Scarica slide 5 oleodinamica e più Slide in PDF di Oleodinamica solo su Docsity! ACCUMULATORS discharging pPp_ Acc + Q p Acc |+ a RAISED WEIGHT SPRING COMPRESSED GAS charging (GRAVITY) PISTON DIAPHRAGM BLADDER energy storage energy reserve (in emergency) pressure level hold (leaks integration, temperature variations) pressure pulsations and fluid hammer dampening elastic component with controlled dampening characteristics PISTON BLADDER DIAPHRAGM nominal volume [L] 0.1...3000 0.2...600 0.07...5 (...50) max pressure [bar] 160...1000 35...1000 10...750 useful volume [% nominal] 85% 80% 80% admissible temp. range [°C] -20...+80 -20...+80 -20...+80 max flow rate [L/S] 120 120 140 po: preload pressure (po = 0.9 p1) p1: minimum working pressure File name SOLTEGNICO DI TORNO p2: maximum working pressure speich0_eng DIPARTIMENTO. ENERGIA Date ; FLUID POWER ACADEMIC YEAR 2014-2015 30 Mar 2015 SPRING AND COMPRESSED GAS ACCUMULATORS BLADDER ACCUMULATOR PISTON ACCUMULATOR DIAPHRAGM ACCUMULATOR DÒ button reinforcement oil to prevent diaphragm extrusion SPRING ACCUMULATOR poppet valve to prevent bladder extrusion oil File name POLITECNICO DI TORINO accmi_eng DIPARTIMENTO ENERGIA Date FLUID POWER ACADEMIC YEAR 2013-2014 19 Jan 2013 DESIGN OF NOMINAL VOLUME OF ACCUMULATOR input: useful volume, min and max pressure VALI = V! ® Vv se VALI Poo Pala > Palo Di output: nominal volume In, /m n -r(2) ;n-r:(2) PD, PD, gas Um Im p a (2) n (2) 7 D, P, va Un Peron = UA (2) (2) _ V, (2) (othermai ) P, Pi Pa polytropic expansion << Za nominal volume Un, Um w-r(2) . (2) 21 P, Pi p prua 004..-—- _- V. AV NOMINAL VOLUME i è 0 I/n 1/m V AV V V, V/ (2) * (2) -1 USEFUL FLUID VOLUME gas PD) D, (stored / returned) conservative dimensioning (max nominal volume) n1 --> at minimum value --> 1 (isothermal compression) Fic nane n2 --> at maximum value --> 1.74. (polytropic expansion) proge accumul eng CENTO ENERGIA Date FLUID POWER (CADEMIC YEAR 2014-2015 16 Jan 2015 "REAL" GAS CHARACTERISTICS FOR NITROGEN pV = ZmRT pV’ = cost. 1.3 +107°C 1.9 . 45 U o +67°0 \ di - rea n $ 12 e hoc s +47°C SG g 18 AZIZ DI #17°C _DE dA 2 se — E _J 79 x 1.7 — +43° 5 SEZ, v 7 a10=== == < 3°C 2 16 ‘ +107°C d SL n 7 S . === 5 T_T 243°0 È ‘ LT 20.9 e 315 9 -88°C 9 , 0.8 1.4 0 100 200 300 400 0 100 200 300 400 Pressure [ bar] Pressure [ bar] File name POLITECNICO DI TORINO accumgraph_eng DIPARTIMENTO ENERGIA Date FLUID POWER (CADEMIC YEAR 2013-2014 ° 21 Jan 2013 DOWN SIZE OF THE PUMP pump flow rate CI c2 A without accumulator a Qe2 7 - - - > volume volume stored in Acc returned from Acc mm Qp D<I TM PVI © De Acc pump flow rate 7 LL] LL] with accumulator time fa 1 LI c toi toa X ) x Vol = Qi ter +Qc3 "02 O, = Vol ” la + lor = L File name LL speich2_eng Date 26 Apr 2013 POLITECNICO DI TORINO DIPARTIMENTO ENERGIA FLUID POWER ACADEMIC YEAR 2013-2014 FURTHER APPLICATIONS levelling 3 system Clamping force ! control maintained Li DU through : 4 accumulator > (Y 7 r CC stored in accumulator (use of a A T variable ' displacement reversible hydrostatic unit) 2 Brake energy | | I I | | I | AL VW] LL] LLI ENGINE CONVENTIONAL L FF J MECH. TRANSMISSION ' Speed control of a reversible hydrostatic unit I File name POLITECNICO DI TORINO speich1_eng DIPARTIMENTO ENERGIA ° FLUID POWER l Date ACADEMIC YEAR 2013-2014 19 Jan 2013 charge phase PARALLEL HYDRAULIC HYBRID VEHICLE KINETIC ENERGY RECOVERY UNDER BRAKING discharge phase File name charge_discharge_eng Date 19 Jan 2013 O POLITECNICO DI TORINO DIPARTIMENTO ENERGIA FLUID POWER ACADEMIC YEAR 2013-2014 SPECIFIC ENERGY [Wh/kg] RAGONE CHART 1.000 100 10 0,1 0,01 10 100 1.000 10.000 100.000 1.000.000 SPECIFIC POWER [W/kg] File name ragone_accumul_eng Date 30 Mar 2015 POLITECNICO DI TORINO DIPARTIMENTO ENERGIA FLUID POWER > ACADEMIC YEAR 2014-2015