Waste Heat Recovery Units (WHRU) recover heat from Gas Turbines or Diesel Engines by heating up a liquid heating medium. The equipment is widely used on offshore oil and gas installations to cover the various heat demand in the process. Techouse is a world leading supplier of WHRUs for the offshore industry.
The purpose of the Waste Heat Recovery Unit is to recover heat from a gas turbine in order to supply heat to cover process heat requirements.
Techouse designs and delivers of WHRUs to our client’s specifications and choice of gas turbines, to meet the required heat demands and adapt the layout to the space available.
Our units are designed to withstand accelerations and blast loads potentially imposed on the units as well as the marine corrosive environment found offshore.
A WHRU is normally assembled to a single lift unit that contains all elements needed to control the heat recovery:
- Inlet transition and exhaust silencer/flow straigthener
- Main and by-pass exhaust damper
- Heat exchanger tube bundle
- By-pass stack
- Main stack
In most of the units the by-pass and the main stack are merged after the heat recovery section. Normally, the full exhaust stacks are included in the WHRU supply. Also, the exhaust silencer, reducing the noise from the gas turbine outlet is part of the supply.
The gas turbine exhaust enters the (WHRU) through a single blade diverter valve or a multi blade louver valve, where the exhaust gas is directed to the tube bundle, to the bypass duct or a combination of both.
The tube bundle consists of several parallel tube circuits. Each circuit consists of finned tubes to enable maximum heat transfer from the exhaust gas of the gas turbine to the heating medium transporting the heat to process consumers. The heating medium enters at the inlet header located at the cold end of the tube bundle, and heat from the exhaust gas is transferred to the heating medium by counter-current heat transfer in the WHRU.
The outlet temperature of the heating medium is controlled adjusting the exhaust damper valve to lead the correct amount of exhaust gas to the heat exchanger tube bundle.
Techouse’s legacy in delivering tailor-made WHRUs is 30 years old starting with the first WHRU in the world to Equinor Gullfaks A (late 1980s) on the Norwegian Continental Shelf. Since then, our team has been responsible for delivery of tailor-made WHRUs worldwide either through ABB Miljø or under Techouse’s former name, KANFA-TEC.