Objective
To demonstrate a new micro-turbine design intended to significantly reduce turbine installed cost, especially at low head and low flow sites. Of particular interest is the widespread use of plastic for many of the turbine and associated equipment parts. An annual energy output of 208250 kWh is expected at a unit cost of IR 0. 156/kWh for this demonstration project. With the benefits of mass production, costs are expected to fall considerably.
During construction changes to several of the original design and manufacturing concepts had to be made.
The finish and dimensioning of some of the plastic components had to be modified and in some cases, the method of production altered.
Installation proved to be more difficult than expected, mainly because of unexpected ground conditions, and changes had to be made in both equipment manufacture and in site assembly to accomodate the new situation.
Despite these difficulties the hydro electric scheme commenced generating in December 1986, operating on a 9 am - 5 pm daily basis, weekdays only.
Since then different operational strategies have been adopted leading to a total energy production of 45,350 kwh by January 1988, all of which was used by the University.
In use the project has demonstrated successfully the operation of the turbine for the hydraulic conditions originally specified.
Mass production of plastic components to suitable dimensions and finishes now appears possibleand installation and assembly techniques proposed seem effective.
Changes will have to be made to the angle of the guide vane assembly, the monitoring system has proved to be basically sound, with few teething troubles.
Some difficulties have been experienced with silting of the waterway, and dredging has been necessary.
This project, at a site belonging to University College Galway, is to demonstrate for very low head and low flow sites a novel micro turbine. Innovative features include :
. the use of plastics in the construction of waterways
. the use of moulding techniques to reduce costs for the manufacture of guide waterways
. the use of a small diameter highspeed propellor turbine removing the need for a gearbox with an asynchronous generator
. manual adjustment of blade pitch to adapt to load variation, and fixed guide vanes
. factory assembly of components for site installation
. use of transport container as a permanent shutering for concrete poured on site.
In these ways, site labour and installation costs are minimised.
Site technical details are :
Hydraulic machine :
- semi Kaplan
- head 1. 5 - 2 m
- flow 2. 6 cums
- speed 510 rpm
- rating 32 kw
The 32 kw turbine was installed in a disused turbine chamber on the site where a suitable head, controlled by an upstream barrage, has been identified.
It is intended that most of the electricity will feed the University buildings, with any surplus being sold to the grid. Novel design features of the turbine and waterways cause rapid acceleration of water (0. 5 m/s to 7. 5 m/s), allowing a small diameter (runner diameter 700 mm) high speed turbine to drive directly an asynchronous electrical generator.
The turbine has been designed for maximum efficiency by careful attention to geometry, materials and surface finish.
To reduce costs, the moulds for turbine fabrication can be re-used for other projects.
It is envisaged that several such turbine sets could be installed accross a suitable river in parallel. Instrumentation has been installed for both control and monitoring /protection purposes.
In this way, the following should be possible :
. controlled system shut-down will be carried out in the event of a fault condition;
. audible alarms will be actuated for this and other fault conditions;
. the location and type of the fault will be determined quickly.
The above is expected to reduce unplanned outages to a minimum. The entire monitoring/protection network is under microcomputer control, with automatic restart and manual over-ride facilities. At 32 kW, the plant is expected to produce about 200,000 kwh per year giving a projected unit cost for the electricity of IRL 0. 156 for the demonstration unit, with a payback of 15 years.
Topic(s)
Data not availableCall for proposal
Data not availableFunding Scheme
DEM - Demonstration contractsCoordinator
2 Dublin
Ireland