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Back Mechanical Mechanical Engineering Dictionary Hydraulics Hydroelectric Power house Service Equipment

Hydroelectric Power house Service Equipment

HEP (Hydroelectric Power) is an environmentally friendly way to generate electricity.

A dam is built to trap water, usually in a valley where there is an existing lake. Water is allowed to flow through tunnels into the dam,to turn turbines and thus drive generators. Notice that the dam is much thicker at the bottom than at the top,because the pressure of the water increases with depth.

The best place for a hydro-electric power station is up in the mountains. This is because it doesn’t get too hot so the water doesn’t evaporate and stays in the dam. Also there is a lot of rain in the mountains ensuring the reservoir is always full.The land also needs to be impermeable so that the water doesn’t infiltrate through the rocks below.

Hydro-electric power is renewable. The Sun provides the water by evaporation from the sea,and will keep on doing so. The Sun evaporates water from the sea and  lakes, which forms clouds and falls as rain in the mountains, keeping the dam supplied with water.

how hydroelectric power is created

For erection and maintenance work the following mechanical systems will be provided:

  • Drainage and dewatering system
  • Service air system
  • Mobile oil purifiers
  • Powerhouse cranes
  • Powerhouse services and utilities
  • Mechanical workshop

Oil Filtration Plant

An oil filtration plant together with the purifier, pumps, clean and dirty tanks shall be provided for purification of the lubrication oil, bearings oil and governor oil.

Powerhouse Crane

One overhead bridge type traveling crane of 10 ton capacity has been proposed for unloading and handling the powerhouse equipment at the loading/erection bay. Besides, the same crane shall be used for assemblies at the loading bay and for erection of plant. The span of the crane shall be 9.20 m (say.). The crane rails shall be placed at EL. 2050 m( say).

The maximum weight to be lifted by the EOT crane would be that of the generator rotor which has a weight of 10 tons. The other equipment to be handled by the crane covers spherical inlet valves, stator assemblies, distributor, runner-shaft assemblies etc.

The crane shall have single trolley with main hook of 10(say) ton capacity and that of auxiliary hook 25 (say) ton. The crane shall be operated from a cabin fixed on the crane. The crane shall be designed in accordance with CMAA or FEM standards.

Heating, Ventilation and Air Condition System (HVAC)

The HVAC system shall be designed in accordance with the guidelines of ASHRAE, AMCA, ASTM, ASME, SMACNA and ARI standards.

The HVAC system shall be designed for the following operating conditions and design criteria:

The power station is located above the ground level, but to avoid the entrance of dirt, no opening in the exterior walls should be foreseen to allow natural ventilation. The power station building will have a forced ventilation system and circulating air through a filter. A fresh air intake will add constantly about 10% fresh air to the recirculation system.

Battery rooms will have their own exhaust air system. The control room will have a separate ventilation system with equipment controlling the air temperature and humidity.

The powerhouse should be designed by targeting the following objectives:

  • To maintain the indoor temperature at a pre-determined level.
  • To provide clean air to air-conditioned space by the filtration of re-circulated and outside (fresh) air.
  • To pressurize the building so as to prevent the infiltration of uncontrolled outside air, areas, workshops etc. by adding heat to the indoor environment.
  • To recover heat dissipated by the equipment in winter and to use it for space heating where possible and useful.

Following is an example of Design criteria for a small Hydro electric power station ( 1 to 5MW) or depend upon the locality and requirement.

Design Criteria

Outdoor design data

Summer Max. 42°C

Inside Design data (summer)

winter Min. -4°C

Admin offices, computer, Control room


All other rooms


Indoor design data (winter)


Admin offices, computer, control room


workshop, corridors, toilets etc.


All other rooms


Ventilation rates

Supply air

Min 2.5l/s/m2/floor area

Out side air

Min. 5% of supply air 4.75 l/s/person

Exhaust air

Toilets / Lockers

10l/s/m2of floor area

Battery Room

20 air changers/hr.


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