Our Past Projects
C2 Technology’s team are proven experts in assessment, design and test of compact, high efficiency, high energy density, variable speed turbo machines and waste energy recovery (WER) systems.
Our members were leading parts of some recent projects in electricity generation and gas compression, including:
- Pressure to power (P2P) conversion from steam and natural gas
- Heat to power (H2P) conversion via organic Rankine cycle (ORC) waste heat recovery (WHR)
- Steam compressor
- Offshore platform compressor (OPC) & downhole gas compressor (DGC)
- Gas compressor test facilities
Pressure to Power - Steam Expander-Generator (SLDE)
In 2016 D&T completed NPD activities and started an NPI process for a 50kW steam-let-down turbo-expander (SLDE) for a global industrial engineering group. The 50kW turbo-expander was designed to operate as an SLDE in parallel with a pressure reduction station.
This unit was a back-pressure expander which produces 50kW electrical power from the expansion of steam from a saturated or superheated state with pressure up to 14barg at the inlet. It consisted of a highly efficient condensing radial turbine directly connected to a permanent magnet generator suspended on gas bearings. It converted exergy of the steam to electrical energy at significantly higher efficiency than competing technologies.
The turbo-expander was extensively tested and performed a 1000-hour customer site endurance test followed by more than 8000 hours of operation connected to an end user’s factory steam grid in an industrial environment with no maintenance and zero blade erosion at the end of the operational tests.
A summary of the machine design parameters can be seen below:
| Architecture | Single stage permanent magnet generator with gas bearings |
| Process media | Steam |
| Inlet temperature | Saturated / super-heated |
| Inlet pressure | 7-14barg |
| Outlet pressure | 1-4barg |
| Rated power | 50kW(net) |
| Speed | 70,000rpm |
| Compliance | Certified for use in the UK |
Pressure to Power - Steam Expander-Generator (SLDE package)
Along with the development of the 50kW turbo-expander, D&T completed NPD of a 50kW & 100kW package to house, monitor and control the turbo-expander. The package was designed to house either a single or dual, in parallel or series, turbo-expander.
The package has been extensively tested as both a 50kW and 100kW system at the customers site in each configuration. It has also been installed into an industrial end user’s factory steam grid as a 50kW turbo-expander generator. It operated more than 8000 hours with very low maintenance requirements.
A summary of the machine design specifications can be seen below:
| Architecture | Single or dual turbo-expander package |
| Process media | Steam |
| Inlet temperature | Saturated / super-heated |
| Inlet pressure | 7-14barg |
| Outlet pressure | 1-4barg |
| Rated power | 100kW(2*50kW)(net) |
| Compliance | Certified for use in the UK |
Pressure to Power - Natural Gas Expander-Generator (GLDE)
In 2017 D&T completed NPD of a 250kW gas let-down expander/generator (GLDE) for a refrigeration engineering company. The 250kW turbo expander was designed to operate in parallel with a pressure reducing valve.
This unit is a 2-stage expander with reheat of working fluid for energy production from pressure reduction within the natural gas distribution network. It is a bolt-up semi-hermetic eco-friendly machine which operates at inlet and outlet pressures of 52barg and 32barg respectively, with an electrical outlet power of 250kW(net). The machine was certified for operation in the US. This machine integrates a permanent magnet generator and the turbines (overhung at each end of the rotor) with the shaft suspended on gas bearings.
The unit was subjected to a comprehensive testing regime at a live gas test site in the UK gas network. The tests carried out included verification of the of a full-scale proof of concept machines performance under steady state conditions as well as verified safety features for both controlled and fast stop scenarios.
A summary of the machine's design parameters can be seen below:
| Architecture | 2 stage permanent magnet generator with gas bearings |
| Process media | Natural gas |
| Inlet temperature | 80°C |
| Inlet pressure | 52barg |
| Outlet pressure | 32barg |
| Rated power | 250kW(net) |
| Speed | 22,000rpm |
| Compliance | Certified for use in the US |
Heat to Power – ORC
In 2016-2017 D&T developed for a leading European compressor manufacturer a H2P system able to recover energy from the hot oil of the compressor lubrication circuit. Around 90% of the electrical energy used by a compressor, is lost to the atmosphere in the form of heat at a low temperature, especially through the lubricant oil cooling process.
To take advantage of these energy sources at low temperatures the most widespread solution is the Organic Rankine Cycle (ORC) which permits the generation of electrical energy “in isolation” or that can be passed into the power circuits. A unique control system developed by D&T allowed the system perform optimally at the variable heat sorce parameters.
The package was built by the client, extensively tested and exibited at ComVac 2017.
A summary of the system design specifications can be seen below:
| Architecture | Closed loop ORC system with pump, expander, evaporator, condencer and regenerator |
| Working fluid | R236fa |
| Oil temperature | 80-100°C |
| Oil flow rate | up to 160l/min |
| Cooling water temperature | 15-17°C |
| Cooling water rate | 50l/min |
| Electrical power output | 2.5-4kWe |
| Compliance | EN 50438:2013 |
Steam compressor
In 2012, along with the development of the 50kW turbo-expander, an EPC order was placed to develop a 50kW turbo-compressor. The 50kW turbo compressor was designed, with two stage configurations, to operate in a range of applications including mechanical vapour recompression (MVR), as a high temperature heat pump or as a low-pressure steam generator.
This unit is based on the same architecture as the steam expander generator and underwent a 1000 hours customer site endurance test. This system never entered an end user site for further evaluation.
On Platform Compressor (OPC)
In 2015-2017 D&T developed for one of the largest oil&gas companies a compressor-booster for offshore installation. A 180kW turbocompressor driven by the high-speed integrated permanent magnet motor was designed with the rotor suspended on active magnetic bearings
The design was fully certified by the notified body for operations in Class 2 Hazardous Zone under gas working pressures up to 80barg.
Unfortunately, quite a sharp drop in gas prices put procurement stage of the project on indefinite hold by the client.
A summary of the system design specifications can be seen below:
| Architecture | Integrated permanent magnet motor-compressor with rotor suspended on active magnetic bearings |
| Working fluid | Natural gas separated from slugs |
| Gas temperature | 80-100°C |
| Working pressure | up to 80barg |
| Pressure ratio | 1.1 |
| Motor power | 180kW |
| Rotational speed | 16,000rpm |
| Compliance | API/UL |
Downhole Gas Compressor (DGC)
In 2013 CET completed a field trial of there downhole gas compressor (DGC) for a large independent oil and natural gas producer in the United States. The 3 stage 45kW downhole turbo gas compressor was designed to operate deployed 2km into a gas well.
The unit is a 3-stage gas compressor with associated inverter electronics. It consists of 3 compressors each with a highly efficient mixed flow impeller directly connected to a permanent magnet motor suspended on gas bearings. The 3 compressors are driven by 3 downhole inverters specifically packaged to operate in the harsh gas well environment. At the well head the system has a surface package that communicates with the downhole equipment, controls the individual compressors and supplies the medium voltage DC power.
Three variants, including the initial prototype and one each of the Italian and American customers units, were extensively tested in a clean natural gas flow loop in the north of England. Subsequently the unit for the American customer was tested in a live gas will in Texas.
A summary of the DGC designs can be seen below:
| Texas DGC | Italy DGC | |
| Architecture | 3 stage permanent magnet motor with gas bearings and downhole inverter drive | 3 stage permanent magnet motor with gas bearings and downhole inverter drive |
| Process media | Unfiltered, wet natural gas | Unfiltered, wet natural gas |
| Inlet temperature | 100°C | 70°C |
| Inlet pressure | 5barg | 15barg |
| Pressure ratio | 2.2 | 1.5 |
| Rated power | 45kW (Net) | 45kW (Net) |
| Rotational speed | 52,500rpm | 60,000rpm |
Erosion Test Facility
In 2014 CET designed, assembled and commissioned a self-contained test loop system for the assessment of solid and liquid particle erosion.
The test loop included provisions to install 3 downhole gas compressors, which provide the motive flow, a downhole electronics module and a calibrated sand injection and recovery system. The flow loop was designed to examine particle impact erosion on the downhole compressor modules in contaminated gas flow environment. Additionally, the test facility had a control suite capable of fully characterising the compressors and/or the downhole electronics.
Subsequent to the commissioning the test facility was used to characterise erosion and fouling of the downhole compressor designs including an investigation into impeller materials and coatings that could extend the deployed life under different operating conditions.
A summary of the system design specifications can be seen below:
| Architecture | Test loop with multistage compressor |
| Process medium | Air |
| Solid particles | Sand |
| Inlet temperature | 100°C |
| Maximum allowable pressure | 12barg |
| Rated power | 45kW (3*15kW) (Net) |