GLOBAL JOURNAL OF ADVANCED ENGINEERING TECHNOLOGIES AND SCIENCES THE INFLUENCES OF AIR INTAKE TEMPERATURE ON THE TURBOCHARGED GASOLINE ENGINE S OTTO CYCLE Feng Liu* * Dertment of Technology, Yinjin Automobile Reir Co., Ltd., Beijng, Chin DOI: 10.5281/zenodo.1446191 ABSTRACT This thesis is bout the clcultions nd reserches of the imroved coolnt system of turbochrged gsoline engine, it introduces the bsic concet of gsoline engine s turbo technology, nd shows the detiled informtion nd rmeters of 486 turbochrged gsoline engine, estblished the formuls of the Otto cycle nd its relevnt rmeters, emhsized to nlyze the influences of the intke ir temerture on the engine s Otto cycle. The effects of the turbo gsoline intke temerture minly contins 2 oints: the outlet temerture of the turbo nd the temerture decline effect of the coolnt system; This thesis comres the effects of gsoline s Otto Cycle which configures or not with middle cooler, utilized therml dynmics clcultion method to reserch, clculte nd nlysis the rmeters of the turbochrged engine s Otto cycle, the results re corresonding with the exeriment(the therml blnce exeriment), the roerty indices re included circulte therml efficiency, exergy efficiency nd verge vlid ressure. Through the contrsts nd nlysis, it obviously shows tht, with the middle coolnt, it hs n dvntge in the verge vlid ressure, intke temerture, nd exergy efficiency. Absolutely it is necessry nd efficient configured with middle coolnt on the turbochrged gsoline engine. KEYWORDS: Intke Air Temerture, Gsoline Engine, Middle Cooler, Otto Cycle. INTRODUCTION The mximum ower tht cn be rovided by gsoline engine is minly determined by the het relesed by the effective combustion of the fuel in the cylinder. The ressuriztion system llows the ir to be comressed before entering the cylinder, incresing its density. Under the sme cylinder working volume, it hs more new ir to enter the cylinder, which cn increse the circulting het bsortion, tht is, the oil suly, nd obtin lrger outut ower[1][2]. Bsic concet of gsoline engine turbo technology Gsoline engine suerchrging technology is now quite mture, nd with the continuous imrovement of the utomobile mnufcturing industry, mny high-erformnce gsoline engines re currently using suerchrging technology. Generlly seking, the turbochrged ower cn be incresed by 40-60% or more thn the originl mchine, nd the fuel economy nd the verge effective ressure cn be imroved, which is n effective wy to strengthen the gsoline engine. STRUCTURES AND PRINCIPLES OF GASOLINE ENGINE TURBOCHARGER COOLING SYSTEM 486 turbochrged gsoline engine overviews: The develoment of the gsoline engine ws crried out on the 486 turbochrged gsoline engine [2]. The relevnt rmeters of the gsoline engine re shown in Tble 1: [43]
Tble 1 Relevnt rmeters of 486 turbochrged gsoline engine Relted with the tble bove, The turbochrger is n exhust turbochrger system [2]: the comressor is co xilly connected with the turbine to form turbochrger, nd the turbine is driven by the exhust energy to drive the comressor to work to chieve intke boost. The gsoline engine exhust turbochrger system includes [3]: comressor, turbochrger, (middle cooler) nd other comonents. Turbochrger Coolnt System Turbochrger coolnt system consists of the following sects: minly including cooling wter ies: connecting wter jckets nd suerchrgers; ir-cooled middle coolers, suerchrgers, etc. In Figure 1 is n middle cooler nd Figure 2 shows turbochrger [4][5][6]. Figure 1. Middle Cooler Figure2. Turbochrger [44]
Equied with middle cooler, the high-temerture gs is cooled before being injected into the cylinder, nd the high-temerture nd high-ressure ir is disersed into mny smll ies, nd the high-temerture ir flows through the norml temerture outside the ie to chieve the urose of cooling nd imrove the chrging efficiency [7]. METHOD OF THE RESEARCHES ON THE INFLUENCES OF THE INTAKE AIR TEMPERATURE ON THE OTTO CYCLE The Otto cycle refers to the idel reversible cycle of constnt volume heting of gsoline engine: n irreversible constnt volume het relese, reversible constnt volume het bsortion nd n idel inner reversible cycle comosed of two degenertive rocesses. The intke ir temerture hs firly direct imct on the Otto cycle of the gsoline engine. The mximum torque of the gsoline engine is the mximum torque seed, the nturl inhltion temerture is 290K, 17, without the middle cooler, the temerture of the ressurized ir cn rech 77, tht is 350K, nd in the cse of equiment middle cooler, The intke ir temerture cn be reduced by 30, tht is 47, 320K.Detils re shown in tble 2[8]. Bsic Formuls (1) Cycle Het Efficiency ----Only 1 for Otto Cycle (1) t 1 1 (2) Averge Vlid Pressure of the Cycle Q 1 (2) cvt 1 c 1 (3) Exergy nd Exergy Efficiency Het Exergy in Het Absortion Ccity Q : T0 B ex, Q QB n, Q (1 ) QB T1 m QB T0 s1 (3) Averge Temerture of Het Absortion: QB T1 m s1 (4) Exergy Efficiency: wnet e x e (5) Among: c t t B c xq, e xq, - Het Exergy, kj/kg ; nq, - Het Anergy, kj/kg ; T 1m - Averge Temerture of Het Absortion, K; QB - Cycle Het Absortion Ccity, kj/kg ; T 0 - Environment Temerture, K; s1 - Entroy Increse during Het Absortion Process, kj/(kg.k); w net 2 0 g 0 2 0 0 1 2 n, Q 2 0 1 T0 -Efficient Exergy(Cycle Work), kj/kg ; Exergy Loss: Q i T s T ( s s ) T ( s ) Q Q T s (6) Among them: i-exergy Loss, kj/kg ; sg -Entroy Genertion, kj/(kg.k) ; s0 - Environment Entroy Increse during Exothermic Process, kj/(kg.k) ; Q 2 -Cycle Het Relese, kj/kg ; 2 -Entroy Increse during Exothermic Process, kj/(kg.k) RESULTS OF THE RESEARCHES ON THE INFLUENCES OF THE INTAKE AIR TEMPERATURE ON THE OTTO CYCLE Boundry Conditions And Reserch Results Tble 2 is the ir intke temerture condition. s [45]
Tble 2 Air Intke Condition The rticle minly reserches nd nlysis the cycle het efficiency, cycle verge vlid ressure nd exergy efficiency in the Otto cycle with nd without middle cooler. Figure 3 nd figure 4 show -v nd T-s chrts of the Otto cycle, mong them, the number with refers to be with middle coolnt, without refers to be without one. Thus, it will led the ir chrging efficiency increse, t the sme time, cquire lrger outut ower. There re severl relevnt rmeters below: Comression rtio: =8.5 (7) Constnt Entroy index: =1.4 (8) c 0.718 kj / ( kg K) (9) V c 1.005 kj / ( kg K) c Without middle cooler, oint 1 stte: 1.75br (11) T 350K (12) With middle cooler, oint 1 stte: ' 1.75br (13) T ' 320K (14) Highest ressure: ' 80br 3 3 (15) Comment: 1 1 Entroy Increse: (10) T1' 1' 320 s11' cln Rg ln 1.005ln 0.09 kj / ( kg K) 0 T1 1 350 (16) Therefore, 1 1 Entroy Increse is minus vlue, oint 1 is t the left down side in T-s chrt(figure 3). Figure 3. -v chrt of Otto cycle [46]
Figure 4. T-s chrt of Otto cycle From formul (2) could be concluded tht the cycle het efficiency is only relted to the comression rtio, so the cycle het efficiency is equl whether the middle cooler is configured. Substituting dt, =57.5% (18) t t c Clcultion of the Cycle Het bsortion Q B 1 1 1 2 constnt entroy rocess, T v T v (19) 1 Then, T T (20) 2 c 2 2 Substitute relevnt dt, T (21) 2 824K Through v v (22) Substitute relevnt dt, (23) 2 3 reversible constnt volume 3 2 (24) T3 T2 Substitute relevnt dt, T (25) 3 1883K (26) Q c ( T T ) 0.718 T ' (1883 1721 K 3 724) 760.4 kj / kg B 2 2 V 3 2 2 2 ' 35br 3 2 c Q ' c ( T ' T ') 0.718 (1721 753) 695.0 kj / kg B V (27) (28) Cycle verge vlid ressure Substitute relevnt dt to formul (2), (29) t 8.63br (30) t ' 8.73br t It is worth mentioning tht: in the theoreticl clcultion, the verge vlid ressure of the t cycle is equl whether or not equied with n middle cooler; but in ctul exeriments, the intke ir temerture will rise due to the bsence of the middle cooler, nd the time will cuse the intke ie sel softened, the intke sel will be not tight, nd smll mount of gs is leked, resulting in the verge vlid ressure of the cycle being t lower thn the verge vlid ressure of the cycle equied t ' with the middle cooler. The secific exerimentl conditions cn be referred to the reference [8][9]. 3 4 constnt entroy rocess, T v T v 1 1 4 4 3 3 1 T4 T3 c 1 (31) (32) T4 800K [47]
Substitute relevnt dt, (33) T ' 731K 4 (34) Het Relese, (35) Q c ( T T ) 0.718 (850 350) 323.1 kj / kg 2 V 4 1 Q2 ' cv ( T4 ' T1 ') 0.718 (731 320) 295.1 kj / kg Efficient Exergy, wnet QB Q2 760.4 323.1 437.3 kj / kg (37) w (38) net ' QB ' Q2 ' 695.0 295.1 399.9 kj / kg Entroy Increse during Het Absortion Process: T3 v3 T3 1883 s cv ln Rg ln 0.718ln 0.718ln 0.593 kj / ( kg K) s T2 v2 T2 824 (39) Het Anergy in Het Absortion Ccity: T s 290 0.593 172.0 kj / kg ' (40) 23 2'3' n, Q 0 23 n, Q Het Exergy ex, Q in QHet B Absortion n, Q 760.4 Ccity: 172.0 588 kj / kg e ' Q ' ' 695.0 172.0 523 kj / kg x, Q B n, Q Averge Temerture of Het Absortion: T 1m T 1m QB 760.4 1282 K s23 0.593 QB ' 695.0 ' 1172K s 0.593 2'3' Exergy Efficiency: wnet' 399.9 η e ' = = = 76.46% x ex,q' 523 wnet 437.3 η e = = = 74.37% x e 588 x,q (43) (44) (45) (46) The bove sitution is inner reversible; however, the system's constnt het relese rocess is irreversible: its verge exothermic temerture is lrger thn the mbient temerture, nd there will be n exergy loss, the sme below. Exergy Loss: i T (47) 0sg Q2 n, Q 323.1 172.0 151.1 kj / kg i' T s ' Q ' ' 295.1 172.0 123.1 kj / kg (48) Tble 3 is the contrst of the Otto cycle reserch results, under Otto cycle, in ddition to the lifting comression rtio, ll the mesures to imrove the theoreticl cycle therml efficiency of the gsoline engine, nd increse the inlet ressure of the cycle strting oint, reduce the intke ir temerture, nd imrove the chrging efficiency re ll beneficil to the increse of the cycle verge effective ressure, the efficiency t of the exergy nd the outut ower. 0 g 2 n, Q c η ex In ddition, the turbochrged gsoline engine equied with n middle cooler hs n intke ir temerture nd circulting verge vlid ressure nd exergy efficiency lso hve certin dvntges. Middle coolnt T 2m (41) (42) (36) Tble 3. Contrsts of reserch results of Otto cycle Therml Het Averge Efficiency bsortion vlid. Exergy Efficiency N 57,5% 760.4kJ/kg 8.63br 74.37% Y 57.5% 695.0kJ/kg 8.73br 76.46% T 0 η t T Exeriment Comrison [48]
Tble 4 shows the contrsts of the clcultion results nd the exeriment result, through the therml blnce exeriment, the bsic dt is corresonding with ech other, it cn be concluded tht the clcultion method nd results re convincing nd corresonding bsiclly. Tble 4. Comrison of the clcultion results nd therml blnce results Prmeter(rted seed) Clcultio n Exerime nt Error Rte Intke Pressure 1.75br 1.85br 20% Outlet Pressure 1074mbr 849mbr 15% Wter Intke Tem. 105 92.7 11% Wter Outlet Tem. 109.2 99.1 12% Difference Tem. between Wter inlet nd outlet 4.2 6.4 25% Through the tble bove, there re still some error rtes between the clcultion nd exeriment results, they re minly cused from the sitution of the exeriment, however, the rtes re bsiclly within the limits of the ccetnce nd resonble, could be ignored[9]. Additionl Introductions The bove re the effects nd dvntges of the middle cooler on the turbochrged gsoline engine; in ddition to the dvntges of imroving the ower nd economy of the gsoline engine, the turbochrging technology itself lso reflects: 1) The qulity nd design size of the turbochrger re reltively smll comred with tht of the gsoline engine. When the turbochrged ressure cn mke the totl mss nd volume of the gsoline engine bsiclly unchnged, the outut ower is gretly imroved, the ower is incresed, the secific ower is The secific volume ower is gretly imroved, which cn reduce the cost er unit of ower nd enhnce the utiliztion rte of mterils; 2) Comred with nturlly sirted gsoline engines, the exhust gs cn be further exnded in the turbine to reduce exhust noise[10][11][12]; 3) After the gsoline engine is turbochrged, it is beneficil to the ower recovery under the condition of thin ir in the lteu, so tht it cn rech or roch the lower ltitude erformnce, more stble, enhnced nd efficient. CONCLUSIONS The concets of the gsoline engine turbochrged system nd the structure nd working rincile of the 486 turbochrged gsoline engine turbochrged system re introduced. The difference in structure nd working rincile of the gsoline engine turbochrged system equied with the middle cooler nd without middle cooler is fter clcultion nd exerimentl reserch, the intke ir temerture, exergy efficiency nd verge vlid ressure of the gsoline engine Otto cycle re obtined. The clcultion nd exerimentl results show correction of the clcultion rocess, nd the middle cooler hs the intke ir temerture nd the exergy efficiency. And the verge effective ressure hs certin dvntges; introduce the dvntges of the gsoline engine turbochrged system on ll sects of the gsoline engine; REFERENCES [1] Liu Feng 2018(Jn.) Reserch on the Exergy of Automobile Engine inner Cylinder Therml Cycle J. Automobile Prts. 41-45 [2] Liu Feng 2017(Nov.) Reserch on the Exergy of Automotive Engine inner Cylinder Therml Cycle J. Auto Time. 89-92 [3] Liu Feng 2017(Mr.) Reserch on the Sbh Cycle of Diesel with Common Ril Injection System nd Diesel Cycle J.Shnghi Auto. 30-34, 46. [4] Liu Feng 2017(Ar.) Clcultion on the Sbh Cycle with Common Ril Injection System Comred with Diesel Cycle J. Automobile Prts. 62-64 [5] Liu Feng 2017(My) The Influences of Common Ril Pressure on Sbh Cycle J. Automobile Prts. 63-65. [6] F Liu. Reserch nd Anlysis on the exergy of Automotive Engine Inner Cylinder Therml Cycle[J]. [49]
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