Genset Roundup

CHP cuts cost and emissions for nursery

Until recently, the Hazlewood VHB Hernhill Nursery in the UK relied on separate deliveries of oil and liquid carbon dioxide (CO2) to meet its electricity, heating and CO2 needs. Now, these requirements are met by a single combined heat and power (CHP) plant.

The Kent-based business produces tomatoes for various supermarkets around the UK. It previously had to take up to two deliveries per day of oil to fire the boilers, as well as CO2 to feed the plants. Now, a new CHP plant based on six Cummins gas-powered generating sets is supplying its greenhouses with power, heat and CO2.

The Cummins power generators were installed as part of a CHP plant that provides 12 MWe of power, heat for 15.2 ha of greenhouses, free CO2 to feed the tomato plants at the nursery and 9 MWe of electricity to export to the main grid.

The CHP plant is 84 per cent efficient
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The CHP plant was built and is operated by Nedalo (UK), a TXU-owned company, and part of Eastern Electricity. As part of the CHP project, six Cummins QSV91 generating sets, each comprising a natural gas-fired engine coupled to a 1900 kVA, 400 V, 50 Hz Stamford Newage alternator, were installed. The gensets are arranged for automatic synchronization with each other and with the mains supply.

The plant aims to maintain a constant temperature of 17à‚°C during the day and 15à‚°C at night in the greenhouses, although the optimum temperature depends on external weather conditions. For example, if it is sunny, a higher temperature is acceptable, while a high temperature with overcast conditions will cause the tomato vines to wilt.

To maintain this temperature the six generating units operate around the clock, with each set providing 2000 kW of heat energy. The units are monitored by a Nedalo control system.

The energy is recovered using a combination of exhaust gas heat exchangers, condensing heat exchangers, pre-coolers and plate heat exchangers. The exhaust gas leaves the stack at just 54à‚°C, having initially started at 550à‚°C. The recovered energy is metered and used to provide hot water for the greenhouse heating system.

Producing CO2

In addition to providing hot water at 98à‚°C, the boilers also produce CO2. It is purified, collected in a CO2 manifold and blown by fan through 12 feed lines. A PLC control system integrates with the CHP plant and the climate control system in the greenhouse.

The six Cummins generators produce 12 MWe of power, heat for 15.2 ha of greenhouses, and free CO2 to feed the tomato plants
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If demand is low, the recovered heat is fed up two 1500 m3 storage tanks. Six dump radiators – one for each generating set – disperse heat when the storage tanks are full and there is no demand for CO2. Hot water in the greenhouse flows through 50 mm diameter steel pipes, which also act as rails for the picking trolleys. The CO2 to feed the plants is distributed through holes in a lay-flat polythene tube at a rate of 1000 ppm.

The plant operator, Nedalo, replaced the existing oil-fired boilers with four high-efficiency, dual-fuel boiler units that run on natural gas or kerosene. These boilers operate in pairs, with two on continuous standby mode.

The CHP plant at the Hernhill nursery is one of several facilities set up by Nedalo to provide cost-effective and clean energy to a range of properties, from hotels to hospitals and leisure centres. Nedalo has CHP installations at two other VHB nurseries, but the Hernhill nursery is the first to operate 24 hours a day.

Nedalo was able to lower the cost of heating the greenhouse due to efficiency of the system and the lower cost of gas compared to heavy oil. In addition, the use of natural gas enables CO2 to be recovered. According to the site manager Vince John-Charles, the plant is 84 per cent efficient.

The nursery manager, Steve Longbottom commented: “Previously we had to buy liquid CO2. It was expensive and created a lot of tanker traffic at the nursery.” He added, “Gas is cleaner burning, which together with the heat and CO2 recovery has helped reduce emissions from the nursery.”

The new CHP plant has reduced cost and emissions for the Hernhill nursery
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Milan metro extension receives power from Atlas Copco

Two generating sets and a portable compressor from Atlas Copco are providing critical air and power supply to Milan’s latest metro extension. The gensets and compressor are being utilised by ELSE, a concreting subcontractor, which is responsible for the consolidation of jet grouting along the 1.5 km Red Line extension.

The Atlas Copco generating sets and portable compressor are helping to build Milan’s metro extension
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The two Altas Copco QAS 108 generating sets are supplying general site power, and electricity for ELSE’s two concrete batching plants. The gensets are rated at 100 kVA at 60 Hz for continuous power and work on average ten hours per day, five days a week.

To prevent damage to the generating sets from the extreme ground wetness – a common problem in Milan – the gensets are fitted with sturdy, weatherproof canopies and are mounted on heavy-duty skid bases, which allows them to be installed on any site conditions without any special foundations.

The Atlas Copco XHAS 365 portable compressors supply air power to ELSE’s drill rig which will drill to depths of between 15 m and 34 m. This will enable ELSE to jet grout down the holes with the compressor operating at a pressure of 10 bar. This grouting is essential to prevent water seepage into the twin bored tunnels.

ELSE project supervisor Mr Carpita believes that the gensets have reduced the cost of power by 20 per cent compared to mains power. The project is scheduled for completion in January 2003.

Floating dock receives Scania generators

Three Cymasa generating sets powered by Scania engines have been delivered to an offshore platform and barge fabricator Adyard in Abu Dhabi.

Two DC14 sets each rated at 375 kVA have been installed at a floating dock which will be berthed at Adyard’s fabrication yard in Musapha, Abu Dhabi.

The DC14 generating sets will provide power for the floating dock.
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The engines have been totally refitted with the twin Scania-powered sets to provide the prime power requirements for the dock. The floating dock, capable on working on vessels weighing up to 3000 t, is about 100 m long and 25 m wide.

NICO Inc., Adyard’s parent company, has taken delivery of a third Scania set, a DC12 engine. The genset has a rating of 375 kVA, and will be used for water side crane duties at NICO’s Dubai port operations.

CHP units run on sewage gas

Clark Energy has installed a Jenbacher AG combined heat and power generating set at a waste water treatment works in Seafield, Edinburgh in Scotland.

The unit runs on methane gas from processed sewage, and provides emergency and peaking power. The installation is part of a contract won by Clarke Energy for the design, supply, installation, testing and commissioning of a CHP set, as well as a power management system.

The Jenbacher 612 generator can run off a quality of methane that would cause other gas powered sets to fail. It can also withstand the hostile properties of biogas, particularly hydrogen sulphide, and has a sophisticated carburation system that enables it to deal with the variations in fuel quality experienced with biogas applications.

Energy efficiency at the plant is maximized by the use of the methane produced when sewage sludge is digested. It is utilised to fuel the CHP generator, this in turn provides electricity for the site and hot water that can be passed through a heat exchanger to assist the digestion.

The CHP plant runs on methane gas from the processed sewage
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The engine has an output of 1.3 MWe and 1.5 MWh, which makes up a proportion of the normal process power demand of 3.5 MW.

However, the installed generating capacity is actually 4.2 MW when the standby diesel generator is online. This 2.9 MW unit is used as an emergency power supply and for use in peak-lopping situations, where it works in conjunction with the power management system, also supplied by Clark Energy.

Pumping gas to Brazil

Three Cummins gensets are being used to pump natural gas via a pipeline from a gas treatment plant in Bolivia to Brazil. The plant in the San Alberto Gas Field, Bolivia, is owned by a consortium led by Brazilian oil company Petrobras.

The plant consists of three Cummins QSV91G gensets powered by 18-cylinder, 180 mm bore, 91-litre gas engines running at 1200 r/min. Two of the engines run continuously producing 2.5 MW to drive the gas processing pumps. The third 1.25 MW genset is on permanent standby or for use during maintenance periods.

Alstom wins three new contracts in Asia

Alstom has won two new contracts in China, and a third contract in Korea for its emergency diesel generators.

Alstom is supplying emergency power supply systems to Korea and China under contracts worth ?13 million
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The first contract, won by a consortium consisting of Alstom and S.E.M.T Pielstick, is worth a8 million ($7.1 million). It is to provide Lanpc’s Daya Bay and Lingao Nuclear power plant in the Guangdong province of China with a fifth diesel generator. The consortium will also have to supply the mechanical and electrical systems and electrical interface equipment for interconnection with the existing plant. Commissioning is planned during outages, scheduled for March 2004.

Alstom Power will also supply four 5 MW diesel generators, other auxiliaries, and an Alspa P320 control system to the Tianwan nuclear plant in Jiangsu Province, China. The gensets are scheduled for commissioning in 2004 and 2005 for the main plant. The engine for both of these contracts will be manufactured in France by S.E.M.T Pielstick.

The third contract is to supply equipment to Hanjung which is providing the main nuclear components for the Ulchin nuclear power plant in Korea. Under the a5 million contract, Alstom Power will supply the generators, and the electrical control and instrumentation systems for the emergency diesel generators.

Scania launches new 16 litre industrial engine

The basic design of the new DC16 engine from Scania means that it is easy to service and repair, and it also uses the same cylinder heads, cylinders, pistons and connecting rods as the proven DI/DC12 engine, ensuring its reliability. Because each cylinder on the engine has its own cylinder head it can be removed by one person, reducing the time and cost of servicing.

Each cylinder head has four valves, which in combination with the cold inlet/injection sides and hot exhaust sides of the engine on the opposite sides of the cylinders maintains a consistent fuel-air mixture, and so improves the engines fuel consumption and emission control.

Scania has also developed its own engine management system to control the engine. The system is programmed using the Communicator Area Network (CAN) language, and is designed to communicate with other systems.

Standby power for Hungary’s new IPP

Two generating sets from Cummins Power Generation are supplying standby power for Hungary’s first independently financed power station in over 60 years. The two CP500 sets are each rated at 575 kVA, and are powered by 12-cylinder KTA19.G4 turbocharged diesel engines.

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The gensets, which were supplied by local distributor CAD Server, are equipped with a Cummins MC150 PLTE automatic control system with mains paralleling, and are housed in acoustically treated plant rooms silenced down to 80 dB (A) at 1 m.

The standby gensets are installed at Budapest’s new $260m Csepel 2 power station which will supply 389 MW of electricity and 139 MW of heat energy to the Hungarian capital. The plant will supply up to seven per cent of the country’s total energy production and will also provide district heating to some 11 000 local houses.

If the turbines at the facility shut down, one of the standby sets will automatically come into operation within 12 seconds. It will supply power for maintenance operations while the second set provides a back up supply.

That’s entertainment

The Australian entertainment industry’s tough demands on noise pollution are being met by Atlas Copco’s QASS180 on-site power generation package. The package can operate in close proximity to a site without impacting upon the background noise level. This is essential when live broadcasts are staged in outdoor environments.

The genset incorporates a Komatsu SA 6D 106, six cylinder liquid cooled diesel engine complete with Woodward PSG electronic governor coupled to a Denyo DB 1981K revolving field brushless alternator.

The engine driven radiator draws cooling air into the container through side mounted, low level louvres. Following a heat transfer from the power pack, it is turned through 90à‚° and passed through an air outlet attenuator where it is then combined with prime mover exhaust gases and then discharged .

Engine exhaust noise is handled by twin in-series critical duty residential silencers. By combining the gases with the radiator cooling air flow at a high level, the gases are diluted and quickly dispersed, thus significantly reducing any resultant pollution irritation. The resulting operational noise is just 44 dB(A) at 7 m.

The Atlas Copco’s QASS180 power generation package will provide on-site power and reduce noise pollution
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The generating set produces a continuous output of 120 kW, 150 kVA at 0.8 factor (165 kVA standby output) and can run at full load without re-fueling for up to 50 hours.

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