Improve boiler operational stability
Performance Assessment – Heat Balance
Improve boiler operational stability and performance by utilising first-principle fluid and thermodynamics.
Our client’s boilers were suffering variations in pressure which were having major secondary effects on the stability of the steam flows and the turbine generated load. These effects were high pressure fluctuations in the steam drum, and significant load swings on the turbine power output.
We investigated the issue to evaluate the characteristics of the steam generation equipment and provide solutions to improve performance and reduce damage caused by cyclic loading.
The steam system heat balance was modelled using the boiler manufacturer’s original design. This created an interactive thermal and fluid dynamic model which demonstrated the effect of pressure drops and temperature changes that occurred with various steam flows.
Using our interactive model, we evaluated the effect that the temperature control system was having on the plant and discovered a flaw in the initial design. The innovative design, created a situation where boiler drum temperature and pressure varied considerably when using the temperature control loop, thereby affecting flow rates and power generation.
The original system design did not account for any significant pressure loss between the boiler outlet and the steam turbine. The plant was designed to run with the turbine on inlet pressure control, as the steam flow varied to achieve a constant pressure at the turbine inlet, the boiler drum pressure was constantly varying and affecting the steam production and as such the flow rates. This instability has a negative effect on power generation and increases the rate at which the equipment degrades.
Using our interactive model, we identified key issues within the original design and recommended modifications to the control system logic, increasing process stability.
We ensured that the problem was identified by analysis and was presented in an easy to understand format. A safe and practical solution was identified, and a conceptual alternate system presented.
The risks involved with high pressure steam systems required special considerations to ensure the safety of the plant would not be compromised and our solution ensured reliable operation of the plant at optimum conditions.
The analysis clearly demonstrated problems with the original plant design, in particular the short comings of the steam temperature control philosophy. It also identified the detrimental effect that the initial design was having on various sections of the boiler system.
A detailed report giving recommendations on how the system should be improved was issued and a presentation made to the clients engineering staff, covering the effect of the original design was having on the boiler and the potential solutions to resolve these issues.