Energy Management at University Farms

Transcription

1 Agriculturl nd Biosystems Engineering Conference Proceedings nd Presenttions Agriculturl nd Biosystems Engineering Energy Mngement t University Frms H. Mrk Hnn Iow Stte University, hmhnn@istte.edu Jy D. Hrmon Iow Stte University, jhrmon@istte.edu Dn D. Schweitzer Iow Stte University, schweitz@istte.edu Follow this nd dditionl works t: Prt of the Agriculture Commons, Bioresource nd Agriculturl Engineering Commons, nd the Oil, Gs, nd Energy Commons The complete bibliogrphic informtion for this item cn be found t be_eng_conf/439. For informtion on how to cite this item, plese visit howtocite.html. This Conference Proceeding is brought to you for free nd open ccess by the Agriculturl nd Biosystems Engineering t Iow Stte University Digitl Repository. It hs been ccepted for inclusion in Agriculturl nd Biosystems Engineering Conference Proceedings nd Presenttions by n uthorized dministrtor of Iow Stte University Digitl Repository. For more informtion, plese contct digirep@istte.edu.

2 Energy Mngement t University Frms Abstrct Energy is n input cost to griculturl production. Knowing typicl vlues cn help frmers to evlute mngement options. Diesel, propne, nd electricl energy used on the frm during selected field opertions, crop drying, nd in swine housing were mesured on Iow Stte University reserch nd demonstrtion frms. Bseline vlues were mesured nd trctor opertion mngement styles were compred. Strtegies for sving fuel were demonstrted in 30 of 35 trctor opertion comprisons. Comprisons of ger/ engine speed, tillge depth, trvel speed, nd use of front-wheel-ssist verged 29, 27, 15, nd 14% more energy used thn the fuel-sving lterntive. Single drive wheels used 8% more energy thn duls, but results were mixed when compring different tire infltion pressures. Energy used in high-temperture drying in bins rnged from 4.67 to 7.70 Mj/kg (2010 to 3310 Btu/lb). Most energy ws used from propne (96%). Propne use verged L/kg (0.018 gl/bu) per percentge point of moisture removed. Minimum ventiltion fns hd the highest duty fctor in curtin-sided swine finishing brn. Electricl use ws greter in tunnel-ventilted thn curtin-sided brns (29.0 vs kwh/pig spce-yr) nd propne use ws greter in wen-to-finish thn finish-only opertions(10.6 L vs. 2.5 L/pig spce-yr, 2.8 gl vs gl/pig spce-yr). Keywords energy efficiency, field opertions, fuel consumption, grin drying, mchinery mngement, swine housing, trctor, ventiltion Disciplines Agriculture Bioresource nd Agriculturl Engineering Oil, Gs, nd Energy Comments This proceeding is from 2015 ASABE Annul Interntionl Meeting, Pper No , pges 1-24 (doi: /im ). St. Joseph, Mich.: ASABE. Posted with permission. This conference proceeding is vilble t Iow Stte University Digitl Repository:

3 An ASABE Meeting Presenttion Pper Number: Energy Mngement t University Frms H. Mrk Hnn, Jy D. Hrmon, nd Dn D. Schweitzer Agriculturl nd Biosystems Engineering Deprtment, Iow Stte University Written for presenttion t the 2015 ASABE Annul Interntionl Meeting Sponsored by ASABE New Orlens, Louisin July 26 29, 2015 Abstrct. Energy is n input cost to griculturl production. Knowing typicl vlues cn help frmers to evlute mngement options. Diesel, propne, nd electricl energy used on the frm during selected field opertions, crop drying, nd in swine housing were mesured on Iow Stte University reserch nd demonstrtion frms. Bseline vlues were mesured nd trctor opertion mngement styles were compred. Strtegies for sving fuel were demonstrted in 30 of 35 trctor opertion comprisons. Comprisons of ger/engine speed, tillge depth, trvel speed, nd use of front-wheel-ssist verged 29, 27, 15, nd 14% more energy used thn the fuel-sving lterntive. Single drive wheels used 8% more energy thn duls, but results were mixed when compring different tire infltion pressures. Energy used in high-temperture drying in bins rnged from 4.67 to 7.70 Mj/kg (2010 to 3310 Btu/lb). Most energy ws used from propne (96%). Propne use verged L/kg (0.018 gl/bu) per percentge point of moisture removed. Minimum ventiltion fns hd the highest duty fctor in curtin-sided swine finishing brn. Electricl use ws greter in tunnel-ventilted thn curtin-sided brns (29.0 vs kwh/pig spce-yr) nd propne use ws greter in wen-to-finish thn finish-only opertions(10.6 L vs. 2.5 L/pig spce-yr, 2.8 gl vs gl/pig spce-yr). Keywords. energy efficiency, field opertions, fuel consumption, grin drying, mchinery mngement, swine housing, trctor, ventiltion. Introduction The uthors re solely responsible for the content of this meeting presenttion. The presenttion does not necessrily reflect the officil position of the Americn Society of Agriculturl nd Biologicl Engineers (ASABE), nd its printing nd distribution does not constitute n endorsement of views which my be expressed. Meeting presenttions re not subject to the forml peer review process by ASABE editoril committees; therefore, they re not to be presented s refereed publictions. Cittion of this work should stte tht it is from n ASABE meeting pper. EXAMPLE: Author s Lst Nme, Initils Title of Presenttion. ASABE Pper No St. Joseph, Mich.: ASABE. For informtion bout securing permission to reprint or reproduce meeting presenttion, plese contct ASABE t rutter@sbe.org or (2950 Niles Rod, St. Joseph, MI USA) ASABE Annul Interntionl Meeting Pper Pge 1

4 U. S. frms spent $16,573,188,000 for gsoline, fuels, nd oils nd $8,261,978,000 for utilities in 2012 ccording to the USDA Agriculturl Census (USDA, 2014). Purchse of diesel fuel, liquid propne (LP), nd nturl gs re included in gsoline, fuels, nd oils. Electricity, telephone chrges, internet fees, nd purchsed wter re included in utilities costs. Iow spent more thn one billion dollrs including $866,990,000 on gsoline, fuels, nd oils (primrily diesel fuel nd LP) nd $329,138,000 on utilities (primrily electricity). University Extension stff estimte energy consumption (Hnn, 2001). Estimtes re frequently bsed on either old or very limited dt. McLughlin et l. (2008) mesured fuel use of 21.6, 13.9, nd 7.3 L/h (2.31, 1.49, nd 0.78 gl/cre) for moldbord plowing, chisel plowing, nd disking (tndem disk hrrow) in southwestern Ontrio. Tillge depth nd trvel speeds were within rnges normlly used in the region, 187 mm (7.4 in.) nd 5.6 km/h (3.5 mi/h) for moldbord plowing, 169 mm (6.7 in.) nd 6.6 km/h (4.1 mi/h) for chisel plowing, nd 59 mm (2.3 in.) nd 6.5 km/h (4.0 mi/h) for disking. Becuse of lck of current fuel consumption dt for field opertions, most mchinery nd crop production budgets developed by Extension stff nd others use vlues estimted from ASABE Stndrds (ASABE Stndrds 2014, 2014b). Estimtes re bsed on fuel consumption models for trctors from OECD trctor tests (Grisso et l., 2008) nd estimtion of drwbr nd rotrypowered lod forces from implement geometry, soil conditions, trvel speed, nd tillge depth. Energy use for grin drying is lso estimted from old or very limited public dt. Morey et l. (1978) drying corn from 22.3% moisture content (m.c.) to 15.8% m.c. with 100 C (212 F) ir used 5.71 Mj of energy per kg of wter removed (2461 Btu/lb) using smll utomtic btch dryer (10.6 m 3 ; 300 bu). Tretments lso included use of high-temperture drying to intermedite moisture contents (e.g. 18 nd 21%) followed by nturl-ir drying. Higher energy efficiencies were ssocited with tretments using lest moisture reduction in the high-temperture dryer. Wilcke nd Bern (1986) dried corn with unheted nturl-ir during two sesons. Corn dried from 24.7% to 13.0% m.c. used 3.02 Mj/kg (1300 Btu/lb) energy per wter removed. Corn dried the following yer from lower initil moisture content, 19.7%, to 14.3% used 4.10 Mj/kg (1760 Btu/lb). Limited field observtions such s these, long with modeling estimtes, hve been used by Extension stff to estimte crop drying energy consumption (Morey nd Cloud, 1980). Wilcke nd Bern (1985) estimted propne energy consumption in high-temperture dryer to rnge from to L/kg per percentge point of moisture removl (0.01 to gl/bu/pt) nd electricl consumption to rnge from to kwh/kg/pt (0.007 to 0.03 kwh/bu/pt). Electricl consumption in nturl-ir dryer ws estimted to rnge from to kwh/kg/pt (0.28 to 0.42 kwh/bu/pt) for drying corn from 20% m.c. nd to kwh/kg/pt (0.31 to 0.71 kwh/bu/pt) for drying corn from 24% m.c. In order for swine producers to guge energy consumption nd the need for energy conservtion mesures, benchmrks for energy usge re needed. Energy benchmrks for swine production re not widely vilble. This is due to the wide vrition in production fcilities nd the fct tht energy usge is often ggregted within whole frm usge. Hrmon et l. (1998) compred three styles of swine finisher (22 kg to 114 kg) nd found tht hybrid ventilted finishing building tht utilized fns for cold wether ventiltion nd sidewll ventiltion curtins for wrm wether ventiltion used 10.9 kwh/pig spce-yr of electricity nd 2.3 L of propne/pig spce-yr (0.6 gl/pig spce-yr). Other studies hve reported utility cost in terms of cost per pig mrketed without identifying the individul contribution of electricity nd heting fuel. Nvi et l (2007) found tht finishing pigs required n verge utility cost of $1.70 (Cndin) per pig mrketed with rnge of $1.30 to $2.10. Predicl nd Nvi (2008) reported the sme verge with broder rnge of $1.2 to $2.60/pig mrketed. Likewise, Finbin (2014) reports tht 58 wen-finish (6 kg to 122 kg) frms reporting in Minnesot in 2012 nd 2013 reported utilities cost of $0.64 (US)/ pig mrketed with fuel nd oil reported to be $1.25/pig mrketed. These numbers illustrte tht there 2015 ASABE Annul Interntionl Meeting Pper Pge 2

5 re inconsistencies in how energy usge is reported nd prtitioned nd highlight the need to find more uniform, descriptive wy of reporting the dt. Mesurement of on-frm energy use is needed to either vlidte older mesurements or estblish new benchmrks using more current technology. Comprison of energy mngement techniques on locl reserch nd demonstrtion frms helps frmers to evlute nd dopt improved energy mngement strtegies. Objective Mesure bseline energy use vlues nd compre mngement techniques where possible on university reserch nd demonstrtion frms. Methods nd mterils Iow Stte University hs reserch nd demonstrtion frms locted throughout the stte. Lrger frms hve 200 cres or more of croplnd. Individul frms reflect locl differences in soil nd climte, s illustrted in Figure 1. Although much croplnd is used for smller scle reserch plots, lrger trcts of bulk cres re frequently tilled nd seeded on smller ISU frm loctions ner the centrl Agriculturl Engineering nd Agronomy Reserch Frm, the Northwest (Allee) Reserch Frm, nd on the Ag 450 teching frm ner Ames. On-site grin drying for ISU frms is present t the Northest, Southwest (Armstrong), nd Ag 450 frms. Livestock opertions on outlying frms re limited due to distnce from cmpus, but swine feeding opertion is present on the Ag 450 teching frm ner Ames. Figure 1: ISU Reserch & Demonstrtion frm loctions. Field opertions 2015 ASABE Annul Interntionl Meeting Pper Pge 3

6 Ech frm prticipting in the trctor study selected trctor for fuel mesurement tht ws commonly used for field opertions. Selected trctor models re shown in Tble 1. A grvimetric fuel mesurement system ws used to void potentil bck-pressure problems in return fuel lines on diesel engines from flow meters. A 49 l (13 gl) uxiliry fuel tnk ws mounted top 100 kg ( 220 lb) lod cell on ech trctor. Weight on the lod cell is displyed in the trctor cb. Plumbing ws dded for diesel fuel to be supplied nd returned from the engine vi either the min or uxiliry fuel tnk, depending on the setting for single flow control vlve. Net weight of fuel consumed (supply return) ws mesured by recording difference in uxiliry tnk weight before nd fter n observtion in the field. Tble 1. Trctors used for fuel mesurements by loction Frm loction Trctor (kw, hp) Agriculturl Engineering Agronomy John Deere 7730 (114, 153) Northest John Deere 7430 b (105,141) nd 6170R c (107, 143) Northern John Deere 7410 (79, 106) Northwest John Deere 2955 (64, 86) Southest John Deere 7430 (105, 141) Southwest John Deere 7420 (87, 117) Western John Deere 6420 (70, 94) Brnd nmes re used for convenience of the reder nd do not imply endorsement or critique by the uthors. b Used during c Used during fter Although field work on the reserch frms is frequently done on smll plot res, n objective ws to mesure fuel consumption of 2.3 kg (5 lb) or more during single observtions s the lod cell mesures fuel in kg (0.1 lb) increments. Another objective ws to obtin multiple replictions if lnd re nd timing of trils llow. Smll plots or frm scheduling frequently conflicted with these objectives. Limited replictions reduced the bility to mesure sttisticl significnce beyond overll trends in dt in some cses. Field re covered by ech observtion ws clculted from implement width nd field distnce trveled (either mesured mnully or with on-bord electronics when vilble on the trctor). Fuel consumption ws then clculted s l/h (gl/cre). Crop drying Grin drying energy consumption ws mesured t the Ag 450, Southwest (Armstrong), nd Northest Frms. Bin dryers re used to ccommodte crop size nd hrvest rte on the frms. Hrvest of reserch plots frequently slows hrvest rte compred to commercil frms. Propne consumed for drying ws mesured by four 910-kg (2000-lb) lod cells underneth the feet of propne tnks recording weight. A dt logging system recorded tnk weight every 30 minutes during drying. Electricl energy ws mesured for drying fns nd mixing ugers. Energy use ws clculted from mesurements of electric current every 30 minutes during grin drying nd mesurement of electricl power fctor twice during the first drying seson in electricl circuits supplying fn nd stirring equipment energy. At the Ag 450 nd Northest Frms, grin is dried s btch-in-bin system with verticl stirring uger mixing the entire grin mss while fn blows heted ir up through grin from the plenum. At the Ag 450 Frm, hrvesting from lrger lnd res filled the bins within dy. At the Northest Frm, bins were filled during plot hrvest. Bin fill ws completed within 3 to 6 dys resulting in shllower lyer drying during erlier stges of the btch. During fll 2013 t the Ag 450 nd 2015 ASABE Annul Interntionl Meeting Pper Pge 4

7 Northest Frms, three btches of drying were ccomplished, two btches in one bin nd single btch in second bin t both loctions. Fll 2014 drying ws similr except tht t the Ag 450 Frm only single btch ws dried in ech drying bin. The drying bin t the Southwest Frm hs bottom sweep uger tht trnsfers grin dried by plenum ir to center verticl uger. The verticl uger lifts grin either bck to the top of the bin grin mss where it is distributed (recirculting btch mode) or lifts nd trnsfers dried grin completely out of the bin into n djcent storge bin (continuous flow mode). Becuse heted ir moves in the opposite direction of grin flow, this is termed counter-flow dryer, nd ws operted in both continuous mode with dried grin immeditely leving the dryer nd btch mode with dried grin being recirculted to the top of the grin mss inside the bin. Drying tempertures of 140 F nd 180 F were used with ech mode during fll During fll 2014 continuous drying ws done t 140 F nd btch drying ws done t 180 F. Full bin cpcity is 9000 bushels. To ccommodte plot hrvest rte, totl grin vilble, nd to observe drying in shllower lyer, the bin ws filled between bout 1900 to 3900 bushels during both btch- nd continuous-flow drying modes. After high-temperture drying mesurements nd t the end of hrvest, the bin ws filled with corn to be dried with nturl ir (fn only). After fll 2013 hrvest, smples from multiple grin probes in lte winter showed the drying front hd progressed bout 2.1 m (7 ft) during lte fll drying before grin in the bin ws removed. Wether conditions following fll 2014 hrvest llowed nturl-ir drying to be completed by lte November. Becuse of prior inctivity, the hightemperture drying system t the Southwest Frm ws refurbished before mesurements strted in fll Bin nd fn specifictions re shown in Tble 2. Tble 2. Bin cpcity nd fn power Cpcity Bin dimeter Fn power Loction Bin m 3 bu m ft kw hp Ag 450 west Ag 450 est Northest est Northest west , Southwest Two 9.7 kw (13 hp) fns Beginning moisture content ws determined by mesuring individul lods with moisture meter used by locl frm stff. An equivlent moisture content, bsed on the mount of corn dry mtter nd wter dded to the bin, ws clculted for corn tht ws dried. If time ws vilble, frm stff t the Ag 450 nd Northest Frms mesured dily intermedite moisture contents during drying from multiple smples tken in the top lyer of corn in the bin. Ending moisture content ws mesured in the sme mnner t Ag 450 nd Northest Frms. At the Armstrong Frm, ending moisture content ws mesured from the exit moisture sensor on the drying system for 1770-l (50- bu) corn increments being trnsferred during five-minute periods nd then clculting equivlent moisture content for totl corn dried during drying period. Energy required to remove wter from the grin ws the sum of propne used for the dryer burner nd electricl energy for drying fns nd the stirring nd recirculting ugers. Totl energy consumed ws divided by the mount of wter removed to provide mesure of energy use for drying in MJ/kg (Btu/lb) of wter removed. Swine housing 2015 ASABE Annul Interntionl Meeting Pper Pge 5

8 Two pproches were used in obtining energy usge dt with swine production. In one pproch swine finishing fcility ws instrumented to collect detiled informtion on fn energy usge, including duty cycles, nd heting energy usge. The second pproch focused on more globl dt by seeking monthly energy dt from production units. The detiled monitoring occurred t the Iow Stte University Ag 450 frm. This frm is mnged by students in mngement clss nd includes swine finishing fcility. This brn hs four rooms 12.2 m x 18.3 m (40 ft x 60 ft). Ech hs cpcity of 300 pigs. The rooms hve three fn stges nd utilize sidewll ventiltion curtins for wrm wether. The first stge includes two Aerotech Clssic AT10SP fns with 124 W (1/6 hp) electric motors nd rted t 30 m 3 /min (1060 cfm) t sttic pressure difference of 25 P (0.1 inches of wter). The exct fn models for the second nd third fn stges could not be confirmed becuse ll mrkings hd been worn wy from the fns. The building owner stted tht the second nd third stge fns were ech 249 W, 61 cm (1/3 hp, 24 ) Hired Hnd Funnel Flow fns rted t 178 m 3 /min (6280 cfm) t sttic pressure of 25 P (0.1 inches of wter). This resulted in nominl mximum mechnicl ventiltion cpcity of 416 m 3 /min or 1.4 m 3 /min-pig (14,680 cfm or 49 cfm/pig). A mke-up ir furnce ws mounted on the exterior of ech room. Monitoring equipment ws instlled on the ISU Ag 450 swine finishing unit to gther informtion on electricl nd propne usge. During fll of 2012 electricl monitoring begn on two of the four rooms within the swine finisher with monitors providing n mperge output of the three fn stges within ech room every 30 seconds. This ws used to estblish duty fctors nd fn energy usge on ech fn stge. In September, 2013 propne meters were dded to ll 4 rooms. Pulse counts were produced for ech cubic foot of propne used on 15 minute bsis. The second pproch ws done by locting entities willing to shre energy usge informtion. One coopertor represented swine production compny tht shred dt for five different hed, tunnel ventilted, wen-to-finish fcilities. Another source ws n electricl utility within Iow which shred dt from 7 different frms. In ddition, one swine producer provided five yers of dt from two of his swine buildings. These were summrized nd ctegorized by building type. Results nd discussion Field opertions Fuel use mesurements during selected field opertions nd tretment comprisons re shown in Tbles Frm stff were encourged, when possible, to compre different tretments. These included using different trnsmission ger nd engine speed settings t the sme trvel speed, different trvel speeds, different tillge depths, different tire infltion pressures ( lower infltion pressure s specified by the tire or trctor mnufcturer for wheel lod, nd n overinflted condition), opertion with nd without front-wheel-ssist engged, or opertion with single or dul tires. Americn Society of Agriculturl nd Biologicl Engineers mchinery mngement stndrds nd dt, S496.3 nd S497.7, were lso used to clculte expected fuel use. A summry of observed differences in the vrious tretment comprisons is shown in Tble 13. Frm mngers nd griculturl economists frequently wnt to know fuel use for vrious field opertions to incorporte into crop input budget estimtes. Averge, lest, nd gretest fuel used by field opertions for tretments observed re shown in Tble 14. Limited replictions (often 3 or 4) generlly precluded the bility to detect sttisticlly significnt differences. Filing to shift up to higher ger nd reduce engine speed (Tbles 3 5) cused n verge 29% more fuel use nd ws demonstrted in 13 of 14 comprisons. Incresing trvel speed required n verge of 14% more fuel nd ws demonstrted in 5 of 7 comprisons (Tbles 6 nd 7). When tillge depth ws incresed, fuel use incresed in ll 3 comprisons by n 2015 ASABE Annul Interntionl Meeting Pper Pge 6

9 verge of 27% (Tble 8). Slightly more fuel ws used in 3 of 5 comprisons between correctly nd overinflted tires (Tble 9), but results vried. Averge fuel difference including ll 5 comprisons ws slightly negtive (- 1%) nd no comprisons were sttisticlly significnt. Not using front-wheel-ssist consumed n verge of 8% more fuel in 4 comprisons (Tble 10, 3 sttisticlly significnt). Tretments compring field opertions with nd without the use of dul rer-drive wheels were done t the Northwest Reserch Frm (Tbles 11 nd 12). In both cses, n verge of 8% dditionl fuel ws used with only single-tire wheels, lthough neither ws sttisticlly significnt. Additionl comprisons from these Tbles t the Northwest Frms were used s pproprite for ger/engine speed, trvel speed, nd depth tretments in summry Tbles 13 nd 14. Fuel-sving strtegies were generlly well demonstrted for shifting up nd throttling bck during reduced drwbr lods, reducing tillge depth, nd mking use of front-wheel-drive. Fuel svings were lso demonstrted t lower trvel speeds, lthough svings were not s gret s trnsmission nd depth, nd results were mixed s engine speed nd torque chrcteristics were mtched to lods. Fuel svings were demonstrted in two comprisons of single vs. dul drive tires. Fuel svings observed were mrginl (often within the rnge of mesurement ccurcy) nd lest pprent when compring tire infltion. Overll, 30 of 35 tretment comprisons showed expected trends in fuel svings nd 14 of the comprisons were sttisticlly significnt. Theoreticl fuel use vlues clculted using procedures from ASABE stndrds were generlly greter thn observed vlues for trvel speed, tillge depth, nd tire infltion comprisons, but lower thn observed vlues for ger/engine speed, front-wheel-ssist, nd dul vs. single tire comprisons (Tble 13). Vritions between observed nd estimted vlues my be due to infield fctors such s turns on short plot rows or inherent vribility in pplying ASABE estimtion techniques. Grisso et l. (2008) reported the ASABE stndrd often over-predicted fuel use unless djusted for individul trctor test dt. Fuel used by vrious field opertions hd wide rnge of tretment men vlues (Tble 14). This suggests better estimtes for crop input budgets my be mde if dditionl fuel sving strtegies re known nd employed by trctor opertors. Compring tillge fuel consumption vlues with those reported by McLughlin et l. (2008), fuel use ws greter for moldbord plowing, less for disking, nd t most sites less for chisel plowing ASABE Annul Interntionl Meeting Pper Pge 7

10 Tble 3. Observed nd theoreticl fuel use t the Northest Iow Reserch Frm with ger/engine rpm. Opertion No. of replictions Tretment Fuel use observed Fuel use theoreticl Ger/engine rpm L/h Gl/cre L/h Gl/cre 2013 Field cultivtion, 8 km/h (5 mi/h) 3 C1/ C2/ α= Strip till, 8.4 km/h (5.2 mi/h) 3 C1/ C2/ α=0.05 NS b NS b Stlk chopping, 8.0 km/h (5.0 mi/h) 3 C1/ C2/ Field cultivtion, 8.0 km/h (5.0 mi/h) 3 C1/ C2/ α=0.05 NS b NS b Subsoiling, 5.9 km/h (3.7 mi/h) 3 B1/ B3/ α=0.05 NS b NS b Lest significnt difference between tretments t 95% confidence level. b No significnt difference t the 95% confidence level ASABE Annul Interntionl Meeting Pper Pge 8

11 Tble 4. Observed nd theoreticl fuel use t the Southwest Iow Reserch Frm, with ger/engine rpm. Opertion No. of replictions Tretment Fuel use observed Fuel use theoreticl Ger/engine rpm L/h Gl/cre L/h Gl/cre 2013 Moldbord plowing, 7.2 km/h (4.5 mi/h) 1 B2/ B3/ B4/ α=0.05 NS b NS b Disking, 7.4 km/h (4.6 mi/h) 4 B3/ C1/ α=0.05 NS b NS b Plnting, 6.4 km/h (4.0 mi/h) 4 B2/ B3/ B4/ α=0.05 NS b NS b 2014 Moldbord plowing, 6.9 km/h (4.3 mi/h) 3 B2/ B3/ B4/ α= Plnting, 6.4 km/h (4.0 mi/h) 4 B2/ B3/ B4/ α=0.05 NS b NS b Lest significnt difference between tretments t 95% confidence level. b No significnt difference t the 95% confidence level ASABE Annul Interntionl Meeting Pper Pge 9

12 Tble 5. Observed nd theoreticl fuel use t the Northern nd Western Iow Reserch Frms, with ger/engine rpm. Opertion No. of replictions Tretment Fuel use observed Fuel use theoreticl Ger/engine rpm L/h Gl/cre L/h Gl/cre Northern Field cultivtion, 10.1 km/h (6.3 mi/h) 2 C2/ C4/ α=0.05 NS b NS b Western Plnting, 8.3 km/h (5.2 mi/h) 8 B4/ C2/ α= Grin drill, 8.3 km/h (5.2 mi/h) 8 B4/ C2/ α= Lest significnt difference between tretments t 95% confidence level. b No significnt difference t the 95% confidence level. Tble 6. Observed nd theoreticl fuel use during chisel plowing with different trvel speeds. Loction No. of replictions Tretment, trvel speed Fuel use observed Fuel use theoreticl Km/h Mi/h L/h Gl/cre L/h Gl/cre Southest α=0.05 NS b NS b Northern α=0.05 NS b NS b Southwest Lest significnt difference between tretments t 95% confidence level. b No significnt difference t the 95% confidence level ASABE Annul Interntionl Meeting Pper Pge 10

13 Tble 7. Observed nd theoreticl fuel use during disking t the Southwest Frm nd rotry mowing nd huling corn t the Western Frm with different trvel speeds. Opertion No. of replictions Tretment, trvel speed Fuel use observed Fuel use theoreticl Km/h Mi/h L/h Gl/cre L/h Gl/cre Disking α=0.05 NS b NS b Mowing hy α= Huling corn c α= Lest significnt difference between tretments t 95% confidence level. b No significnt difference t the 95% confidence level. c Fuel use, L/km or Gl/mi Tble 8. Observed nd theoreticl fuel use with tillge depth t the Southwest Iow Reserch Frm.. Opertion No. of replictions Tretment, disking depth Fuel use observed Fuel use theoreticl cm in L/h Gl/cre L/h Gl/cre 2013 Disking, 7.4 km/h (4.6 mi/h) α=0.05 NS b NS b 2014 Disking, 7.6 km/h (4.7 mi/h) α=0.05 NS b NS b Lest significnt difference between tretments t 95% confidence level. b No significnt difference t the 95% confidence level ASABE Annul Interntionl Meeting Pper Pge 11

14 Tble 9. Observed nd theoreticl fuel use with tire infltion t the Ag Engineering Agronomy Frm during 2013, nd the Northern nd Southwest Iow Reserch Frms during Loction/opertion No. of replictions Tretment, tire pressure Fuel use observed Fuel use theoreticl rer/front, kp rer/front, psi L/h Gl/cre L/h Gl/cre Ag Engineering Agronomy Frm Chisel plowing, 7.7 km/h (4.8 mi/h) 3 69/138 10/ /207 20/ b α=0.05 NS c NS c Chisel plowing d, 7.7 km/h (4.8 mi/h) 3 69/138 10/ /207 20/ b α=0.05 NS c NS c Northern Frm Chisel plowing d, 5.8 km/h (3.6 mi/h) 3 97/235 14/ /235 20/ b α=0.05 NS c NS c Southwest Frm Chisel plowing d, 5.8 km/h (3.6 mi/h) 3 69/221 10/ /221 20/ b α=0.05 NS c NS c Disking, 7.6 km/h (4.7 mi/h) 4 69/221 10/ /221 14/ b α=0.05 NS c NS c Summer, fter smll grin hrvest. b Lest significnt difference between tretments t 95% confidence level. c No significnt difference t the 95% confidence level. d Fll, fter grin hrvest ASABE Annul Interntionl Meeting Pper Pge 12

15 Tble 10. Observed nd theoreticl fuel use t the Western Iow Reserch Frm, with nd without mechnicl front wheel drive. Fuel use observed Fuel use theoreticl Opertion No. of replictions MFD L/h Gl/cre L/h Gl/cre Plnting, 8.3 km/h (5.2 mi/h) 8 disengged engged b α= Grin drill, 8.3 km/h (5.2 mi/h) 8 disengged engged b α=0.05 NS c NS c Huling bles d 4 disengged e e 4 engged e e b α= Rotry mowing, 6.9 km/h (4.3 mi/h) 4 disengged engged b α= Mechnil front wheel drive. b Lest significnt difference between tretments t 95% confidence level. b No significnt difference t the 95% confidence level. d Fuel use, L/km or Gl/mi e Drft used for roller pcker Tble 11. Observed nd theoreticl fuel use t the Northwest Reserch Frm during field cultivtion using dul wheels, vrying depth, nd trvel speed. Opertion No. of Replictions Tretment Wheels Trvel speed Depth Fuel use observed Fuel use theoreticl km/h mi/h cm in. L/h Gl/cre L/h Gl/cre Field cultivtion 6 dul dul dul single dul α=0.05 b Loose soil in second pss; other field cultivtion opertions were secondry tillge, but first pss on firm ground. b Lest significnt difference between tretments t 95% confidence level ASABE Annul Interntionl Meeting Pper Pge 13

16 Tble 12. Observed nd theoreticl fuel use t the Northwest Reserch Frm during plnting using dul wheels, vrying ger/throttle opertion, nd trvel speed. Opertion No. of replictions Tretment Wheels Ger/engine rpm Trvel speed Fuel use observed Fuel use theoreticl km/h mi/h L/h Gl/cre L/h Gl/cre Plnting 5 dul 5/ dul 5/ single 5/ dul 6/ single 6/ single 6/ single 6/ b α= Soil previously field cultivted t 8 cm (3 in.) depth; other tretments were previously field cultivted t 13 cm (5 in.) depth. b Lest significnt difference between tretments t 95% confidence level. Averge Gretest Lest Tble 13. Number of tretment comprisons showing expected trend nd sttisticl significnce, percentge tretment difference in observed fuel use, nd verge difference of ASABE predicted vlues from observed vlues. Tretment comprison No. of comprisons Percentge difference of observed fuel use Averge percentge difference of ASABE predicted vlue Totl Trend Sttisticl significnce b Ger/engine speed Trvel speed Tillge depth Tire infltion Front wheel ssist Dul vs. Single tires Expected trend observed. b Sttisticlly significnt t the 95% confidence level ASABE Annul Interntionl Meeting Pper Pge 14

17 Tble 14. Observed fuel use on university frms by field opertion. Opertion No. of mens Averge Lest b Gretest c L/h Gl/cre L/h Gl/cre L/h Gl/cre Chisel plow Plnt Field cultivte Disk Moldbord plow Grin drill Rotry mower Subsoiler Strip till Stlk chopper Move bles d Hul corn d Number of tretment mens used to clculte verge. b Lest tretment men for field opertion. c Gretest tretment men for field opertion. d Fuel use L/km or Gl/mi ASABE Annul Interntionl Meeting Pper Pge 15

18 Crop drying Conditions nd energy used during crop drying re shown in Tbles Severl fctors involved in the drying process limit the bility to mke direct comprisons between loctions, individul bins t the loctions, nd even drying btches in specific bin. Fctors tht ffect drying include different incoming corn moisture, different corn moisture t the end of drying, different mbient ir conditions during drying, nd different loding rtes resulting in different depths of corn tht fns hd to push ir through. Although direct comprisons re not possible, reltive mesurements cn be useful to ssess wht my hve ffected energy consumption during drying ASABE Annul Interntionl Meeting Pper Pge 16

19 Tble 15. Conditions during corn drying t Iow Stte University frms during fll Cpcity Drying ir temperture Dte Outside ir temperture Loction Drying style Mg Wet bu C F Beginning Ending C F Ag 450 west stirred btch Oct 28-Oct Ag 450 west stirred btch Nov 12-Nov Ag 450 est stirred btch Nov 12-Nov Northest est stirred btch Oct 24-Oct Northest est stirred btch Oct 8-Nov Northest west stirred btch Nov 13-Nov Southwest counterflow btch Oct 21-Oct Southwest counterflow btch Oct 22-Oct Southwest continuous flow Oct 24-Oct Southwest continuous flow Oct 25-Oct lb units or wet bushels. Tble 16. Energy used for corn drying t Iow Stte University frms during fll Cpcity Moisture content, % Energy per wter removed Propne use Electricity use Loction Drying style Mg Wet bu Beginning Ending Mj/kg Btu/lb L/pt/kg Gl/pt/bu kwh/pt/kg kwh/pt/bu Ag 450 west stirred btch Ag 450 west stirred btch Ag 450 est stirred btch Northest est stirred btch Northest est stirred btch Northest west stirred btch Southwest counterflow btch Southwest counterflow btch Southwest continuous flow Southwest continuous flow lb units or wet bushels ASABE Annul Interntionl Meeting Pper Pge 17

20 Tble 17. Conditions during corn drying t Iow Stte University frms during fll Cpcity Drying ir temperture Dte Outside ir temperture Loction Drying style Mg Wet bu C F Beginning Ending C F Ag 450 west stirred btch Oct 18-Oct Ag 450 est stirred btch Oct 18-Oct Northest est stirred btch Oct 23-Oct Northest est stirred btch Oct 31-Oct Northest west stirred btch Nov 5-Nov Southwest continuous flow Oct 11-Oct Southwest counterflow btch Oct 15-Oct Southwest nturl ir Nov 10-Nov lb units or wet bushels. Tble 18. Energy used for corn drying t Iow Stte University frms during fll Cpcity Moisture content, % Energy per wter removed Propne use Electricity use Loction Drying style Mg Wet bu Beginning Ending Mj/kg Btu/lb L/pt/kg Gl/pt/bu kwh/pt/kg kwh/pt/bu Ag 450 west stirred btch Ag 450 est stirred btch Northest est stirred btch Northest est stirred btch Northest west stirred btch Southwest continuous flow Southwest counterflow btch Southwest nturl ir lb units or wet bushels ASABE Annul Interntionl Meeting Pper Pge 18

21 Energy used to remove wter from grin rnged from 4.67 to 7.70 Mj/kg (2010 to 3310 Btu/lb). Morey et l. (1978) observed 5.7 Mj/kg when corn ws dried from 22% m.c. Most energy ws used from propne (96% verge) rther thn electricity in these high-temperture drying systems. Energy consumption verged L/pt/kg (0.018 Gl/pt/bu) for propne nd kwh/pt/kg (0.022 kwh/pt/bu) cross ll high-temperture drying tests (Tbles 16 nd 18). These vlues re ner the mid-point of the rnges estimted by Wilcke nd Bern (1985). Electricl energy used for nturl-ir drying in 2014 ws slightly below the rnge estimted by Wilcke nd Bern. Becuse propne energy use predomintes during high-temperture drying, useful mesure for dryer opertors in the U.S. is the mount of propne used per thousnd bushels of corn dried. Results from the high-temperture drying tests (Figure 2) show strong reltionship (R 2 = 0.92) between propne use nd initil corn moisture content, with ech dditionl moisture point requiring pproximtely 16.2 gl (61 L) propne per thousnd bushels (i.e., 56,000 lb incoming corn). Energy use per mss of wter removed versus verge outside ir temperture during drying is shown by individul drying btches for ech of the three drying loctions in Figure 3. Greter mbient ir temperture s ir is pre-heted by solr energy would be expected to improve drying efficiency unless reltive humidity lso correspondingly increses to remin t constnt vlue. Energy use vlues t or below bout 5.8 Mj/kg (2500 Btu/lb) generlly occurred when mbient ir tempertures were 10 C (50 F) or greter, or with the drying system t the Southwest Frm. At the Ag 450 Frm bins were filled quickly, within bout dy. As strtegy to reduce overll energy consumption, the burner ws usully turned off t bout 16% m.c. nd fn-only energy ws used to cool grin nd remove the lst percentge points of moisture. This resulted in higher kwh/pt/bu vlues for electricl use thn estimted by Wilcke nd Bern (1985) in some cses, but voided propne consumption during the finl drying stge. At the Northest Frm, it took three to six dys to completely fill ech bin during plot hrvest. Corn ws initilly dried in shllower lyer, llowing the fn to not work ginst s much sttic ir pressure. In this lyer drying technique, dditionl corn ws dded s drying progressed. In 2013, initil corn moisture content ws wetter t the Northest Frm. At the Southwest Frm, incoming grin moisture content ws generlly drier thn the other two loctions. Corn depth during drying ws held to only bout 1.2 m (4 ft) during most btch- nd continuous-flow modes (except lst btch mode in 2014 ws bout 2.1 m, 7 ft). Btch- or continuous-flow drying ws completed in one dy during dylight hours for these shllow-lyer dryings. Airflow ws in counterflow mode with wet grin meeting high-temperture ir ner the bin floor rther thn the whole mss of grin inside the bin drying s one s with stirred btches. This type of counterflow bin dryer is more commonly used in continuous-flow mode.

22 250 Propne use, gl/1000 bu Initil grin moisture content, % Figure 2. Propne use per 1000 bu versus initil corn moisture content Energy use, Btu/lb wter Averge ir temperture, F Ag 450 Northest Southwest Figure 3. Drying energy used per pound of wter removed versus verge mbient ir temperture during drying ASABE Annul Interntionl Meeting Pper Pge 20

23 Swine housing Electricl dt hs been processed for the Ag 450 finishing rooms for the period of December 10, 2012 through December 17, Amperge for ech 30 s period ws recorded nd verged for ech fn. In order to trnslte mperge into energy usge, the typicl voltge nd mperge were multiplied by the power fctor for ech fn. Power fctor ws mesured for ech fn model using Fluke Power Logger (Fluke 1735, Everett, Wsh). For the stge 1 fns, power fctor of 0.97 ws mesured. For stges 2 nd 3 the power fctor ws mesured s These were different thn wht ws originlly estimted (0.92 nd 0.70). Tble 19 provides the overll dt summry for electricl usge. This ws tbulted continuously, including periods tht pigs were not present in the building. Production fcilities normlly hve n unpopulted period between pig groups to fcilitte snittion tht rnges from few dys to week or more so no djustment ws mde for these periods. Tble 19. Electricl energy used for fn ventiltion for 300 hed curtin-sided finisher, ISU Ag 450 frm. Est room West room Stge 1 Stge 2 Stge 3 Stge 1 Stge 2 Stge 3 Duty fctor 93.0% 15.8% 0.4% 97.2% 11.5% 0.54% Avg. mps kwh/yr kwh/yr-pig spce % of totl 81% 18% 1% 84% 15% 0.5% Totl fn 11.0 kwh/yr-pig spce 11.2 kwh/yr-pig spce kwh/yr is clculted ssuming 220 V nd the mesured power fctor for ech fn, 0.97 for stge 1 nd for stges 2 nd 3. In Tble 19, duty fctor refers to the percentge of hours monitored which ny prticulr fn stge ws operting. In the Ag 450 fcility the minimum ventiltion fns typiclly operted even when the sidewll ventiltion curtin ws open. Therefore, in this sitution the only time stge 1 fns did not operte ws between groups of pigs when the building stood empty or during mlfunction. Stge 2 operted less thn 20% while stge 3 operted less thn one percent of the time. The low percentge for stge three my hve been, in prt, due to fn mlfunctions. The totl consumption per yer for ech fn ws divided by the niml cpcity of ech room to yield prtitioning of energy usge by fn stge. This illustrtes tht selection of energy efficient minimum ventiltion fns is n importnt considertion becuse of the high duty fctor nd high percentge of the energy expelled on the first fn stge. It should be noted tht stge 3 in the west room required less mperge thn the stge 3 fn in the est room. This could be becuse replcement motor my hve been instlled on one of the fns or some other mlfunction. Overll, the rooms tended to hve similr electricl consumption for fn ventiltion, 11.0 nd 11.3 kwh/yr-pig spce. Propne usge ws mesured in ech of the four finishing rooms. However, the heter mlfunctions were frequent nd the frm stff opened doors between rooms to het the room 2015 ASABE Annul Interntionl Meeting Pper Pge 21

24 without functioning heter. The building s whole, between September 23, 2013 nd June 1, 2015, used totl of 40,818 L (10,783 gllons) of propne. This is equivlent to 17 L of propne per pig spce/yr (4.5 gllons/pig-spce-yr). The usge in this finishing fcility ws higher thn most frmers rising pigs in wen-to-finish use s gol which is typiclly 7.6 L propne per pig spce-yr (2 gl). This ws likely due to the leky nture of the building nd reltively poor mngement of ventiltion curtins. Dt received from outside sources ws compiled nd is presented in Tble 20. As expected, electricl cost ws greter for ll tunnel ventiltion brns (29.0 kwh/pig spce-yr) versus hybrid brns tht use nturl ventiltion during wrm months through the usge of sidewll ventiltion curtins (20.9 kwh/pig spce-yr), independent of niml size. It ws lso expected tht those frms which hve wen-to-finish fcilities (10.6 L or 2.8 gl/pig-spce-yr) strting with 6 kg pigs (13 lbs) hve much higher propne usge thn do those tht re purely finishing pigs, which strt pigs t 25 kg (55 lbs) (2.5 L or 0.67 gl per pig spce-yr). It should lso be noted tht the vlues vry considerbly within ech type of building s well s between building types. Severl fctors could contribute to this vrition. The time of yer in which the buildings re stocked cn influence the energy usge. Smll pigs plced in winter will increse the propne usge while hving lrge pigs in August my dd to the electricl usge due to incresed need for cooling. Mngement such s controller settlings, mintennce nd building lekge cn ll impct these figures s well. Tble 20. Propne nd electricl usge on vrious swine finishing frms. Electricl Usge/yr Propne Usge/yr Description kwh/pig spce Yers of Dt L/pig spce Gl/pig spce Yers of Dt Hybrid- fns with side-wll ventiltion curtins, Finishing hed hed hed hed Averge Tunnel ventiltion, Finishing hed hed Averge 28.6 Hybrid-fns with side-wll ventiltion curtins, wen-to-finish hed Tunnel ventiltion with electric brooders, wen-to-finish hed Tunnel ventiltion with gs brooders, wen-to-finish hed hed hed hed hed Averge ASABE Annul Interntionl Meeting Pper Pge 22

25 Conclusions Within the rnge of conditions mesured, the dt support the following conclusions. Fuel ws sved during field opertions in 30 of 35 tretment comprisons (14 sttisticlly significnt). Fuel-sving strtegies were generlly well demonstrted for shifting up nd throttling bck during reduced drwbr lods, reducing tillge depth, nd mking use of front-wheel-drive (verge incresed fuel use of 29, 27, nd 14%, respectively if fuel sving strtegy ws not used). Fuel svings were lso demonstrted t lower trvel speeds (fuel use incresed n verge of 15% t higher speeds) but results were more mixed s engine speed nd torque chrcteristics mtched to lods. Fuel use incresed 8% when single tires were used rther thn duls in two comprisons. Fuel-sving results were mrginl (often within the rnge of mesurement ccurcy) nd lest pprent when compring tire infltion. Fuel use vlues clculted using procedures from ASABE stndrds were generlly greter thn observed vlues for trvel speed, tillge depth, nd tire infltion comprisons, but lower thn observed vlues for ger/engine speed, front-wheel-ssist, nd dul vs. single tire comprisons. Energy used per wter removed during high-temperture drying rnged from 4.67 to 7.70 Mj/kg (2010 to 3310 Btu/lb). Propne use ws responsible for 96% of energy consumption during hightemperture drying nd verged L/kg (0.018 gl/bu) per percentge point of moisture removed. Conditions such s initil corn moisture content nd verge mbient ir temperture during ech drying tretment were unique. Greter mbient ir temperture tended to use less energy, s did the drying system on the Southwest Reserch Frm. Minimum ventiltion fns hd the highest duty fctor (>93%) nd the highest energy consumption of ll the fn stges in hybrid, sidewll curtin ventilted finishing brn indicting tht selection of energy efficient stge 1 fns is n importnt considertion. Approximtely 11 kwh/pig spceyr ws used for fn ventiltion in this fcility. Tunnel ventilted brns tend to use more electricity thn do hybrid curtin-sided brns (29.0 vs kwh/pig spce-yr). Wen-to-finish brns tended to use more propne the do finishing brns (10.6 L vs. 2.5 L/pig spce-yr, 2.8 gl vs gl/pig spce-yr). Mngement, mintennce nd controller settings tend to cuse vrition in energy usge. Acknowledgments This project ws supported by the Iow Energy Center. ISU Extension nd Outrech Ag Engineer Shwn Shouse ssisted in crop drying mesurements nd nlysis. Student interns Kyle Wester, Json Schuster, nd Anthony Bttzzi ssisted in set up of instrumenttion nd dt nlysis. ISU Reserch nd Demonstrtion Frms stff including Richrd Vndepol, Mich Smidt, Myron Rees, Ken Pecinovsky, Bernie Hvlovic, Rndy Brech, Lyle Rossiter, nd Kent Berns long with Greg Vogel t the Ag 450 Frm ssisted in cquiring mesurements nd setting up instrumenttion. References ASABE Stndrds EP496.3 Agriculturl mchinery mngement. St. Joseph, Mich.:ASABE. ASABE Stndrds. 2014b. EP497.7 Agriculturl mchinery mngement dt. St. Joseph, Mich.:ASABE. BESS Agriculturl Ventiltion Fns: Performnce nd Efficiency. Bioenvironmentl nd 2015 ASABE Annul Interntionl Meeting Pper Pge 23