Product Specifications and Design Guide

Transcription

1 Product Specifications and Design Guide Evacuated tube collectors ESC V6 ESC V12 ESC V18 With galvanised steel installation systems

2 General information Collectors should be aligned such that they face south where possible. Generally, the manifold is always to be installed uppermost. A minimum slope of 15 is required for installation on roofs, as well as on flat roofs, to facilitate self-cleaning. Do not remove the white protective sheet from the evacuated tubes until after the solar energy system has been commissioned. In the solar circuit, use brazed joints or olive connections only. Thermally insulate the pipes in accordance with the German Heating Installations Ordinance HeizAnlV. Ensure that the pipes are heat resistant (150 C) and UV resistant (pipes laid outdoors). Fill the solar energy system with Tyfocor-LS heat transfer medium only. The evacuated tube collectors are hail resistant in accordance with DIN EN However, we recommend including storm and hail damage in your building insurance. Our materials guarantee does not cover such damage. Work must comply with the relevant safety standards of DIN, DIN EN, DVGW, TRF and VDE. Solar collectors require registration or permits in accordance with the corresponding valid state regulations. Installation, maintenance and repairs must be carried out by authorised service personnel. The pipework of the solar circuit in the lower part of the building must be bonded as specified by VDE. The solar energy system may only be connected to existing or new lightning protection systems or equipotential bonding by authorised service personnel. The respective state s specific standards and safety regulations must be adhered to. Carefully read through these planning instructions.

3 Standards, regulations and EC directives Regulation Name Roof-mounting DIN VOB 1) : Roof covering and sealing work DIN VOB 1) : Plumbing work DIN VOB 1) : Scaffolding work DIN 1055 Design loads for structures Connection of thermal solar energy systems DIN EN Thermal solar systems and components - Collectors - part 1: General requirements DIN EN Thermal solar systems and components - Custom-built systems - part 1: General requirements; German version DIN V ENV Thermal solar systems and components - Collectors - part 1: General requirements; German version DIN Solar heating systems with water or water mixes as heat transfer media; Safety design requirements DIN Solar heating systems with organic heat transfer media; Safety design requirements Installation and equipping of water heaters DIN 1988 Technical rules for drinking water supply systems (TRWI) DIN Water heaters and water heating systems for drinking and process water; Requirements, marking, equipment and inspection DIN VOB 1) : Heating systems and central water heating systems DIN VOB 1) : Gas, water and sewage installation work in building interiors DIN VOB 1) : Insulation works on technical installations AVB 2) Water DVGW W 551 Drinking water heating and piping systems; Technical measures to prevent the growth of legionella Electrical connection DIN VDE 0100 Installation of power installations with rated voltages of up to 1000 V DIN VDE 0185 Lightning protection system VDE 0190 Main equipotential bonding of electrical systems DIN VDE 0855 Antenna systems - to be applied correspondingly DIN VOB 1) : Electrical cabling and conduit systems in buildings Important regulations for the installation of solar collector systems 1) VOB German construction contracting regulations part C: General technical contract conditions for construction work 2) Tender templates for construction work in the area of building construction, with particular reference to residential construction

4 Benefits and advantages Intelligent design and installation: Suitable for installation on pitched roofs, flat roofs, walls, free-standing and facade installation. For heating drinking water and heating water for partial solar heating and swimming pool water, as well as for solar cooling. Great flexibility due to collector units of different widths. Up to 15 m 2 can be connected in series. Exceptional design. Quick installation thanks to completely pre-assembled collector units and simple, flexible on-roof and flat roof installation sets. Simple connection technology for adding multiple collectors beside one another with pre-installed screw fittings. No additional piping or thick insulation required. The flow and return pipe can be connected to the collector either on the left or on the right. Tubes can be replaced without draining the collector circuit - dry connection. Simple connection of hydraulic connecting lines with olive connection technology. Reliability: High reliability and long service life via the use of high-quality, corrosion-resistant materials such as thick borosilicate glass, copper and anti-corrosion coated aluminium. Permanent vacuum seal of the tubes thanks to pure glass bonds without glass-metal transitions. Pure glass-glass composite, thermos flask principle. High reliability due to dry connection of the evacuated tubes to the solar circuit. Recycling: Fully recyclable thanks to easy-to-dismantle design and re-usable materials. Energy yield and performance: Extremely high energy yield with small gross surface of the collectors. Circular absorber surface guarantees that each individual tube is always optimally aligned with the sun. Exceptionally high solar coverage rates are possible. High efficiency via highly-selective coating on absorber. The evacuated tubes reduce thermal losses of a solar collector as there is no air in the vacuum which could transport the heat from the surface of the absorber to the outer glass tube which is affected by the weather. The heat transfer medium flows directly through the tubes without an intermediate heat exchanger in the collector. The circular absorber collects both the direct and diffuse solar irradiation optimally at all times. The CPC reflector and direct flow through the evacuated tubes make a significant contribution to an extremely high energy yield. Optimal thermal insulation via a vacuum, which results in high efficiency, particularly in winter and at low irradiation. Unused excesses in the summer are lower than with flat plate collectors. At the same time, the yield in winter is significantly higher. It is also ideal for low-flow systems with stratified charging and heating support.

5 Structure and function of the collectors Historic roots - the invention of the thermos flask The Scottish Physicist James Dewar invented a double-walled vessel with a vacuum-insulated cavity in the thermos flask. Emmet developed the first evacuated tubes based on the thermos flask principle to utilise solar energy in His patents from this time still form the basis for state-of-the-art evacuated tube technology. The efficiency of this old and familiar thermos flask technology did not reach a high standard until state-of-the-art coating technologies and highly-selective coatings were applied. Today s technology ECOTHERM evacuated tube collectors consist of 3 main components which are completely pre-assembled: evacuated tubes, CPC reflectors and the manifold with the heat conduction unit Evacuated tubes The evacuated tube is a product which has been optimised in terms of geometry and performance. Evacuated tubes consist of two concentric glass tubes which are sealed in a semi-circular shape on one side and are joined to one another on the other side. The space between the tubes is evacuated and then hermetically sealed (evacuated insulation). To use solar energy, the internal glass tube is coated with an environmentally friendly, highly selective layer on the outside, thus turning it into an absorber. This coating is thus protected in the vacuum cavity. The aluminium nitrite sputter coating used is characterised by extremely low emissions and excellent absorption. Copper pipe / stainless steel pipe Heat transfer plate Absorber coating Evacuated tube CPC reflector

6 The CPC reflector To increase the efficiency of evacuated tube collectors, a highly reflective, weather-proof CPC (Compound Parabolic Concentrator) is fitted behind the evacuated tubes. The reflector geometry guarantees that direct and diffuse sunlight strikes the absorber, even when the angles of irradiation are unfavourable. This significantly improves the energy yield of a solar collector. Unfavourable angles of irradiation are caused by light striking the collector at an angle (azimuth angle) (mounting surface does not face south, solar movement from east to west, diffuse irradiation). e.g. direct solar irradiation e.g. angled, direct solar irradiation e.g. diffuse solar irradiation

7 Manifold and heat conduction unit The manifold contains the insulated collecting and distributing pipes. The flow and return pipe can be connected on the left or on the right, as selected. Each evacuated tube contains a direct flow U-shaped pipe which is connected to the collecting or distributing pipe such that each individual evacuated tube has the same hydraulic resistance. This U-shaped pipe is pressed against the inside of the evacuated tube with the heat transfer plate. Flow/return connection Sensor immersion sleeve Collecting pipe / distributing pipe Thermal insulation Manifold U-pipe CPC reflector Heat transfer plate Evacuated tube

8 Technical data Technical specifications for ESC V6/ V12/ V18 Series ESC V6 ESC V12 ESC V18 Number of evacuated tubes η 0 (aperture), DIN or EN % c 1 with wind, in relation to aperture W/(m 2 k) c 2 with wind, in relation to aperture W/(m 2 k 2 ) K θ,trans (50 ), in relation to aperture K θ,long (50 ), in relation to aperture Yield forecast kwh/m 2 a Grid dimensions (length x height x depth) m 0.70 x 1.64 x x 1.64 x x 1.64 x 0.1 Gross surface area m Aperture area m Collector contents - OEM I Collector contents - INOX I Weight - OEM kg Weight - INOX kg Max. permitted operating overpressure bar Max. stagnation temperature C Connection width, flow/return mm Collector material - OEM Collector material - INOX Al / Cu / glass / silicone / PBT / EPDM / TE Al / stainless steel / glass / silicone / PBT / EPDM / TE Glass tube material borosilicate glass 3.3 Selective absorber coating material Glass tube, aluminium nitrite (Ø ext./ø int./wall thickn./tube lgth.) mm 47/37/1.6/1500 OEM colour (aluminium frame profile, anodised) aluminium grey INOX colour (aluminium frame profile, powder-coated) RAL 7015 Colour (plastic parts) black Thermal shock test ITW test number 06COL513/1 Hailstone test according to DIN EN TÜV test number 435/ EC type examination - INOX TÜV test number Z-IS-DDK-MUC EC type examination - OEM TÜV test number Z-IS-DDK-MUC DIN CERTCO registration number Heat transfer medium 011-7S113R and 001-7S134R Tyfocor LS

9 Pressure loss Pressure loss of the tube collectors ESC V6/ V12/ V18 Heat transfer medium: Tyfocor LS; medium temperature medium: 40 C ESC V18 ESC V12 ESC V ,25 0,5 0,75 1 1,25 1,5 1,75 2 2,25 2,5 2,75 3 3,25 3,5 3,75 4 4,25 4,5 4,75 5 Flow rate [l/min]

10 Heat output The collector output is calculated based on the collector efficiency ( ) depending on the strength of the irradiation (G*) and the aperture area per collector unit (A). It provides information on the thermal output of the collector at a specific irradiation strength. The following equation is used to calculate the collector output: with: If the difference between the collector temperature and the ambient temperature ( ) is zero, the collector has zero heat loss to the surrounding air and the efficiency is maximum; this is known as optical efficiency. Part of the solar irradiation (G*) which strikes the collectors is lost due to reflection and absorption. The optical efficiency takes these losses into consideration. When the collectors heat up, they dissipate heat to the surrounding area via conduction, radiation and convection. The heat transmission coefficient a 1 and a 2 incorporate these losses. The almost horizontal power curves mean that CPC collectors generate high outputs even at great temperature differences between the collector temperature and the ambient temperature, in contrast to flat plate collectors. Power curve of the ESC V6 /V12 /V18 tube collectors at an irradiation G* of 1000 W/m Power output per collector unit[w] Power curve (G* = 1000 W/m ) ESC V18 ESC V12 ESC V ( ϑ ϑ m a ) [K ] ESC V18

11 In general, less solar irradiation is available for use as solar energy (for water heating and heating support) in the six winter months and in transitional periods (e.g. 400 W/m 2 ). The temperature differences between the collector temperature and the ambient temperature are also very high due to the low temperatures outside. The following tables (source: ITW test report number 06COL513) give an exact overview of how the collector output changes depending on the radiation strength and temperature difference. The values specified are for vertical irradiation. Power output per collector unit [W] for ESC V6 Irradiance 400 W/m W/m W/m Power output per collector unit [W] for ESC V12 Irradiance 400 W/m W/m W/m Power output per collector unit [W] for ESC V18 Irradiance 400 W/m W/m W/m

12 Notes on solar controllers The solar controllers for tube collector systems should have a push-start function. This push-start function prevents excessive temperature differences between the temperature measured at the collector sensor and the temperature in the lower/middle part of the tubes. The push-start (activation) of the pump is to be started approx. two to three times per minute for approx. 3-5 seconds when a temperature increase is detected at the collector sensor to pump the hotter solar fluid to the measuring point.

13 Design of the collector connection lines An average throughput of l/h per m 2 of aperture area (approx l/min per m 2 ) can be assumed when selecting the piping dimensions. We recommend low-flow operation for large-scale solar energy systems, as the specific flow rate can be reduced to l/h m 2 (approx l/min per m 2 ). In order to keep piping work to a minimum, we recommend that you connect max. 9.0 m 2 (high-flow) and 15 m 2 (low-flow) of collector aperture area in series. In order to minimise the pressure loss due to the solar energy system piping, the flow speed in the copper piping should not exceed 1 m/s. We recommend flow speeds of between 0.3 and 0.5 m/s. The cross sections should be dimensioned in accordance with throughput and speed as in a standard heating system. We recommend that you use standard copper piping and gunmetal fittings when installing the collectors. The connection points of the pipes should be brazed or connected using olive connections due to the high stagnation temperatures. No galvanised pipes, galvanised fittings or graphite seals may be used. Hemp may only be used in conjunction with pressure and temperature resistant sealant. The components used must be resistant to the heat transfer medium. The thermal insulation of pipes outdoors must be temperature and UV radiation-resistant and resistant to bird damage. Guidelines for selecting pipe diameter dimensions for series connection of ESC V6 / V12 / V18 collectors and a pump with a head height of max. 6 m. High-flow Aperture area m Flow rate litres/min Copper pipe dimensions 12 x 1 12 x 1 12 x 1 15 x 1 15 x 1 15 x 1 15 x 1 18 x 1 Low-flow Aperture area m Flow rate litres/min Copper pipe dimensions 12 x 1 12 x 1 12 x 1 12 x 1 12 x 1 12 x 1 12 x 1 12 x 1 Aperture area m Flow rate litres/min Copper pipe dimensions 12 x 1 12 x 1 15 x 1

14 Connection options Legend Corrugated hose return (cold) Corrugated hose flow (hot) with collector sensor Connection options for 1 collector Caution: Sensor is positioned on the flow side (hot). Connection options for 2 or more adjacent collectors Caution: Sensor is positioned on the flow side (hot). Reverse connection of the flow direction is possible. Connection options for 2 or more collectors above one another Caution: Sensor is positioned on the flow side (hot).

15 Connection options for 1 or 2 adjacent collectors and 2 or 3 collectors above one another Caution: Sensor is positioned on the flow side (hot). Note! In order to facilitate bleeding and equalise the collector arrays, one shut-off ball valve should be built into each outlet. Connection options for 1 or 2 adjacent series connections and multiple series connections above one another Caution: Sensor is positioned on the flow side (hot).

16 Sample system Sample system for solar water heating N M L B K A Flow Return F B C D B E G H I J A) Collector B) Gate valve C) Non-return valve D) Solar pump E) Flow regulation valve F) Pressure gauge G) Safety valve H) Blow-off tank I) Primary shutoff ET J) Expansion tank K) De-aerator L) Filling fitting M) Gravity loop to prevent microcirculation in the pipeline N) Hot water storage tank Sample system for solar water heating with heating support Q P S R O O) Primary tank P) Heat generator Q) Heating circuit R) Buffer storage tank with integrated hot water storage tank S) For solar energy systems with heating support, we recommend that you install a primary tank. Solar energy systems which are too large for the six summer months often stagnate, i.e. the membrane of the expansion tank is protected by the cold primary content of the primary tank.

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18 Space requirement for flat roofs The ESC V6 / V12 / V18 evacuated tube collector can be installed on flat roofs, on slightly sloping roofs (up to 20 ) or in gardens. The spacing between the angle frames must also be adhered to on sloping roofs. It may be necessary to add auxiliary rafters. If applicable, a stress analysis is to be carried out on the substructure. Space requirements for a single-row collector array: A B Dimension A according to number of collectors Number of collectors ESC V6 / V12 / V (m) (m) (m) Dim. B and C according to installation angle Installation angle (m) Dim. B Dim. B Dim. C Dim. C ESC V6 / V12 / V18

19 Weight and positioning of the concrete slabs Note! Flat roofs covered with gravel : clear gravel from the area where the concrete slabs are to be placed. Flat roofs with plastic roof sheeting: place the concrete slabs on protective overlays (building protection mats, pos.1). B Arrange the concrete slabs as shown in the figure to the left. A ESC V6 / V12 / V Dim. A (m) Dim. B 30 (m) 1.23 Dim. B 45 (m) 0.92 Building height of up to 8 m Collector type Number Angle Required weight Required weight of the angle of the of the front of the rear frames frame concrete slab concrete slab ESC V6 V12 V kg 75 kg ESC V6 V12 V kg 75 kg Building height of up to 20 m Collector type Number Angle Required weight Required weight of the angle of the of the front of the rear frames frame concrete slab concrete slab ESC V6 V12 V kg 112 kg ESC V6 V12 V kg 112 kg

20 Specifications The flow or return pipe can be connected to the collector on the left or on the right, as selected. The connection is made using premounted 15 mm olive connections. Reducing fittings to 12 mm are available in the accessory connection sets. One integrated sensor immersion sleeve is available on each collector connection side. The sensor is always located on the hot flow side. Upon delivery, the collector is covered by a sun protection sheet. This facilitates trouble-free commissioning of the solar energy system even in strong sunlight. It prevents the heat transfer medium being vaporised, rendering commissioning impossible. Remove the sun protection sheet after commissioning. The collector must be commissioned 4 weeks after installation at the latest.