Steam Distribution System Energy Efficiency Measures
The steam distribution system maintenance makes a significant contribution to energy efficiency in steam system. Measures to consider include:
- Steam loss through open bypass valves
- Steam loss through failed open steam traps
- Heat loss through un-insulated or improperly insulated piping and equipment.
To determine if your ship could benefit from a steam distribution system maintenance program, normally steam lines and steam traps surveys need to be done at regular intervals. The inspection activities will include steam pipes, insulation, traps, steam supply/discharge on or around heat exchange devices etc. Fundamental to such inspections is the collection of good data. Aspects to consider include:
Reduce steam leakage:
As part of day routines, checks should be made for steam leaks. The steam leaks should be rectified as soon as observed.
Heat loss due to inadequate insulation:
The boiler and steam lines along with condensate return to the hot well must be well insulated. Over a period of time insulation is damaged or worn out. Any analysis by thermography or any other thermal measurement system could identify the hot spots. Improvement of damaged insulation due to repair work must be done. All these will reduce the heat losses from the system thus improve energy efficiency.
Steam trap losses:
Steam traps are used to discharge condensate once it is formed, thus the main function is to prevent live steam from escaping and to remove air and non-condensable gases from the line. However, it is a largely neglected part of the steam distribution system. Steam traps that are stuck open allow live steam to escape thus resulting in loss of heat and increasing the load of the condenser. Steam trap that is stuck shut results in reduced capacity of the equipment it is being supplied to. Overall, steam traps must be checked at planned intervals to show their good working conditions (MariEMS 2017).