Post on 09-Aug-2020
transcript
Hydro Electric Power
Direct conversion of
potential energy to
work - not a heat
engine
out222
2
22in111
2
11 wvPu
2
VgZqvPu
2
VgZ ++++=++++
Ideal Turbine:
1
2w
CFtWW
wmW
gZw
gZw
actual
1actual
1ideal
•
••
=
=
=
=
wideal = ideal work, no friction
or losses
g = acceleration of gravity
Z1 = gross head
wactual = actual work
= turbine-generator
efficiency
W = maximum power
produced
m = maximum water mass
flow rate
W = work out
t = time
CF = capacity factor
Penobscot River Flow Duration
http://waterdata.usgs.gov/me/nwis/uv/?site_no=01034500&PARAmeter_cd=00065,00060
http://waterdata.usgs.gov/me/nwis/uv/?site_no=01034500&PARAmeter_cd=00065,00060
Workers replacing flash boards on Milford dam, Feb. 2010
Example: Penobscot River West Enfield Hydro Project
Gross head = 19 feet
Maximum design flow rate = 14,500 ft3/s
Turbine-generator efficiency = 77%
Capacity factor = 73%
Construction cost = $45,000,000
Interest rate = 8%
Operations cost = 1¢/kW hr
Determine:
a) Ideal work, ft lbf/lbm
b) Actual work, ft lbf/lbm
c) Mass flow rate, lbm/s
d) Maximum power, kW
e) Work produced in one year, kW hr
f) Cost/kW hr
a) Determine ideal work, ft lbf/lbm:
m
f
ideal
m
2
f
2ideal
1ideal
lb
lbft019w
ftlb232
slbft19
s
ft232w
gZw
.
.
.
=
=
=
b) Determine actual work, ft lbf/lbm:
m
f
actual
m
f
actual
idealactual
lb
lbftw
lb
lbftw
ww
6.14
77.00.19
=
=
=
slb000905m
s
ft50014
ft
lb462m
Vm
m
3
3
m
/,
,.
=
=
=
•
•
••
c) Determine the mass flow rate, lbm/s:
kW00018W
hp
kw746
lbft550
shp
lb
lbft6314
s
lb800904W
wmW
fm
fm
,
..,
=
=
=
•
•
••
d) Determine the maximum power, kW:
This is maximum output -
Nameplate (average) capacity is 13,000 kW
because full flow is not always available
hrkWW
hrkWW
CFtWW
000,000,115
73.)24(365000,18
=
=
=•
e) Determine the work produced in one year, kW hr:
hrkW
$0.0414
hrkW
costtotal
hrkW
$0.01
hrkW
$0.0314
hrkW
costtotal
hrkW
costfuel
hrkW
costoperating
hrkW
costinterest
hrkW
costtotal
hrkW
$0.0314
hrkW115x10
(0.08)$45x10
W
Pi
hrkW
costinterest6
6
=
+=
++=
===
f) Determine the cost per kW hr:
Note that fuel cost is 0 and plant
has a projected life of over 50 years
Sta Input Name Output Unit Comment
32.2
19
77
62.4
14500
8760
73
45000000
8
0.01
wideal
g
Z1
wactual
eta
Wdot
mdot
rho
Vdot
W
t
CF
A
P
i
Interestcost
Totalcost
opcost
19
14.63
17954
904800
114820000
3600000
0.031355
0.041355
ft*lbf/lbm
ft/s^2
ft
ft*lbf/lbm
%
kW
lbm/s
lbm/ft^3
ft^3/s
kW hr
hr
%
$
%
$/kW hr
$/kW hr
$/kW hr
ideal work
acceleration of gravity
gross head
actual work
turbine-generator efficiency
Max power produced
Peak hydraulic capacity mass flow rate
water density
Peak hydraulic capacity
Actual energy produced
Time
Annual capacity factor
Annual interest cost
Principal
annual interest rate
interest cost/KW hr
total cost/KW hr
operations cost/kW hr
TKSolver solution
Countries with the most hydro-electric capacity
Canada, 341,312 GWh (66,954 MW installed)
USA, 319,484 GWh (79,511 MW installed)
Brazil, 285,603 GWh (57,517 MW installed)
China, 204,300 GWh (65,000 MW installed)
Russia, 173,500 GWh (44,700 MW installed)
Norway, 121,824 GWh (27,528 MW installed)
Japan, 84,500 GWh (27,229 MW installed)
India, 82,237 GWh (22,083 MW installed)
France, 77,500 GWh (25,335 MW installed)
Name Country Completed Maximum
generation
Annual
production
Three Gorges
Dam
China 2008 22,500 MW
Itaipu Brazil/
Paraguay
1983 12,600 MW 93.4 TW hr
Guri Venezuela 1986 10,200 MW 46 TW hr
Grand Coulee United
States
1942/1980 6,809 MW 22.6 TW hr
Savano
Shushenskava
Russia 1983 6,400 MW
Robert
Bourassa
Canada 1981 5,616 MW
Churchill Falls Canada 1971 5,429 MW 35 TW hr
Iron Gates Romania/
Serbia
1970 2,280 MW 11.3 TW hr
1012W hr
Largest hydro-electric projects
Three Gorges Dam
China
22,500 MW
Weight of reservoir will
tilt earth’s axis nearly 1”
Itaipu
Brazil/Paraguay
640 feet high
5 mile long dam
12,600 MW
Grand Coulee Dam
Columbia River, Washington
6,800 MW
Advantages:
•Renewable, no fuel required
•No emissions
•Long life
•Can control river flow for flood control
Disadvantages:
•Changes river flow and ecology
•Consumes land and displaces people when built
(80,000,000 people worldwide displaced by dam
projects)
•Risk from dam failure
•1889 Pennsylvania 2,200 deaths
•1959 France 412 deaths
•1963 Italy 2,000 deaths
•1972 W. Virginia 118 deaths
http://www.penobscotriver.org/assets/BeforeandAfterAerialPhotos9-20-12.jpg
Great Works dam being removed 2012
Veazie dam removed 2013
The New England Clean Energy Connect project coupled with heat pump
use could significantly reduce Maine’s oil use and carbon emissions.