)熱無補償電路，更小覆土深度應(yīng)規(guī)則和城市熱網(wǎng)設(shè)計規(guī)范（cjj34-90），一次覆土厚度7.2.15個執(zhí)行，是直徑大小成正比。
When there is no compensation for direct burial, the buried depth of the pipeline considering the stability of the requirements, general soil cover thickness, burial depth, stability, than the use of compensation for direct burial without preheating and compensation circuit, minimum soil cover depth should be rules and urban heat network design code (cjj34-90), the first soil cover thickness 7.2.15 implementation, is proportional to the diameter.
