The future is about decentralised energy supply – according to the designers of OPRA Turbines B.V. in Hengelo, The Netherlands. The Dutch company develops and manufactures gas turbines which, as a combined heat and power plant (CHP) secure, for example, the heat and power supply on ships and oil drilling platforms as well as in industrial plants.
High powered yet small sized
The ‘made in Hengelo’ OP16 radial gas turbine boasts the advantage that it can be equipped with three alternative combustion systems. This allows operation with very different gases, even contaminated ones. Regardless of the fuel used, high-level efficiency is achieved – and this during the turbine’s entire service life, enabling the operator to benefit from low energy costs. In addition to this, the ready-to-install units are very compact. Due to their extensive operational temperature range between -60°C and +50°C they can be used on oil drilling platforms near the Arctic Circle as well as in fertilizer factories and chemical plants on the equator.
The heart of every OP16 gas turbine is a veritable engineering masterpiece where compression of 6.7:1 is achieved in just one stage when the rotor runs at a speed of 26,000 rpm. At a total power output of 1.8 megawatts, the turbine reaches more than 90 per cent overall efficiency with 25 per cent electrical efficiency.
Task: torque shock absorption
A great deal of detailed design has been incorporated in connecting the two main components – the gas engine gearbox and the turbine. The internal combustion engine torque shocks at this interface are compensated to the extent that the generator guarantees very smooth running. This is where a coupling is needed that prevents or shifts critical resonances. In addition to this, the coupling has to compensate for alignment errors which may occur during assembly and operation.
This module combines the highly resilient BoWex flange coupling together with the RADEX-N torsionally stiff steel lamina coupling. This double-cardanic unit transmits torques up to 15,000 Nm and ensures best balance between dampening and stiffness. The component, which was designed and manufactured for OPRA, has already been proving its worth in practice. It assures very smooth running of the gas turbine as well as minimum maintenance. An overhaul of the intensely used turbine is initially required after 42,500 hours of operation. The turbine coupling is not the only KTR drive element employed in the OP16 series. The pump used for the lubricating oil tank and the hydraulic start-up system is connected to the pump drive by a bellhousing and a ROTEX flexible jaw coupling. This makes sure that OPRA's 'power packs' are able to perform reliably 24 hours a day even under adverse conditions such as in arctic temperatures, offshore, on ships and in refineries or in polluted landfill and biogas plant environments.
Highly flexible flange coupling
Torsionally stiff steel lamina coupling
Flexible jaw coupling