On December 18, it was reported that the heating system in Zhengzhou City has been in a state of extreme operation, and during the cold wave, heating companies in Henan and many places across the country announced the extreme operation of the heating system.
What is the "limit state" of the heating system and what are its manifestations?How much energy does Zhengzhou consume for heating in a day?What is the basis for the design of outdoor air temperature for heating?The reporter conducted interviews and combing.
What is the "limit state" of a heating system?
Since mid-December, the outdoor temperature in Zhengzhou has fallen below the outdoor temperature of the heating design -38. It belongs to continuous extreme weather conditions. The reporter learned from the interview that the so-called "limit state" of the heating system refers to the limit value of operational safety.
It is reported that the cold wave is the longest duration of extreme weather in Zhengzhou in recent years, as the temperature drops, Zhengzhou's heat source, pipe network, temperature and pressure have reached the safety limit, if the heat supply continues to increase, there will be potential safety hazards.
Under extreme operating conditions, all kinds of heating facilities are unstable, especially increasing the safety risks such as leakage and rupture of the pipe network, and overload operation of heating facilities." The staff of Zhengzhou Heating Group said that under the premise of reducing the number of leaks in the pipe network and ensuring the safe operation of the pipe network, Zhengzhou Heating Group has done a good job in ensuring heat supply, focusing on strengthening regulation for communities with low temperatures, and making the greatest efforts to achieve a balanced heat supply.
Outdoor design temperature in Zhengzhou in winter.
Why -38℃？On what basis?
In 2012, the Ministry of Housing and Urban-Rural Development approved the "Design Code for Heating, Ventilation and Air Conditioning of Civil Buildings" as a national standard, numbered GB50736-2012. Its content regulates a series of contents such as indoor air design parameters, outdoor design calculation parameters, outdoor air calculation parameters, heat metering and room temperature control of central heating system.
The design code integrates the data of the number of days in the urban heating period, the average temperature, the average annual temperature, the wind speed, the wind direction, the percentage of sunshine in winter, the maximum depth of frozen soil, the number of days and the start and end time of the average daily average temperature +5, and the average temperature during the average temperature +5, etc., and has corresponding requirements for the outdoor design temperature of the city in winter.
Among them, the outdoor design temperature in Zhengzhou, Henan Province in winter is -38, Luoyang is -3, Anyang is -47, Beijing is -76, Hebei Shijiazhuang is -62, Jinan, Shandong-53, Shanxi Taiyuan is -101, Shenyang, Liaoning is -169, Dalian is -98, Jilin Changchun is -211, Heilongjiang Harbin is -242℃。
Zhengzhou's heating system is in the "limit state".
What about energy usage?
It is understood that on December 7, before the cold wave, Zhengzhou Thermal Power sent a letter to the thermal power plants to ensure heat supply during the cold wave, requiring the power plants to do a good job in equipment management and coal reserves in advance, and to ensure that the maximum capacity of heat supply is provided during the severe cold period, and at the same time send a gas source ** application to China Resources Gas, and the maximum daily natural gas consumption during the cold wave reaches 5.4 million cubic meters.
Long-term ultra-low temperatures.
Which communities are most affected?
It is reported that at the same time that the design temperature in Zhengzhou cannot be fully satisfied, the continuous cold wave weather has greatly reduced the thermal insulation of the building. The greater impact is the old community buildings, especially the top floor, the ground floor, and the side households of the old community can feel the room temperature drop significantly, in addition, there are some due to the blockage of indoor heating facilities, or due to the decoration of the heating equipment to cover up, and the doors and windows are not tightly closed.
Zhengzhou heating staff said that if citizens have useful heat problems at home, they can call Zhengzhou Heating Service **68890222 and the services of various heating branches for consultation and solution.
According to statistics, since December 9, a total of 2 leaks and 2 suspected leaks have occurred in Zhengzhou's long-distance pipeline and primary pipeline network, all of which have been repaired to eliminate potential heating safety hazards.
Henan and many heating enterprises across the country announced.
The heating system operates at its limit.
The reporter combed through recent public reports and found that in addition to Zhengzhou, heating enterprises in Henan Province and many provinces across the country have also announced that the heating system is operating at its limit.
On December 10, Shandong Public Thermal Power Group issued an announcement that the continuous low temperature and freezing weather is rare in history, and the temperature is expected to be lower than the outdoor average daily temperature (-5 in Jining City) for many consecutive days. Due to the instability of various heating facilities under extreme operating conditions, especially the increase in safety risks such as pipe network rupture and emergency repair, and extreme load operation of heating facilities, it is recommended that users prepare for indoor heat preservation, auxiliary heating and cold prevention measures to jointly cope with the impact of extremely cold weather.
On December 12, the Beijing Municipal Urban Management Committee required all districts and heating enterprises to pay close attention to the meteorological conditions in their regions, strengthen risk early warning research and judgment, and operate the heating system at the rated maximum output under the premise of ensuring the safety of heating operation.
On December 12, Li Wei, spokesman of Henan Anyang Yihe Heating Group, told the local ** that in accordance with the requirements of the relevant design standards of the national code, the limited outdoor average temperature of the Anyang central heating design is -47. If the outdoor temperature is lower than -10, it will seriously exceed the design capacity of central heating.
On December 14, Taishan District, Tai'an City, Shandong Province, Tai'an City, Tai'an City, Tai'an City, Kaiyuan Heating, successively issued announcements saying that the minimum temperature during the cold wave is expected to reach -18, breaking through the "Design Code for Heating, Ventilation and Air Conditioning of Civil Buildings" in Tai'an City7 Design limits for central heating systems. Heating units, heating pipe networks and operating equipment have all been running at full capacity, and the low heat consumption rate of residential areas and non-energy-saving building users will still have room temperature drops and uncomfortable physical feelings, especially the heating of residents in old residential areas will face severe challenges.
On December 17, Dalian, Liaoning Province fell below the calculated outdoor temperature of Dalian heating design -9 for three consecutive days8. 143 heat source points in Dalian are running at full capacity, and the local heating department reminds that the extremely cold weather lasts for a long time, the wind is strong, the heat dissipation loss of the house is large, and the room temperature drop of 2 to 3 is within the normal range.
Source: Dahe Daily Yu ** reporter Yang Guang.