After the beginning of spring, it is still cold and the outdoor temperature drops sharply, and the heating pressure also increases. Line patrol heating workers need to "take pulse and consult" in an underground well 4 meters deep to check whether there are loopholes in the pipeline.

The reporter followed them to the Duofu Road section in Taiyuan City, Shanxi Province. It took 8 hours to check the operation of 23 well rooms with a total length of 7 kilometers.

At 8 o'clock in the morning, the reporter came to the Jiancaoling Heating Branch of Taiyuan Heating Group. It was relatively empty and the cold wind whistled. The smoke just came out of the large chimney for heating in the distance was blown to the side by the wind. The reporter could only lower his head and advanced against the wind. After changing into the work clothes of the thermal power company and wearing a safety helmet, the reporter and the line patrol workers held a shift meeting before the inspection work, and officially started the experience work of the day.

Followed the inspection car to the first inspection point. When the reporter was still curious about which manhole covers were a group of inspection points, the surrounding inspection workers had already started to isolate the work area with great skill. Zhao Linqi, deputy director of the Pipeline Network Office of Jiancaoping Heating Branch of Taiyuan Heating Group, explained to reporters: "The current well rooms are full of two eyes, which is equivalent to having two doors in one home. These two doors are usually diagonally distributed, which is more conducive to ventilation underground."

Located to the well room to be inspected, the reporter followed the line patrol workers to place warning piles, construction warning signs and risk notice signs, and then prepared to open the manhole cover. The manhole cover is very heavy, and it is difficult for an adult man to lift it independently, so several people must work together to complete it. An experienced worker took the reporter to pry a side of the manhole cover with a well hook, and then placed the wrench between the gaps to prevent the manhole cover from hurting his fingers. "This is all experience. The manhole cover weighs about 200 kilograms. If you don't put anything on your back, your hands will easily be injured." Zhao Linqi said.

Immediately afterwards, the reporter followed the line patrolman to place the axial fan and rescue tripod that circulates the downhole air in the corresponding position, took out the oxygen meter and began to measure the downhole oxygen content. Due to the high temperature downhole and the space is closed, if the oxygen content is insufficient, it is easy to cause fainting. Therefore, a respirator on the well is indispensable.

The reporter is preparing to go down the well. Photo by Xinhua News Agency reporter Fan Xinyang

As soon as the manhole cover was raised, a wet heat came to my face. After confirming that the downhole oxygen content was qualified, the reporter put on his seat belt and followed Wen Xiaoliang, a staff member of the pipeline station, to prepare for the downhole operation. The ladders underground were very rough and were full of rust. "You must wear gloves. It's a trivial matter to get your hands dirty. Be careful to make a big cut." Wen Xiaoliang told reporters while going down the ladder.

Inspector Wen Xiaoliang introduced the situation to reporters underground. Photo by Xinhua News Agency reporter Zhang Zhe

The reporter went downstairs to inspect the mines. Photo by Xinhua News Agency reporter Fan Xinyang

Unlike previous imagination, the underground space is not cramped. It is as big as a small room. It enters the underground from the ground at minus 10 degrees Celsius. The warm water overwhelms the reporter's calves, and the stuffy environment makes people start to sweat.

"It's quite warm down." The reporter told Wen Xiaoliang.

"It's cold now, and the temperature difference between the upper and lower parts is very large. I'm sweating down there, and it's dry as soon as I go up. You dry your forehead when you go up and don't catch a cold." Wen Xiaoliang reminded reporters.

The reporter and Wen Xiaoliang moved slowly in the water under the well. While patrolling, he explained: "Last summer we went down the well more frequently, and we inspected, inspected, repaired and updated the underground equipment in advance, so there were many problems this winter."

The underground space was very dark. The only light source after entering the depths was the searchlight on the reporter's head. Several pipes that exceeded the circumference of the adult's arms came into view. Wen Xiaoliang took the reporter to check the expansion and contraction of the compensator. He said: "It is normal for the underground pipeline to expand and contract, but if the changes are too large, it is easy to leak. The compensator is a device used to adjust the changes in the pipeline."

Climb out of the well, and the cold wind blew the sultry heat away. The reporter couldn't help but shivered, feeling like "ice and fire". Zhao Linqi introduced that the lower the ground temperature, the higher the underground temperature will be. This temperature difference is generally around 40 degrees Celsius.

The reporter and the line patrol workers didn't have time to rest and rushed to the next checkpoint without stopping. This pipeline of more than ten kilometers is responsible for heating for thousands of households around. In the jurisdiction under Zhao Linqi, a total of 206 kilometers of road sections need to be operated. Each section is inspected on average once a week to ensure that heating is foolproof.

When the day's inspection work was over, the reporter felt muscle aches. This "underground journey" allowed the reporter to touch the warm pulse of the city and remember those figures that competed with boredom in the dark. This is the weight of "warmth" and the protection deeply buried underground. (Reporters Fan Xinyang and Zhang Zhe)