Redundant steam lines should either be removed or blinded
Redundant steam lines should either be removed or blanked. This saves the unnecessary distribution losses in the line.
When steam flows through a pipeline, there are some fixed losses that are associated with it called distribution losses.
These distribution losses may either be in the form of steam condensation that occurs due to heat loss via radiation through steam lines or direct steam loss via leakages.
It is sometimes observed that certain sections of a plant are operational only for a portion of the year or have been discarded. However, steam continues to flow into the lines in these sections. Thus, even though the sections are not in operation, steam is consumed in order to make up for the fixed losses.
It is recommended that such redundant steam lines should either be removed or blanked. This will reduce the unnecessary steam consumption and thus save fuel.
Eg: In case of steam lines, the table below gives the amount of fuel (FO) lost annually per meter length:
Pipe Size (mm) | Surface Temperature (°C/°F) | |||
Uninsulated Steam lines | Insulated steam lines | |||
50 | 100 | 150 | 50 | |
25 | 15 | 74 | 160 | 7 |
50 | 28 | 133 | 288 | 13 |
75 | 40 | 190 | 410 | 19 |
100 | 50 | 250 | 472 | 25 |
150 | 68 | 360 | 680 | 38 |
Assumptions:
- Ambient temp : 30°C for still air
- Surface temperature of insulation: 40°C
- Total hrs of operation: 8100
- External pipe surface: Mild steel