Cornell University, through its Professor Dean Thurston, was making district energy history in the United States as early as the 1880's. The University was one of the first of its kind using electricity to light the grounds from a water-powered dynamo in 1883. In 1888-89, the University installed a central steam distribution system encased in logs. This eventually grew to three district plants on the Engineering Quadrangle, behind the Arts College, and on the state campus (located in Beebe Hall). Special thanks to Thomas Clougherty, who documented the history of these early systems.
Shortly after WWI, it was realized that the independent district systems should be replaced with a remotely located, unified Central Heating Plant. From that vision, the present system was born.
Central Heating Plant Technical History
The Central Heating Plant (CHP) was built in 1922 to provide central steam heat to the endowed campus and replace existing facilities. The original facility consisted of the west half of the building; the west stack and four (#1-4) B&W "Sterling" three drum boilers. These boilers produced saturated steam at 200 psig. They were rated for 35,000 lb./hr. using a "Coxe" traveling grate stoker. Pennsylvania anthracite was the fuel.
In 1930, the east side was added with two additional boilers (6 & 7) and the east stack. In 1940, superheaters were added to boilers #6 & #7 and a desuperheating system was installed (of which no trace remains today). This steam was fed to two 300kW Elliott non-condensing turbine-generator sets.
In 1949, the plant was again expanded to include Boiler #8. This boiler was intended to produce electricity and was rated at 900 psig, 825°F. The stoker was a "Harrington" design and was reputed to be the largest of its kind in the world. The fuel was buckwheat anthracite. Field erection for this boiler appears to have been done on a time and material contract to Riley Stoker, the manufacturer. The intent of producing 8 MW of electricity was never carried out and the boiler was brought on line at 200 psig. Riley has no records of any design modifications to the unit to allow operation at 200 psig.
In 1959, the piping system was extensively modified. The feedwater system, de-aerating feed tank, and surge tank were installed in their present configuration. Boilers #1 & #2 were replaced with B&W two drum units, fired by American Engineering "Vibragrate" water cooled stokers. These units were rated at 210 psig., 540°F. The flooding of the anthracite coal fields in the early 1950's made this fuel expensive. Sometime in that decade, bituminous coal became the coal type. These new boilers were the first in the plant designed to use this fuel. The reasoning for installing superheaters in boiler #1 & #2 is unclear, but plans for future generation capacity is a likely candidate.
In 1969, boilers #6 & #7 were replaced with Erie City (Zurn) type "O" package boilers. A 1,000,000 gallon storage tank and a fuel handling system for #6 oil was installed. These boilers were rated for 205 psig., 480°F. 1970 saw the removal of boilers #3 & #4, and the installation of boiler #5. This unit was originally intended to be dual fuel, but due to budgetary reasons, the boiler was not connected to the west stack. The existing short stub stack precludes the use of oil. Boiler #5 is rated for 221 psig, at 502°F.
The water treatment system, inclusive of the treatment plant was upgraded in 1972 and again in 1980.
During the early 1970's, oil was the primary fuel for the entire plant. Approximately 10,000,000 gallons were burned annually. Hurricane Agnes (1972) washed out the rail line from the nearby community of Freeville. Because no one foresaw a need to burn coal, it was abandoned. 1973 saw the oil embargo and by 1979 the price had gone from less than $1.00 per million BTU's to over $3.00 per million BTU's. In 1976, the University chose to rehabilitate boiler #8 and the associated coal handling systems. The coal pile, conveyors, leachate pit, and other equipment were modernized at this time, following a coal pile fire. The boiler was converted to properly burn bituminous coal and new superheater and economizer elements were installed.
Due to a rapid rise in steam load, boiler #2 was converted to oil in 1978. Because of the price of oil, the boiler is largely used for peaking duty. Until oil pricing fell, a capital project was underway to reconvert the unit to coal. This effort was shelved.
With oil prices peaking in 1979, a replacement for the second boiler #1 was purchased and started-up in 1981. This is a Zurn spreader stoker unit rated at 400 psig, 550°F. This unit was originally equipped with two series mechanical dust collectors and a "sidestream" type baghouse which never functioned properly. Opacity problems forced the addition of a full baghouse in 1987, even though the unit operated within the NYSDEC requirements (.3 lb/million BTU) for total particulate emissions.
The early 80's were a time of intensive intermediate and long term planning. Cogeneration was found to have a reasonable payback on the expected remaining life of the existing plant. Planning for the cogeneration effort was done in 1984, engineering in 1985, and installation in 1986-87.
The cogeneration effort was one of the most comprehensive in the plant's history. Boiler #8 and boiler #1 received many repairs and upgrades to improve their performance and efficiency. Both got new safeties and/ or trim. Other systems affected were the PRV's, piping, feedwater, water treatment, locker room facilities, etc. A new electrical system was installed with a paralleled 750 kW (standby) diesel generator. The entire plant was converted to 480 volt, high-resistance grounded "wye". A new Bailey Controls Network 90 distributed digital control system was installed. The effort was accomplished with several independent projects.
The turbine generators were installed in the former university fleet maintenance garage. A new garage was built out of project funds. Two turbines were installed to allow better matching of unit efficiencies to the campus steam load profile. Both machines are equipped with extensive heat recovery systems and produce power with a typical heat rate of 5000 BTU/kWh (approximately twice the efficiency of a typical coal fired electric generating plant).
In 1987, a full fabric filter (baghouse) was retrofitted to boiler #1. This effort greatly reduced the air pollution due to burning coal at the facility and was very innovative in its use of a variable speed motor driven induced draft fan. In 1997 a baghouse was added to boiler# 8 including a new turbine driven induced draft fan. These have rendered the emissions from the stacks virtually invisible.
The second generation (Erie City/Zurn) of boilers #6 & #7 were replaced in 1993 with two Foster-Wheeler D type package units. New PRVs and feedwater/transfer pumps (two of three are turbine driven) were also installed with this project. These boilers were unique at the time for their low-NOx gas and #6 oil burners. It is believed that there are few other heavy oil boilers that are permitted to modern NOx RACT standards without flue gas recirculation. It is also interesting to note that the physical appearance and architectural integrity of the Central Heating Plant has been maintained through 80 years of expansion and renovation.
The years 1996-2001 saw extensive changes to the emissions monitoring equipment and plant controls. Rather than install full continuous monitoring, Cornell proposed and was permitted to operate, a predictive emissions system for boilers #6 & #7. This concept used the chemical makeup of the fuels burned, the boiler characteristics, and the amount of steam produced to mathematically estimate the actual emissions. In addition, new opacity monitors and other emission related equipment was installed. As of 2001, Cornell is operating under a new campus wide EPA Title V air emission permit, and installed actual NOx monitors to replace the predictive system.
In 1999-2000, Cornell supplemented its 1985 Bailey digital control system with new PC-based operator interfaces and networking capabilities.
From 2001 through 2004, the plant had many minor projects completed to address maintenance needs.BACK TO THE TOP