Power (Cogeneration)
Oil Service
PurLube:
If you’ve worked in a power plant‚ you know how difficult it is to keep water out of your machinery and lubrication systems. When water finds its way into a lube oil system‚ it increases the risks of corrosion‚ wear and premature failure.
Commonly installed in a kidney loop off of the main lube oil console; the Purlube is able to pull lubrication oil from the system and return it after treatment. Inside the PurLube‚ oil is heated to 180F without causing thermal or oxidative stress to the oil. Next‚ a venture draws air into the oil creating small air bubbles. When the air bubbles mix with the heated stream of lube oil‚ the volume and surface area of the bubbles expand causing any moisture that contacts the bubbles’ surface to evaporate into the heated air inside the bubbles. The oil stream is them passed through a settling tray allowing the bubbles to come to the surface and break‚ allowing the formerly entrained water to simply escape as evaporating water vapor.
The PurLube system removes all three forms of water contamination in lubrication oil – free‚ emulsified and dissolved – to lower than 100ppm. Additionally‚ the discharge does not contain any oil or emulsion and maintenance is relatively low because the system only has one moving part‚ the oil recirculation pump.
Oil Mist:
Oil mist is a centralized lubrication system used to lubricate specific rolling element bearings‚ pump bearings‚ electric motor drivers‚ bearing housing of small steam turbines with sleeve bearings and purge gearboxes.
The LSC Oil Mist in the oil mist system uses compressed air to atomize oil into micro-size particles‚ which can be effectively moved to lubrication points up to 600 feet (180 meters)‚ through piping and tubing. The benefits of oil mist and lubrication are well documented. Providing the right amount of lubrication to your rotating equipment lowers the bearing temperature‚ reduces energy loss and extends the life of your equipment. Oil mist has reduced bearing failures in centrifugal pumps and electric motors by 90% and increased mean time between failure for mechanical seals by 100%.
Rotor Jacking
Large frame-sized turbines found in utility scale steam‚ combustion and combined cycle power plants use high-pressure hydraulic oil pumps to lift the turbine shaft from its sleeve bearings before the turbine is started. Hot turbines that are being shut down are put on “turning gear” drive. This allows the turbine to rotate very slowly while it cools so its shaft does not sag due to its weight. A hydraulic oil motor drives a gear which maintains this slow rotation of the turbine shaft.
When evaluating a pump for this application‚ ensure that the pump and inlet piping are properly sized to handle cold start conditions because lower temperature affects the viscosity of the lubrication oil and Net Positive Inlet Pressure Available (NPIPA). The lift capability of a pump decreases with temperature.
Suitable pumps here are three screw and crescent internal gear pumps.
| Flow Rates up to | Pressures to up to | Max Fluid Temperature | CIRCOR Brand, Series & Pump type |
|---|---|---|---|
|
13 m^3/h 55 GPM |
210 bar 3,046 psi |
80C 176F |
Allweiler SD Three Screw |
|
28 m^3/h 125 GPM |
345 bar 5000 psi |
82C 180F |
IMO CIG Crescent Internal Gear |
|
91 m^3/h 400 GPM |
151 bar 2‚200 psi |
120C 250F |
IMO 12D Three Screw |
Lubrication
If it is large and rotates‚ it most certainly needs a pumped lubrication system. Pumps and engineered systems that supply lubrication oil to rotating equipment generally operate 24/7 making reliability of paramount importance.
On a typical lubrication oil skid‚ there are generally three pumps‚ a primary‚ a standby and an emergency backup pump. You may also find a seal oil pump included for the hydrogen cooled generators. These pumps and engineered system supply lubrication oil to the main journal bearings‚ generator bearings‚ reducing gear‚ accessory gear‚ high pressure hydraulic oil and generator seal oil.
The required flow rates depend on the size of the rotating equipment. In large steam and gas turbine applications flow rates as high as 2‚500GPM are required vs. stationary diesel applications where less than 500GPM required.
Users may have a choice between centrifugal and three screw pumps in these applications and there are trade offs between the technologies that engineers should be aware of. Centrifugal pumps typically have a lower initial cost; however‚ three screw pumps have a lower life cycle cost when you factor in operating efficiency and thus energy costs and maintenance costs.
CIRCOR also produces complete lubrication engineered systems for rotating equipment throughout the power plant. These applications include turbine‚ boiler feed‚ condensate‚ and recirculation pumps.
CIRCOR provides optimal pump technologies with three screw‚ two screw and centrifugal pumps.
| Flow Rates up to | Pressures to up to | Max Fluid Temperature | CIRCOR Brand, Series & Pump types |
|---|---|---|---|
|
2.7 m^3/h 12 GPM |
7 bar 101 psi |
90C 194F |
IMO AB ACD Three Screw |
|
11 m^3/h 48 GPM |
16 bar 232 psi |
155C 311F |
IMO AB ACE Three Screw |
|
28 m^3/h 125 GPM |
345 bar 5‚000 psi |
82C 180F |
IMO CIG Crescent Internal Gear |
|
48 m^3/h 210 GPM |
17 bar 250 psi |
107C 225F |
IMO 3G Three Screw |
|
51 m^3/h 225 GPM |
16 bar 232 psi |
120C 250F |
Allweiler ALLlub RUV Three Screw |
|
51 m^3/h 225 GPM |
16 bar 232 psi |
180C 356F |
IMO AB ACG Three Screw |
|
91 m^3/h 400 GPM |
34.5 bar 500 psi |
121C 250F |
IMO 3D Three Screw |
|
180 m^3/h 793 GPM |
16 bar 232 psi |
121C 250 F |
IMO AB ACF Three Screw |
|
450 m^3/h 1‚982 GPM |
16 bar 232 psi |
90C 194F |
IMO AB LPQ Three Screw |
|
453 m^3/h 2‚000 GPM |
16 bar 232 psi |
150C 356F |
Allweiler TriLub Three Screw |
|
490 m^3/h 2‚158 GPM |
16 bar 232 psi |
80C 176F |
Houttuin 215.10 Vertical Submersible Two Screw |
|
550 m^3/h 2‚500 GPM |
16 bar 232 psi |
120C 250F |
Allweiler NSSV Centrifugal |
|
600 m^3/h 2‚642 GPM |
16 bar 232 psi |
80C 176F |
Houttuin 211.10 Horizontal Two Screw |
|
750 m^3/h 3‚300 GPM |
21 bar 300 psi |
260C 500F |
IMO 323F Three Screw |
|
1‚100 m^3/h 4‚844 GPM |
16 bar 232 psi |
80C 176F |
Houttuin 216.10 Horizontal Two Screw |
Fuel Unloading / Forwarding / Transfer
There are a wide range of fuels that a plant can burn and they arrive into a power plant through various means – rail car‚ ship‚ tank truck‚ etc.. Unloading pumps feed directly into a storage tank often times without a control valve/system and are found on the ‘vehicle’ or may be part of the tank storage system.
Our experience shows that when fuel is allowed to sit in a rail car‚ tank truck‚ etc. the viscosity of the fluid can increase. This change results increased input torque requirements and potentially the delivered. In positive displacement pumps‚ the delivered flow will increase and in centrifugal pumps the amount will decrease. It is important when sizing your pump to consider the properties of the fluid‚ pressure‚ supply and operational objectives.
Some storage systems use a “day tank” that holds about a day’s worth of “treated” (Filtered‚ additives added‚ and/or blended) fuel near the power plant leaving the larger volume storage somewhat more remote from the generating facility. Transfer pumps are needed to keep the day tank supplied as well to move oil from one tank to another. Also‚ transfer or forwarding pumps will be needed to send fuel oil to the inlet of the fuel injection pumps from either the day tank or the main storage tanks.
The distance that the fuel has to travel is an important consideration. Be sure to calculate the frictional loss in your pipeline so you know the maximum discharge pressure and the size of the driver required to overcome the pressure differential.
Commonly used pumps in this application include three screw‚ two screw and centrifugal.
| Flow Rates up to | Pressures to up to | Max Fluid Temperature | CIRCOR Brand, Series & Pump type |
|---|---|---|---|
|
91 m^3/h 400 GPM |
34.5 bar 500 psi |
121C 250F |
IMO 3D Three Screw |
|
272 m^3/h 1‚200 GPM |
70 bar 1‚015 psi |
82C 180F |
IMO 8L Three Screw |
|
317 m^3/h 1‚400 GPM |
100 bar 1‚450 psi |
250C 482F |
Allweiler SN Three Screw |
|
480 m^3/h 2‚120 GPM |
16 bar 232 psi |
140C 284F |
Allweiler NB Centrifugal |
|
750 m^3/h 3‚300 GPM |
21 bar 300 psi |
260C 500 F |
IMO 323F Three Screw |
|
792 m^3/h 3‚500 GPM |
97 bar 1‚400 psi |
121C 250F |
Warren FSXA Two Screw |
|
1‚100 m^3/h 4‚844 GPM |
16 bar 232 psi |
100C 212F |
Houttuin 216.40 Horizontal Two Screw |
|
1‚100 m^3/h 4‚844 GPM |
16 bar 232 psi |
100C 212F |
Houttuin 211.40 Vertical Two Screw |
|
2‚300 m^3/h 10‚158 GPM |
16 bar 232 psi |
140C 284F |
Allweiler NT Centrifugal |
|
2‚500 m^3/h 11‚008 GPM |
16 bar 232 psi |
140C 212F |
Houttuin 236.40 Horizontal Two Screw |
Cogeneration Overview
As the name implies‚ cogeneration means multiple forms of generation. In a cogeneration plant‚ the power plant will generate electricity with a combustion‚ steam turbine or stationary diesel engine to generate electricity. The post combustion steam is the diverted to a secondary source for either district heating of hospitals‚ prisons‚ oil refineries‚ commercial buildings‚ paper mills or for process support. Thus in one process a cogeneration plant is producing electricity and heat or process support. It is an efficient process and in some ways similar to the operation of a combined cycle power plant.
Cogeneration is a popular in the Scandinavian and Eastern European countries with smaller pockets of applications in the United States such as New York City.
| Pump Applications | Engineered System Applications | Oil Service |
|---|---|---|
|
Fuel Unloading/Forwarding/Transfer |
Unloading/Forwarding/Transfer |
PurLube |
|
Rotor Jacking |
Lubrication |
Oil Mist |
|
Lubrication |
Fuel or Burner Injection |
|
|
Fuel or Burner Injection |
|
|
Fuel or Burner Injection
Fuel injection or burner pumps and the engineered systems that they are mounted on dispense fuel directly into the gas turbine or oil fired boiler. These pumps and engineered systems provide a mission critical operation for the power plant with the main pumps mounted in a three 50% capacity configuration: one as a hot standby; one for up to 50% load; and a third pump coming on for loads in the 50 to 100% range or two 100% capacity pumps (one running with one standby).
Pump applications require flow rates in the 50 to 400gpm range per pump for utility scale combustion‚ steam and combined cycle turbines with discharge pressures in the 700 to 1800 psi range. In specific applications‚ CIRCOR has worked with manufacturers to develop pump solutions that can handle discharge pressure of 2000 psi at a flow of 500GPM. Stationary diesel applications require lower flow rates and pressures.
Coal fired steam plants use Fuel or Burner injection pumps to pump oil into the burner to either keep the coal burning or speed the temperature rise in the boiler. In some applications where Bio-Mass fuel is incorporated the fuel or burner injection pumps will be operated in order to produce an even combustion temperature to compensate for varying BTU content in the Bio-Mass fuel. In combustion and combined cycle plants‚ liquid fuels (distillate‚ fuel oil #4‚ #6‚ etc.) are used as back up supply for the primary fuel natural gas.
Consistency of output and smooth pulsation free flow are primary criterion for purchase in fuel or burner injection pump applications making three screw‚ two screw or crescent internal gear pumps as the suitable choice. Often times‚ pumps are sized for 125 – 150% of the delivered flow requirements. Engineers design for future expansions and planned upgrades and design a bypass system to accommodate the excess flow delivered. Users should recognized that excess pumping costs money and running a bypass systems 24/7 can quickly eat up savings.
Finally‚ Allweiler brand ALLHEAT thermal oil centrifugal pumps are used in small decentralized biomass combined heat and power plants in an Organic Rankine Cycle (ORC) process. In this application‚ silicon oil is vaporized in a boiler and used in a steam turbine instead of water/steam. The heat cannot be transferred directly from the burner to the silicon oil as the heat is too high. Therefore‚ thermal oil is heated to around 150F/300C and this heat is then transferred to the silicon oil.
| Flow Rates up to | Pressures to up to | Max Fluid Temperature | CIRCOR Brand & Series |
|---|---|---|---|
|
28 m^3/h 125 GPM |
345 bar 5‚000 psi |
82F 180C |
IMO CIG Crescent Internal Gear |
|
78 m^3/h 343 GPM |
280 bar 4‚061 psi |
150C 302F |
Allweiler VH Three Screw |
|
91 m^3/h 400 GPM |
34.5 bar 500 psi |
120C 250F |
Imo 3D Three Screw |
|
91 m^3/h 400 GPM |
103 bar 1‚500 psi |
120C 250F |
IMO 6D Three Screw |
|
91 m^3 / h 400 GPM |
151 bar 2‚200 psi |
120C 250F |
IMO 12D Three Screw |
|
272 m^3/h 1‚200 GPM |
70 bar 1‚015 psi |
82C 180F |
IMO 8L Three Screw |
|
750 m^3/h 3‚300 GPM |
21 bar 300 psi |
260C 500F |
IMO 323F Three Screw |
|
792 m^3/h 3‚500 GPM |
97 bar 1‚400 psi |
121C 250F |
Warren FSXA Two Screw |
|
1‚450 m^3/h 6‚380 GPM |
25 bar 363 psi |
400C 752F |
ALLHEAT Centrifugal |
|
2‚500 m^3/h 11‚008 GPM |
80 bar 1‚160 psi |
400C 752F |
Houttuin Engineered Two Screw |