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Enron Mail |
Just so that everyone is aware, the units at Station 4 can be operated at l=
evels above their rated horsepower of 4,000 during periods of lower ambient= temperatures. Clark ambient rating increase from 100% torque at 100degF t= o 108% torque at 40degF. I realize that this rating is weather dependent, = but the horsepower is available if weather temperatures permit. =09To obtain ambient rating as ambient temperatures permit, three unit modi= fications would have to be implemented; these might be handled by unit cont= rol programming only. Clark allows ambient rating when jacket water and lu= be oil temperatures can be driven down proportionally to 135 and 125 degF r= espectively. Jacket water and lube oil control valves may be needed to red= uce jacket water and lube oil temperature as ambient temperature permits, a= nd unit control programs would require modification to accommodate ambient = ratings. =20 =09There may be environmental emission issues such as permitting the site f= or the higher horsepower. Also, previous checks with Legal indicated these= units could operate in the ambient rated zone if the units were purchased = with this capability; ambient rating capability was part of the original pu= rchase and stated as such in the unit purchase orders. =09Again, I am just making sure everyone is aware of the unit capability at= Station 4. Ken N Young From:=09Eric Faucheaux/ENRON@enronXgate on 10/24/2001 02:11 PM To:=09Darrell Schoolcraft/ENRON@enronXgate, Rich Jolly/ET&S/Enron@ENRON, Ar= nold L Eisenstein/ENRON@enronXgate, Dan Pribble/ENRON@enronXgate, Gary Maes= tas/Enron@EnronXgate cc:=09Morgan Gottsponer/ENRON@enronXgate, Steven January/ENRON@enronXgate, = John R Keller/ENRON@enronXgate, Ronald Matthews/ENRON@enronXgate, Dennis Al= ters/ENRON@enronXgate, David Roensch/ET&S/Enron@ENRON, Kenneth Young/ET&S/E= nron@ENRON=20 Subject:=09FW: TW Sta. 4 capacity in 3 unit scenario=20 Viewing Tip: maximize window and increase zoom to 150% to get better view o= f figures below (View, Zoom..., select percent number and type 150) Based on recent capacity concerns or inquiries by E&C, Gas Control and Oper= ations regarding Compressor Station 4 capacity in a 3 unit Red Rock Project= , Planning and Optimization have re-evaluated models to put these concerns = to rest. Figures 1 and 2 below detail steady state results from modeling t= hat Planning used for determining the respective capacities, as have been p= rovided in the past. =20 Figure 1 shows the pipeline simulation maximizing horsepower at CS 1, 2 & 3= to pull discharge pressure off of CS 4, thus allowing CS 4 to operate with= in its Rated HP (11800 BHP). Note: CS 1, 2, & 3 in the first diagram Figur= e 1 are modeled conservatively using 83% efficiency; however, Gary Choquett= e represents that having evaluated the horsepower curves made available by = the vendor, there is still much horsepower available for compression at CS = 1, 2 & 3. The compression efficiencies at the stations may be achieved as = high as 87%, thus providing more capacity to pull gas from CS4. It is cust= omary Planning practices to error on the conservative side until facilities= are installed. Once installed and the true performance can be realized th= en the opportunity shall exist for further optimization. Based upon the pipeline model with CS1, 2, & 3 at 83% efficiency, the range= of conditions that may be expected at CS4 are suction pressures between 76= 9 - 776 psig with discharge pressure at about 923 psig. The HTSCompress mo= del for CS4 has been modified to closely match field performance testing. = These results shown in Figure 2 also represent that the 1230 MMcfd capacity= will be more than achievable even at the lesser operating conditions shown= . However, if any capacity shortfalls might be experienced, several measures = can be implemented to improve conditions (some of which are currently plann= ed). 1.=09Operate San Juan Junction pressures at or above 960 psig (currently ac= hievable, measure would provide higher suction pressure to CS4)=20 2.=09Perform engine and compressor overhauls at CS4(work is slated for Marc= h-April 2002 timeframe) 3.=09Install/modify scrubbers and inlet piping at CS4 to reduce inlet pipin= g losses (work is slated for post Red Rock, scrubbers from CS 1, 2, & 3 wil= l be relocated to CS4) 4.=09Relocate evaporative cooling skirts from CS 1 or 2 after Red Rock unit= installation to CS 4 to prevent horsepower derating due to high ambient te= mperatures. 5.=09Modify programming at CS4 to optimize speed control maximizing availab= le HP (this done at existing CS 1 & 2 have realized 1% throughput improveme= nts). Also modifying unloading sequence could be considered. 6.=09Pig/clean main and loop lines from CS 5 to CS 4 (pipeline efficiency i= n this segment is lower compared to segments due west, cleaning would incre= ase suction pressures at CS4 or allow lower junction pressures.) 7.=09Maximize available HP at CS1, 2, & 3 (all horsepower at 86% efficiency= as shown in second diagram Figure 1) Should further discussion be required, do not hesitate to give us a call. = A conference call can be scheduled if needed; otherwise, save this informat= ion for August 2002. EF =3Dsj?*I=14???=04??B|??=08?????3-=04=09?_?h=1F=05I?? ??????=3D???r?Z?+=12?
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