Revamping of a boiler in a Waste-to-Energy plant in Tarragona

By AITESA

Introduction

The increase in the calorific value of municipal waste has posed a challenge for the waste-to-energy plants, since it implies a higher heat input in the incineration furnaces, exceeding the original design values. To improve system efficiency and increase steam production, the existing boiler was modified to incorporate new heat transfer elements.

Solution: Performance Optimization Engineering

AITESA has developed the detailed engineering for the modification of the boiler, with the objective of increasing the vaporization capacity without compromising the integrity of the system. The implemented solution is based on the incorporation of three evaporator panels in the furnace hearth, allowing a higher thermal absorption in low corrosion areas and optimizing the heat transfer.

The project included a detailed analysis using thermal and mechanical simulations, evaluating different boiler and economizer modification scenarios. After comparing several configurations, the study confirmed that the optimal option was the incorporation of three evaporator panels and optimal economizer cleaning, ensuring the best balance between performance and operational safety.

The scope of our work included:

Thermal and mechanical calculation of the boiler modification.
Design and manufacturing drawings of the supplementary evaporator.
Disassembly and assembly procedures, ensuring safe integration.
Structural verification of the first smoke passage with the incorporation of the new panels.
Engineering of auxiliary elements, including hydraulic calculation, piping design, supports and revision of control and safety valves.

Results: System Performance and Safety Optimization

The superheaters remain in a low corrosion zone, avoiding premature degradation problems.
The surface areas of the installed superheaters are still sufficient according to the spray water flow rate obtained: between 0.20 and 0.26 t/h.

The study carried out by AITESA confirms that the installation of three panels is the optimal solution to guarantee the efficiency and safety of the boiler.