??? 利用 電伴熱產品所產生的熱量來補償需伴熱的管道等工藝裝置所散耗的熱量，以維持其相應的介質溫度來滿足工藝要求。所以正確計算出管道等工藝裝置的熱耗散量，對伴熱所需的介質溫度是至關重要的。為此在計算熱耗散量前，必須先找出有關的幾個重要參數：如TA（管道等介質維持溫度）。TB（當地最低環(huán)境溫度）、d（管道的外徑）、do（管道內徑）、δ（保溫層厚度）。另外還需知道保溫材料的名稱和敷設環(huán)境（室內或室外、地面或埋地）。當知道了這些參數，再借助于有關的計算方式和表就能進行具體計算，從而得到所需的散熱量。 管道及附件耗散熱量的計算
確定管道的熱耗散量
??? 首先應知道管道的口徑、保溫層材料及厚度和所需維持溫度之差△T，查管道散熱量表，（乘以適當的保溫系數），就能得到單位長管道的散熱量，如果管子在室內則再乘以0.9。如果伴熱的是塑料管道，因為塑料的導熱性遠低于碳鋼（0.12:25），故可用0.6-0.7的系數對正常散熱量加以修正。
例1：某廠有一管線，管徑為1/2"，保溫材料是硅酸鈣，厚度10mm，管道中流體為水，水溫需保持10℃，冬季最低氣溫是-25℃，環(huán)境無腐蝕性，周圍供電條件380V、220V均有，求管道每米熱損失？
??? 步驟一：△T = TA - TB =10℃-（-25℃）=35℃
??? 步驟二：查管道散熱量表，管徑1/2"。10mm保溫層。
??????????? 當△T =30℃熱損失為11.0w/m，當△T =40℃熱損失為14.9w/m，△T =35℃時，每米損失可采用中間插入法求得（因表中無QB值）。
????????? ???QB=11.0w/m+（14.9w/m - 11.0w/m）[（35-30）÷（40-30）]=12.95w/m
??? 步驟三：保溫層采用硅酸鈣，查保溫材料修正數表乘以保溫系數f及綜合系數1.4
??????????? Qr=1.4QB×f=1.4×12.95w/m×1.50=27.195w
??? 答案：管道每米損失熱量27.195W
保溫材料修正數表
|
保溫材料 |
保溫系數F |
導熱常熟（w/m.k）10℃ |
|
玻璃纖維 |
1.0 |
0.036 |
|
巖棉（管殼） |
1.22 |
0.044 |
|
棉管殼 |
1.11 |
0.04 |
|
珍珠巖 |
1.31 |
0.047 |
|
聚氨酯泡沫塑料 |
0.67 |
0.024 |
|
聚苯乙烯泡沫塑料 |
1.86 |
0.031 |
|
硅酸鈣 |
1.50 |
0.054 |
|
石棉繩 |
1.83 |
0.066 |
|
復合硅酸鹽氈FHP-VB |
0.65 |
0.0234 |
|
硅酸鋁耐火纖維板 |
1.0 |
0.036 |
?
確定管道閥體的散熱量
??? 閘閥散熱量通常是相聯(lián)口徑管道每米熱損失的1.22倍；如果是球閥，則可用0.7乘以閘閥熱耗量，如果蝶型閥（節(jié)流閥），則乘以0.5；如果是浮式球閥，則乘以0.6。
??? 從產品規(guī)格中可知電伴熱帶的工作電壓，功率值。如算出單位長度熱損失大于電伴熱帶單位長度的發(fā)熱額定值，則可用以下方法來彌補：
??? ● 采用卷繞法（如果用此法，則要先求出熱損失對電伴熱帶發(fā)熱功率的比值。如在2"管道上熱損失是24w/m，而電伴熱帶功率20w/m，則比值=24/20是1.2倍，查電伴熱帶跨距表可知2"管道上間距為280mm的這種繞法能滿足管道的熱耗散。）
??? 除上面的兩種方法外，還可采取增加保溫層厚度或采取導熱系數較低的保溫材料等附加措施彌補。
電伴熱帶跨距表（單位：mm）
|
管徑 |
每米管子所需電伴熱帶數（比值） |
|
1.1 |
1.2 |
1.3 |
1.4 |
1.5 |
|
1″ |
229 |
152 |
102 |
102 |
76 |
|
5/4″ |
305 |
203 |
152 |
127 |
102 |
|
3/2″ |
330 |
229 |
178 |
152 |
127 |
|
2″ |
432 |
280 |
229 |
203 |
178 |
|
5/2″ |
508 |
356 |
280 |
229 |
203 |
|
3″ |
610 |
432 |
330 |
280 |
254 |
|
13/4″ |
711 |
483 |
381 |
330 |
280 |
|
4″ |
787 |
533 |
432 |
356 |
305 |
|
9/2″ |
889 |
610 |
483 |
406 |
356 |
|
5″ |
990 |
660 |
533 |
457 |
381 |
|
6″ |
1168 |
787 |
635 |
533 |
457 |
|
8″ |
1500 |
1041 |
838 |
711 |
610 |
?
??? 電伴熱帶跨距表中保溫材料是采用玻璃纖維為標準的，如用其字材料可參見保溫材料修正表的系數進行修正，如前面例1所述。 為完善整個加熱系統(tǒng)，還須考慮法蘭，彎頭及管道金屬托架散熱損失所需的電伴熱帶長度及預留供電電源接線用的長度，同時還要考慮預留供中間接線盒接線長度。法蘭一般加上2倍的管徑長度，彎頭加上1.5倍的管徑長度；管道金屬托架加上3-5倍的管徑長度，預留電源接線長度一般為1米，中間接線盒預留約0.5米。當計算出有關管道各附件的長度后，再加伴熱管所需的電伴熱帶長度，我們就能得到整個系統(tǒng)所需電伴熱帶的總長度。
?
管道散熱量表
|
保溫厚度
mm |
溫差℃
△T |
管道大小 |
15 |
20 |
25 |
32 |
40 |
50 |
65 |
|
內徑mm |
1/2 |
3/4 |
1 |
5/4 |
3/2 |
2 |
5/2 |
|
英制(時)1/4
外徑mm14 |
21 |
27 |
34 |
42 |
48 |
60 |
76 |
|
? |
20 |
6.2 |
7.2 |
8.5 |
10.1 |
12.1 |
13.6 |
16.4 |
19.3 |
|
30 |
9.4 |
11.0 |
12.9 |
15.4 |
18.5 |
20.4 |
24.9 |
29.4 |
|
40 |
12.7 |
14.9 |
17.5 |
20.8 |
25.0 |
27.9 |
33.7 |
39.7 |
|
20 |
20 |
4.0 |
4.6 |
5.3 |
6.2 |
7.3 |
8.0 |
9.5 |
11.1 |
|
30 |
6.2 |
7.0 |
8.1 |
9.4 |
11.1 |
12.2 |
14.5 |
16.8 |
|
40 |
8.3 |
9.5 |
10.9 |
12.7 |
15.0 |
16.5 |
19.6 |
22.8 |
|
60 |
12.8 |
14.7 |
16.9 |
19.6 |
23.1 |
25.5 |
30.2 |
35.1 |
|
25 |
20 |
3.6 |
4.1 |
4.6 |
5.3 |
6.2 |
6.9 |
8.1 |
9.3 |
|
30 |
5.4 |
6.2 |
7.1 |
8.1 |
9.5 |
10.4 |
12.3 |
14.2 |
|
40 |
7.4 |
8.4 |
9.5 |
11.0 |
12.9 |
14.1 |
16.6 |
19.2 |
|
60 |
11.4 |
12.9 |
14.7 |
17.0 |
19.8 |
21.8 |
25.6 |
29.6 |
|
80 |
15.6 |
17.7 |
20.2 |
23.3 |
27.2 |
29.9 |
35.1 |
40.6 |
|
100 |
20.1 |
22.8 |
26.1 |
30.1 |
35.1 |
38.6 |
45.4 |
52.5 |
|
30 |
20 |
3.3 |
3.7 |
4.2 |
4.8 |
5.5 |
6.1 |
7.1 |
8.1 |
|
30 |
5.0 |
5.6 |
6.3 |
7.3 |
8.4 |
9.2 |
10.8 |
12.4 |
|
40 |
6.7 |
7.6 |
8.6 |
9.8 |
11.4 |
12.5 |
14.6 |
16.8 |
|
60 |
10.3 |
11.7 |
13.2 |
15.1 |
17.6 |
19.2 |
22.5 |
25.9 |
|
80 |
14.2 |
16.0 |
18.2 |
20.8 |
24.1 |
26.4 |
30.9 |
35.5 |
|
100 |
18.3 |
20.7 |
23.4 |
26.8 |
31.1 |
34.1 |
39.8 |
45.8 |
|
120 |
22.7 |
25.6 |
29.0 |
33.2 |
38.6 |
42.2 |
49.3 |
56.7 |
|
140 |
27.2 |
30.8 |
34.9 |
40.0 |
46.4 |
50.8 |
59.4 |
68.3 |
|
160 |
32.1 |
36.2 |
41.1 |
47.1 |
54.6 |
59.8 |
69.9 |
80.4 |
|
180 |
37.1 |
42.0 |
47.6 |
54.5 |
63.2 |
69.2 |
80.9 |
93.0 |
|
40 |
20 |
2.8 |
3.2 |
3.6 |
4.0 |
4.6 |
5.0 |
5.8 |
6.6 |
|
30 |
4.3 |
4.8 |
5.4 |
6.1 |
7.0 |
7.7 |
8.9 |
10.4 |
|
40 |
5.8 |
6.5 |
7.3 |
8.3 |
9.5 |
10.4 |
12.0 |
13.7 |
|
60 |
9.0 |
10.1 |
11.3 |
12.8 |
14.7 |
16.0 |
18.5 |
21.1 |
|
80 |
12.3 |
13.8 |
15.5 |
17.6 |
20.2 |
21.9 |
25.4 |
28.9 |
|
100 |
15.9 |
17.8 |
20.2 |
22.7 |
26.0 |
28.3 |
32.8 |
37.3 |
|
120 |
19.7 |
22.1 |
24.8 |
28.1 |
32.2 |
35.1 |
40.6 |
46.2 |
|
140 |
23.7 |
26.5 |
29.8 |
33.8 |
38.8 |
42.2 |
48.8 |
55.6 |
|
160 |
27.9 |
31.2 |
35.1 |
39.8 |
45.6 |
49.7 |
57.4 |
65.5 |
|
180 |
32.3 |
36.2 |
40.6 |
46 |
52.9 |
57.5 |
66.5 |
75.8 |
|
50 |
20 |
2.6 |
2.8 |
3.2 |
3.6 |
4.1 |
4.2 |
5.0 |
5.7 |
|
30 |
3.9 |
4.3 |
4.8 |
5.4 |
6.2 |
6.7 |
7.7 |
8.7 |
|
40 |
5.3 |
5.9 |
6.5 |
7.3 |
8.4 |
9.1 |
10.4 |
11.8 |
|
60 |
8.1 |
9.0 |
10.1 |
11.3 |
12.9 |
14.0 |
16.0 |
18.1 |
|
80 |
11.2 |
12.4 |
13.8 |
15.5 |
17.7 |
19.1 |
22.0 |
24.9 |
|
100 |
14.4 |
16.0 |
17.8 |
20.1 |
22.8 |
24.7 |
28.4 |
32.1 |
|
120 |
17.8 |
19.8 |
22.1 |
24.8 |
28.3 |
30.6 |
35.1 |
39.8 |
|
140 |
21.5 |
23.8 |
26.6 |
29.9 |
34.0 |
36.8 |
42.3 |
47.9 |
|
160 |
25.3 |
28.1 |
31.3 |
35.2 |
40.1 |
43.4 |
49.8 |
56.3 |
|
180 |
29.2 |
32.5 |
36.2 |
40.7 |
46.4 |
50.2 |
57.6 |
65.2 |
|
80 |
20 |
2.1 |
2.3 |
2.6 |
2.8 |
3.2 |
3.4 |
3.8 |
4.3 |
|
30 |
3.2 |
3.5 |
3.9 |
4.3 |
4.8 |
5.2 |
5.8 |
6.5 |
|
40 |
4.4 |
4.8 |
5.2 |
5.8 |
6.5 |
7.0 |
7.9 |
8.8 |
|
60 |
6.7 |
7.4 |
8.1 |
9.0 |
10.1 |
10.8 |
12.1 |
13.5 |
|
80 |
9.2 |
10.1 |
11.1 |
12.3 |
13.8 |
14.8 |
16.6 |
18.6 |
|
100 |
11.9 |
13.2 |
14.3 |
15.9 |
17.8 |
19.1 |
21.5 |
24.0 |
|
120 |
14.7 |
16.1 |
17.8 |
19.7 |
22.0 |
23.6 |
26.6 |
29.7 |
|
140 |
17.7 |
19.4 |
21.4 |
23.6 |
26.5 |
28 |
32.0 |
35.7 |
|
160 |
20.9 |
22.9 |
25.1 |
27.8 |
31.2 |
33.4 |
37.7 |
42.1 |
|
180 |
24.1 |
26.5 |
29.1 |
32.2 |
36.1 |
38.7 |
43.7 |
48.7 |
|
80 |
100 |
150 |
200 |
250 |
300 |
350 |
400 |
450 |
500 |
600 |
|
3 |
4 |
6 |
8 |
10 |
12 |
14 |
16 |
18 |
20 |
24 |
|
89 |
114 |
168 |
219 |
273 |
324 |
374 |
426 |
476 |
530 |
630 |
|
23.0 |
28.8 |
41.1 |
52.6 |
64.7 |
76.1 |
83.3 |
94.6 |
105.9 |
117.2 |
139.7 |
|
35.0 |
43.8 |
62.5 |
80.8 |
98.5 |
115.8 |
26.7 |
143.9 |
161.1 |
178.3 |
212.6 |
|
47.3 |
59.2 |
54.5 |
108.2 |
133.2 |
156.6 |
171.3 |
194.6 |
161.1 |
178.3 |
212.6 |
|
13.0 |
16.0 |
22.5 |
28.5 |
34.9 |
40.9 |
44.7 |
50.7 |
56.7 |
62.6 |
74.6 |
|
19.8 |
24.4 |
24.3 |
43.4 |
52.5 |
62.3 |
68.0 |
77.1 |
86.2 |
95.3 |
113.4 |
|
26.7 |
33.0 |
46.3 |
58.7 |
71.9 |
84.2 |
92.0 |
104.3 |
116.6 |
128.9 |
153.4 |
|
41.2 |
50.9 |
71.4 |
90.5 |
110.8 |
129.9 |
141.8 |
160.8 |
179.7 |
198.7 |
236.5 |
|
10.9 |
13.4 |
18.6 |
23.5 |
28.7 |
33.5 |
36.5 |
41.4 |
46.2 |
51.1 |
60.7 |
|
16.6 |
20.3 |
28.3 |
35.7 |
43.6 |
51.0 |
55.6 |
63.0 |
70.3 |
77.7 |
92.4 |
|
22.4 |
27.5 |
38.2 |
48.3 |
59.0 |
69.0 |
75.2 |
85.2 |
95.1 |
105.1 |
124.9 |
|
34.5 |
42.4 |
59.0 |
74.5 |
90.9 |
106.3 |
115.9 |
131.3 |
146.7 |
162.0 |
192.6 |
|
47.4 |
58.2 |
81.0 |
102.3 |
124.8 |
146.0 |
159.2 |
180.3 |
201.4 |
222.4 |
246.5 |
|
61.2 |
75.2 |
104.5 |
132.0 |
161.1 |
188.5 |
205.5 |
232.8 |
260.0 |
287.1 |
341.5 |
|
9.50 |
11.6 |
15.9 |
20.1 |
24.4 |
28.5 |
31.0 |
35.1 |
39.2 |
43.2 |
51.3 |
|
14.4 |
17.6 |
24.3 |
30.5 |
37.1 |
43.3 |
47.2 |
53.4 |
59.6 |
65.8 |
78.1 |
|
19.5 |
23.8 |
32.8 |
41.3 |
50.2 |
58.6 |
63.8 |
72.2 |
80.6 |
88.9 |
105.6 |
|
30.3 |
36.6 |
50.6 |
63.6 |
77.4 |
90.4 |
98.4 |
111.4 |
124.3 |
137.1 |
162.9 |
|
41.2 |
50.3 |
69.4 |
87.3 |
106.3 |
124.0 |
135.1 |
152.9 |
170.6 |
188.3 |
223.6 |
|
53.2 |
65.0 |
89.7 |
112.8 |
1377.2 |
160.2 |
174.5 |
179.4 |
220.3 |
243.1 |
288.7 |
|
65.9 |
80.4 |
111.0 |
139.6 |
169.9 |
198.3 |
216.1 |
244.4 |
272.8 |
301.1 |
357.5 |
|
79.3 |
96.8 |
133.5 |
168.0 |
204.4 |
238.6 |
259.9 |
294.0 |
328.1 |
262.1 |
430.1 |
|
93.3 |
113.9 |
157.2 |
197.7 |
240.6 |
280.8 |
306.0 |
346.1 |
386.2 |
426.3 |
506.2 |
|
108.1 |
131.9 |
182.0 |
228.9 |
278.6 |
325.2 |
354.2 |
400.7 |
447.1 |
493.5 |
586.2 |
|
7.6 |
9.2 |
12.6 |
25.7 |
19.0 |
22.1 |
24.0 |
27.4 |
30.2 |
33.3 |
39.4 |
|
11.6 |
14.1 |
19.1 |
23.9 |
28.9 |
33.6 |
36.6 |
41.3 |
45.9 |
50.6 |
60.6 |
|
15.7 |
19.0 |
25.9 |
32.3 |
39.1 |
45.5 |
49.4 |
55.8 |
62.1 |
68.5 |
81.1 |
|
24.3 |
29.3 |
39.9 |
49.8 |
60.3 |
70.1 |
76.2 |
86.0 |
95.8 |
105.6 |
125.1 |
|
33.3 |
40.2 |
54.8 |
68.4 |
82.7 |
96.2 |
104.6 |
118.0 |
131.5 |
144.9 |
717.7 |
|
43.0 |
52.0 |
70.8 |
88.3 |
106.8 |
124.2 |
135.1 |
152.4 |
169.8 |
187.1 |
221.7 |
|
53.3 |
64.4 |
87.6 |
109.3 |
132.3 |
153.9 |
167.3 |
188.8 |
210.3 |
231.7 |
274.5 |
|
64.1 |
77.4 |
105.4 |
131.5 |
259.1 |
185.1 |
201.2 |
227.1 |
252.9 |
278.7 |
330.2 |
|
75.4 |
91.1 |
124.1 |
154.8 |
187.3 |
217.9 |
236.9 |
267.3 |
297.7 |
328.1 |
388.7 |
|
87.3 |
105.5 |
143.7 |
179.3 |
216.9 |
252.2 |
274.3 |
309.5 |
344.7 |
379.9 |
450.1 |
|
6.5 |
7.8 |
10.5 |
13.1 |
15.7 |
18.2 |
19.8 |
22.3 |
24.7 |
27.2 |
32.2 |
|
9.9 |
11.9 |
16.0 |
19.9 |
23.9 |
27.7 |
30.1 |
33.9 |
37.6 |
41.4 |
48.8 |
|
13.4 |
16.1 |
21.7 |
26.9 |
32.3 |
37.5 |
40.7 |
45.8 |
50.9 |
56.0 |
66.2 |
|
20.7 |
24.8 |
33.4 |
41.4 |
49.9 |
57.8 |
62.7 |
70.6 |
78.5 |
86.3 |
102.1 |
|
28.5 |
34.1 |
45.9 |
56.8 |
68.4 |
79.3 |
86.1 |
96.9 |
107.7 |
118.5 |
140.1 |
|
36.7 |
44.0 |
59.2 |
73.4 |
88.3 |
102.4 |
111.1 |
125.1 |
139.1 |
153.0 |
180.9 |
|
45.5 |
54.4 |
73.3 |
90.9 |
109.4 |
126.8 |
137.6 |
154.9 |
72.2 |
189.5 |
224.0 |
|
64.4 |
77.2 |
103.9 |
128.7 |
154.9 |
179.5 |
194.9 |
219.4 |
243.9 |
268.3 |
317.2 |
|
45.5 |
54.4 |
73.3 |
90.9 |
109.4 |
126.8 |
137.6 |
154.9 |
72.2 |
189.5 |
224.0 |
|
54.7 |
65.6 |
88.2 |
109.3 |
131.6 |
152.2 |
165.5 |
186.4 |
207.2 |
227.9 |
269.4 |
|
64.4 |
77.2 |
103.9 |
128.7 |
154.9 |
179.5 |
194.9 |
219.4 |
243.9 |
268.3 |
317.2 |
|
74.6 |
89.4 |
120.3 |
149.0 |
179.4 |
207.9 |
225.6 |
254.0 |
282.4 |
310.7 |
367.2 |
|
4.8 |
5.7 |
7.4 |
9.0 |
10.7 |
12.3 |
13.3 |
14.9 |
16.4 |
18.0 |
21.1 |
|
7.3 |
8.6 |
11.3 |
13.7 |
16.3 |
18.7 |
20.2 |
22.6 |
25.0 |
27.4 |
32.1 |
|
9.9 |
11.6 |
15.2 |
18.5 |
22.0 |
25.3 |
27.3 |
30.6 |
33.8 |
37.0 |
43.5 |
|
15.3 |
17.9 |
23.5 |
28.6 |
34.0 |
39.0 |
42.1 |
47.1 |
52.1 |
57.1 |
67.0 |
|
20.9 |
24.6 |
32.2 |
39.2 |
46.6 |
53.5 |
54.8 |
64.7 |
71.5 |
78.3 |
92.0 |
|
27.0 |
31.8 |
41.6 |
50.6 |
60.2 |
69.1 |
74.6 |
83.5 |
92.3 |
101.2 |
118.8 |
|
33.5 |
39.3 |
51.1 |
62.7 |
74.5 |
85.5 |
92.4 |
103.4 |
114.3 |
125.3 |
147.1 |
|
40.3 |
47.3 |
62.9 |
75.4 |
89.6 |
102.9 |
11.2 |
124.4 |
137.5 |
150.7 |
176.9 |
|
47.4 |
55.7 |
72.9 |
88.8 |
105.5 |
121.1 |
130.9 |
146.4 |
161.9 |
177.4 |
208.3 |
|
54.9 |
64.5 |
84.4 |
102.8 |
122.2 |
140.3 |
151.5 |
169.5 |
187.5 |
205.4 |
241.2 | | 
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