The Performance of First Transpired Solar Collector Installation in Turkey

Available online at www.sciencedirect.com

ScienceDirect Energy Procedia 91 (2016) 442 – 449

SHC 2015, International Conference on Solar Heating and Cooling for Buildings and Industry

The performance of first transpired solar collector installation in Turkey Dogan Eryener*, Hacer Akhan Trakya Universty, Edirne 22180, Turkey

Abstract In 2014, Turkey consumed 12 billion cubic meters of natural gas for space heating which accounts 26 percent of general natural gas consumption. Using several technologies to collect solar heat is one of the solutions to reduce the energy consumption in buildings. Among these technologies are transpired solar collectors, which are relatively new solar energy technology in Turkish energy market despite its wide and effective use in North America and Europe over the past 30 years to save energy in buildings by heating ventilation air using solar energy. In 2012, the first transpired solar collector on an industrial building was installed in Turkey, Cayirova. The installation on the south facing wall of PIMSA manufacturing building is a total of 770 m² with six large associated air handling units. This paper presents a review of the performance of the first transpired solar collector in Turkey. The energy drawn from solar collector and delivered to the building each month over the period of two years is monitored and analyzed. Results cover monitoring for the period of February 2013 - April 2013 and January 2014 - March 2014, when the transpired solar collector was operating. The monitoring system includes twenty-four thermocouples embedded in transpired solar collector with connected air handling units, two in the building, two outside on the wall and twenty-four automatic damper controllers all connected to a building management system. It has shown that transpired solar collector provides a significant amount of the heating required by the building. Heat outputs from transpired solar collector installation are also compared with the simulation outcomes of Retscreen solar air heating analysis software developed by the Canadian government. © 2016 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license © 2015 The Authors. Published by Elsevier Ltd. (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review by the scientific conference committee of SHC 2015 under responsibility of PSE AG. Peer-review by the scientific conference committee of SHC 2015 under responsibility of PSE AG

Keywords: Transpired solar collector; Solar air heating

* Corresponding author. Tel.: +0-284-226-1225(1115); fax: +0-284-226-1225. E-mail address: [email protected]

1876-6102 © 2016 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review by the scientific conference committee of SHC 2015 under responsibility of PSE AG doi:10.1016/j.egypro.2016.06.172

Dogan Eryener and Hacer Akhan / Energy Procedia 91 (2016) 442 – 449

1. Introduction Nomenclature M Cp ǻT

fan mass flow rate specific heat capacity the temperature difference between outside air temperature and TSC duct temperature

A solar air heating system, also called a transpired or perforated plate collector (TSC), is a building-integrated renewable energy technology that pre-heats or re-heats building ventilation air. One of the most important features of the TSC is a synchronized heat and fresh air operation, also the system provides energy savings by reducing temperature difference between the building wall and ambient. This paper presents a review of the performance of the first TSC installation in Turkey, Cayirova, which was installed in 2012 in an automotive production plant, owned by PIMSA Automotive. The energy drawn from solar collector and delivered to the building each month over the period of two years is monitored and analyzed. Results cover monitoring for the period of February 2013 - April 2013 and January 2014 - March 2014, when the transpired solar collector was operating. 2. Overview of solar thermal collectors in Turkey According to the report of Turkish Renewable Energy General Management, the estimated thermal solar energy potential of Turkey is approximately 380 billion kWh per year. Turkey is one of the leading countries with 4 million m2 solar thermal collector and 7.1 GWth, in the world. However, in Turkey, solar thermal collectors are mainly used in private households to heat water, despite the fact that the potential of solar thermal energy is much higher comparing to other types of energy. On the other hand, it should be noted that solar air heating market is relatively new in Turkey. Although various researches and applications have been made about TSCs in Turkey, commercial use in building heating is not as common as in the rest of the world. In general, the first idea that comes to mind is system that provides hot water by solar energy, when solar energy heating system is mentioned. 3. Transpired solar collectors A transpired solar collector (TSC) is a solar thermal system which can be used to preheat the ventilation air supply in buildings, using solar radiation as its energy source. John Hollick first developed TSC that was used for heating outside air directly [1]. Research and investigation into using solar air collector for solar heating systems first appears in the 90s. The basic heat loss theory for solar air collector was presented by Kutscher and Christensen [2]. Kutscher used the derived equations to develop a predictive model for thermal performance [3]. Van Decker investigated heat exchange effectiveness more thoroughly for three-dimensional flows [4]. Van Decker and Hollands extended the correlation for the effectiveness to no-wind conditions circular holes on a square or triangular pitch [5, 6]. Gunnewiek included the effects of wind on flow inside the plenum in their previous study [7]. Leon and Kumar developed a model used for drying [8]. High absorbing efficiency can be realized in TSCs compared to conventional solar air heating collectors [9-13]. The scheme of TSC, which heats fresh air by using solar energy, is seen in figure 1. The absorber plate is mounted on the wall with a distance of 10 cm - 30 cm. With the effect of negative pressure, which is created by a fan, the fresh air passes through the plenum air via the holes on the absorber plate. Solar energy is transferred to the air while the ambient air passed through the plenum. The heated air moves towards the top of the plenum and then is sent to the ventilation duct.

443

444

Dogan Eryener and Hacer Akhan / Energy Procedia 91 (2016) 442 – 449

Fig. 1. The transpired solar collector.

4. Overview of TSC installation 4.1 Building description, solar air handling design and monitoring In this study, the first application of TSC has been applied by PIMSA Automotive in Turkey. PIMSA Automotive Gebze in TOSB Facility Complex is comprised of one multistoried manufacturing plant and office building, one warehouse, one auxiliary service building and an outdoor parking garage surrounding the main building’s west and south borderlines. The facility is continuously occupied since August 2012. The system has been designed for the purpose of pre-heating ventilation/make up air, improving the air balance and comfort of the building, displacing onsite auxiliary heating fuel consumption, and recapturing building heat loss. The TSC installation on the south facing wall of PIMSA manufacturing building is a total of 770 m² with air handling units. There are six large supply TSC fans in manufacturing building, 3 units per floor. Each TSC connected fan provides 2.95 m3/s of fresh air and has an auxiliary heating coil when solar heat is insufficient. Figure 2 shows front view of TSC layout.

Fig. 2. Front view of TSC.

PIMSA TOSB facility utilizes a computerized building automation system called Building Management System (BMS) which is used for the monitoring of the performance of TSC. BMS includes controls and sensors for the heating, cooling, ventilation, lighting, and safety systems of the manufacturing plant and office building. BMS is capable of evaluating the systems performance by logging short and long-term historical data according to parameters set up by the operator (sample rate, duration, change of value, etc.). This information is then used to investigate and/or correct equipment performance, building interior conditions and to document indoor air quality issues. In PIMSA facility, there are 39 temperature sensors located in five floors of the office building. Also the monitoring system includes twenty-four thermocouples embedded in TSC with connected air handling units, four in manufacturing spaces, two outside on the wall and twenty-four automatic damper controllers all connected to a

Dogan Eryener and Hacer Akhan / Energy Procedia 91 (2016) 442 – 449

building management system. Figure 3 shows BMS, which is used for the monitoring of the performance of SW5, one of six installed fans.

Fig. 3. BMS for monitoring of the performance of TSC.

4.2. Retscreen analysis overview The resulting estimated energy savings were calculated through the use of Retscreen feasibility analysis software [14]. TSC in PIMSA plant delivered 521557 kWh/year of renewable energy according to Retscreen simulations. Retscreen simulation results validated by real monitoring data, which is taken from BMS of PIMSA during 20132014. According to Retscreen analysis, TSC reduced greenhouse gas emissions by 103 tons of CO2 a year at PIMSA plant. Table 1. Site conditions for the Retscreen model. Parameter

Case

Indoor set temperature

20°C

Max. supply temperature

45°C

Min supply temperature

15°C

Collector area

770 m2

Collector depth

0,3 m

Flow rate

63720 m3/h

Latitude

40,7°N

Longitude

29,8°E

Elevation Solar collector absorptivity

0,92

18m

Azimuth

0,0

Tilt

90° wall

Floor area

9720 m2

R-value-roof

2,0 m2.°C/W

R-value-wall

1,5 m2.°C/W

Weather data

Golcuk

Operation schedule

7/24

445

446

Dogan Eryener and Hacer Akhan / Energy Procedia 91 (2016) 442 – 449 Table 2. Average daily solar radiation values. Month

Average daily solar radiation-horizontal

Average daily solar radiation- 90°

kWh/m²/d 1.67 2.31 3.49 4.46 5.91 6.71 6.79 5.93 4.69 2.99 1.88 1.39 4.03

kWh/m²/d 2.49 2.61 2.96 2.74 2.76 2.73 2.87 3.21 3.61 3.16 2.65 2.14 2.83

January February March April May June July August September October November December Annual

Table 3. Annual average summary of Retscreen simulation. Case

Unit

Solar heating delivered

521557

Net annual GHG emission reduction

103

kWh tCO2

5. Performance of TSC Trakya University Mechanical Engineering Department monitored TSC installation at PIMSA Automotive in Cayirova for 6 months. Results cover monitoring for the period from February 2013 to April 2013 and January 2014 to March 2014 when TSC was operating. The monitoring comprises 6 thermocouples embedded in the wall, 6 in the delivery duct, two in the building and one outside, below TSC, all connected to one BMS. In addition, a set of sensors on a rack monitors air temperature stratification. A display of system output has been developed and used on collected data. The energy drawn from TSC and delivered to the building in each month during six months study. The energy delivered by TSC calculated from the well-known heating and ventilation equation (1)

ܳ ൌ ‫ ܯ‬ൈ ‫ܥ‬௣ ൈ οܶ

where M = fan mass flow rate, Cp = specific heat capacity and ǻT is the temperature difference between outside air temperature and TSC duct temperature. Table 4 shows TSC energy delivery in kWh below. Results show that there is an accordance with Retscreen simulations. It can be seen that 113037 kWh of energy was collected in 2013, and 246924 kWh of energy was collected in 2014 for three months monitored. The difference between energy delivered in 2013 and 2014 is related with operation time of TSC air handling units. Figures 4-8 show the performance of TSC at PIMSA plant. As shown in Figures 4-8, TSC provides very efficient heating and performance during the winter months. The temperature rise is recorded up to 45ÛC and 100% immediate heating power saving is achieved on sunny days. Monthly energy and monetary savings of TSC at PIMSA plant are shown in Table 5, up to 62% saving is obtained. Table 4. TSC energy delivery. Month

TSC Energy delivered, 2013 , kWh

January

No data

TSC Energy delivered, 2014, kWh 105741

February

30918

83117

March

36861

58066

April

45258

No data

8.07

7.21

5.25

5.58

253484.73

73264.58

68835.79

54745.89

73331.39

83117.42

105741.72

105403.83

45258.05

36861.74

30918.52

40064.27

Average Monthly Energy Savings of TSC (kWh)

39.25%

46.00%

41.58%

61.77%

53.55%

56.48%

54.63%

Relative Savings (%)

5818.22

7401.92

7378.27

3168.06

2580.32

2164.30

2804.50

Monetary Savings (TL)

Dogan Eryener and Hacer Akhan / Energy Procedia 91 (2016) 442 – 449

16.37

229873.61

19.49

211781.12

18.59

4064.62

T(SW6)

33.90%

171273.54

T(SW)

T(SW5)

58066.02

20.49

Date

T(SW4)

Date

Table 5. Monthly energy and monetary savings of TSC at PIMSA plant. Average Daily Average Monthly Operating Time of TSC Heating Requirements (hour) (kWh) Date

December 2012

February 2013

March 2013

April 2013

December 2013

January 2014

45 40

35

30 25

20 15

T(amb)

T(SW3)

Fig.4. Changing of the solar supplied air (SW) and ambient temperature during the system operation.

T(SW2)

25.12.2012 03.02.2013 12.02.2013 03.04.2013 19.04.2013 19.04.2013 19.04.2013 20.04.2013 05.12.2013 06.12.2013 08.12.2013 10.12.2013 11.12.2013 13.12.2013 14.12.2013 16.12.2013 17.12.2013 19.12.2013 21.12.2013 23.12.2013 24.12.2013 27.12.2013 04.01.2014 07.01.2014 10.01.2014 13.01.2014 16.01.2014 20.01.2014 23.01.2014 26.01.2014 29.01.2014 01.02.2014 03.02.2014 07.02.2014 10.02.2014 11.02.2014 12.02.2014 13.02.2014 14.02.2014 15.02.2014 16.02.2014 17.02.2014 24.02.2014 02.03.2014

10 5

0

-5

40

35

30

25

20

15

10

5

0

T(SW1)

Fig. 5. Temperature rises in six different air intakes of TSC.

25.12.2012 03.02.2013 03.02.2013 07.02.2013 20.03.2013 19.04.2013 19.04.2013 19.04.2013 19.04.2013 19.04.2013 19.04.2013 20.04.2013 20.04.2013 05.12.2013 08.12.2013 12.12.2013 16.12.2013 19.12.2013 21.12.2013 23.12.2013 26.12.2013 03.01.2014 06.01.2014 08.01.2014 11.01.2014 14.01.2014 16.01.2014 18.01.2014 21.01.2014 24.01.2014 28.01.2014 31.01.2014 02.02.2014 04.02.2014 07.02.2014 10.02.2014 11.02.2014 12.02.2014 13.02.2014 14.02.2014 14.02.2014 15.02.2014 16.02.2014 16.02.2014 17.02.2014 28.02.2014

Temperature ( C )

February 2014

March 2014

Air Temperature Rises ( C )

447

448

Heating Power (kW ) 160

140

120

80

100

60

40

Air Gap Temperature ( C ) 60

50

40

30

20

Date

T(SW4) T(SW5) T(SW6)

Dogan Eryener and Hacer Akhan / Energy Procedia 91 (2016) 442 – 449

T(SW3)

Fig. 6. Air gap temperatures in six different TSC locations.

T(SW2) T(amb)

25.12.2012 03.02.2013 03.02.2013 06.03.2013 03.04.2013 19.04.2013 19.04.2013 19.04.2013 19.04.2013 19.04.2013 20.04.2013 20.04.2013 06.12.2013 10.12.2013 13.12.2013 18.12.2013 20.12.2013 22.12.2013 25.12.2013 03.01.2014 06.01.2014 08.01.2014 11.01.2014 14.01.2014 17.01.2014 20.01.2014 22.01.2014 25.01.2014 30.01.2014 02.02.2014 03.02.2014 07.02.2014 10.02.2014 11.02.2014 12.02.2014 13.02.2014 14.02.2014 15.02.2014 15.02.2014 16.02.2014 17.02.2014 28.02.2014

10

0

T(SW1)

Date

Building Heating Power Requirement

25.12.2012 01.02.2013 06.02.2013 21.02.2013 06.03.2013 22.03.2013 27.03.2013 09.04.2013 16.04.2013 19.04.2013 05.12.2013 08.12.2013 11.12.2013 14.12.2013 17.12.2013 20.12.2013 23.12.2013 26.12.2013 31.12.2013 03.01.2014 06.01.2014 09.01.2014 12.01.2014 15.01.2014 18.01.2014 21.01.2014 25.01.2014 28.01.2014 31.01.2014 03.02.2014 06.02.2014 09.02.2014 12.02.2014 15.02.2014 19.02.2014 24.02.2014 28.02.2014

20

SW Heating Power

Fig. 7. Changing of building heating requirement and TSC heating power during the system operation.

100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0%

SW

Date

Fig. 8. Changing of relative savings of TSC.

25.12.2012 01.02.2013 06.02.2013 21.02.2013 06.03.2013 22.03.2013 27.03.2013 09.04.2013 16.04.2013 19.04.2013 05.12.2013 08.12.2013 11.12.2013 14.12.2013 17.12.2013 20.12.2013 23.12.2013 26.12.2013 31.12.2013 03.01.2014 06.01.2014 09.01.2014 12.01.2014 15.01.2014 18.01.2014 21.01.2014 25.01.2014 28.01.2014 31.01.2014 03.02.2014 06.02.2014 09.02.2014 12.02.2014 15.02.2014 19.02.2014 24.02.2014 28.02.2014

0

Relative Energy Savings (%)

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6. Conclusion Energy protection in buildings is becoming more important day by day. Although TSCs are widely used to produce hot air from exterior side of buildings all over the world, they are relatively unknown and have had few applications in Turkey. In addition to the fact that TSC provide hot air and insulation at serious levels, they are systems that keep on energy saving when there’s not sun. This study shows that TSC has been successfully implemented in Turkey. References [1] Hollick J.C.,Unglazed Solar Wall Air Heaters, Conserval Engineering Inc., 200 Wildcat Rd. Downsview, Ontario M3J 2N5, Canada, Available online 2 July 2003 [2] Kutscher, C.F., Christensen, C., Barker, G., ‘Unglazed Transpired solar collectors: an analytic model and test results’, In: Proceedings of ISES Solar World Congress, 1991, Elsevier Science, 1991, vol. 2:1. pp. 1245–1250. [3] Kutscher, C.F., Christensen, C., Barker, G., ‘Unglazed transpired solar collectors: heat loss theory. ASME Journal of Solar Engineering’, 1993, vol.115 (3), pp.182–188. [4] Van Decker, G.W.E., Hollands, K.G.T., Brunger, A.P. ‘Heat exchange effectiveness of unglazed transpired-plate solar collector in 3D flow’, In: Goietzburger, A., Luther, J. (Eds.), Proceedings of EuroSun 96, Freiburg, Germany. DGS–Sonnen energie Verlags GmbH, Munchen, Germany, 1996, pp. 130–846. [5] Van Decker, G.W.E., Hollands, K.G.T., ‘An empirical heat transfer equation for the transpired solar collectors, including no-wind conditions’, In: Proceedings of the ISES 99 Solar World Congress, Australia, 1999 [6] Van Decker, G.W.E., Hollands, K.G.T., Brunger, A.P., ‘Heat exchange relations for unglazed transpired solar collectors with circular holes on a square or triangular pitch’, Solar Energy, 2001, vol. 71 (1), pp.33–45. [7] Gunnewiek, L.H.; Brundrett, E.; Gunnewiek, L.H., ‘Flow distribution in unglazed transpired plate solar air heaters of large area’, Solar Energy, (0038-092X) 10/1/1996, vol.57, Iss.4, pp.227. [8] Leon, M. Augustus; Kumar, S.; Leon, M. Augustus., ‘Mathematical modeling and thermal performance analysis of unglazed transpired solar collectors’, Solar Energy, (0038-092X) 1/1/2007, Volume 81, Iss.1; p.62-75. [9] Biona M., Culaba A., Serafica E., Mundo R., “Performance Curve Generation Of An Unglazed Transpired Collector For solar Drying Applications”, www.retsasia.ait.ac.th. [10] Wang C., Guan Z., Zhao X., Wang D., “Numerical Simulation Study On Study On Transpired Solar Ai r Collector”, Renewable Energy Resources and a Greener Future, VIII-3-4, Shenzhen, China, 2006. [11] Bulut H., Durmaz A. F., “Bir HavalÕ Güneú Kollektörünün TasarÕmÕ, ømalatÕ ve Deneysel Analizi”, I. Ulusal Güneú ve Hidrojen Enerjisi Kongresi, Eskiúehir, 2006. [12] Augustus Lean M., Kumar S., “Mathematical Modeling and Thermal Performance Analysis of Unglazed Transpired Solar Collectors”, Solar Energy, 2007, 81, 62-75. [13] Kutscher C., Christensen C., Barker G., “Unglazed Transpired Solar Collectors: Heat Loss Theory”, ASME J. Of Solar Eng., 1993, 115, 3, 182-188. [14] www.retscreen.net

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