Perhitungan Ballast System [PDF]

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PERHITUNGAN SISTEM BALLAST 1. a. b. c.



DAFTAR CODE/REFERENSI YANG DIGUNAKAN LR Rules and Regulation Chapter 13 Roy L Harrington, Marine Engineering Machinery Outfitting Design Manual Vol. I



2. a. b. c. d. e.



ALGORITMA PERHITUNGAN Perhitungan volume displacement Perhitungan Displacement Perhitungan kapasitas pompa ballast Perhitungan diameter pipa utama ballast Perhitungan head pompa ballast - Perhitungan instalasi di kamar mesin - Perhitungan head di pipa hisap - Perhitungan head di pipa discharge - Perhitungan total head losses f. Perhitungan daya pompa (Pw) g. Perhitungan daya motor (Pm) 3. INPUT PARAMETER DESAIN a. Perhitungan volume displacement Lwl = panjang garis air kapal B = lebar kapal T = sarat kapal Cb = coefficient block b. Perhitungan Displacement ▼ = volume displacement ρ = massa jenis air laut c. Perhitungan kapasitas pompa ballast V = volume air laut untuk ballast t = waktu yang dibutuhkan untuk mengosongkan tangki ballast d. Perhitungan diameter pipa utama ballast Q = kapasitas pompa ballast v = kecepatan aliran e. Perhitungan pompa ballast - Perhitungan instalasi di kamar mesin hs = head statis pompa hp = head perbedaan tekanan hv = head perbedaan kecepatan - Perhitungan head di pipa hisap (hl1) ν = viskositas Rn = bilangan reynould λ = kerugian gesek mayor losses = head karena panjang pipa suction side minor losses = head karena asesoris yang ada pada pipa suction - Perhitungan head di pipa discharge (hl2) ν = viskositas Rn = bilangan reynould λ = kerugian gesek



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PERHITUNGAN SISTEM BALLAST mayor losses = head karena panjang pipa discharge side minor losses = head karena asesoris yang ada pada pipa discharge - Perhitungan total head losses (Hl) hs = head statis pompa hp = head perbedaan tekanan hv = head perbedaan kecepatan hl1 = head di pipa hisap hl2 = head di pipa discharge f. Perhitungan daya pompa (Pw) Hl = total head losses ρ = massa jenis air bilga Q = kapasitas pompa η = efisiensi pompa g. Perhitungan daya motor (Pm) Pw = daya pompa η = efisiensi pompa 4. OUTPUT PARAMETER DESAIN a. Perhitungan volume displacement ▼ = volume displacement b. Perhitungan Displacement Δ = displacement c. Perhitungan kapasitas pompa ballast Q = kapasitas pompa ballast d. Perhitungan diameter pipa utama ballast dH = diameter dalam pipa utama ballast e. Perhitungan pompa ballast - Perhitungan instalasi di kamar mesin hs = head statis pompa hp = head perbedaan tekanan hv = head perbedaan kecepatan - Perhitungan head di pipa hisap (hl1) hl1 = head di pipa hisap - Perhitungan head di pipa discharge (hl2) hl2 = head di pipa discharge - Perhitungan total head losses (Hl) Hl = total head losses f. Perhitungan daya pompa (Pw) Pw = daya pompa g. Perhitungan daya motor (Pm) Pm = daya motor pompa 5. DETAIL PERHITUNGAN a. Perhitungan volume displacement LWL = 124.8 m B= 21.2 m T= 8.3 m Cb = 0.75 Cbwl = 0.75



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PERHITUNGAN SISTEM BALLAST ▼ = Lwl x B x T x Cbwl = 16470 m3 b. Perhitungan Displacement ρ= 1.025 Δ = ▼ x ρ air laut = 16881.6024



ton/m3 ton



Berat air ballast (Wb) = ( 10 - 15 %) x Δ : Wb = 1688.16024 ton Volume air laut yang dibutuhkan untuk tangki ballast = V = Wb / ρ air laut = 1376.9 m3



Diambil harga =



c. Perhitungan kapasitas pompa ballast Volume tersebut direncanakan dapat dikosongkan dalam waktu = sehingga kapasitas pompa Q= V/t 0.000277778 m3/hr = m3/s = 225.721311 0.0627 0.0627004145 d. Perhitungan diameter pipa utama ballast Q= Axv dimana A = luasan pipa = v = kecepatan aliran ( 2~4) m/s diambil = Q= Axv Q = π x dH2 / 4 x v dH = ( Q ×4 )



√



π ×v



dH = 0.18475333



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D



m = 184.7533



10%



6.1 jam



1 ×π ×D 2 4 2.34



m/s



141.85



15795.316663 mm2 0.0157953167 mm Pow(((({Vol}/{t})*4)/(3.14*{v})),0.5)



Pipa dipilih jenis carbon steel, yang ada dipasaran sesuai JIS 71 01 15 Inside diameter (dm) = 155.2 mm Ketebalan = 5.0 mm Outside diameter = 165.2 mm Nominal pipe size = 150A minimal thickness (L.R Regulation) = 4.5 mm e. Perhitungan pompa ballast - Perhitungan instalasi di kamar mesin head statis pompa (hs) diasumsikan sebesar =



9.3



0 m (Pdis = Psuc) head perbedaan kecepatan (hv) karena kecepatan antara sisi isap dan keluar sama maka hv = (v2dis - v2suc)/2g = 0 m (v dis = v suc) head perbedaan tekanan (hp) = (Pdis - Psuc)/γ =



- Perhitungan head di pipa hisap head karena gesekan dipipa hisap bilangan Reynold (Rn) : viskositas v = 0.822



cst pd 30oC =



0.000000822 m2/s



PERHITUNGAN SISTEM BALLAST Rn = v . D / υ Rn = 441810.219 gunakan rumus = 0,02+0,0005/D



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maka aliran bersifat = turbulen



sehingga dapat diketahui kerugian geseknya (λ) = 0.02+0.0005/D = 0.023222 panjang pipa ( L ) suction side adalah = 100 m λ x L x v2 / (D x 2g) = 4.180007 m mayor losses (hf) = minor losses ( head karena asesoris yang ada pada pipa) no jenis n k nxk 1 Elbow 90o 5 0.75 3.75 2 filter 2 0.58 1.16 3 Butterfly valve 7 0.6 4.2 4 Gate valve 1 1.2 1.2 5 Sambungan T 5 1.8 9 6 NRV 1 2 2 total 21.31 minor losses = k total x v2 / (2g) minor losses = 5.953318 m Head losses pipa hisap (hl1) = 10.13332 m - Perhitungan head di pipa discharge bilangan Reynold (Rn) : cst pd 30oC = 0.000000822 m2/s viskositas v = 0.822 Rn = v . D / υ Rn = 441810.219 maka aliran bersifat = turbulen gunakan rumus = 0,02+0,0005/D sehingga dapat diketahui kerugian geseknya (λ) = 0.02+0.0005/D = panjang pipa ( L ) discharge side adalah = 100 m λ x L x v2 / (D x 2g) = 4.180007 m mayor losses (hf) = minor losses ( head karena asesoris yang ada pada pipa) jenis N k nxk no 1 Elbow 90o 0.75 3.75 5 2 filter 0.58 0 0 3 Butterfly valve 6 0.6 3.6 4 NRV 2 2 1 Sambungan T 1.8 14.4 5 8 total 23.75 minor losses = k total x v2 / (2g) minor losses = m 6.634974 Head losses pipa discharge (hl2) = 10.81498 m total head losses (hl) = hl1 + hl2 = 20.94831 m Total Head (H tot) = hs+hp+hv+hl = 30.24831 m f. Perhitungan Daya poma ballast daya pompa (Pw) = Hl x ρ air bilga x Q x g / ηpomp daya pompa (Pw) = 20053.84 watt daya motor (Pm) = Pw / ηstandart pomp = 21109.3 watt = 21.1093 Kw = 28.70452 HP



dimana; ρ Air bilga = ηpomp= ηstandart pomp=



0.0232216495



1025 kg/m3 0.95 0.95



PERHITUNGAN SISTEM BALLAST f.



Spesifikasi Pompa Ballast. Merk IRON PUMP Type CN (X) 125/200 Kapasitas 210 m3/hr Head 50 m Putaran 3000 RPM Frekuensi 50 Hz



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Table 12.2.4 Minimum thickness for steel pipes



External Pipes in diameter, D, general, in mm in mm



Venting, overflow and sounding pipes for structural tanks, in mm



Bilge, ballast and general sea-water pipes, in mm



10,2-12 13,5-19 20 21,3-25 26,9-33,7 38-44,5 48,3 51-63,5 70 76,1-82,5 88,9-108 114,3-127 133-139,7 152,4-168-3



1,6 1,8 2,0 2,0 2,0 2,0 2,3 2,3 2,6 2,6 2,9 3,2 3,6 4,0



4,5 4,5 4,5 4,5 4,5 4,5 4,5 4,5 4,5



3,2 3,2 3,6 3,6 4,0 4,0 4,5 4,5 4,5 4,5 4,5



177,8 193,7 219,1 244,5-273 298,5-368 406,4-457,2



4,5 4,5 4,5 5,0 5,6 6,3



5,0 5,4 5,9 6,3 6,3 6,3



5,0 5,4 5,9 6,3 6,3 6,3



NOTE The pipe diameters and wall thicknesses given in the Table are based on common international standards. Diameter and thickness according to other National or International Standards will be considered.



r steel pipes Bilge, air, overflow and sounding pipes through ballast and fuel tanks, ballast lines through fuel tanks and fuel lines through ballast tanks, in mm 6,3 6,3 6,3 6,3 6,3 7,1 8,0 8,0 8,8 8,8 8,8 8,8 8,8 8,8 8,8



ble are based on common international standards. Diameter and thickness l be considered.



SISTEM DAN PERLENGKAPAN KAPAL PROGRAM STUDI TEKNIK MESIN PERENCANAAN DAN KONSTRUKSI KAPAL



PERHITUNGAN SISTEM BALLAST



Dikerjakan Oleh Rev.



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