HCE Tubes

Parabolic Trough

The Rioglass Solar UVAC 70-7G is the last generation of receiver tubes based on 20 years of in-field experience. The continuous innovation of our product design and production processes have enabled us to offer an optimized product with high and state-of-the-art performance. Our Anti-Reflective coating is high performing and extremely durable ensuring optimized energy transmission for the lifetime of the tube. The selective coating improved over many years and sophisticated vacuum technology and design have enabled us to offer you extremely good absorption and low emissivity.

Linear Fresnel

In order to improve the energy output, our customers incorporate super-heated steam section into their Linear Fresnel plants. Our Rioglass Solar UVAC 70-7G is the last generation of receiver tubes that is an evacuated receiver tube suitable for these high temperature application reducing the heat losses by means of the vacuum between the steel tube and the glass tube. The receiver tubes provide our customers with the best Cost of Ownership. The continuous innovation of our product design and production processes have enabled us to offer an optimized product with high and state-of-the-art performance: the Anti-Reflective coating is high performing and extremely durable ensuring optimized energy transmission for the lifetime of the tube and the selective coating improved over many years and sophisticated vacuum technology and design have enabled us to offer you extremely good absorption and low emissivity.

Assembly

• length: 4386 mm ± 2,0 mm at 20°C ambient temperature

• effective aperture length: ≥ 96.7 % of the bulk length at 350°C working temperature

Absorber

• outer diameter: 80,0 mm + 0,30 / – 0,30 mm

• wall thickness: 2,0 mm + 0,2 / – 0,2 mm

• steel-type: EN1.4541 or AISI321

• average solar absorptance of all receivers delivered: α ≥ 0,955 (95,5%) 2) ASTM

• absorptance of single absorber: αASTM ≥ 0,9452)

• average thermal emittance of all receivers delivered (400°C): ε ≤ 0.0953) (9,5%)

• emittance of single absorber (400°C): ε ≤ 0.123)

Glass Envelope

• borosilicate glass 4)

• outer diameter: 136 mm ± 3.0 mm

• antireflective coating on ≥ 95,0% of aperture length

• average solar transmittance of coated area of all receivers delivered: τ ≥ 0.9652) (96,5 %)

• transmittance of single glass envelope in coated area: τ ≥ 0,960 2) (96,0 %)

Weight

• 31 kg +3,0 kg / -3,0 kg (unfilled)

Vacum

• initial residual gas pressure ≤ 10-4 mbar

Heat loss

260 W/m (@ 400°C)

185 W/m (@ 350°C)

125 W/m (@ 300°C)

Average values only valid for operation with Rioglass shields

• mean heat loss values corresponding to emittance = 9.5%

• heat loss single values may vary due to deviation of emittance data’s

Heat transfer fluid (HTF)

non-corrosive thermal oil with an effective partial pressure of dissolved hydrogen of pH2 < 30 Pa 5)

Recomended wellding filler material

DIN1.4316 or DIN1.4551

Maximum Operating Temperature

Maximum bulk fluid temperature: 400 ºC

Flow rate

Reynolds number Re > 20.000

Operating pressure

≤ 37 barg

Operating conditions

Solar concentration ratio: C < 100

Environmental conditions

• Min / max temperature ambient: -10ºC / +50ºC

• Max. relative humidity: 95%

• Max. design wind speed: 40 m/s

• Max. base wind speed: 30 m/s – wind class 3

• Max. equivalent acceleration 0,4 g in case of seism

• Compliance with maximum C2 corrosivity class conditions according to ISO9223

Design and manufacturing codes

The RIOGLASS PTR®80-4G receivers are designed, manufactured and inspected in compliance to the following regulations

• Pressure Equipment Directive 2014/68/UE of the European Parliament

• ASME Sec. VIII Div. 1

Further requirements included in referred standards such as EN10217-7, A249, etc. are considered with the RIOGLASS PTR®80-4G receiver.

Standards for power or process piping (ASME B31.1 or ASME B31.3) are not designated for the RIOGLASS PTR®80-4G solar receiver as a component of pressure vessel. However, by following the requirements of ASME Sec. VIII Div. 1, RIOGLASS PTR®80-4G receivers fulfil also applicable requirements of ASME B31.1 and ASME B31.3.

Assembly

• length: 4.060 mm ± 2,0 mm at 20°C ambient temperature

• effective aperture length: ≥ 96.7 % of the bulk length at 350°C working temperature 1)

Absorber

• outer diameter: 88,9 mm + 0,15 / – 0,35 mm

• wall thickness: 2,5 mm + 0,25 / – 0,25 mm

• steel-type: DIN 1.4541 or similar

• average solar absorptance of all receivers delivered: αISO ≥ 0,957 (95,5%) 2) | αASMT ≥ 0,960 (95,5%) 3)

• absorptance of single absorber: αISO ≥ 0,945 2)

• average thermal emittance of all receivers delivered (400°C / 752ºF): ε ≤ 0.095) (9,5%) 4)

• emittance of single absorber (400°C): ε ≤ 0.105 4)

Glass envelope

• borosilicate glass 5)

• outer diameter: 142 mm ± 2.5 mm

• antireflective coating on ≥ 95,0% of aperture length

• average solar transmittance of coated area of all receivers delivered: τ ≥ 0.970) (97 %) 2)

• transmittance of single glass envelope in coated area: τ ≥ 0,960 2) (96,0 %) 2)

Weight

• 35 kg ± 10% (unfilled)

Vacum

• initial residual gas pressure ≤ 10-4 mbar