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  2. Finance Committee - Agenda - 4/15/2020 - P189

Finance Committee - Agenda - 4/15/2020 - P189

By dnadmin on Mon, 11/07/2022 - 13:32
Document Date
Fri, 04/10/2020 - 14:58
Meeting Description
Finance Committee
Document Type
Agenda
Meeting Date
Wed, 04/15/2020 - 00:00
Page Number
189
Image URL
https://nashuameetingsstorage.blob.core.windows.net/nm-docs-pages/fin_a__041520…

121 Mount Vernon St., Boston, MA 02108, USA
Phone: +1617 242 2204 Fax: +1617 242 2205

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WWwWw.mMmavel.com

1.2 Revised Site Parameters

Mavel provided a proposal in March 2019 for installation of a Kaplan bulb turbine type Mavel KA1800K4 connected
to a synchronous generator via an angle-drive gearbox. At the original design head of 21 feet and rated unit discharge
of 800 cfs, the turbine would have an installed power of 1,226 kW measured at the turbine shaft. The generator
power would be 1165.2 kW based on gearbox and generator efficiencies.

A conference call was held on June 5, 2019 to review the March proposal. The Owner commented that the proposed
design was the most effective in minimizing changes to the existing structure. Concern was expressed for the amount
of possible excavation into the structure foundation and requested a review to determine if the unit centerline and
lower gallery floor could be raised to reduce risk. Revised design parameters for the site were provided for the
review. The revised parameters are an operating head of 19.9 ft. and flow rate of 750 cfs.

Mavel committed to review the arrangement and provide a revised proposal, which follows here.

13 Mavel Equipment Recommendation

Mavel affirms the original recommendation to replace the existing equipment at the Jackson Mills HPP with a Kaplan
bulb turbine type MAVEL KA1800K4. The turbine will have a runner diameter of 1800 mm, four runner blades and a
steel scroll case. The turbine will be connected to a synchronous generator via an angle-drive gearbox. The turbine
speed will be 240 rpm and the generator speed will be 720 rpm. At the design head of 19.9 feet and rated unit discharge
of 750 cfs, the turbine will have an installed power of 1,127 kW measured at the turbine shaft. The generator power
will be 1059 kW based on gearbox and generator efficiencies.

The estimated annual energy production for the operation of Jackson Mills HPP at full capacity based on the site
hydrology would be 4,161,354 kWh.

Cross Section of a Mavel Kaplan Bulb Turbine with Gearbox

The MAVEL KA1800K4 double regulated Kaplan bulb turbine was selected for the TGC replacement at Jackson Mills
HPP in order to maximize the potential of the site while minimizing changes to the existing civil structure.

Project No. 0-29029.Rev.3 www.mavel.com Jackson Mills Upgrade

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Finance Committee - Agenda - 4/15/2020 - P189

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