Regulation Conditions Influence on the Thermic and Exergic Efficiency Factors Size with the Heat Exchanger of a Coiled Type

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1 Journal of Energy and Power Engineering 10 (016) doi: / / D DAVID PUBLISHING Regulaion Condiions Influence on he Thermic and Exergic Efficiency Facors Size wih he Hea Exchanger of a Coiled Type Trofymchuk Oleksandr Oleksiuk Anaoliy and Shyikova Irina Insiue of Telecommunicaions and Global Informaion Space Naional Academy of Sciences of Ukraine Kiev Ukraine Received: March / Acceped: March / Published: May Absrac: The hermal engineering research has been execued for he hreecircui hea exchanger of a coiled ype ha provides he hermal loads regulaion for he heaing and ho waer supply sysems. A processing curve of he warmh supply regulaion a a combined heaing and ho waer supply load was used a ha. I is imporan o know he processes running inside he apparaus for he echnical characerisics improvemen of he hreecircui hea exchanger of a coiled ype. The ask soluion will allow save he maerials consumpion for he hreecircui hea exchangers of a coiled ype manufacuring in he fuure. Key words: Heaing-accumulaing uni hreecircui hea exchanger independen heaing supply sysem. 1. Decision Problem The fuel-energy complex research has allowed o disclose a huge power-saving poenial in he municipal hea-and-power engineering [1]. Power-and-resource-saving unis and sysems ge a special urgency in he realizaion of his poenial in connecion wih he power engineering crisis expansion. While changing he main conrolled parameers and facors one can obain a considerable increase of he exploiaion efficiency and opimizaion of hea exchanger as well as he heaing supply sysem in oal [].. The Laes Research and Publicaions Analysis The quesions of he heaing device mahemaical paern creaion were discussed in many auhors works. A series of funcional relaions he consiuen parameers of which can be known by he apparen way Corresponding auhor: Trofymchuk Oleksandr docor of echnical sciences professor research fields: mahemaical modeling and energy saving in heaing sysems. or can be defined aking ino consideraion some assumpions is assigned [3]. The heaing exchanging device consrucion was calculaed and he inensificaion processes were considered in previous works. The unis choice calculaion was developed a he analyical research and engineering mehods of he heaing exchanging devices invesigaion [4 5]. 3. Objecives The scienific foundaion and developmen of he heaing exchanging devices for he independen heaing and ho waer supply sysem consrucion efficien resoluions calculaion and choice of he reasonable consrucive varian are he objecives of he work. 4. The Basic Maerial According o he curve he basic parameers of he heaing hermofor have been defined subjec o he ouside air emperaure change a regular inervals ha has influenced he size of he hermic efficiency facoras well as he exergic one during he whole heaing period and even in summer as far as he ho waer supply sysem works all he year round [6 7].

2 88 Regulaion Condiions Influence on he Thermic and Exergic Efficiency Facors Size wih he Hea Exchanger of a Coiled Type dx A4 '' G'' Q'' Q'1 '1 G' 1 Q''G' 4 " 4 A 3 A1 dx Fig. 1 Q'3'3G'3 3 ''3 G''3Q''3 A3 1 " 4 GHW " " 1 ''1 G ''1 Q ''1 Scheme of he heaing-accumulaing uni dismounable consrucion wih he hea exchanger of a coiled ype. The primary hea-carrier τ1 τ he secondary hea-carriers for he heaing 10 and 0 and ho waer supply sysems h and c emperaures ha have been limied o he ouside air emperaure o have served as he fundamenal calculaing daa. The change of he primary hea-carrier capaciy GlH GlHWS and G for he heaing and ho waer supply a he permanen capaciies of he secondary (heaing) hea-carriers GlH GlHWS for he same sysems has been issued proporionally o he changes of he emperaure pressures of he primary hea-carrier as well as he secondary ones (Fig. 1). The hreecircui hea exchanger work efficiency evaluaion has been carried ou by he comparison of he hermic η and exergic ηe efficiency facors quaniies wih he quaniies η ηe for he heaing sysem and also for he ho waer supply sysem η ηe by means of wo rapid waer-heaers ha accomplish he same ask as one hreecircui hea exchanger of a coiled ype does. Two equal sysems ha help o achieve he formulaed objec are discussed a ha. The hea carrier parameers in he node poin are defined for equal hermal loads on heaing and ho waer supply according o he processing curve of regulaion in heaing-accumulaing uni wih hreecircui hea exchanger of a coiled ype and wo rapid hea exchangers working under he same condiions. The daa depending on he ouside air emperaure and he acceped curve of regulaion where τ = f(н) and τ = f(н). The qualiaive regulaion of he warmh supply for he heaing and local quaniaive one for he load of he ho waer supply a he warmh source are carried ou over he range ouside air emperaures from НО = -3 С ill н = 1.6 С. As for he consumpion of he heaing hermofors GlH GlHWS hey keep consan (Fig. ). The comparaive analysis of he hea exchanging efficiency in a hreecircui hea exchanger of a colied ype in comparison o he rapid ones a he equal consumpion of he hea carrier in local heaing and ho waer supply sysems has been conduced for visual clariy. The magniudes of hermic and exergic efficiency facors for hreecircui hea exchanger and he summarized magniudes for he regular rapid ones produced by he indusry are shown in Fig. 3. The characer of he curve conduc for he hermic efficiency facor as well as for he exergic one in hese hea-exchanging devices are approximaely equal bu i differs in he absolue magniude in favour of he hreecircui hea exchanger. The exergic efficiency facor curves have some burs for he increase ha is explained by he increase of he consumpion of he heaing hermofor in he salien poin of he processing curve н = 1.6 С a ransfer from he qualiaive regulaion o he local quaniaive one and hen gradual decrease o н = +8 С ha mees he beginning of he heaing period. Only ho waer supply load akes place in summer period bu he exergic efficiency facor coninues o recede because of he exergy loss increase in he conour of he ho waer supply sysem as far as he emperaure drop of he heaing hermofor keeps

3 Regulaion Condiions Influence on he Thermic and Exergic Efficiency Facors Size wih he Hea Exchanger of a Coiled Type 89 н ( C) Fig. Processing curve of he warmh supply regulaion a he combined heaing and ho waer supply load. +8 C Fig. 3 Comparison of hermic and exergic efficiency facors of he hreecircui hea exchanger of a coiled ype wih he rapid ones depending on he condiions of he warmh supply regulaions. consan and he emperaure drop of he heaed waer reduces a he expence of he cold waer-pipe waer х. л emperaure increase in he summer period a he enry of hea exchanger. Comparison of he effeciveness of he hreecircui hea exchangers of a coiled ype work wih he help of exergic and hermodynamic analisys allows o presen visually he appropriaeness of he hreecircui hea

4 90 Regulaion Condiions Influence on he Thermic and Exergic Efficiency Facors Size wih he Hea Exchanger of a Coiled Type exchanger of a coiled ype for he independen heaing and ho waer supply sysems a independen heaing uni wih heaing-accumulaing uni use. The processing of he resuls of he hreecircui hea exchangers of a coiled ype research has been conduced a he compuer. The exergic efficiency facor η e = serves as he objecive funcion a he hermodynamic opimizaion as far as i reflecs direcly hermodynamic unimprovabiliy of he engineering sysem he correc calculaion of he objecive funcion is possible only in view of compilinig of he exergic balance on basis of which he unified exergic indicaor is defined е he sysem efficiency facor changing depends mosly on is mode of operaion where he ouside air emperaure expendiures and calculaed emperaures of he primary and secondary hea carriers for he heaing and ho waer supply sysems serve as he main parameers. Using he saisical valuaion of he resuls of he regression equaion coefficiens and correlaion coefficiens hermic efficiency facor η is characerized wih he equaion: η = T н 0.07T н T 3 н T н (1) where T o is he ouside air emperaure K. The valuaion of he saisical relevancy of he regression equaions and conformiy equaions coefficiens is verified wih he Fischer crierion [1]: () where is he mean-square deviaion compiles S ост y y n is he remanen mean-square deviaion. We check he equaion conformiy by he Fischer crierion. The able quaniy of he Fischer crierion for he hreecircui hea exchanger of a coiled ype is: F 3 circ. = for rapid F rap. = Exergic efficiency facor η 3х е for he hreecircui hea exchanger of a coiled ype is described wih he empirical equaion of he hird degree: η 3х е = T н T н T 3 н (3) and he exergicefficieny facor for he rapid hea exchangers is: η speed е = T н T н T н (4) The able quaniies of he Fischer crierion [8] argue ha he derived regression equaions are significan a he 0.05 percen degree (99.95% of he confiden probabiliy). The received empirical formulae allows o opimize he hermic and exergic efficiency facors quaniies ha allows o increase he effeciveness of he hreecircui hea exchangers of a coiled ype for he heaing and ho waer supply sysems from a independen heaing uni wih heaing-accumulaing uni hea exchange. 5. Conclusions The received resuls can be used while developing he recommendaions on he increase of he exergic effeciveness of he hreecircui hea exchangers of a coiled ype for heaing-accumulaing uni ha are insalled on he independen heaing uni of he serial producion. The exergic efficiency facor calculaion mehod will allow o give he qualiaive valuaion for newly projecible hea exchanging devices of a coiled ype in which he exergic efficiency facor is higher wihin he limis of.70%-38.67%. Using he exergic calculaion of he sysem mehod one can define more precisely he exergic efficiency facor of any hea exchanging device. References [1] Oleksiuk A. A Energy-and-Resource-Saving Heaing Supply Sysems wih he Individual Heaing Poins and Mulicircui Hea Exchangers. Docor of science degree compeiion disseraion Donbas Naional

5 Regulaion Condiions Influence on he Thermic and Exergic Efficiency Facors Size wih he Hea Exchanger of a Coiled Type 91 Academy of Civil Engineering and Archiecure. [] Oleksyuk A. A. and Shiikova S. G IPC F4D 11/00/ beguachung hea exchanger smog ype for independen sysems of heaing and ho waer supply. Ukraine Paen filed April 013 and issued Ocober [3] Denisenko Y Heaing Uni Mahemaical Paern Srucural Idenificaion Objecive Soluion. SyuSU Herald 6 (10): 4-9. [4] Shiikova G. I Influence of Regulaion Modes on he Thermic and Exergic Efficiency Facors Magniude in he Hea Exchanger of a Coiled Type. Inerdeparmenal Scienific and Technical Collecion Consrucional Indusry 57 (): [5] Shiikova G. I Hea Exchange in he Hea Exchanger of a Coiled Type for he Independen Heaing and Ho Waer Supply Sysems Simulaion. Donbas Naional Academy of Civil Engineering and Archiecure Herald 5 (109): [6] Sadaware Y. A. and Hiware T. 01. Non Convenional Sources of Energy. In Proceedings of he Inernaional Conference on Emerging Froniers Technology 8. [7] Aronson K. E Hea Exchangers of Power Plans. In Texbook for High Schools edied by Aronson K. E. Blinkov S. N. and Brezgin V. I. Ekaerinburg: Sokra 968. [8] Samarskii A. A. and Vabishchevich P. N Compuaional Hea Transfer. Moscow: Ediorial URSS 784.