(navigation image)
Home American Libraries | Canadian Libraries | Universal Library | Community Texts | Project Gutenberg | Children's Library | Biodiversity Heritage Library | Additional Collections
Search: Advanced Search
Anonymous User (login or join us)
Upload
See other formats

Full text of "History and development of the Buzzard Point station, Potomac Electric Power Company / Charles F. Janes"

HISTORY AND DEVELOPMEl^IT 
of the 
BUZZARD POINT STATION 
P0T01.IAC ELECTRIC POWER COllPANY 



■am 



CHARLES F. JANES 



Presented As Requirement 
For Initiation 
Maryland Beta Chapter 
Tau Beta Pi Association 



r 



HISTORY AND DEVELOPMENT OF THE BUZZARD POINT STATION 
POTOLIAC ELECTRIC POWER COMPANY 

SmCLIARY 

Since t896 Washington has teen served "bj the Potomac 
Electric Power Company, which bought out all of Its competi- 
tors and built the present plant at Banning in T906. This 
initial installation of 25,000kw. was added to, from tinie to 
time, to keep up with the growing demand for power until it 
was developed to the greatest extent, to which it could be 
operated economically in 193T, when it had a total capacity 
of 208,000 kw. In March T933, the 230,000 volt line connect- 
ing Washington with the Safe Harbor hydro-plant on the Sus- 
quehanna was put into service, InBuring Washington a reliable 
supply of povrer under all circumstances. To keep pp with the 
demand, plans were drawn up for a new plant, which it was fin- 
ally decided to build at Buszard Point in Southwest Washington. 
This plant was opened in November 1933 as a base load station 
with a capacity of 35,000 kw. Because of its modem design 
and the fact that it operates as a base load station. Buzzard 
Point operates at a much higher efficiency than any other unit 
of the Potomac Electric Power Company. 



HISTORY AND DE\^ELOPMEFT OF THE PUZ2ARD POINT STATION 
POT CMC ELECTRIC POWER COMPANY 

BACKQ-RQUND 

Prom the' Initial Installation at Bennlng In t906 of 
5-5|000 kw. , vertical type tiirbine- generators there have "been 
frequent additions and Improvements of equipment with subse- 
quent removal of otsolete units, until the addition of a new 
30,000 kw. imit in 1931 completed the economic development of 
this station. The total capacity of Bennlng was now 208,000 kw. 
which, Bincb the removal of the old plant at I4th and B Streets 
was the total source of power for the District of Columbia and 
vicinity. 

With an eye toward improving the reliability as well 
as the quantity of service, p modern 230,000 volt transmission 
line was built to connect with, the line from Baltimore to the 
Safe Harbor hyrdo-plant on the Susquehanna river in March 1933» 
It was realized that the Banning plant was subject to river 
conditions, as happened on March 2, 1914 vfhen it was forced to 
shut down bacauee an extra low tide left it without adequate 
condensing water; and again, on August 23, 1933 it was drowned 
out by flood, end the new inter- connection with Safe Harbor 
showed its worth. A maximum load of 60,000 kw. can be taken 
from Safe Harbor or sent to Baltimore in case of lov; water in 
the Susquehanna. 

As early as January 1931 plans were considered for 
"building a new steam plant to operate in conjunction with 



-O. 



Bermlng. The site for the new plant was considered very care- 
fully. The number of possible. site a finally came down to three: 
Siesboro Point on the south side of the Anacoetla river, site 
of the old wartime steel plant; some point on the Virginia side 
of the Potomac above Alexandria; and Buzzard Point on the north 
side of the Anacostla river, near the Army Yfar College. Objec- 
tions to the first tv;o were that cables would have to be laid 
across the river to the main load centers, and that they are 
farther from these load centers- 

Other advantages of Buzzard Point arej an ample sup- 
ply of condensing water is available; coal or other fuel can 
be brought by rail or water; and the area is zoned for indus- 
trial purpoaea. The fact that Buzzard Point was in line for 
future development as a park called for careful consideration 
of architectural design. 

The deai^ called for an initial installation of one 
35 1 000 kw, unit and two boiler units, with space for another 
similar unit, the tv/o to be operated from separate boilers. 

Construction was sto,rted late in 1932 and the sta- 
tion put In operation as a base load station in conjunction 
with Benning and Safe Harbor on November T6, 1933* The total 
cost of the plant approximated ^5,000,000. 

The ultimate development of the site will Include 
four more 50,000 kw. generators for a total capacity of 
270,000 kw. 



1 



'3- 



FSATURES OF THE STATION 

The arrangement of the boiler operating room and tur- 
bine room is such that the operators of one are easily accessible 
to the other. The boiler units are Bab cock and Wilcox single 
pass. Ions crossdrum 72 in. by 35 ft. 6 in. t.ype designed to bum 
a variety of coals, fuel oil or natural gas. Tfest Virginia coal 
Is used at present. Boiler pressure of 650 lb. and temperature 
at the tiorblne throttle of 835 deg.F. allow maximum efficiency 
T^ith a great degree of reliability. A simple regenerative cycle 
with three stage bleeding for feed water heating is used. 

Because of the probability of rapid fluctuation in 
load when naming a steam station in parallel with a hydro- sta- 
tion, the boilers were designed to give maximum "pick up" ability 
from low load conditions. 

Due to its proxlnilty to the many public "buildinss of 
the Mall, It was extremely important to eliminate smoke ctodi4 
tions. For this purpose the stack is provided with a Cottrell 
eleotro-statlc precipitator in addition to comolete automatic 
combustion control. 

The boilers are each provided with two Riley mills 
and six burners. The present capacity of the boilers is 375»- 
000 lb. of steam per hour, representing nearly t2,000 boiler 
horse power. The boilers are completely water cooled and equip- 
ped with a slag screen Just above the burners, composed of stag- 
gered tubes covered with refractory material, which causes the 
slag to run down and drip off Into the pit. The burners are 
fired downward so that the flame impinges on the slag at the 



-4- 



bottom causing the larger particles to be thrown off. The 
superheater is arranged in two sect lone with a desuperheater 
between, to control the temperature of the steam as It leaves 
the boiler. 

The turbine is a single cylinder, eighteen stage 
General Electric unit rated at 35,000 kw. at t,800 r.p.m. It 
Is set crosswise of the turbine room over a 30,000 sq.ft. Inger- 
soll-Rand condenser of the single- pass, two- compartment type. 
Bleeding for feed water heating Is done from the 7th, Ttth and 
I4th stages. The heaters are Foster-'«Yheeler direct contact type 
requiring a pump for each heater. 

The generating unit Is a General Electric unit rated 
at 38,888 kva. at 90^ power factor, 60 cycles, T3,800i, volts. 
The exciter unit consists of direct connected main and pilot 
exciters, A spare motor driven exciter of 200 kw. capacity is 
installed for use in emergency. The generator is air coaled 
using river water as the cooling medium. 

The lubrication system is very Interesting. With the 
use of high temperature steam the danger of fire from leaking 
oil became increasingly great. There have been several disas- 
trous fires due to this cause. With this in mind the designers 
of Buzzard Point incorporated a system whereby much danger is 
eliminated. All high pressure oil lines are enclosed inside low 
pressure return lines, thereby greatly reducing the danger of 
leakage. All the oil pumping equipment is located in a small 
fireproof room under the turbine itself. It is protected by a 
Lux carbto dioxide automatic extinguishing system and is com- 



-5- 



pletely enclosed "by Itself. There Is a separate room for oil 
storage, cleaning and filtering, which is protected by a steam- 
smothering system. 

The station auxiliaries are all driven by electric 
motors with the exception of one feed water pump, which is driven 
by a 700 horse power, single stage non- condens Ing turbine for 
use in emergency. This turbine is capable of gaining full speed 
from cold start in 30 seconds. The three feed pumps are seven 
stage centrifugal ptjmps each capable of handling hot vmter s.t 
357 deg.F. at the rate of 800 gallons per minute. 

Since ultimately each boiler will operate a single 
turbine all the auxiliaries are grouped separately. A 4,000 kva. 
13,800/2,300 volt, three phase transformer supplies the auxilia- 
ries of each main unit. 

All except the smaller motors and the ooal handling 
motors are 2,300 volt units, the others being 440 volts. The 
forced draft fa.ns are run by constant speed squirrel cage motors, 
speed control of the fans being done by hydraulic couplings. 
These couplings give wide range control with high efficiency. 
The speed Is controlled by changing the oil level in the coupling. 

The electrical equipment Is concentrated at one end of 
the building. The top floor houses the switch-board room , in 
which the main switch-board, automatic voltage control unit and 
station battery charging set are located. The switch- board is of 
the bench type with vertical back panel. The various indicating 
instruments and control switches are located here. In back of 
the main switch-board on a separate panel are the various relays 
and recording instruments. Located In a glass enclosed room off 



-6- 



the main switch- 'board room le the automatic voltage regulator 
equipment, which is of the FA-4 type. The battery charglns e- 
qulpment is at one side of the control room , separated "by an 
iron cage • 

The two main 13»800 volt busses occupy the fourth 
floor of the electrical bay. They are enclosed in reinforced 
concrete structures, as are the oil circuit breakers and dis- 
connect switches located on the third and fifth floors. These 
oil circuit breakers are G-eneral Electric imits rated at t,500,- 
000 kva rupturing capacity and have sji arc-ruptiaring time of 
8 cycles compared to e 60 cycle timing wave. The disconnects 
are all of the remote mutual gang operated except the H tie 
disconnects which are motor gang, operated and controlled from 
the main switch- "board. On the second floor are the feeder re- 
actors, rated at 5%, On the first floor are the out-going feed- 
er disconnects and potheads, and the cable test bus. The station 
service control swltch/feoard is located between the turbine 
room and the boiler- operating room. From it are controlled the 
auxilliarles of the plant. 

Buzzard Point is tied in with Benning by a J3tv tie- 
line and with Takoma by another 53 Irv line thro-ugh SUB- 13, lo- 
cated at 135th and Harvard streets. Six 13,800 volt feeders 
connect with SUB- 16 in the downtown area, direct from the sta- 
tion busses. Another 13,800 volt serves the Bureau of Engrav- 
ing and Printing. The 13,800 volt feeders are of the three con- 
ductor, 350,000 circular mil type H cables. The transformer 
system for the 33 kv tie- lines consists of three 20,000 kva 



-7- 



transformers, two of vrhich are phase changers. 

Because of the danger of the load being dropped In 
case of a 3-phase fault in the "busses of one of the substations 
these busses were split at SUB- 13, SUB-T6, and SUB-5, Buzzard 
Point feeds both parts of the busses at SUB- 13 and SUB- 16 with 
separate cables therefore Insuring continuance of service in 
case of a fault. SUBS- 13 and 5 connect with Takoma and thence 
to Safe Harbor, therefore It Is important that they be free 
from disturbance. SUB-16 is Important because it serves the 
main business district of the city as well as the G-ovemment 
buildings of the Mall. 




20,000 kva, 13, 800/33,000 volt transformers 
at Buzzard Point Plant 



The archetecture of the building is simple and pro- 
mises not to mar the beauty of ejny future development at Buzzard 



-s- 



Point. The 90 ft. building looks somewhat modernistic with its 
high windows, square comers and octagonal stack, which Is 180 
ft. high. The construction is of steel, "brick and concrete "block 
and is finished In a dull white shade. The station was designed 
and "built by Stone and Webster Engineering Corporation in co- 
operation with Potomac Electric Power Company officials and en- 
gineers . 

OPERATION OF THE PLAMT 

Since Buzzard Point Station has been In operation it 
has shown very high efficiency due both to its careful design 
and to the fact that it Is operated as a base load station. 
The great Increase of efficiency over the older units at Bennlng 
is shown by the accompanying chart. The best efficiency of the 
old vertical 5,000 kw. units at Bennlng was about 2.05 Ihs. of 
coal per kwh. while Buzzard averaged for the year 193^».888 lbs. 
per kwh, ajid in 1935.. B81 IT^s. per kwh. 

Following are a few statistics for these years: 

193^ 1935 

Gross generation 202,267,000 222,886,000 
Station service 11,266,700 11,740,900 
Net generation 191,000,300 211,145,100 
Hours of operation 7|746 7* 515 

Coal burned (lbs.) 169,782,500 186,628,100 
BTU/lbs. coal 14,305 14,195 

Lbs. coal/kwh. .888 .881 

Overall boiler efficiency 84,28 85.7 



-9- 



It is Interesting to note how the efficiency goes up 
as the steam pressiire Increases. The older imlts were operated 
at 200 Its, and then Improvements of design made It possible to 
operate safely at 400 lbs. which led to greater economy. At 
present the highest pressure, with Its accompanying high tem- 
peratxjLre, that can be used safely with the metal available is 
around 65O lbs,, which is that used at Buzzard Point. Other 
contributing factors to the high efficiency of the station are 
use of pulverized coal fuel with Its ease of combustion control, 
and the use of an air preheater and three stage bleeding for feed 
water heating. 

Buzzard Point Plant, as a whole strikes me as being 
a well designed plant from the standpoint of ease of operation 
and efficiency. Very few men are needed to tend the plant in 
normal operation. Probably the near future will see the addition 
of another 35,000 lew generator which can be operated almost as 
easily as the present one. 



The Electrical World — December 50, 1933. 

The T7ashlnston Star — 1933 

The Washington Public Library — 'ffashingtonlana Div. 

Potomac Electric Power Company Engineers: 

Mr, W. J. Lank — Assistant chief engineer 
Mr. R. B, Kellogg — Plant engineer. Buzzard Point 
Mr. C. E. Miller — Test engineer, " **. 
Mr. H. B. Pollack— Switch-board 

operator, '* " 
Ifr. J. W. Thomas — Watch engineer, " " 
Mr. C. B, Tyson Jr. -- Plant clerk. 



1 



Potomac Electric Power Co. 



Electrical Engineer's Office 



Subject 




r 




"^ 



k 








G-eneral view of the plant from the south-west. 



F 







^'L. 




A view of the front of the "building in which the 
office and lobby are located. The plant fronts on 
the Ana cost la River. 





'H 



y ii 










}*K«««*W*5#%™W5«*',*a'J 



-JWja™'*-^«*.-^v-jrj mwjrjfjri^j'.fr rtr4nKtV^^j*'^*»-j*jtjt'>A*» VIKKAC 



j| 



The two 13,800/2300 volt Btation service transformers. 



I 




Plan and croBS-seetlon of Buz,2,ard Point Station.