Standard Operating Procedures
College Avenue Central Heating Plant
Boiler Operations (Rev 1.1)
April 23, 2013
Chief Engineer: prepared by:
Michael Snyder Asbjorn Nyhus
.Table of Contents
- Plant Overview ------page 3
- Systems ------page 4
- City Water ------page 4
- Water Softeners ------page 4
- De-Aerator ------page 4
- Cascades ------page 4
- HTHW Pumps ------page 5
- Condensate ------page 5
- Flash Tank ------page 5
- Natural Gas and Oil ------page 5
- Boilers ------page 6
- Boiler #3 Startup Procedure ------page 7
- Boiler #4 Startup Procedure ------page 8
- Boiler #5 Startup Procedure ------page 9
- Isolating Cascade Tanks ------page
- Operators Daily Responsibilities ------page 10
- Logbook procedures ------page 11
- Water Testing ------page 12
- Lockout and Tag procedures ------page 14
- Hot Work Permit Process ------page 16
- Troubleshooting ------page
- Emergency Contact List ------page
- Policies and Procedures ------page
Plant Overview
Introduction
The College Ave Central Heating Plant (CHP) Bldg # 3082 is located at 620 George Street. The system uses 3 high pressure steam boilers with cascade heaters to generate High Temperature Hot Water (HTHW) for distribution to various buildings on the campus. The plant is staffed 24 hours a day, 7 days a week/ 365 days a year. It has a capacity of 85 million btu/hr. of heating in the form of hot water, all supplied within one mile of piping distribution. High Temperature Hot Water heating is supplied to Campbell Hall, Hardenbergh Hall, Frelinghuysen Hall, and the SAC. Also, Clothier Hall, Hurtado Health Center, Brett Hall, Tinsley Hall, Mettler Hall, Stonier, the Gymnasium, Demarest Hall, Wessel’s Hall, and the Bishop House. Medium Temperature Hot Water is supplied to the Alexander Library and its addition, and the SCILS building. Low pressure steam is supplied to Brower Commons for cooking purposes. Low pressure steam is also used to heat Records Hall/Post Office, and The Learning Center.
Systems
City Water:
CHP receives city water in two locations entering the plant. Located in the field house adjacent to the plant is the main feed into the plant. This line enters the plant and converges with the secondary line in the corner of the plant next to boiler #4. From there the city water branches to multiple locations with the primary lines feeding the water softening system with bypasses to the DA, Cascades and Boilers.
Water Softeners:
The water softeners are located behind boiler #3 against the wall. There are two softeners in tandem that primarily feed the De-Aerator with softened water. The water softeners work using a brine solution utilizing salt as the softening agent. Operators should check the salt levels in the container next to the softeners to ensure that it is full at all times. This check should be performed by the day shift operator at least once every day.
De-Aerator:
The De-Aerator (DA) is a large, insulated tank-car-shaped pressure vessel located above the water softeners. It uses low pressure steam from the LP header to produce pre-heated feedwater for the cascade tanks and the boilers. At elevated temperature even minute quantities of O2 cause severe corrosion in pipes, feedwater pumps and boilers. A DA should scrub O2 levels down to 5-10 ppb (parts per billion). A vent pipe on the DA removes non-condensable gases. The addition of sulfites chemically ensures a “zero” level of dissolved gas in the feedwater.
Cascade Tanks:
The two vertically mounted cascade tanks receive DA water when running the plant in normal configuration. They are fed by two cascade pumps located behind the water treatment room. The cascades can also be fed via bypassed softened or bypassed city water. The cascades heat water utilizing high pressure steam from the HP header. The cascades feed the boilers as well as providing High-Temperature-Hot-Water (HTHW) to the Dormitories and other campus locations. Cascade water is pumped using a combination of 4 pumps in parallel to deliver it to the areas served. These pumps are located below the cascade tanks.
HTHW Pumps:
The cascade tanks are fed into 4 HTHW pumps that are piped in parallel. This allows the system to be run from any single pump or combination of pumps. These HTHW pumps feed the library heat exchangers as well as the boilers. These pumps also feed other campus buildings.
Condensate:
In a heat exchanger, the steam transfers its latent heat to a process fluid (HTHW). The steam is held in the heat exchanger by a steam trap until it condenses, at which point the trap passes the condensate into the condensate return system. The condensate is then returned to the DA for re-treatment and subsequent return to the system. The condensate tank is located behind boiler #4.
Flash Tank:
The flash tank is used to collect and cool discharges of hot water from the boiler blow downs, boiler drains, cascade tanks and DA drain. It utilizes city water and an atmospheric vent to cool the hot discharge below 150 degrees Fahrenheit with a maximum 5 PSIG. The flash tank is located behind boiler #4.
Boilers:
CHP utilizes 3 High Pressure steam boilers that are fired using either natural gas or #2 heating oil. Oil is used only during periods of extended cold and can be used up to 20 days per year.
Boiler #3
Manufacturer: Superior
HP 1740
MAWP 250
Operating Pressure 100
Safety Valve Settings 145,150
Serial # 2665-3885
Boiler #4
Manufacturer: B&W
HP 1176
MAWP 300
Safety Valve Settings 165,170
Serial # 22791
Boiler #5
Manufacturer: Springfield
HP 580
MAWP 270
Safety Valve Settings 145,150
Serial # HSB575
Boiler Startup Procedures:
Boiler #3
Initial Conditions / Checks:
1) Check boiler drum level. Ensure 60% level using BOTH digital display AND sight glass.
2) Verify main steam stop valve # __ is open.
3) Verify non-return valve # __ is open.
4) Verify header valve # __ is open.
5) Verify feedwater from Cascade valve #s __ and __ are open.
6) Verify feedwater controller is set to AUTO.
7) Verify at least one feed pump #s __ and/or __ are set to AUTO.
8) Check DA Tank level.
9) If the is no pressure on the boiler, ensure vent vale # __ is open. Close valve when steam begins to issue from valve # __
10) Ensure boiler controls are in MANUAL and set drum pressure setpoint to 15 psig when starting boiler with no pressure.
11) Do not place in AUTO until boiler has reached operating pressure (85 psig typical).
12) Boiler Startup (Natural Gas):
13) Ensure gas valve train valves are open (see gas train documentation page ?)
a) #
b) #
c) #
d) #
e) #
14) Select fuel type GAS from boiler control panel.
15) Turn burner control to ON.
16) When boiler is cold, slowly raise drum pressure setpoint until operating pressure is reached.
17) Boiler Startup (Oil)
18) Ensure oil gun is installed and in place (oil guns are located behind the boilers).
19) Close atomizing steam line condensate drain valve # __.
20) Open atomizing steam supply valve # __ at boiler.
21) Open atomizing steam header valve # __.
22) Ensure oil train valves are open
a) #
b) #
c) #
d) #
e) #
23) Start oil pump (see oil train documentation – page ?)
Boiler #4
Initial Conditions / Checks:
1) Check boiler drum level. Ensure 60% level using BOTH digital display AND sight glass.
2) Verify main steam stop valve # __ is open.
3) Verify non-return valve # __ is open.
4) Verify header valve # __ is open.
5) Verify feedwater from Cascade valve #s __ and __ are open.
6) Verify feedwater controller is set to AUTO.
7) Verify at least one feed pump #s __ and/or __ are set to AUTO.
8) Check DA Tank level.
9) If the is no pressure on the boiler, ensure vent vale # __ is open. Close valve when steam begins to issue from valve # __
10) Ensure boiler controls are in MANUAL and set drum pressure setpoint to 15 psig when starting boiler with no pressure.
11) Do not place in AUTO until boiler has reached operating pressure (85 psig typical).
12) Boiler Startup (Natural Gas):
13) Ensure gas valve train valves are open (see gas train documentation page ?)
a) #
b) #
c) #
d) #
e) #
14) Select fuel type GAS from boiler control panel.
15) Turn burner control to ON.
16) When boiler is cold, slowly raise drum pressure setpoint until operating pressure is reached.
17) Boiler Startup (Oil)
18) Ensure oil gun is installed and in place (oil guns are located behind the boilers).
19) Close atomizing steam line condensate drain valve # __.
20) Open atomizing steam supply valve # __ at boiler.
21) Open atomizing steam header valve # __.
22) Ensure oil train valves are open
a) #
b) #
c) #
d) #
e) #
23) Start oil pump (see oil train documentation – page ?)
Boiler #5
Initial Conditions / Checks:
1) Check boiler drum level. Ensure 60% level using BOTH digital display AND sight glass.
2) Verify main steam stop valve # __ is open.
3) Verify non-return valve # __ is open.
4) Verify header valve # __ is open.
5) Verify feedwater from Cascade valve #s __ and __ are open.
6) Verify feedwater controller is set to AUTO.
7) Verify at least one feed pump #s __ and/or __ are set to AUTO.
8) Check DA Tank level.
9) If the is no pressure on the boiler, ensure vent vale # __ is open. Close valve when steam begins to issue from valve # __
10) Ensure boiler controls are in MANUAL and set drum pressure setpoint to 15 psig when starting boiler with no pressure.
11) Do not place in AUTO until boiler has reached operating pressure (85 psig typical).
12) Boiler Startup (Natural Gas):
13) Ensure gas valve train valves are open (see gas train documentation page ?)
a) #
b) #
c) #
d) #
e) #
14) Select fuel type GAS from boiler control panel.
15) Turn burner control to ON.
16) When boiler is cold, slowly raise drum pressure setpoint until operating pressure is reached.
17) Boiler Startup (Oil)
18) Ensure oil gun is installed and in place (oil guns are located behind the boilers).
19) Close atomizing steam line condensate drain valve # __.
20) Open atomizing steam supply valve # __ at boiler.
21) Open atomizing steam header valve # __.
22) Ensure oil train valves are open
a) #
b) #
c) #
d) #
e) #
23) Start oil pump (see oil train documentation – page
Cascade Tank Procedures
Normal Operations:
The level of the cascade tanks is automatically controlled by the Eurotherm panel (fig 1) located across from MCC-2 near the HTHW pumps. The Eurotherm uses a pressure sensor to detect level in the tanks. It maintains 75% level in the tanks by modulating a valve located adjacent to the steps that lead to the DA (fig 2). The feedwater pumps (fig 3) are left in the AUTO position unless there is an emergency level condition. Under normal conditions the tank level may vary between 65% and 85% depending on load. As long as the levels remain in this range, no operator intervention should be necessary.
* When the valve is closed and the pumps are running the pressure relief valve (Fig 4) will open and re-circulate the water back to the DA. If the level in the Cascades exceeds 85% the system will turn OFF the pumps automatically.
Troubleshooting Cascade System:
If the Cascade Tanks are overfilling (above 85%):
1. Check the modulating valve (Fig 2) indicator (Fig 5) to ensure that it is closed. The figure to the right shows it closed 0 = closed, 90 = fully open.
2. It is normal for the valve to be partially open even if the tanks are above 75%.
3. The valve can be manually closed by turning the valve handle on top counter-clockwise.
4. The pumps can be left in auto.
5. If the tanks continue to overfill you can turn off the pumps (Fig 3).
6. You can also shut the manual feed valve #629 (Fig 6)
7. If you shut the manual valve #629 you MUST turn off the pumps (Fig 3).
If the Cascade Tanks are below 60% the following steps can be taken.
- Check DA level to be sure it isn’t low as well.
- Ensure that the feed pumps are running and the pneumatic valve is open. (Figs 3,2 & 5)
- If the valve is stuck closed you can bypass the valve by opening valve # 630 & valve # 632 (Fig 7)
- If there is a shortage of water coming from the DA you can open the city water bypass located above the water treatment room (Fig 8)
Operator’s Daily Responsibilities
When starting any shift, an operator shall:
1) Check ALL water levels. This includes the DA, Cascades, and all 3 boilers.
2) Physically check all pump operations.