Interrelation between configuration of electrodes for induction electric charging and collector current wind EHD power generator

WRJX 1996

INTERRELATION ELECTRIC

BETWEEN

CONFIGURATION

CHARGING AND COLLECTOR

OF ELECTRODES

FOR INDUCTION

CURRENT WIND EHD POWER GENERATOR

MSATO

Department of Electrical Engineering,Faculty of Engineering,HachinoheInstitute of Technology, 88- 1 Myo,Hachinohe 03lJapan

ABSTRACT This work aims to realize induction electric

a wind electrohydro-

dynamical (EHD)

charging with a water jet.The

electrodes

power generator

using

for induction electric charging

are composed of an orifice of which inner radius is 1.5mmand a ring made of a copper wire of which diameter is 1.5tnm.Itis important to design the electrodes that maximize induction electric

charge.In

this paper,it is experimentaly

clarified that the ring electrode

of inner

diameter of 3.7~1ngives the collector short current of the wind EHD power generator more than that of 4.7cm but has dispersion 4.7cm

of the collector

short current

more than that of

.

KEYWORDS Electrohydro-dynamical

generator;wind

power;induction

electric charging; collector short

current.

INTRODUCTION The author has conducted

a variational

analysis

of the optimal

conversion

process

of

incompressible EFD generation (Sate et al., 1976).The optimal shape of an EFD power generation duct has also been discussed and its effectiveness has been demonstrated by 1981). In this case, the method of field emission was used

experimental

means(Sat0 et al.,

for injection

of the charge into the working

fluid in the generation

duct.However,the

variational analysis of the optimal conversion process of compressible EHD generation has not been attempted.Accordingly,this paper deals with wind EHD power generation that directly converts wind power to electric power.The working fluid is air that is compressible. Marks (1982) reported the experimental

results of the wind EHD power generator using induction

827

WFEC 1996 electric

charging

In this case, a water jet issuing under water

pressure

from a small

diameter (25- 100 u m) orifice was used.It is important to design the electrodes that maximize induction

electric

electrode

and the distance

charge-This

paper describes

from the orifice

influences

of the diameter

to the ring on the relation

of the ring between

the

collector short current of the wind EHD power generator and the applied voltage to the ring.

PRINCIPLE

OF WIND EHD POWER GENERATION

EXPERIMENTAL The experimental

AND

APPARATUS

apparatus of the wind EHD power generator

charging is shown in Fii.l.Instead

using induction electric

of wind power,the gas flow by a compressor was used.Liquid

aerosol particles are simultaneously formed and charged instantaneously between the orifice and the ring.The downstream

charged droplets give up their charge to the collector

in moving gas.The collector electrode

electrode

placed

is connected to the load resistance and

charges accumulate there.The charged droplets in the energy conversion region and electric charges at the collector

electrode

charged droplets are transported electric

force in the opposite

exert Coulomb’s force on each other.Consequently,the to the collector

direction

electrode

while they are pushed by the

to the gas flow.Threrfore,wind

power is directly

transformedinto electric energy in this process.

01

Fig.1. Experimental apparatus. RESULTS AND DISCUSSION Figure 2 shows influence of the polarity of the applied voltage to thering electrode relation

between

the collector

short current and the applied voltage.The

on the

collector

was

shorted to measure a quantity of charge generated by using induction electric charging.The collector

short current

is increased

in proportion

to the applied yoltage.The

collector

short current in case of positive polarity is 3.4 times as much as negative polarity.Figure

828

WREC 1996

3 shows influence of diameter

of the ring electrode

short current and the applied voltage.The the collector

short current

on the relation between

ring electrode

the collector

of inner diameter of 3.7~10gives

more than that of 4.7cm but has dispersion

of the collector

short current more than that of 4.7cm. The relation between the collector short current and the distance from the orifice to the ring is linear as shown in Fig.4.Because induction

electric

charging gets wider in range as the distance between

the ring becomes longer.But it is seemed that the optimal distance

the space for

the orifice

and

between the electrodes

exists.

Applied voltage ( kV ) Fig.2. Influence of polarity on relation between collector short current and applied voltage.

Applied voltage ( kV) Fig.3. Infhtence of diameter of the ring on relation between collector short current and applied voltage.

a29

WREC1996

i

01 Distance between the electrodes ( m 1

Fii.4. Relation between collector short current and distance from the orifice to the ring.

REFERENCES Sato,M.and Y.Ozawa

(1976).0ptimal

duct configuation

of EFD electric

power generation.

Electrical Engineering in Japan,% 23- 30 Sato,M.and M.Baba (1981)Characteristics

of incompressible type EFD power generator using

optimal configuration duct.1981 National ConfInstitute of Electrical Engineers of Japan,965 Marks&M.

(1982).A charged aerosol wind/electric power generator using induction electric

charging with a micro water jet.Institute of Electrical and Electronics Engineers,496- 591

830