Issue 1 (37), 2018 ISSN CHOICE OF MIXTURES OF AGENTS IN HEAT PUMPS FOR HEATING AND COOLING MEDIA WITH LIMITED CAPACITY

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1 Issue 1 (37), 2018 ISSN UDC A L Shurais 1, A V Rulev 2, E Yu Usacheva 3 CHOICE OF MIXTURES OF AGENTS IN HEAT PUMPS FOR HEATING AND COOLING MEDIA WITH LIMITED CAPACITY JSC «Giproniigaz» Russia, Saraov, shurais@niigazru 1 D Sc in Engineering, Prof, General Direcor Saraov Sae Technical Universiy Named afer Y A Gagarin Russia, Saraov, usachev-ap@mailru 2 D Sc in Engineering, Prof of he Dep of Hea, Venilaion, Waer Supply and Applied Fluid Dynamics 3 PhD suden of he Dep of Hea, Venilaion, Waer Supply and Applied Fluid Dynamics Saemen of he problem The goal of he sudy is o make he selecion of he componens of a zeorope mix and concenraions of is low-boiling componen wih a lower boiling poin, which is he minimum value of he difference beween is average emperaure in he evaporaor and condenser of hea pumps used for heaing and cooling environmens wih limied hermal capaciy Resuls This paper provides a descripion of he mehod and mehodical provisions for deermining he minimum magniude of he difference of average emperaures of a zeorope mix in he condenser and he evaporaor, which is achieved by he selecion of is componens and he values of he concenraion of he low-boiling componen Conclusions The proposed mehod and assumpions on achieving he minimum value of he difference of he average emperaures of a zeorope mix in he condenser and evaporaor by choosing each of he wo similar ones based on he physical properies of is componens and he values of he concenraion of he low-boiling componen on he basis of he dependence of he sauraion emperaure of he mixure in he evaporaor and condenser of he hea pump on he relaive amoun of is vaporized liquid phase I was shown ha here is a significan influence of he emperaures of he heaed and cooled environmens wih limied hea capaciy on he selecion of he componens of a zeorope mix and he value of is low-boiling componen, he one ha produces he minimum value of he difference of average emperaures of condensaion and boiling, and as a resul, he maximum energy efficiency Keywords: choice, mix, operaing agen, compressor, hea pump, sysem hea gas provision and venilaions, heaing, cooling, medium wih limied hea capaciy Inroducion During he use of renewable hermal sources ha have a limied volumeric capaciy, eg, he air whose emperaure considerably changes during cooling in he evapora- Shurais А L, Rulev А V, Usacheva Ye Yu,

2 Russian Journal of Building Consrucion and Archiecure or and heaing in he hea pump condenser, he use of subsances wih consan boiling and condensaion emperaures as working subsances is characerized wih a reducion in he energy efficiency of is use [5, 13, 21] Simulaneously implemenaion of a cycle wih variable emperaures of media wih a limied hea capaciy as well as working subsances in he condensers allows he energy efficiency of hea pumps o be improved [1, 2, 19] The use of working subsances consising of zeoropic mixures wih variable emperaures in he evaporaor and condenser of he hea pump has been sudied by A A Sukhikh, K S Generalov, I A Akimov [13], V G Bukin, Yu A Kuzmin [1, 2], М Kim and oher foreign auhors [16 18], L А Оgurechnikov, N N Mezenseva [8, 9] as well as oher research insiuions of Moscow Power Engineering Insiue, Kuaeladze Insiue of Thermal Physics (Siberian Deparmen of he Russian Academy of Sciences), Asrakhan Sae Technical Universiy, ec In [9] i is concluded ha he condensaion and boiling emperaures in he evaporaor of he hea pump have a significan effec on he composiion of he zeoropic mixures of emperaures The former also depend on changing emperaures of heaed and cooled media wih a limied hea capaciy However, o he bes of our knowledge, he problems of choosing he bes combinaions of mixures of working subsances and heir composiion in compression hea pumps of sysems of hea and gas supply and venilaion for heaing and cooling of media wih a limied hea capaciy providing a maximum energy efficiency 1 Jusificaion of brands of working subsances for use as componens of he zeoropic mix in hea pumps Working subsances used as componens of he zeoropic mixure in hea pumps should no damage he amospheric ozone layer [7] and have any negaive effec on climae change [3], be fire-safe, easy o use, cos-efficien, have no impac on human healh, have variable boiling and condensaion emperaures ha are mos suiable for heaing and cooling of media wih a limied hea capaciy in sysems of hea and gas supply and venilaion Presenly here are no working subsances ha perfecly comply wih all of he requiremens Eg, freons R11, R12, which used o be common and could be used as componens of he zeoropic mixure in sysems of hea and gas supply and venilaion, have a negaive impac on he amospheric ozone and hea-reflecing layer Therefore he choice of he componens for he zeoropic mixure is individual for heaing and cooling of such media as waer, air and naural gas in sysems of hea and gas supply and venilaion given all he posiive and negaive facors of heir influence According o he analysis, zeoropic mixures ha consis of R22/R142b, R32/R134а, R32/R152а or sauraed hydrocarbons R290/600 (propane and buane), R600а/R601 (isobu- 54

3 Issue 1 (37), 2018 ISSN ene and n-penane), R290/R601а (propane and isopenane), R600а/R601b (isobuene and new penane) Eg, according o he aciviy of he depleion of he Earh s ozone layer, sauraed hydrocarbons are considered compleely safe These gases do no cause he greenhouse effec, have no negaive impac on climae change, human body, hey are exraced immediaely from naural gas and are considerably more cos-efficien ha oher working subsances Mixures of R22/R142b, R32/R134а, R32/R152а are characerized wih low ozone-depleion aciviy and cause no greenhouse effec A considerable drawback of zeoropic mixures is a reducion in he coefficien of hea emission in he inernal surface of hea exchange pipes working subsance sysem of he evaporaor and condenser of he hea pump (Fig 1) due o a reducion in he ceners of vapor formaion and a drop in he diameer of he bubble ha breaks away compared o each of he componens of he mixure [4] Denoaions in he zeoropic mixure: а b are pressing of he vapor phase in he compressor 4; b c is condensaion of he vapor phase in he condenser 6; c d is a reducion in he emperaure of he sauraed liquid phase in he conroller 9; d a is evaporaion of he sauraed liquid phase in he evaporaor 1 сн, ск is he iniial and final emperaure of condensaion of he vapor phase of he zeoropic mixure in he condenser, о С; сн, ск is he iniial and final boiling emperaure of he liquid phase of he mixure in he evaporaor, о С Fig 1 Scheme of he hea pump operaing using zeoropic mixures wih a counerflow of he mixure and a medium wih a limied hea capaciy in he evaporaor and condenser: 1 is a counerflow pipe evaporaor; 2 is a space beween he pipes in he evaporaor 1; 3 is a pipeline of he vapor phase of he zeoropic mixure for joining wih he oupu of he evaporaor 1; 4 is a compressor; 5 is a pipeline of he vapor phase of he zeoropic mixure for joining wih he oupu of he compressor 4; 6 is a counerflow pipe condenser; 7 is a space beween he pipes in he condenser 6; 8 is a pipeline of he liquid phase of he zeoropic mixure for joining wih he oupu of he counerflow pipe condenser 6; 9 is a conroller for reducing he emperaure of he saurared liquid phase of he zeoropic mixure; 10 is a pipeline of he liquid phase of he zeoropic mixure for joining he conroller 9 wih he oupu of he pipe evaporaor 1 55

4 Russian Journal of Building Consrucion and Archiecure In addiion, during heaing and cooling of media wih a limied hea capaciy such as air and oher gaseous subsances i is of no much imporance The calculaions performed according o [4, 6, 15] show ha a reducion in he oal coefficien of hea emission is no over 55 % This is due o he fac ha he main proporion of he coefficien of hea ransfer is in he hea emission coefficien in he ouer surface of he ribbed hea exchange pipes medium wih a limied hea capaciy sysem ha is characerized wih a lower forced flow compared o he zeoropic mixure This reducion in he inensiy of hea exchange and hus an increase in capial invesmens in hea exchange surfaces of he evaporaor and condenser in his case is much lower compared o ha of operaional expenses due o an increase in he coefficien of ransformaion of he compression hea pump A drawback of sauraed hydrocarbons as hey are used as he componens of zeoropic mixures is heir flammabiliy Therefore indusrial hea pumps se up in he premises should be fied wih fire deecors Simulaneously during he use as a drive of a compressor of a gas engine ha is mos suiable for heaing media wih a limied hea capaciy of sysems of gas and hea supply and venilaion, seing up a fire deecor is essenial as i is based on he fire safey regulaions for gas supply srucures according o SP and Federal Sandards and Regulaions (FNiP) for indusrial safey Safey Regulaions of Gas Disribuion Gas Consumpion Neworks (Ac by he Federal Environmenal, Engineering & Nuclear Supervision Agency from November 11, 2013, no 542) In addiion, for modern hea pumps ha are no much filled even for leaking of he enire working subsance is concenraion in a premises wih he geomeric volume of 15 m 3 is nine and more imes lower han he lower concenraion limi of flammabiliy of he mixure R600а and R601 ha is со % [10, 12] Moreover he compression and evaporaion equipmen and all he elemens in bivalen sysems filled wih a working subsance are commonly oudoors Considering he oal combinaion of advanages and disadvanages, presenly over 35 % of refrigeraors in households of Europe and Asia run on isobuane R600a, propane R290, mixures of sauraed hydrocarbons as hey are more commonly used, cos-efficiency and economic susainabiliy 2 Developing mehods and ways of achieving a minimum difference of average emperaures of condensaion and boiling of he zeoropic mixure in he condenser and evaporaor of he hea pump The main drawback of exising hea pumps using pure subsances for heaing and cooling of media wih a limied hea capaciy as working subsances are large differences of he emperaures beween: 56

5 Issue 1 (37), 2018 ISSN a working subsance wih a consan boiling emperaure in he evaporaor and a medium wih a limied hea capaciy ha causes a considerable reducion in he parameer in a space beween he pipes; a working subsance wih a consan condensaion emperaure in he condenser and a medium wih a limied hea capaciy ha causes a considerable reducion in he parameer in a space beween he pipes in he condenser; a working subsance in he evaporaor and condenser and hus a low energy efficiency of he hea pump These large differences are due o he following The emperaure of a working subsance being used ha consiss of one subsance during boiling in he evaporaor and a ransiion from he vapor ino he liquid sae in he condenser is consan Addiionally for more complee hea exracion he emperaure of a medium wih a limied hea capaciy should go down and conversely, in he condenser i goes up This causes an increase in he average difference of he emperaures beween a working subsance and a medium wih a limied hea capaciy in he evaporaor and condenser of he hea pump compared o when he emperaures of a working subsance and a medium wih a limied hea capaciy and hus a difference of heir emperaures will be consan hroughou he enire process The use of working subsances consising of zeoropic mixures wih variable emperaures in he evaporaor and condenser allow a considerable reducion in he difference beween he emperaures in he evaporaor and condenser of he hea pump The objecive of he paper is o decrease he difference beween he emperaures of a working subsance of a zeoropic mixure in he evaporaor and condenser of he hea pump down o a minimal value ha corresponds wih is maximum energy efficiency The hea pump ha implemens he cycle wih variable emperaures of he zeoripic hydrocarbon mixure used as a working subsance and media wih a limied hea capaciy used as sources of hea and drain wih counerdirecions of heir flow (see Fig 1) operaes in he following way In he counerflow pipe evaporaor 1 (Fig 1) he zeoropic mixure consising of wo componens wih similar physical properies (eg, isobuene and penane (R600а/R601), propane and buane R290/R600, propane and isopenane R290/R601а) ransforms from he liquid ino he vapor sae a a variable emperaure from he iniial a he inpu o he final a he oupu of he evaporaor 1 due o hea provided from a hea source wih a limied hea capaciy from a space beween he pipes 2 Change in he emperaure of a wo-componen zeoropic mixure in he counerflow pipe evaporaor 1 is shown in he emperaure area of a hea 57

6 Russian Journal of Building Consrucion and Archiecure exchanger graph (Fig 2) As a resul of cooling, he hea source wih a limied hea capaciy reduces is emperaure from he iniial вн a he inpu o he final вк a he oupu from a space beween he pipes 2 of he evaporaor (Fig 2) Temperaure, C Area, F, m 2 Fig 2 Graph of changes in he emperaures of he zeoropic mixure and medium wih a limied hea capaciy ha allows a minimum difference beween he average emperaures o be evaluaed in he counerflow evaporaor and condenser of he hea pump: cψ=0,0%, cψ=100% are he consan emperaures of condensaion of he vapor phase of pure subsances in he condenser, о С; cψ=0,0%, cψ=100% are he consan emperaures of boiling of he liquid phase of pure subsances in he evaporaor, о С; вн, вк are he iniial and final emperaure of a medium wih a limied hea capaciy, eg, he air in a space beween he pipes in he evaporaor, о С; вк, вн are he final and iniial emperaure of a medium wih a limied hea capaciy, eg, he air in he condenser, о С;, are he emperaure pressures beween hea exchanging flows respecively in he counerflow condenser and evaporaor, о С; сср, сср are he average emperaures of condensaion and boiling of he zeoropic mixure in he condenser and evaporaor respecively, о С Denoaions of he processes in pure subsances: a b is compression of he vapor phase in he compressor 4; b c is condensaion of he vapor phase in he condenser 6; c d are reducion in he emperaure of he sauraed liquid phase in he conroller 9; d a is evaporaion of he sauraed liquid phase in he evaporaor 1 58

7 Issue 1 (37), 2018 ISSN The wo-componen zeoropic mixure in he counerflow pipe evaporaor 1 and a hea source wih a limied hea capaciy in he space beween he pipes 2 move in opposie direcions a an average difference beween he zeoropic mixure and he hea source wih a limied hea capaciy ha is and consan a any poin of he evaporaor (he cycle a-b-c-d-a, Fig 2) A sauraed vapor phase forming in he counerflow pipe evaporaor 1 from he zeoropic mix- ure hrough he pipeline 3 wih he emperaure are direced ino he compressor 4 Here i should be noed ha for he sake of simpliciy he scheme in Fig 1 does no include a regeneraive hea exchanger recommended in [2, 13, 19] for overheaing of he vapor phase a he oupu of he evaporaor 2 over due o he hea of he liquid phase a he oupu of he condenser 6 and hus prevening hydraulic shocks in he compressor 4 owing o he drops ha were no compleely evaporaed in he evaporaor 1 However he fac ha he regeneraive hea exchanger is no included ino he scheme in Fig 1 has almos no effec on he objecive of he sudy, ie a selecion of he componens and composiion of he zeoropic mixure when a minimum difference beween he condensaion and boiling emperaures of he mixure is achieved In he compressor 4 he vapor phase is compressed up o he pressure Р when is emperaure becomes equal o he iniial value From he compressor 4 he sauraed liquid phase from he zeoropic mixure is direced hrough he pipeline 5 ino he counerflow pipe condenser 6 In he counerflow pipe condenser 6 he zeoropic mixure ransforms from he vapor o he liq- uid sae a a variable emperaure from he iniial a he inpu o he final a he oupu (Fig 2) due o he emission of he hea condensaion of he zeoropic mixure hrough he walls of he counerflow pipe condenser 6 o a heaed medium wih a limied hea capaciy flowing in a space beween he pipes 7 As a resul, a medium wih a limied hea capaciy результате is heaed and increases is emperaure from he iniial вн a he inpu o he final вк a he oupu from a space beween he pipes 7 of he condenser (Fig 2) The condensing zeoropic mixure in he counerflow pipe condenser 6 and a heaed medium wih a limied hea capaciy flowing in a space beween he pipes 7 move in he opposie direcions a an average difference of he emperaures beween he zeoropic mixure and a hea source wih a limied hea capaciy ha is, which is consan a any poin of he condenser 6 (he cycle a-b-c-d-a, Fig 2) The sauraed liquid phase formed in he counerflow pipe condenser 6 from he zeoropic mixure hrough he pipeline 8 is direced ino he conroller 9 where is pressure is reduced o he value ha corresponds wih he emperaure of he sar of boiling ha is necessary for 59

8 Russian Journal of Building Consrucion and Archiecure cooling of a medium wih a limied hea capaciy Then he sauraed liquid phase of he zeoropic mixure wih he emperaure of he sar of boiling is direced hrough he pipeline 10 ino he counerflow pipe evaporaor 1 In he counerflow pipe evaporaor 1 he sauraed liquid phase of he zeoropic mixure is sauraed again and he cycle is repeaed in he sequence similarly described above The novely of he suggesed mehod is ha each of he wo componens of he zeoropic mixure similar in heir physical properies as well as he value of he molar concenraion of a lowboiling componen of he mixure ψ i is seleced so ha a minimum difference beween he average emperaures of condensaion and boiling by means of choosing based on he expression сср сср min, (1) where ψ i is he i-h value of he molar concenraion of a low-boiling componen in he zeoropic mixure from wo componens wih similar physical properies a ψ i = ψ н, ψ х,ψ y, ψ k, mole %;, are he average emperaures of condensaion and boiling of he zeoropic сср сср mixure respecively in he counerflow condenser and evaporaor, о С According o [5], a maximum energy efficiency, ie a maximum coefficien of ransformaion for he cycles of hea pumps wih a variable emperaure is achieved a a minimum difference beween he average emperaures of he zeoropic mixure in he condenser and evaporaor If for he counerflow condenser and evaporaor he difference beween he emperaures is larger han ск сн, he formula (1) can be wrien as follows [6]: сн сн ск ln ск сн min (2) сср сср If for he counerflow condenser and evaporaor he difference beween he emperaures is larger han сн ск, he formula (1) can be wrien as follows [6]: ск ск сн ln сн ск min (3) сср сср The values of he iniia, curren and final emperaures of condensaion in he condenser in he range сн as well as iniial, curren and final emperaures of boiling in he evaporaor сн depending on he relaive qualiy (dryness) Х of he zeoropic mixure ha is boiled or condensed a a specified molar concenraion of a low-boiling componen ψ i are de- 60

9 Issue 1 (37), 2018 ISSN ermined according o he firs law by Konovalov considering he Raoul s and Dalon s law and he Anoine equaion [11]: i 1- Х Р i Р10 Р10 В2 В1 А2 А1 С2 С1, (4) where Р is an absolue pressure of he zeoropic mixure in he evaporaor and condenser of he hea pump, Pа 10 5 ; А 1, В 1, С 1 are he coefficiens ha are ypical of a componen wih a lower emperaure of boiling and condensaion a he pressure of he mixure Р in cerain emperaure ranges ; А 2, В 2, С 2 are he coefficiens ha are ypical of a componen wih a higher emperaure of voiling and condensaion a he pressure of he mixure Р in cerain emperaure ranges The coefficiens А 1, В 1, С 1 and А 2, В 2, С 2 used in he formula (4) are given in [14] The emperaure of he sar of boiling of he zeoropic mixure in he evaporaor is calculaed in he Celcius degrees using he formula (4) when a curren emperaure is made equal o, ie = a he relaive amoun of he boiled away zeoropic mixure Х = 0 and he end of boiling = a Х = 1 The emperaure of he sar of condensaion of he zeoropic mixure in he condenser = is deermined in he Celcius degrees using he formula (4) a he relaive amoun of he condensed zeoropic mixure Х = 1 and he end of condensaion = a Х = 0 a specified Х is calculaed using he formula (4) by means of he rial-and-error mehod Noe ha a difference caused by he use of he calculaion formula (4) based on Dalon s and Raoul s laws and he Anoine equaion for zeoropic mixures paricularly for sauraed hydrocarbons a he absolue pressure of up o 10 МPа wih he daa of immediae measuremens is 45 % [20] Changes in he emperaure of he boiled away or condensed mixure in he range of changes in he dryness Х from 0 o 10 firs of all causes changes in he emperaure of he heaed or cooled medium wih a limied hea capaciy The iniial emperaure of a medium wih a limied hea capaciy, eg, he air depending on changes in he emperaure, dryness and consumpion of he zeoropic mixure for he counerflow hea exchanger is deermined using he equilibrium equaion beween a working subsance and medium wih a limied hea capaciy in he evaporaor and condernser of he hea pump: for he evaporaor wih a limied hea capaciy: вн Gвсв в к G c rс Xс cс( с к с н) ; (5) c G в в 61

10 Russian Journal of Building Consrucion and Archiecure for he condenser: вн Gвсв в к G c rс Х с cс ( с н с к) (6) c G Here G с, G в is a molar consumpion of he zeoropic mixure and a medium of a limied hea capaciy, mole/h; r, r is he average laen hea of evaporaion (vapor formaion) of he c c zeoropic vapor and liquid mixure in he evaporaor and condenser, kj/mole; с, с is he average specific hea capaciy of a medium wih a limied hea capaciy, eg, he air in he evaporaor and condenser, kj/(moleк); с, с is he average specific hea capaciy of he с с zeoropic vapor and liquid mixure in he emperaure range of boiling away and condensaion in he evaporaor and condenser, kj/(moleк); X, X is a relaive amoun of he boiled away or condensed (dryness) zeoropic mixure in he evaporaor and condenser Working subsances for he zeoropix mixure and molar concenraion of is low-boiling componen ha a minimum difference beween he average emperaures correspond wih are chosen in he following sequence 1 A zeoropic mixure consising of wo componens is chosen ha has an iniial condensaion emperaure ha is larger han a medium wih a limied hea capaciy compared by he emperaure pressure ha is assumed o be abou = 5070 К; an iniial boiling emperaure ha is smaller han a hea source wih a limied hea capaciy by he emperaure pressure ha is assumed o be abou = 5070 К 2 According o he formula (4) using he mehod of selecion, he absolue pressures Р, curren and final condensaion emperaures in he condenser as well as he absolue pressures Р, curren and final boiling emperaures in he evaporaor are deermined for differen values of molar concenraion ψ i = ψ н, ψ х,ψ y, ψ k, mole % 3 Calculaions o deermine he difference сср сср в с в с using he formulas (2) or (3) for a range of values of molar concenraion ψ i = ψ н, ψ х,ψ y, ψ k and hen he minimum value is seleced Therefore according o he suggesed mehod, he componens of a zeoropic mixure and concenraion of is low-boiling componen are deermined ha will provide a minimum difference beween he emperaures сср сср min and hus a maximum energy efficiency of he hea pump в в 62

11 Issue 1 (37), 2018 ISSN Based on he suggesed mehodological assumpions, he componens of a zeoropic mixure and he concenraion wih a lower boiling emperaure were chosen when a minimum difference is provided beween is emperaures in he condenser and evaporaor of he hea pump used for heaing and colling of media wih a limied hea capaciy in sysems of gas and hea supply and venilaion The selecion was performed using he example of wo zeoroipc mixures wih each having similar physical properies of he componens: a zeoropic mixure R600а (isobuane) R601 (n-penane) wih he concenraion of a low-boiling componen R600а (isobuane) acceped in he range ψ i = mole % wih he sep 20 mole % a zeoropic mixure R290 (propane) R600 (n-buane) wih he concenraion of a lowboiling componen R290 (propane) acceped in he range ψ i = mole % wih he sep 20 mole % The emperaure pressure beween hea-exchanging flow in he counerflow condenser and evaporaor is acceped o be = =7 0 С The emperaure of a medium wih a limied hea capaciy a he oupu of he condenser is вк = 65 0 С, hen к вк is = 65+7 = 72 0 С The emperaure of a medium wih a limied hea capaciy a he oupu of he evaporaor is = 43 0 С, hen вн = вк is = 43 7 = 36 0 С According o he resuls of he calculaions, a minimum difference beween he average em- peraures of he condensaion and boiling ( ск сср ) =18 о С = min based on he expression (4) is achieved for a zeoropic mixure R600а (isobuane) R601 (n-penane) for he molar concenraion of a low-boiling componen R600а (isobuane) in he mixure is ψ i = 45 mole % The resuls of he calculaions also show ha as he molar concenraion of a low-boiling componen which is ψ i = 00 mole% and ψ i = 100 mole% is achieved, he mixure urns ino a pure subsance wih consan condensaion emperaures of he vapor phase c 0,0% cons c, 100% cons in he condenser and wih consan evaporaion empera- ures of he vapor phase cψ=0,0% cons, cψ=100% cons in he evaporaor 63

12 Russian Journal of Building Consrucion and Archiecure According o he expression (1), he difference beween he average emperaures of condensaion in he condenser and ha of boiling increases up o he maximum values ha are = 36 о С, c 0,0% c 0,0% = 36 о С, c 100,0% c 100,0% and conversely, he energy efficiency of he hea pump decreases down o he minimum The cycle of he hea pump a ψ i = 00 mole% and ψ i = 100 mole% (see Fig 2) is presened as a-b-c-d-a According o he calculaions, he emperaures of heaed and cooled media wih a limied hea capaciy have a significan effec on he choice of he componens of a zeoropic mixure and concenraion of is componen wih a lower emperaure of boiling Changes in he emperaures of a medium wih a limied hea capaciy a he oupu of he condenser вк and evaporaor вн causes a choice of oher brands of zeoropic mixures and oher values of he proporion of a low-boiling componen in hem Conclusions 1 The analysis of possible use of working subsances as componens of a nonazeoropic mixure in hea pumps showed ha he mixures R22/R142b, R32/R134а, R32/R152а have a lower ozone-depleion aciviy and mixures of sauraed hydrocarbons R290/600 (propane and buane), R600а/R601 (isobuene and n-penane), R290/ R601а (propane and isopenane), R600а/R601b (isobuene and new penane) are considered compleely safe based on he degree of he depleion of he Earh s ozone layer These gases do no have any significan greenhouse effec and no impac on climae change, human body Mixures of hydrocarbons are more cos-efficien han oher working subsances 2 The novely of he suggesed mehod is ha minimum differences beween he eaverage emperaures of condensaion and boiling are achieved by choosing each of he wo componens of a zeoropic mixure wih similar physical properies and he molar concenraion of is lowboiling componen ψ i based on he dependence of he emperaure of is sauraion in he condenser and evaporaor of he hea pump on a relaive amoun of he boiled away mixure 3 The emperaures of heaed and cooled media wih a limied hea capaciy are proved o have a significan effec on he choice of he componens of a zeoropic mixure and he molar concenraion of is low-boiling componen ψ i when a minimum difference beween he average emperaures of condensaion and boiling and hus a maximum energy efficiency is achieved References 1 Bukin V G, Kuz'min A Yu Kholodil'nye mashiny, raboayushchie na neazeoropnykh smesyakh khladogenov [Refrigeraing machines, working on non-azeoropic mixures of refrigerans] Asrakhan, AGTU Publ, p 64

13 Issue 1 (37), 2018 ISSN Bukin V G, Kuz'min A Yu Eksperimenal'noe issledovanie malykh kholodil'nykh mashin na smesi R22/R142b [Experimenal sudy of small refrigeraing machines in a mixure of R22/R142b] Kholodil'naya ekhnika, 1996, no 5, pp Kioskii prookol k ramochnoi konvensii Organizasii Ob"edinennykh Nasii ob izmenenii klimaa [The Kyoo Proocol o he framework Convenion Unied Naions on climae change] Available a: hp://bellonaru/2007/05/08/kioskij-prookol-k-ramochnoj-konvens (accessed ) 4 Kuepov A M, Serman L S, Syushin N G Gidrodinamika i eploobmen pri paroobrazovanii: ucheb posobie dlya vuzov [Hydrodynamics and hea ransfer during evaporaion: proc manual for schools] Moscow, Vysshaya shkola Publ, p 5 Marynovskii V S Tsikly, skhemy i kharakerisiki ermoransformaorov [Cycles, schemes and characerisics of hermoformers] Moscow, Energiya Publ, p 6 Mikheev M A, Mikheeva I M Osnovy eploperedachi [Basics of hea ransfer] Moscow, Energiya Publ, p 7 Monreal'skii prookol po veshchesvam, razrushayushchim ozonovyi sloi [The Monreal Proocol on subsances ha Deplee he ozone layer] Available a: hp://wwwunorg/ru/documens/decl_conv/convenions/ pdf/monrealpdf (accessed ) 8 Ogurechnikov L A, Mezenseva N N Analiz effekivnosi ispol'zovaniya smesei ozonobe-zopasnykh khladogenov v parokompressionnykh eplovykh nasosakh [Analysis of he efficiency of using mixures of ozonesafe refrigerans in seam compression hea pumps] Energeika i eploekhnika, 2008, no 12, pp Ogurechnikov L A Kondensasiya R32/R134a v ekhnologii eplonasosnogo eplosnabzheniya [Condensaion of R32/R134a in hea pump echnology heaing] Kholodil'naya ekhnika, 2011, no 2, pp Preobrazhenskii N I Szhizhennye gazy [Liquefied gas] Leningrad, Nedra Publ, p 11 Rulev A V, Usachev A P, Shurais A L, Usacheva T A Sisemnye issledovaniya po povysheniyu inensivnosi eploobmena regazifikaorov szhizhennogo uglevodorodnogo gaza [Sysem researches on increase of hea exchange inensiy of liquefied peroleum gas regasifiers] Saraov, Sara gos ekhn un- Publ, 2010, 244 p 12 Saskevich N L, Vigdorchik D Ya Spravochnik po szhizhennym uglevodorodnym gazam [Handbook of liquefied hydrocarbon gas] Leningrad, Nedra Publ, p 13 Sukhikh A A, Generalov K S, Akimov I A [Tess of he hea pump for hea supply of he individual house] Trudy MGUIE «Tekhnika nizkikh emperaur na sluzhbe ekologii» [Proc MSUEE "low emperaure sysems in he service of ecology»] Moscow, MGUIE Publ, 2000, pp Tilicheev M D Fiziko-khimicheskie svoisva individual'nykh uglevodorodov Vyp 2 [Physical and chemical properies of individual hydrocarbons Vol 2] Moscow- Leningrad, Gosopekhizda Publ, p 15 Usachev A P, Rulev A V Razraboka meodicheskikh polozhenii po eplovomu rascheu promyshlennykh rubnykh isparielei smesei szhizhennogo uglevodorodnogo gaza [Developmen of mehodical provisions on hermal calculaion of indusrial pipe evaporaors of mixures of liquefied peroleum gas] Teplovye prosessy v ekhnike, 2013, vol 5, no 8, pp Ho-Saeng Lee, Hyeon-Ju Kim, Dong-gyu Kang, Dongsoo Jung Thermodunamic performance of R32/R152a mixuru for waer source hea pumps Enege, 2012, vol 40, iss 1, pp

14 Russian Journal of Building Consrucion and Archiecure 17 Jianyong Chen, Janlin Yu Performance of a new refrigereion cycle using refrigeran mixure R32/R134a for resinial air-condiijner applicaions Enerdy and Buildings, 2008, no 40 (11), pp Kim M, Kim M S, Kim Y Experimenal sudy on he performance of a hea pump sysem wih refrigeran mixures composiion change Energy, 2004, vol 29, iss 7, pp Kim T S, Shin J Y, Kim M S, Ro S T Cycle analysis and hea ransfer characerisics of a hea pump using R22/ R142b refrigeran mixures Inernaional Journal of Refrigeraion, 1994, vol 17, no 6, pp Nysewander C H, Sage B H, Lesey W N Phase Equillbria in hydrocarbon sysems Indusrial and Engineering Chemisry, 1940, vol 32, no 1, pp Shurays A L, Rulev A V, Usacheva E Yu Assessing Energy Efficiency of Compression Hea Pumps in Drying Processes when Zeoropic Hdrocarbon Mixures are Used as Working Agens Inernaional Conference «Topical Problems of Archiecure, Civil Engineering, Energy Efficiency and Ecology: MATEC Web Conf, 2016, vol 73, pp 1 9 doi: /maecconf/ Available a: hps://wwwmaecconferencesorg/aricles/maecconf/pdf/2016/36/maecconf_pacee2016_02015pdf (accessed ) 66