Analysis on the thermal insulation of long-distance steam heating pipes

doi:10.3969/j.issn.2097-0706.2023.04.007

Abstract

Abstract:

In order to solve the thermal insulation problem in the long-distance transportation of cogeneration steam，a pipe network project undertaken was simulated to study its heat dissipation characteristics under different laying schemes.And the steam parameters at the network's user side were calculated based on the design load.The simulation results show that laying an air layer and soil over the steam heating pipes can reduce the heat loss of the pipes to a certain extent，so as to improve the thermal insulation of the pipelines.The heat loss of the directly buried section is less than that of the overhead pipe section.Since the increase of the load will reduce the temperature drop of the pipe and increase the pressure drop，condensation will occur at some user ends when the load of the pipe network is low.This simulation facilitates the theoretical study on heating pipe allocation optimization.

Key words: numerical simulation, cogeneration, heating pipe network, energy conservation and loss reduction, steam heating

CLC Number:

TK11：TM621

SHANG Yongqiang, WANG Wenfeng, WANG Weishu, GUO Jiawei, ZHENG Haonan, GE Xuewen. Analysis on the thermal insulation of long-distance steam heating pipes[J]. Integrated Intelligent Energy, 2023, 45(4): 47-51.

Figures/Tables 11

Fig.1

Table 1

Fig. 2

Table 2

Thermal conductivity of the thermal insulation material

保温材料	导热系数λ/[W·（m·K）^-1]
玻璃棉	$λ = 2.907 1 × 102 + 1.102 2 × 10 - 4 T + 7.652 29 × 10 - 10 T 3$
摩根	$λ = 0.03 + 0.000 2 × (T - 150)$
CNT	$λ = 0.031 + 0.000 092 5 × (T - 70)$

Table 2

Table 3

Empirical coefficient of turbulence equation

项目	$C μ$	$C 1 ε$	$C 2 ε$	$σ k$	$σ ε$
数值	0.09	1.44	1.92	1.00	1.30

Table 3

Fig.3

Fig.4

Fig.5

Fig.6

Table 4

Table 5

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管道规格	流域直径	管壁厚度	第1层保温层厚度	第2层保温层厚度	外套管厚度
DN400	426.0	9.0	60.0	60.0	9.0
DN350	377.0	9.0	75.0	75.0	9.0
DN300	325.0	8.0	85.0	85.0	9.0
DN250	273.0	6.5	100.0	100.0	9.0
DN200	219.0	6.0	90.0	90.0	9.0
DN150	159.0	4.5	45.0	45.0	8.0
DN100	108.0	4.0	55.0	55.0	8.0
DN50	89.0	4.0	50.0	50.0	7.0

用户	出口温度
用户	工况1	工况2	工况3
1	553.955 27	580.648 16	584.533 41
2	563.985 96	584.435 39	588.390 79
3	517.457 21	540.011 03	543.169 64
4	489.135 11	507.781 73	510.398 30
5	514.697 21	559.722 06	564.175 38
6	515.845 23	555.672 93	570.058 44
7	503.812 30	548.355 90	561.833 22
8	489.903 49	535.947 00	548.531 85
9	472.416 50	512.943 70	523.423 40
10	514.710 33	561.504 36	569.574 81
11	443.391 42	553.667 77	561.410 87
12	521.563 37	567.407 03	576.137 87
13	428.303 68	530.041 37	537.095 65
14	445.738 34	538.129 33	561.410 87
15	504.258 78	557.478 22	565.625 21
16	507.633 15	558.861 97	567.065 72

用户	出口压力
用户	工况1	工况2	工况3
1	1.903	1.740	1.662
2	1.907	1.775	1.697
3	1.898	1.761	1.686
4	1.893	1.755	1.681
5	1.881	1769	1.648
6	1.862	1.723	1.518
7	1.862	1.722	1.519
8	1.856	1.705	1.502
9	1.830	1.662	1.473
10	1.876	1.736	1.578
11	1.875	1.703	1.545
12	1.876	1.733	1.575
13	1.869	1.672	1.515
14	1.870	1.692	1.545
15	1.864	1.677	1.520
16	1.863	1.677	1.520