Electricity Production Via Daily Water Flow in Building

Introduction

Our group has selected the Water Faucet Micro-Generator project in order to utilize knowledge and experience obtained from different power engineering classes.  The most difficult part of the project will be synchronizing the speed at which we can spin the turbine with the optimal speed of the motor/generator.  We may need to boost the signal from the motor in order to obtain our goals. This project will be exciting because it will allow us to design and build a small hydro-generation system.  This system will give insight into the complex task of finding a reliable energy source for future use.

Objectives

The main goal for this project is to generate 220 V at 50 Hz and up to 100 W of ac power for household use.  The goal of 100 W may be somewhat ambitious, as we will be limited by the kinetic and potential energy of the water.  When water strikes the turbine, after being pressurized, the motor will act as a generator to provide power.  This project is intended to function as a backup power supply in the case of an emergency loss of power.

Benefits of the Water Faucet Micro-Generator to the end customer:

·         Emergency backup power supply

·         Non-polluting generation for operation in enclosed areas

·         Readily available supply of fuel (water)

·         Provides an alternative to gasoline-powered generators

·         Save money by using water instead of gasoline

·         No flammable components

Product Features of the Water Faucet Micro-Generator:

• Easy hook up of faucet to hose
• Draining of water will be provided
• Self-contained water compartment for safe household use
• 2 outlets allowing multiple devices to be powered
• 220 V at 50 Hz output
• 100 W maximum load

Block Diagram

Water:  The water is the driving force for the turbine.  It will be obtained through a standard household faucet and transported to the turbine via a hose.  The kinetic and potential energy from the water will be transformed into rotational energy by the turbine.

Turbine:  The turbine will be a plastic wheel with fins based on the Pelton Wheel design.  The turbine will be enclosed in a box and attached to the motor shaft through the center bore of the turbine.  The water will run through a nozzle and spray against the turbine to cause the turbine to rotate and thus drive the motor shaft.

Motor/Generator:  A permanent magnet dc motor will be used as a generator.  The turbine will turn the shaft of the motor and alternating fields experienced by the rotor will induce a current in the rotor windings thus transforming rotational energy into electrical energy.  The leads of the motor will be connected to a dc-dc converter.

DC-DC Converter: The input of the dc-dc converter will come from the leads of the motor.  The voltage of the motor output will vary with the speed of the motor and the speed of the motor will vary with the pressure of the water.  Thus, the dc-dc converter will serve to stabilize the voltage in order to generate a constant input voltage for the dc-ac stage of conversion.

DC-AC Inverter:  The dc-ac inverter will take a constant dc voltage as input from the dc-dc converter and generate 120 volts at 60 hertz for the output.  Since most household electrical goods require 120 volt 60 hertz input, the same value would be the most logical choice for the output of the inverter.

Circuit Breaker:  Safety measures should be taken with all electrical devices.  A circuit breaker will provide safety from short-circuiting the electrical outlet or the load.  If the electrical outlet is shorted, the breaker will trip and break the circuit thus preventing electric shock and damage to generator components.

Electrical Outlet:  A standard electrical outlet will be attached to the circuit breaker for easy hookup to household products.

Performance:  120 +- 5% output voltage at 60 hertz, 100 Watt maximum power output

1.1  Design Block Diagram

             

1.2  Subprojects

The Rainfall Powered Battery Charger is divided into 3 distinct subprojects: water collection, mechanical devices, and electrical devices.

Water Collection – consists of 2 plastic 10’ residential gutters, connected in series with a gutter coupler. These gutters are attached to the outside of a building (i.e. a fire-escape). For testing purposes, a hose connected to a calibrated faucet is the source of water, simulating water rainfall during a rainy day. 

Mechanical Devices – consists of the turbine, the gear and the motor. The turbine is constructed from an ordinary bicycle wheel, and PVC caps that are implemented as propeller blades. A shaft and a gear box bridge the turbine and the motor together. The gear ratio is determined by the rated speed of the motor and the average spinning speed of the turbine. The motor is a Permanent Magnet DC motor capable of generating upwards of 30 Watts at low torque.

Electrical Devices – consists of the DC to DC converter and the battery. The DC converter transforms the unsteady input DC voltage to a constant 12V DC output. It is powered from the input voltage, but uses minimal power for its operation. The converter charges a lead acid battery that provides up to 36 Watt-Hours of power.