Chapter 5 - Publications, US Army Corps of Engineers

More documents

Recommendations

Info

EM 111O-2-17(.)] 31 Dec 1985 low-head projects, where head varies directly with discharge, an efficiency versus discharge relationship can be derived (see Section 5-7n). (5) For projects where head varies independently of discharge, an efficiency versus discharge curve can be used if head does not vary substantially. Where head does vary substantially, several alternatives are available. For projects with four or more units, there is considerable flexibility of operation. The number of units that are placed on-line at any given discharge would be selected such that they would all be operating at or near the point of best efficiency for the given discharge. In these cases, an efficiency versus head curve can be developed. Figure 5-11 shows an efficiency vs. head curve for a multiple-unit Francis installation. This curve was developed from the turbine performance curve shown on Figure 5-8, based on the units operating at the Pint of best efficiency at each head. The efficiency values from Figure 5-8 were reduced by an additional two percent to account for generator losses. Where a project is normally “block loaded” (see Figure 5-10, the plant would always operate at or NETHEAD (FEET) Figure 5-11. Net head vs. efficiency curve for Francis turbine (multiple-unit installation) 5-34
EM 1110-2-1701 31 Dec 1985 near full plant output. An efficiency versus head curve could be developed for this type of project as well. (6) Where it is considered necessary to model the variation of efficiency with both head and discharge, several techniques are available. One example is the procedure used in North Pacific Division~s HYSSR model (see Appendix C), where three efficiency versus head curves are used: . operation at best efficiency ● operation at full gate discharge ● operation at rated capacity (or overload capacity~ if the units have an overload capacityj Because all of the major plants in the NPD system are multiple-unit plants, it can be assumed that the number of units on line will be varied so that all plants will operate at or near the point of best efficiency for flows up to 80 percent of the plantts full gate hydraulic capacity. Between 80 percent and full gate discharge, the model interpolates between the best efficiency and full gate curves. Between full gate discharge and rated capacity, it inter~lates between the full gate and rated capacity curves. At higher discharges, the rated capacity curve is used. At heads below rated head, the rated capacity curve would not apply. (7) Other approaches for treating both head and discharge can be used as well, including table look-up, but care should be taken to insure that the efficiency algorithm will load the proper number of units to give the best overall plant efficiency at each discharge level. Also, if the project is a peaking plant, the algorithm should not utilize the average discharge for the period to compute efficiency. It should use instead either a weighted average discharge or a ‘block loadingn discharge (see Section 5-6g), whichever best describes the projectts operation. (8) Accurately modeling the variation of efficiency with both head and discharge is a complex operation, and including such an algorithm in an energy model substantially increases running time. Accordingly, it should be used only for projects where the increased accuracy of results is important. For most projects, modeling the variation of efficiency with either discharge or head will provide satisfactory results. 1. Losw (1) In determining the net head available for power generation, it is necessary to account for head loss in the water passages. These losses include primarily friction losses in the trashrack, intake 5-35
Page 1 and 2: 5-1. CHAPTER 5 DETERMINING ENERGY P
Page 3 and 4: EM 1110-2-1701 31 Dec 1985 erations
Page 5 and 6: EM 111O-2-17O1 31 Dec 1985 In this
Page 7 and 8: EM 1110-2-1701 31 Dec 1985 (SSR) me
Page 9 and 10: EM 1110-2-1701 31 Dec 1985 (3) ~~e
Page 11 and 12: EM 1110-2-1701 31 Dec 1985 tailwate
Page 13 and 14: EM 111O-2-17O1 31 Dec 1985 selected
Page 15 and 16: (6) It is difficult to generalize a
Page 17 and 18: EM 1110-2-1701 31 Dec 1985 tally. F
Page 19 and 20: EM 1110-2-1701 31 Dec 1985 where th
Page 21 and 22: EM 1110-2-1701 31 Dec 1985 . head r
Page 23 and 24: ~ CASE 3: RATED AT MINIMUM HEAD I /
Page 25 and 26: EM 1110-2-1701 31 Dec 1985 (7) The
Page 27 and 28: EM 1110-2-1701 31 Dec 1985 (5) For
Page 29 and 30: EM 1110-2-1701 31 Dec 1985 (1) Not
Page 31 and 32: EM 111O-2-17O1 31 Dec 1985 river re
Page 33: EM 111O-2-17O1 31 Dec 1985 TABLE 5-
Page 37 and 38: EM 111O-2-17O1 31 Dec 1985 both cos
Page 39 and 40: EM 1110-2-1701 31 Dec 1985 generall
Page 41 and 42: 450 400 1 * I USABLEHYDRO ENERGYIN1
Page 43 and 44: EM 1110-2-1701 31 Dec 1985 should b
Page 45 and 46: EM 1110-2-1701 31 Dec 1985 (1) Head
Page 47 and 48: EM 1110-2-1701 31 Dec 1985 size and
Page 49 and 50: EM 111O-2-17O1 31 Dec 1985 minimum
Page 51 and 52: 1500 \ \ 1400 \ \ 1300 \ \ 1200 i 1
Page 53 and 54: 1500 1400 {n\ 1 ‘\ l\ 1300 / \ I
Page 55 and 56: 1. (1) releases Compute Dependable
Page 57 and 58: 1300 , I 1200 i I I 1100 1000 300 2
Page 59 and 60: EM 1110-2-1701 31 Dec 1985 Figure 5
Page 61 and 62: kW=—= QHe (400 - 20 cfs)(31 feet)
Page 63 and 64: EM 111O-2-17O1 31 Dec 1985 (5) Ente
Page 65 and 66: EM 1110-2-1701 31 Dec 1985 (1) Sequ
Page 67 and 68: EM 1110-2-1701 31 Dec 1985 (3) The
Page 69 and 70: EM 1110-2-1701 31 Dec 1985 periods.
Page 71 and 72: 5-1o. bDDWiOnOf SSR to PrO.iects wi
Page 73 and 74: EM 1110-2-1701 31 Dec 1985 b. Bata
Page 75 and 76: EM 1110-2-1701 31 Dec 1985 portion
Page 77 and 78: EM 111O-2-17O1 31 Dec 1985 make a p
Page 79 and 80: TABLE 5-5 Factors for Converting Di
Page 81 and 82: Routing Worksheet EM 1110-2-1701 31
Page 83 and 84: Explanation of Data in Table 5-6 EM
Page 85 and 86:
EM 1110-2-1701 31 Dec 1985 In the s
Page 87 and 88:
Equation 5-16 would be revised to t
Page 89 and 90:
EM 1110-2-1701 31 Dec 1985 follow a
Page 91 and 92:
EM 111O-2-17O1 31 Dec 1985 the rese
Page 93 and 94:
EM 1110-2-1701 31 July 1985 power (
Page 95 and 96:
EM 1110-2-1701 31 July 1985 except:
Page 97 and 98:
EM 111O-2-17O1 31 Dec 1985 heavily
Page 99 and 100:
EM 1110-2-1701 31 Dec 1985 energy.
Page 101 and 102:
1st reservoir storage above EM 1110
Page 103 and 104:
EM 1110-2-1701 31 Dec 1985 (4) Figu
Page 105 and 106:
EM 1110-2-1701 31 Dec 1985 maintain
Page 107 and 108:
EM 1110-2-1701 31 Dec 1985 (3) Tabl
Page 109 and 110:
EM 1110-2-1701 31 Dec 1985 (3) In s
Page 111 and 112:
EM 1110-2-1701 31 Dec 1985 The back
Page 113 and 114:
Maximize Maximize firm energy 74,00
Page 115 and 116:
EM 1110-2-1701 31 Dec 1985 (2) The
Page 117 and 118:
MAXIMUM POWER POOL POWER GUIDE CURV
Page 119 and 120:
EM 111O-2-17O1 31 Dec 1985 . to exa
Page 121 and 122:
EM 1110-2-1701 31 Dec 1985 (3) If t
Page 123 and 124:
EM 111O-2-17O1 31 Dec 1985 (3) ~ It
Page 125 and 126:
EM 1110-2-1701 31 Dec 1985 QHet (18
Page 127 and 128:
EM 1110-2-1701 31 Dec 1985 Figure 5
Page 129 and 130:
EM 1110-2-1701 31 Dec 1985 assured
Page 131 and 132:
EM 1110-2-1701 31 Dec 1985 ● a hi
Page 133 and 134:
i. Coordination with Other Entities
Page 135 and 136:
EM 1110-2-1701 31 Dec 1985 TABLE 5-
Page 137 and 138:
40, 35 .00 .00 30.00 25.00 20.00 15
show all

Chapter 5 - Publications, US Army Corps of Engineers

Create successful ePaper yourself

Delete template?

Save as template?