At Struthers Energy & Power our highly experienced team of thermal, mechanical and process engineers provide bespoke packaged solutions for Heat

Recovery and Energy Generation. We specialise in the following products:

Circular Waste Heat Recovery Units

Our Waste Heat Recovery Units offer an extremely reliable, low maintenance solution for Gas Turbine heat recovery in Onshore, Offshore, FPSO and Platform applications. Our CWHRUs incorporate an integral concentric exhaust gas bypass system and radial vane control damper.

Our unique, patented Circular WHRUs utilise helically wound finned tube coil technology to produce a light weight, extremely efficient and durable heat exchanger Coil. We design and size our units based on the specific requirements of each project. We typically supply units for Gas Turbines in the power output range of 5 – 35MWe and exhaust gas temperatures up to 580°C. The coil manufacturing process means that there are typically 80% less pressure part welds required compared to a traditional serpentine coil. Our circular coils are manufactured from a range of carbon, alloy and stainless steels depending upon the application and client requirements.

Our Circular units are the No. 1 choice Worldwide for both retrofit or new build projects due to fast installation time (typically 1 day), reduced footprint, low COG and reduced equipment weight, which all result in overall project cost savings.

Our patented designs enable either Vertical or Tangential inlet to suit the configuration of the upstream GT exhaust.

Our CWHRUs are shipped fully assembled from our UK Manufacturing Works to minimise site installation requirements. They offer an extremely lightweight and compact solution for waste heat recovery for both Onshore and Offshore Oil and Gas installations.

Our circular unit incorporates both the Bypass and Coil ducts within a single cylindrical casing making the unit extremely compact.

Our integral radial vane control damper is positioned below the Bypass and Coil ducts. It is hydraulically actuated, and the position of the vanes is modulated to regulate the flow of exhaust gas though the Coil in order to precisely control the thermal output of the WHRU. Any excess heat automatically passes to atmosphere via the bypass duct. The design is inherently failsafe, because at any damper position there is always a route to atmosphere for the GT exhaust gas.

The control damper design has been in operation since 2008 with some 45 units in operation worldwide. It has proven to be extremely reliable, robust and low maintenance.

We offer our WHRUs as a complete turnkey package including the damper hydraulic control unit and interface junction box. All WHRUs are fully assembled at our Works and we conduct a Factory Acceptance Test of the Damper system, which is open for witness by our Client’s Engineers and Inspectors.

Struthers have been supplying Circular WHRUs to the oil and gas industry for more than 20 years, and are proud to have over 100 of our WHRUs in operation worldwide. Our reference list of delivered projects can be downloaded here.

Traditional Waste Heat Recovery Units

Traditional WHRUs employ the standard “serpentine” layout of finned tubes and tubesheets to form the Heat Transfer Coil and typically they have a separate, external Bypass duct. They too can be installed in both horizontal and vertical orientations, with the exhaust gas flow regulated by multi-louvre dampers. A failsafe linkage is coupled between the coil and bypass dampers to ensure there is always an open route to atmosphere for the GT exhaust gas.

Our WHRUs offer a cost effective, efficient and extremely reliable solution, where equipment footprint and weight are not restricted (typically onshore installations). We supply units sized for a wide range of gas turbine capacities (from 3MWe to 50MWe), with Coils manufactured from a variety of steels: Carbon A106, P11, P22 and stainless steel (304, 316, 321H) to suit the most arduous of operating environments.

Similar to our circular units, our WHRUs are a ‘Cold Casing’ design, which provides a 60°C external skin surface temperature. Our internal lining system is designed in-house and incorporates stainless steel liner plates to withstand the high gas velocities exiting the GT.

Our WHRU packages are fully assembled at our Works and a Factory Acceptance Test is performed prior to shipping.

Images above: Struthers Energy & Power WHRU installation, Algeria. WHRUs packed ready for shipping and a completed 321H Stainless Steel coil prior to hydrotest.

Image Left: Trial assembly of two WHRU packages prior to FAT. Image Right: Final installation of Hydrotested Coil into WHRU Casing.

Circular Heat Recovery Steam Generators

Heat Recovery Steam Generators (HRSGs) are a key component in combined cycle gas turbine power plants. They capture waste heat from the GT exhaust, which would otherwise be lost to atmosphere. They convert this heat to raise superheated steam, which is used to generate electricity, thereby increasing the amount of electrical energy generated by the GT fuel input.

Struthers Energy and Power specialise in the supply of Circular HRSG Packages, where our Patented helically wound finned tube coil technology is used to provide an extremely compact solution for offshore, onshore applications and simple to combined cycle retrofits, where equipment footprint and weight are restricted.

We offer the complete turnkey package for conversion of open cycle GTs (generators and mechanical drive) to combined cycle. Our CHRSGs combined with our Patented Power Module provide an integrated solution from GT exhaust outlet through to Steam Turbine Generator export metering.

Image Above: Two Circular HRSGs supplied to Mjørud, Norway who then packaged them into a complete Module for the Eldfisk 2/7E platform. The two CHRSGs recover heat from 1 x LM2500 and 2 x LM1600 gas turbine generators

We design our CHRSGs bespoke for each project, with a single CHRSG catering for gas turbines sized between 15MWe (Titan 130) and 35MWe (LM2500 + G4) and an exhaust gas temperature of up to 580°C. Steam conditions are achievable up to 45BarG, 480°C depending on turbine exhaust gas parameters.

We can offer the option of an integral bypass damper arrangement (similar to our CWHRUs) or an external bypass damper/stack arrangement.

Image Left: Typical model view of CHRSG packed within module. Image Right: Twin CHRSGs providing superheated steam from 3 Gas Turbine Generators

Power Module

Our Patented Power Module integrates all the necessary systems into a single, modular package for the conversion of steam into electrical power.

The module combines an Air Cooled Condenser (ACC) with the complete balance of plant (deaerator, feedwater system, condensate system, water treatment plant) together with a steam turbine generator, power distribution and control system. It is specifically designed to interface with single or multiple CHRSGs

Typically, a 25MWe Power Module has a footprint of just 52m x 14m. It is a modular system, where ‘bays’ can be added to cater for specific power outputs and ambient conditions. It is a compact, cost effective and rapid solution for executing combined cycle projects.

Typical applications for the Power Module include:

Conversion of Open Cycle Gas Turbines to Combined Cycle.
Waste to Energy Power Plants

Packaged Biomass and Waste to Energy Power Plants

Struthers Energy and Power offer a number of solutions to efficiently and reliably convert waste fuel, (typically waste biomass and RDF) into clean energy.
We utilise proven fluidised bed combustion coupled with our hybrid once through steam boiler to create a fully packaged system which also incorporates an integrated gas cleaning annular bag filter system (Patented).

Our packaged waste fuel systems are sized for thermal duties of up to and can provide dry saturated or superheated steam depending on the project requirements (Process steam or Power Generation). The fluid bed, radiant, convective and gas cleaning (bag filter) passes are all contained within a single, compact module which also includes a full steam driven sootblowing system.

This packaged system is particularly suited to projects where space is a premium – typically our clients have an existing industrial Heat or Power demand and wish to install embedded generation to provide clean and renewable energy within the site.

For larger scale projects, we supply our modular fluidised bed combustor, boiler package and Power Module. Due to equipment size, the fluid bed, radiant, convective and gas cleaning sections are separate Modules. The thermal capacity of the system is up to Higher thermal outputs are accommodated through installation of multiple trains.

The below reference plant is a 23MWe Grade C Waste Wood Power Plant. It has two boiler trains integrated with a single Power Module:

Image Above: Tansterne Advanced Biomass Plant, UK.

Struthers were incredibly proud to be the major Mechanical, Electrical, Thermal and Process Design Contractor for the Tasterne Advanced Biomass Plant for Solar 21.

Waste to Energy

Combustion of Refuse Derived Fuel (RDF) to provide clean energy is a cost-effective means of diverting waste from traditional landfill to generate clean/renewable energy – (RDF can be up to 50% organic content).

We have supplied modular boiler projects processing a variety of waste fuels, including RDF and Automotive Shredder Residue: