phần iv tính toán cơ khí
toàn bộ phần tính toán cơ khí đã chỉnhsửa
Ngày tải lên :
02/07/2014, 08:15
... kc 0,05 Tính hệ số Kc 0,098 0,14 0,15 25÷250 Dt 2( s − C a ) Kc Kc =875 >250 σ ct kc Et Kc= Tính lực nén chiều trục cho phép [P]=πKcEt(s-Ca)2cos2 kc α TÍNH ÁP SUẤT TÍNH TỐN CHO PHÉP,[p] Tính chiều ... CHO PHÉP,[p] Tính chiều dài tính tốn đáy nón,L L=Chiều cao đáy nón Tính đường kính tính tốn đáy nón D D= 0,9 Dt1 + 0,1Dt cos α D= 0,9 Dn1 + 0,1Dn cos α Hay Tính áp suất tính tốn cho phép đáy nón,[p] ... dày thân S = 4(mm) Tính - chọn bề dày đáy nắp thiết bò Tính tốn đáy nắp hình nón chịu áp suất ngồi π P= Tính lực tính tốn P nén lên đáy Tính hệ số kc BẢNG GIÁ TRỊ kc Dt 50 100 150 200 Dn p 250...
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TÍNH TOÁN CƠ KHÍ VÀ CÁC THIẾT BỊ PHỤ TRỢ
Ngày tải lên :
22/04/2013, 16:06
... mol khí dòng khí vào tháp hấp thụ, (kmolSO2/kmolkk) • yr – Phần mol khí dòng khí tháp hấp thụ, (kmolSO2/kmolkk) • G – Suất lượng hỗn hợp khí, (kmolhh/h) • Gtr – Suất lượng khí trơ, (kmol khí ... Max( Pk, Pư) Ptháp = 4530 (N/m2) CHƯƠNG 4: TÍNH TOÁN CƠ KHÍ VÀ CÁC THIẾT BỊ PHỤ TRỢ 4.1 Tính toán thiết bị phụ trợ: 4.1.1 Ống dẫn khí vào tháp: Vận tốc khí vào tháp nằm khoảng – 15 m/s (theo bảng ... đối khí hỗn hợp khí thải tháp hấp thụ, (kmolSO2/kmolkk) • xv – Phần mol khí pha lỏng vào tháp hấp thụ, (kmolSO2/kmolhh) • xr – Phần mol khí pha lỏng khỏi tháp hấp thụ, (kmolSO2/kmolhh) • yv – Phần...
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TÍNH TOÁN CƠ KHÍ VÀ CÁC THIẾT BỊ PHỤ TRỢ
Ngày tải lên :
15/06/2013, 13:15
... đáy nắp Sd=Sn=6mm 4.3 .Tính toán ống dẫn tháo liệu 4.3.1 .Tính toán ống dẫn khí vào: Vận tốc khí ống khoảng 10-30 m/s Chọn tốc độ dòng khí vào dòng khí Wk = 20 (m/s) Lưu lượng khí vào Gv=Gy = 1000 ... theo chuẩn : Dv=150¿ ) 4.3.2 Tính toán ống dẫn khí : Vận tốc khí ống khoảng 10-30 m/s Chọn tốc độ dòng khí vào dòng khí vr= 20 (m/s) Với hiệu suất tháp hấp thu Lưu lượng khí Gr = Gv - Dr = √ Gr 0.785×v ... G.10-4N 2.5 4.7 4.7.1 150 120 130 215 30 Tính toán thiết bị phụ trợ Tính toán quạt thổi khí Lưu lượng khí 1000m3/h = 0.278 m3/s Chiều cao tổng cộng tháp tính đáy nắp H = Hthân + 2H2đáy + 2H2gờ...
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Sổ tay tính toán cơ khí P1 potx
Ngày tải lên :
04/07/2014, 07:20
... Reheating-Regenerative Turbine Cycle 1.48 Steam Rate for Reheat-Regenerative Cycle 1.49 Binary Cycle Plant Efficiency Analysis Steam-Turbine Regenerative-Cycle Performance 1.71 Reheat-Regenerative Steam-Turbine ... 1.53 Bleed-Steam Regenerative Cycle Layout and T-S Plot 1.55 Bleed Regenerative Steam Cycle Analysis 1.59 Reheat-Steam Cycle Performance 1.110 ECONOMIC ANALYSES OF ALTERNATIVE ENERGY SOURCES 1.112 ... 60 percent RH, an 85 percent effective evaporative cooler can alter the inlet-air temperature and moisture content to 85ЊF (29ЊC) and 92 percent RH, respectively, using conventional humidity...
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Sổ tay tính toán cơ khí P2 ppt
Ngày tải lên :
04/07/2014, 07:20
... SYSTEMS AND AUXILIARIES 2.2 River flow River flow POWER GENERATION FIGURE a Once-through circulating-water system discharges warm water from the condenser directly to river or sea Fig 1b Recirculatingwater ... magnesium, and 40 to 60 years for zinc and aluminum Protective coating further reduces the effective wetted surface area and lowers the required protective current at the same time as it limits the current ... alternative trash rakes, such as the catenary or other moving-belt rakes, should be considered These are rarely put into original domestic installations There are many other alternative types...
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Sổ tay tính toán cơ khí P3 pdf
Ngày tải lên :
04/07/2014, 07:20
... Use as given at the website COMBUSTION COMBUSTION 3.23 Compute the relative weights of the products of combustion on the basis of a per unit relative weight of carbon Since the relative weight ... factors are given in the Babcock & Wilcox Company—Steam: Its Generation and Use and similar treatises on fuels and their combustion A tabulation of these factors is given in Table An alternative, and ... Companies All rights reserved Any use is subject to the Terms of Use as given at the website COMBUSTION COMBUSTION 3.9 tively Thus, wta ϭ 11.5(0.7509) ϩ 34.5[0.0572 Ϫ (0.1382 / 8)] ϩ 4.32(0.0043)...
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Sổ tay tính toán cơ khí P4 pps
Ngày tải lên :
04/07/2014, 07:20
... duct with constant-speed fan drive; (b) two-speed fan drive; (c) inlet vanes or inlet louvres with a constant speed fan drive; (d ) multiple-step variablespeed fan drive; and (e) hydraulic or electric ... steamturbine drives In a plant with ac auxiliary motor drives, slip-ring motors with damper integration must be used between steps, making the installation expensive Although dc motor drives would ... pressures and capacities Plotting these values gives curve ABCD Fan speed is 1200 r / Plot the power-input curve GHK for a two-speed drive, type b This drive might be a motor with additional winding,...
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Sổ tay tính toán cơ khí P5 pps
Ngày tải lên :
04/07/2014, 07:20
... the procedure given, substituting the hp output for the kW output of the turbine (3) Where a marine plant has more than two stages of feedwater heating, follow the procedure given in (1) above ... the Terms of Use as given at the website FEEDWATER HEATING METHODS 5.14 POWER GENERATION FIGURE Percentage of improvement in turbine heat rate vs stages of extraction Give the typical temperatures ... steam-turbine reheat cycles, Fig 7, use an array of feedwater heaters in a regenerative feedwater heating system The heaters progressively increase the condensate temperature until it approaches the steam...
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Sổ tay tính toán cơ khí P6 ppt
Ngày tải lên :
04/07/2014, 07:20
... effective pressure, engine displacement in ft3 / (min ⅐ bhp), and brake thermal efficiency? Calculation Procedure: Compute the brake mean effective pressure Compute the brake mean effective pressure ... EFFECTIVE PRESSURE AND HORSEPOWER A 500-hp (373-kW) internal-combustion engine has a brake mean effective pressure of 80 lb / in2 (551.5 kPa) at full load What are the indicated mean effective ... indicated mean effective pressure Indicated mean effective pressure imep lb / in2 for an internal-combustion engine is found from imep ϭ bmep / em, where bmep ϭ brake mean effective pressure, lb...
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Sổ tay tính toán cơ khí P7 potx
Ngày tải lên :
04/07/2014, 07:20
... Reactivity, is N ϭ 2, because this is the highest of such ratings for Health The Fire and Reactivity ratings are 0, 0, respectively, for a boiler feed pump because there are no Fire or Reactivity ... pump were suddenly given a 300-gal/min (27.9 L / s) flow-rate demand at its crossing point on a larger system-head curve, the hp required might be excessive Hence, the pump drive motor must be chosen ... reserved Any use is subject to the Terms of Use as given at the website TABLE Resistance of Fittings and Valves (length of straight pipe giving equivalent resistance) PUMPS AND PUMPING SYSTEMS 7.24...
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Sổ tay tính toán cơ khí P8 pps
Ngày tải lên :
04/07/2014, 07:20
... the respective pipe sections, ft / s (m / s) ag ϭ effective velocity of the pressure wave, ft / s V1, V2, Vn ϭ velocity of fluid in the respective pipe sections, ft / s (m / s) VE ϭ equivalent ... ft / s (1282.9 m / s) Thus, equivalent fluid velocity and effective velocity of the pressure wave in the compound pipe are both less than either velocity in the individual sections of the pipe Related ... Find the equivalent fluid velocity and effective pressure-wave velocity for the compound pipe Use the equation VE ϭ L1V1 ϩ L2V2 ϩ ⅐ ⅐ ⅐ ϩ Ln Vn L1 ϩ L2 ϩ ⅐ ⅐ ⅐ ϩ Ln to find the equivalent fluid...
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Sổ tay tính toán cơ khí P9 ppsx
Ngày tải lên :
04/07/2014, 07:20
... effectiveness of both types of towers are about equal Data given on cooling towers elsewhere in this handbook can be helpful to the designer in choosing the best type of tower to use for a given ... desirable than an indoor air intake is when the outside air is polluted with corrosive vapors, excessive dust, abrasive sand, etc., which would be injurious to people or machines Under these circumstances ... weight Select the compressor drive Air compressors can be driven by electric motors, gasoline engines, diesel engines, gas turbines, or steam turbines The most popular drive for reciprocating air...
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Sổ tay tính toán cơ khí P10 ppt
Ngày tải lên :
04/07/2014, 07:20
... jam Lubricant Abrasive Abrasive shell Sometimes sticky Abrasive Shell abrasive Abrasive Mild abrasive Abrasive May be abrasive Adheres Corrosive Abrasive Adheres Abrasive Abrasive Hygroscopic Adheres ... Corrosive if wet Polisher Sometimes difficult Dusty Sticky Abrasive Abrasive Sticky if hot Caustic Caustic Explosive dust Explosive dust b b b b b b, c b b, c b b, c g, b Keep clean Corrosive if ... Corrosive if wet Mild abrasive Sluggish Free-flowing May arch May pack May pack Sticky Sticky if wet Sluggish Fragile Flows freely Flows freely Sticky Abrasive Free-flowing Abrasive Mild abrasive...
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Sổ tay tính toán cơ khí P11 ppt
Ngày tải lên :
04/07/2014, 07:20
... Terms of Use as given at the website HEAT TRANSFER AND HEAT EXCHANGE 11.36 PLANT AND FACILITIES ENGINEERING The individual products calculated from the four equations are added to give the sum of ... Any use is subject to the Terms of Use as given at the website HEAT TRANSFER AND HEAT EXCHANGE 11.16 PLANT AND FACILITIES ENGINEERING produce a conservatively sized heater, we find A ϭ 230,000 / ... decreasing the baffle spacing Since the maximum tube length is fixed by the conditions given, the alternatives are increasing the number of tubes and / or adjusting the baffle spacing To estimate...
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Sổ tay tính toán cơ khí P12 potx
Ngày tải lên :
04/07/2014, 07:20
... overall coefficient, multiply the given value above by 5.68 to obtain the W / m2 ⅐ ЊC Thus, the values are: 0.908; 3.4; 5.68; 1.42; 6.42; 1.19; 0.79, respectively Compute the temperature differences ... (0.21)(1104)(5) ϭ 1160 (339.9W); Ceiling ϭ (0.14)(1104)(20) ϭ 3090 (905.4 W) Summing these individual heat leakages gives 16710 Btu / h (4896 W) Determine the sensible heat load Using the conventional ... environmental restrictions, engineers must be able to evaluate the performance of alternative refrigerants The procedure given above shows exactly how to perform this evaluation for any refrigerant whose...
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Sổ tay tính toán cơ khí P13 pot
Ngày tải lên :
04/07/2014, 07:20
... method of sizing aeration tanks Compute the waste activated sludge (WAS) and return activated sludge (RAS) requirements Control of the activated sludge process is important to maintain high levels ... recommended solids loading rate on an activated sludge settling tank also varies depending upon the type of activated sludge process used and may be computed by dividing the total solids applied by ... the activated sludge system occur THICKENING OF A WASTE-ACTIVATED SLUDGE USING A GRAVITY BELT THICKENER A wastewater treatment facility produces 58,000 gal / day (219.5 m3 / d) of waste activated...
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Sổ tay tính toán cơ khí P14 pot
Ngày tải lên :
04/07/2014, 07:20
... that by imposing a negative discharge on the positive discharge from the well there will be in effect zero flow from the well, provided the negative discharge equals the positive discharge Then, the ... ft (4.6 m) Driven wells seldom are more than 40 ft (12.2 m) deep or more than in (51 mm) in diameter when used for small water supplies Bigger driven wells are constructed by driving large-diameter ... present Based on the data given for this water-supply system, method b, c, or d would probably be suitable Because method b has proven highly effective, it will be chosen tentatively, pending later...
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Sổ tay tính toán cơ khí P15 pdf
Ngày tải lên :
04/07/2014, 07:20
... building, or both It is often cost-effective to use larger pipe sizes in a grid because the installation costs are relatively the same Table shows the relative pipe capacity for different size pipes ... corrosive characteristics of the water and / or to excessive design velocities of flow; and (4) to eliminate water-hammer damage and objectional whistling noise effects in the piping due to excessive ... appropriate for determining the corresponding equivalent lengths of fittings and valves in this step Using the tentative sizes for the BDC, compute corresponding equivalent lengths for valves and fittings...
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Sổ tay tính toán cơ khí P16 pptx
Ngày tải lên :
04/07/2014, 07:20
... per hour cubic feet per minute dry-bulb dew point effective room latent heat effective room sensible heat effective room total heat effective sensible heat factor degrees Fahrenheit feet per minute ... presented in this handbook DETERMINATION OF EXCESSIVE VIBRATION POTENTIAL IN MOTOR-DRIVEN FAN Determine if the motor-driven fan in Fig 15 will have excessive vibration The motor is 110-V, 60 Hz, 2400 ... which must deliver a stated flow in lb / h (kg / h) at a given lb / in2 (kPa) will require a larger power input as the fluid density decreases Likewise, if a pump must deliver a given flow in gal...
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Sổ tay tính toán cơ khí P17 pps
Ngày tải lên :
04/07/2014, 07:20
... computed from the relation given, Ps computed from the relation given, ƒs computed from the appropriate relation (water or air) given earlier, and the monthly delivery found from ƒs (monthly ... the attractiveness of solar energy Studies by private groups and government agencies continue to show that the green building initiative is both economically and environmentally attractive A dollar ... system And the total annual useful energy delivered divided by the total annual load is the annual solar load fraction Compute the monthly energy delivery Set up a tabulation such as that in Table...
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