Birol Kılkış a, Şiir Kılkış b, Şan Kılkış c,* Abstract

Transcription

1 Optimum hybridization of wind turbine, heat pump, and thermal energy torage ytem for nearly zero-exergy building (NZEXB) uing rational exergy management model Birol Kılkış a, Şiir Kılkış b, Şan Kılkış c,* a Başkent Univerity, Energy Engineering Graduate Program, Ekişehir Yolu 20 km Bağlıca 06810, Ankara, urkey b ÜBİAK, Atatürk Bulvarı 221, Kavaklıdere Ankara, urkey c U Delft, Aeropace Engineering, Kluyverweg 1, Delft 2629 HS, the Netherland Abtract he definition Nearly-Zero Exergy Building (nzexb) i a new concept regarding 4DE (Fourth-Generation Ditrict Energy) ytem. It recognize different energy exchange between the ditrict and the building at different exergy level. In nzexb ytem, a multitude of utainable ytem and renewable energy reource are mobilized. heir optimum bundling in deign and load allocation i a complex problem and mut be baed on a robut platform of a common objective, which in thi cae i the minimization of exergy detruction that eventually lead to additional CO 2 emiion. An optimization model wa developed for a ground-ource heat pump with thermal energy torage coupled to a wind turbine. Coefficient of performance (COP) and Primary Energy Ratio (PER) were redefined in term of exergy to erve the objective function of minimizing exergy detruction. In developing the optimization model, the Rational Exergy Management Model (REMM) wa employed, which aim to increae the balance among the upply and demand exergie and help to etablih a circular exergy flow. he impact of everal deign variable like the type of terminal unit, the ize and efficiency of the wind turbine, reervoir temperature, and the plit of the turbine electricity between the heat pump and the building were invetigated. It ha been concluded that heat pump play a major role in achieving nzexb tatu provided that an optimum bundling with other utainable ytem and equipment i achieved Stichting HPC Selection and/or peer-review under reponibility of the organizer of the 12th IEA Heat Pump Conference Keyword: Heat pump performance; exergy analyi ; net-zero-exergy building ; Rational Exergy Management Model ; wind turbine LowEx building ; primary exergy ratio ; exergy coefficient of performance Nomenclature Symbol Decription Symbol Decription a Heat pump contant (Eq.2) d, de Demand, deign, detroyed C Cot E, EX, x Exergy COP Coefficient of performance f Primary Energy Source (Fuel) c, d Coefficient (Eq. 3, Eq. 10, Eq. 5) HP Heat pump E Electrical power, W o Environment E x Exergy, W r Reervoir, return h Overall heat tranfer coefficient, W/K z ref Reference m Exponent in Eq. 5 H, H hermal, heat n Exponent in Eq. 3 p Pump * Correponding author. el.: ; fax: addre: bkilki@bakent.edu.tr.

2 OF Overizing factor Supply O Operative temperature, K z emperature power for overall heat tranfer coefficient, h PER Primary energy ratio Acronym PEXR Primary exergy ratio AC, DC Alternating, direct current Q hermal power, W CHP Combined heat and power emperature, K GSHP Ground-ource heat pump X Electrical power plit to the building HVAC Heating, ventilating, air-conditioning and heat pump y, z Coefficient in Eq. 16 and Eq. 12 LowEX Low-exergy η, η I Firt-law efficiency nzexb Nearly-zero exergy building ΔP Unit preure drop due to overizing nzeb Nearly-zero energy building Ψ R REMM efficiency PV Photo-voltaic ε Unit exergy, W/W or kw/kw REMM Rational Exergy Management Model Subcript ES hermal energy torage a Comfort air W Wind turbine 1. Introduction Heat pump are becoming particularly important for the net (or nearly) zero energy building. he main claim i their high Coefficient of Performance (COP) according to the Firt-Law of hermodynamic but the Primary Energy Ratio mut be factored in for a better undertanding of their performance: PER= η IH COP {Quantity flow of energy from the primary reource} (1) hi equation how how much primary energy in term of quantity i ued for unit heat provided/extracted by a heat pump with a given COP, where η IH i the overall thermal efficiency covering the entire energy flow proce tarting from the fuel input to the thermal power plant and ending up to the point of ue at the heat pump, including tranmiion and ditribution loe. Eq. 1 i alo ueful in predicting the primary CO 2 emiion that i the reponibility of the heat pump. However, a will be hown later, there are other avoidable CO 2 emiion reponibility of the heat pump due to exergy detruction and mimatche in upply and demand exergie. he mot recent EU28 average for η IH i about 0.43 [1] minu for tranmiion and ditribution loe of the power output at the plant (2013 World average) [2]. In many other countrie, thi figure i le than 0.3. herefore, η IH at bet i 0.4. If for example, eaonal average of a pace heating ground-ource heat pump COP H i 3, then thi heat pump hardly beat a condening natural-ga boiler with an average efficiency of 0.90, becaue PER of the heat pump in thi cae i only 1.2. Fig. 1. Embedding boundarie of a heat pump and emiion point [5] PER further decreae if a building demand higher heating fluid temperature. herefore, the trend i to ue 2

3 LowEx (Low-Exergy) building [3], with moderate demand for comfort heating and cooling temperature. A logical approach i to eliminate ditribution loe by generating mechanical power on ite and drive the heat pump directly, and better to mention i, to ue on-ite cogeneration ytem [4]. hee point remind that in evaluation of the performance of a heat pump may not be conidered iolated from the ource and the demand point. Figure 1 how the proper boundary election of a heat pump operation (dotted line) [5]. Fig. 1 how that a heat pump i functionally embedded between the thermal ource (in heating mode)/ink (in cooling mode) and the application point like a nearly-zero energy building (nzeb) or nearly-zero exergy building (nzexb). In order to normalize the heat upply and demand rate plu toring energy in order to time hift energy obtained from interrupted renewable energy reource and ytem like wind turbine and PV ytem, an energy torage ytem i eential between the building and the heat pump. Furthermore, the ame heat pump i linked to the power plant uing primary energy reource and linked by the power tranmiion and ditribution line. he entire ytem ha CO 2 and other harmful emiion reponibilitie not only due to energy inefficiencie but alo the exergy detruction at everal point. CO 2 emiion are greatly reduced in LowEx building with high COP heat pump and radiant panel ytem [6]. hi i epecially true if an optimum operating temperature i calculated [7]. In thi token, radiant panel ytem are exergetically the bet couple to heat pump in net zero energy building [8]. COP of a heat pump in heating i directly related to the upply temperature of the heat pump. In an approximated form over a relatively mall range of 35 o C 70 o C: a COPH ( r ) (2) It i evident that for a given reource (reervoir) temperature r, like the ground temperature for a hallow geothermal ytem, COP H increae with decreaing, o that pace heating with low upply temperature are becoming more and more important for utainable and green building. On the other hand, the heat output of terminal equipment, Q decreae with a decreae in : Q a ) n c( (3) Here c and n are the characteritic of the pecific equipment ued. a i the indoor comfort temperature. o be more precie, a may be replaced by O, namely the operative temperature, becaue mot of the terminal equipment type, like panel heating and cooling ytem tranfer heat with both convection and radiation in different proportion depending upon the type of the equipment. Eq. 3 clearly how that heating capacity of a given terminal equipment of any type with a power of n decreae if decreae. hi conflict, i.e. while trying to decreae in order to increae the heat pump COP H, reduction of the heating capacity of the terminal equipment the building may be reolved imply by overizing the equipment [7, 9]. If the terminal unit are operated at a different temperature than their deign value, namely d, then the overizing factor, OF i: n ( d a ) (4) OF ( a ) Equipment overizing may be done either by erie extenion or parallel addition of equipment [4]. In erie overizing, the hydronic circuit length become longer (i.e. the length of the tube coil in a panel heating or cooling ytem), thu the head lo become proportional to the OF. However, according to a pecific pump curve, the flow rate decreae and therefore the average fluid flow acro the tube length further decreae, which end up in a further decreae of the heat output while the average fluid temperature decreae [9, 10], requiring a larger OF. hi i epecially important in long circuit and ditrict heating ytem [11]. Additional preure loe due to ingularitie of overizing make the relationhip between the preure head increae ΔP and OF different than a linear one. In parallel overizing, the flow rate, V increae proportionally with OF, thu the relationhip between ΔP and OF become primarily a parabolic one or imilar: m P d OF (5) Here, d and m depend upon the type of overizing, the equipment ued, and pecific application of overizing. Equation 3 and 4 how that terminal equipment with the power n cloe to one, like panel heating ytem are preferable to other type of unit like fan-coil with n about 1.4, becaue if n i high then the need for overizing will be higher. An economical optimization methodology wa developed for determining the mot economical olution by overizing the heat pump and/or overizing the equipment [7]. A further parametric tudy for deign 3

4 optimization of nzeb building wa carried out [10]. Yet economical and Firt Law analye may not be ufficient to decribe the actual performance of renewable and heat pump and their true impact on the environment by applying the principle of the Second Law of hermodynamic. Exergy analyi i becoming more critical and decriptive for ytem operating at low temperature and uing low-enthalpy renewable energy reource with or without heat pump. In order to accomplih uch a tak, an exergy-baed methodology for deign optimization and analyi have been developed in thi tudy. So far in the literature, almot all performance analye have been motly baed on the Firt Law of hermodynamic. Epecially with the advent of ditrict energy ytem, connected building are not only exchanging power but alo everal level of heating, cooling, and dometic water exergy. Becaue thee exergie may not match with the exergy upply of the ditrict, an nzeb building may not be an nzexb building [12]. An example follow in Fig. 2. A green building exchange both electrical and thermal power with a ditrict energy ytem. On an annual bai, the building receive 10,000 kw-h of AC electrical and provide 10,000 kw-h AC electrical energy with the ame quality. At the ame time, the building receive kw-h of heat in the form of hot water annually from the ditrict at an average upply temperature of 353 K (80 o C) and provide kw-h of thermal energy at an average temperature of 343 K (70 o C) annually. Electrical and thermal power i generated in the premie of the green building (olar PV, olar collector, wind turbine, heat pump, bioga-operated combined heat and power). According to the current practice, thi building i an ideal net-zero energy building, becaue on an annual bai it receive and return the ame quantity of electrical and thermal energy. hi concluion i baed on the Firt Law of hermodynamic, without taking into account the exchange of the quality (Exergy) of heat. In fact, the temperature of hot water received i higher than the hot water upplied to the grid. Fig. 2. hermal and power relation between nzeb and ditrict [12] he quality of heat upplied from the grid, namely the unit exergy of the 1 kw-h of the upply heat, ε according to the ideal Carnot Cycle mut be conidered: 1 ref (1kW - h) (6) ref i the equilibrium environment reference temperature. In thi example, it i taken to be 283 K (Average ground temperature at hallow ground loop of the heat pump). he green building receive annually15000 kwh. he total upplied exergy E x i: E x = (1-283/353) = 2974,5 kw-h. Repeating the ame calculation for the exergy of the annual heat upplied to the grid from the green building: E xr = (1-283/343) = 2623,9 kw-h. E xr i le than E x and the exergy balance i in deficit. hee exergy-baed reult conclude that, although the building eem to be a net-zero energy building, it i not when both the firt and econd law of thermodynamic are conidered. hi conideration i alo very important for CO 2 emiion calculation. herefore, beide the definition of LowEx building NZEXB and nzexb, thee definition mut follow: NZEXB: Net-zero Exergy Building i a building, which i connected to a ditrict energy ytem and on an annual bai, upplie an equal amount of the um of thermal exergy at different temperature and power exergy to the ditrict to the total amount that receive from the ditrict.. 4

5 nzexb: Nearly- zero Exergy Building i a building, which atifie 80% of the NZEXB target. LoWEXB: Low-Exergy Building i a building, which can atify all thermal load between 40 o C and 17 o C. E PEXR E f ref Q 1 Q ref f IH COP 1 f ref 1 ref 1 f COP PER IH (7) Here, ε i the unit exergy of the heat upplied by the heat pump at a temperature of. he heat pump demand electrical power at a rate of 1/COP per unit heat output power. hi power i upplied by the primary fuel by an overall efficiency of η IH at an adiabatic flame temperature f. Defining COP EX in the following format, COP EX ref 1 (8) COP ref 1 f PEXR {Quality flow of energy from the primary reource} (9) IH COP EX PEXR deal with the quality flow of primary energy reource up to the demand point, while PEX deal with the quantity flow. It i worth to mention that PEXR take into account the type (exergy) of the fuel input in term of it unit exergy, which enable a more comprehenive analyi, where PER i inenitive to the type or quality of fuel. hu, the type of fuel, whether it i renewable or not i not ditinguihable, leaving the analyi of the performance of a heat pump incomplete. For the ame example given earlier in thi paper (η IH = 0.4, COP H = 3, PER = 1.2), if f i 2000 K, d i 333 K, and ref i 283 K, then the correponding PEXR from Eq. 7 i: PEXR PER 283 f Quantity of plant power Quality of plant power Primary Energy Reource at f Overall efficiency η IH Reervoir (Ground) Heating GSHP Cooling Heat ink (Ground) x COP x COP EX Supply quantity Supply quality Demand quantity Demand quality Fig. 3. Energy and exergy flow chain for a heat pump performance Comparion of thi value with, PER, which i 1.2 how that PER alone may be mileading for deigner and energy planner. PER may only be ueful to a certain extent in economic analye, but not in environmental and technical iue. Ye, on one ide thi ground-ource heat pump provide 20% point more heat output (utilizing reervoir heat) than the primary energy reource ued, but on the other ide, it more importantly ue a highexergy foil fuel with a unit exergy of about 0.86 W/W (ε f) but produce only hot water (low-exergy) at 333 K, correponding to a unit exergy of 0.15 W/W (ε ). hi mean that there exit a big exergy detruction in the proce, which at the ame time tranlate into additional emiion [13]. If thi ytem need to have a breakeven value for PEXR= 1, then the required COP may be calculated. From the above arithmetic, thi COP ha to be With the current technology, thi i a hardly achievable value compared to practically maximum COP value of 6. Heat pump need to be driven with on-ite or cloe-to-ite renewable energy reource and ytem for better environmental performance. For example, if the foil fuel i replaced with olar power having ε f = 0.49 W/W [4], then PEXR improve to Furthermore, if the heat demand temperature i reduced from 333 K to 313 K conidering a LowEX building, the reult become complicated due to the fact that, while the upply temperature i reduced, upply exergy i alo reduced. hi reduce PEXR, but at the ame time the ame 5

6 reduction in the upply temperature increae the heat pump COP. For example, if the COP increae from 3 to 4.5, then PEXR become 0.35, hardly equal the previou value. One may conclude that the ue of LowEX building technology may not be ufficient to improve the exergy performance of a heat pump ytem. A more effective olution i to ue on-ite renewable ource. For example, if η IH increae from a grid power value of 0.4 to 0.7, then PEXR increae to herefore, we ugget the future prioritie: 1. Ue local power 2. Ue renewable energy reource (wind, olar, etc.) for power production on-ite 3. Ue high COP heat pump 4. Ue LowEX building 5. ry deep geothermal rather than hallow geothermal reource to increae r in ground-ource heat pump, while the additional cot are taken into account and a careful optimization i made. Literature urvey Almot all reearch deal with the heat pump alone. Even heat pump ytem with wind turbine or other renewable ytem are treated eparately from each other. Furthermore, mot of the literature are baed on the quantity of the primary fuel conumption and analyze the aociated CO 2 emiion accordingly. he reult are only ueful for economic evaluation like the pay-back period. Fig. 4 on the left-hand ide how uch an approach, where the operating fluid temperature i optimized for a compromiing ituation for equipment veru heat pump overizing in order to minimize the cot of intallation and operation [14, 15]. According to thi graph, the required heating capacity of the heat pump veru terminal unit output are in conflict and thi conflict may be reolved at an optimum overizing plit at the optimum operating fluid temperature. he right-hand ide graph in Fig. 4 how the reduction in the pay-back period of a pecific example in term of the power plit (X) between the heat pump and the building (1-X) received from the on-ite wind turbine [16]. According to thi graph dedication of the entire power to the heat pump (X=1) eem to be economical. However, from the exergy point of view it ha been hown above in term of PEXR that once the electrical power i generated it mut tay a power intead of converting it to thermal power. hi how that one need a common bae by converting exergy to cot or vice vera [4]: he cot of exergy detruction per unit upply exergy may be embedded into cot equation, like life cycle cot analyi optimization [17]. (10) Here, c i the unit cot in Euro. A recent approach i the GreenHP initiative, which aim at developing a new, highly efficient urban heating ytem baed on retrofitting of building [18]. hi i indeed a very promiing initiative, becaue the energy performance of building in Europe are quite poor [19]. In thi repect, Dietle [20] preented an optimization approach on a component to ytem ynthei, baed on the firt-law. aro et al. [21] tudied on exergy analyi of heat pump. hey gave a good account of heat pump alone by conidering exergy tranport between the component, to the load, and to the environment. Regarding exergy and energy analye about wind energy-coupled heat pump, Ching-Song J. et.al. analyzed direct wind turbine and olar collector coupled heat pump with emphai on the Firt-Law [22]. Performance of a rooftop wind olar hybrid heat pump in term of the Second-Law wa invetigated for home and wa concluded that olar ytem have low exergy efficiency and therefore wind energy mut be prioritized. In thi repect, Qin-Yi Li et al. [23] performed an exergetic analyi of a dometic-cale ytem combining a 5 kw wind turbine and an array of 11.4 m 2 copper flat-plate olar collector a well a two heat pump, capable of producing pace heating, hot water, cooling and electricity [24]. hey found that wind power can provide 7.6% of the yearly heat pump power demand to atify the thermal load of a 198 m 2 reidential building in Beijing. he ytem can yearly reduce 31.3% carbon dioxide emiion compared with conventional energy ytem. Dincer and Roen dicued wind turbine driven heat pump giving fundamental equation regardle of analyzing their mutual energy and exergy relation [25]. 6

7 5] Birol kılkış/ 12th IEA Heat Pump Conference00 (2017) P Power plit, X [16] Fig. 4. Economy-baed optimum fluid temperature and power plit analyi Development of the REMM-baed optimization model In thi model, there i a wind turbine ytem (W), which provide electric power to the ground-ource heat pump (GSHP). It alo provide electricity to the nzexb. he power plit i denoted by X, which i the ratio of the power dedicated to the GSHP at deign condition to the total power generation capacity of the wind turbine at deign condition. Exce power i tored in the form of heat produced by the GSHP in ES. he model i hown in Fig. 5, which i divided into three ection, namely the upply, torage, and demand. he demand ide i the building with floor heating ytem and i going to be overized by adding more parallel circuit. Inverter exergy detruction are eliminated by uing DC power in the building and the entire ytem (lighting, appliance, pump etc.). Auming that the ES tank i properly inulated, two major exergy demand point are identified namely the circulation pump, namely P1 and P2. In the optimization proce P3 i not included, becaue it i fixed at deign condition. hu, the model reduce to optimize the operating fluid temperature, which affect COP, COP EX, equipment (floor panel) overizing, and circulation exergy demand. In thi model, the overizing related exergy demand are identified by the following expreion derived for unit heating load in nzexb: Pump P2: Baed on Eq. 4 and Eq. 5, {Here E i exergy} (11) Here, d and a are the deign value for the equipment upply temperature and the indoor comfort air temperature, repectively. h and o are given value for a pecific deign and environment. ES: ES ha a heat lo with an overall heat tranfer coefficient of h, to it environment at a temperature o. (12) Fig. 5. nzexb with GSHP and wind turbine 7

8 Pump P1: hi pump follow P2 and in thermal energy balance between the heat pump and nzexb, E P1 i Equal to E P2, with the exception that it mut take into account of η ES. he reervoir pump P3 ha a fixed operation (practically independent of ) o that it i not taken into account for the optimization proce. E P1 = E P2 /η ES (13) Heat Pump (14) hen the partial objective function become: ΣE = E P1 + E P2 + E ES + E HP {minimize} (15) Here E i exergy. he performance of the wind turbine for unit power output depend on in term of REMM efficiency Ψ RW. hi value may be added to Eq. 15 with a weighing factor, y for complete optimization. ΣE = E P1 + E P2 + E ES + E HP+ y/ψ RW {minimize} (16) [4] (17) For a given deign, Eq. 15 i a function of the ingle variable, o that Eq. 18 give the optimum. de/d = 0, (18) Cae tudy A pecific deign example imilar to the arrangement given in Fig. 5 ha been optimized. he deign input and other equipment parameter are: n = 1.3, d =1, η P2 = 0.9, η ES = 0.85, η HVAC = 0.9, h = 20, a = 2, z = 1.1, a = o = 293 K, d = 333 K, ref = 283 K, η W = 0.40, y = 5, r = 288 K, y = 10. Uing thee value in Equation 16 and 17 with a imple earch yield the optimum. Reult are given in the next ection. Sample Reult A parametric tudy for a limited number of variable were carried out. It i poible to analyze the impact of all other variable of the model. Here, the impact of on ΣE i analyzed firt, which reveal the optimum value. From Fig. 6, the optimum value of i found to be 308 K (35 o C) for an equipment with n = 1.3. Fig. 6. Variation of the total exergy demand with due to overizing for the cae tudy, n = 1.3 By varying the equipment exponent (n) between 1 and 1.4, the optimum temperature change ha alo been determined and hown in Fig. 7. Here, the minimum i achieved for an equipment with n = 1, which 8

9 approximately correpond to a radiant floor panel in heating. he variation of PEXR, which i the mot important parameter in thi model i maximum for n = 1 and = 305 K, which i hown in Fig. 8. Fig. 7. Variation of the optimum temperature with equipment (n). Dicuion of reult and concluion Fig. 8. Variation of PEXR with hi tudy ha preented a new model in order to provide a tool for optimizing the operating fluid temperature of a GSHP coupled to a wind turbine, which collectively erve an nzexb building. In thi model the energy and exergy interaction among the upply, torage, and demand are fully recognized and expreed in the objective function, all reduced to the operating temperature. Such a model, which encompae thermal energy torage (ES) alo enable to optimize the energy torage for wind energy in the form of heat, both in ES (daily or weekly) and in the ground (in cooling: eaonal torage). Yet it i debatable to whether converting electrical energy into heat jut for comfort purpoe i rational or not. From an exergy point of view, it i not quite rational. Intead, electricity mut be ued in more value adding application in the built environment, epecially in ditrict energy ytem, rather than pace heating, which can be accomplihed by wate heat or olar heat in the ditrict. Even PV ytem may be mobilized, which add on power generation capacity over the wind turbine upply. he ue of olar power generation ytem in general and wind generation ytem together aure a more daily utained power upply, becaue there i about ix hour of time difference between peak olar and peak wind period. hi tudy demontrated that the new PEXR and COP EX definition, which bring a new performance metrication cheme, upplementing the Firt Law i intrumental in optimally hybridizing the renewable energy bundle and utainable ytem. If the abolute purpoe i to ue wind energy both for appliance, lighting etc. in nzexb and alo to heat and cool the building in a remote area (off the grid in particular) an optimum power uage plit may be the firt tep to make the wind energy ue in pace comfort purpoe more acceptable, provided that the operating fluid temperature i optimized. he cae tudy preented herein how that the terminal unit for pace heating mut have their n value cloe to one (panel heating). Fig. 7. demontrate thi rule: if n increae above one, increae, which reduce PEXR (Fig. 8). Other important deign parameter are the pump efficiency, ES inulation, ES efficiency, COP of the heat pump, and the efficiency of the wind turbine. More thee value are improved, then at an optimum plit of wind power (X), GSHP ue for comfort purpoe in an nzexb building may become reaonable and admiible. hee argument alo apply for other renewable ytem like cogeneration unit running on bioga, aborption ytem, and ORC [25]. the model developed in thi tudy let the deigner to optimize any deign variable to any ort of objective function elected. Reference 9

10 [1] [2] [3] LowEx Low Exergy Sytem for Heating and Cooling of Building Guidebook, IEA ECBS, Annex 37, ISBN (oft back ed.) < Lat viited on October 23, [4] Kılkış, B. and Kılkış, Ş Yenilenebilir enerji kaynakları ile birleşik ıı ve güç üretimi (In urkih): Combined heat and power production with renewable energy reource, urkih Society of HVAC and Sanitary Engineer, MD, echnical Publication 32, ISBN , Doğa Publication Inc., Itanbul. [5] Kilki, B. Deign, contruction, operation, and optimization of hallow geothermal ytem. IEA Annex 27, 4 th national working meeting, 31 October 2016, İtanbul. [6] Kilki, B. Exergy metrication of radiant heating and cooling. ASHRAE ranaction 2011;117-1: [7] Kilki, B. Rationalization and optimization of heating ytem coupled to ground-ource heat pump. ASHRAE ranaction 2000; 106-2: [8] Kilki, B. Role of panel heating and cooling in net zero energy building. ASHRAE ranaction 2010; 116-2: [9] Kilki, B Equipment overizing iue with hydronic heating ytem. ASHRAE J 40 (1); [10] Kilki, S. and Kilki, B. A parametric tudy for integrated deign optimization of low-energy building. ASHRAE ranaction 2011; 117-1: [11] Kilki, B. Rationalization of low-temperature to medium-temperature ditrict heating. ASHRAE ranaction1998; 104-2: [12] Kilki, B. An economic analyi tool for trigeneration ytem in net-zero exergy building (NZEXB), Paper No. 4, Abtracted: ISSN , XII International HVAC+R and Sanitary echnology Sympoium, March 31-April 2, İtanbul, [13] Kılkış, Ş A rational exergy management model to curb CO 2 emiion in the exergy-aware built environment of the future, PhD hei, Bulletin/Meddelande No. 204, ISBN , KH Royal Intitute of echnology, Stockholm, Sweden. [14] Kilki, B. An analytical optimization algorithm for wind energy coupled GSHP ytem for utainable building HVAC, Proceeding of IMECE03, Wahington DC, November IMECE , [15] Kilki, B. An analytical optimization tool for hydronic heating and cooling with low-enthalpy energy reource ASHRAE ranaction 2012; 108-2: [16] Kilki, B. and Kilki, S. Rational exergy management and optimization of power plit in a heat pump polygeneration ytem, Conference Proceeding, ICCI 20017, May, İtanbul, [17] Kilki, B. From floor heating to hybrid HVAC panel-a trail of exergy-efficient innovation, ASHRAE ranaction 2006; : [18] Zottl, A., Fleckl,., and Palm, B.E., GreenHP: Deign and performance of the next generation heat pump for retrofitting building, S-16-C034, ASHRAE ranaction 2016, Vol. 122, Pt. 2 [21] aro,. L.; Gaggioli, R. A.; Domanki, P. A., Exergy analyi of heat pump, N ; ASHRAE ranaction, Vol. 93, No. Part 2, , [22] Ching-Song J. et.al. Development of a wind directly forced heat pump and it efficiency analyi, International Journal of Photoenergy; 2013: ID , [23] Quin, Y. L., Chen, Q., Zhang, X., Performance of a rooftop wind olar hybrid heat pump ytem for building, Energy and Building; 65: 75-83, [24] Dincer, I. and Roen, Exergy: Energy, Exergy and utainable development. 2 nd. Ed. Elevier, 2013 [25] Kilki, B. and Kilki San. echnical, economical, and environmental comparion baed on exergy about utilizing heat of cogeneration for comfort cooling with ORC driven chiller or heat pump veru aborption/adorption cycle. ASME ORC 2013, Proc. on CD, 7-8 October,