PSI - Issue 20

Ivanov V.N. et al. / Procedia Structural Integrity 20 (2019) 222–229 Ivanov V.N. et al. / Structural Integrity Procedia 00 (2019) 000–000

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The average recovery time in the conditions of Yakutia can be taken 1, 2 hours more than in Moscow, which is shown by experimental data. In this regard, in order to guarantee the provision of repair and restoration work, for heating systems connected to heat networks, it is proposed to introduce a minimum value of heat resistance index β for a given area. The indicator β , which characterizes the ratio of the values of specific heat capacity and heat loss of the room, is associated with the thermal massiveness of the external walls. Therefore, the massiveness of exterior walls for mass buildings should, depending on the terrain, be set to a minimum value, below which it cannot be connected to centralized networks in terms of maintainability. Thus, the indicator of heat resistance can be used as one of the indicators for choosing the optimal combination of centralized and decentralized heat supply, taking into account the provision of repair and rehabilitation works. The relevance of this issue is increasing in connection with the development of energy-saving buildings, which require increased standards for heat transfer resistance. In the conditions of Yakutia, it is necessary to apply only combined building structures to fulfill these norms. The duration of repair work in emergency situations, defined by the formula (3) for buildings with various enclosing structures, is given in Table 3.

Table 3. The duration of repair work in case of emergency.

z, hour t out , о С

t int , о С

-55

-50

-40

-30

-20

Stone building

22 20 18 16 22 20 18 16 22 20 18 16 22 20 18 16

21.0 17.7 14.3 10.8 17.3 14.6 11.8

23.5 20.0 16.3 12.5 19.4 16.5 13.5 10.3

30.0 25.8 21.5 17.1 24.7 21.3 17.7 14.1

39.5 34.6 29.5 24.1 32.5 28.5 24.3 19.8 14.9 13.0 11.1

55.1 49.0 42.4 35.6 45.4 40.4 34.9 29.3 20.8 18.5 16.0 13.4 16.1 14.3 12.4 10.4

Brick building

8.9

Wooden building

7.9 6.7 5.4 4.1 6.1 5.2 4.2 3.1

8.9 7.6 6.2 4.7 6.9 5.8 4.8 3.7

11.3

9.8 8.1 6.5 8.7 7.5 6.3 5.0

9.1

Effective three-layer panel

11.5 10.1

8.6 7.0

The service of operating heat supply systems in the Arctic and the Far North is faced with the task not only to operate normally, but also not to allow an emergency situation. Accidents in the winter can have disastrous consequences for the safety of the population and have large material costs. At low ambient temperatures, stopping the operation of the heating system can lead to the freezing of the entire system for the entire subsequent heating period, without the possibility or sufficiently difficult restoration of the operating state. 4. Conclusions Thus, we can distinguish the following conclusions: 1. The service life of the elements of the heat supply systems of buildings in the long heating season, which is characteristic in the conditions of Eastern Siberia, is reduced to 17 - 33% relative to regulatory data. 2. The calculation of the cooling time of thermal networks and building premises shows that buildings with low thermal stability cool faster than thermal networks, therefore the cooling time of external thermal networks with a