Solar Ray Collector
OBJECTIVE:
- To determine the efficiency of the solar ray collector under various experimental conditions.
1. Illumination with halogen lamp. Water temperature θe≈ 20°C.
a) Complete collector b) Collector without glass plate 2. Illumination with halogen lamp. Water temperature θe ≈60°C.
c) Complete collector d) Complete collector, cold jet of air impinges e) Collector without glass plate f) Collector without glass plate, cold jet of air impinges
INTRODUCTION:
Solar ray collectors transform solar radiation into heat and transfer that heat to water. Then solar heat can be used for heating water, to back up heating systems. The heart of a solar collector is the absorber, which is usually composed of several narrow metal strips. The carrier fluid for heat transfer flows through a heat-carrying pipe, which is connected to the absorber strip. In plate-type absorbers, two sheets are sandwiched together allowing the medium to flow between the two sheets. Absorbers are typically made of copper or aluminum.
CALCULATION:
Important formula for calculating the useful power, PN and efficiency, η:
1. Useful power, PN = c · m · (θo - θi)
where, m = 100 g/min = 1.667 x 10-3 kg/s c = specific thermal capacity of water = 4.182 kJ/kg · K θo = average absorber outlet temperature θi = average absorber inlet temperature
2. Efficiency, η = PN / (qi x A)
where, qi = 1 kW/m2
A = 0.12 m2
Sample calculation:
PART A
I. Complete collector ( t=15 min ) - useful power, PN = c · m · (θo - θi) = (4.182 kJ/kg · K) · (1.667 x 10-3 kg/s) · (32.5 – 28.5) K = 0.0279 kW - efficiency, η = PN / (qi x A) = 0.0279kW / (1 kW/m2 x 0.12 m2) = 0.232
II. Complete without glass plate ( t=15min ) - useful power, PN = c · m · (θo - θi) = (4.182 kJ/kg · K) · (1.667 x 10-3 kg/s) · (35.0 - 30.0) K = 0.0348 kW
- efficiency, η =
- To determine the efficiency of the solar ray collector under various experimental conditions.
1. Illumination with halogen lamp. Water temperature θe≈ 20°C.
a) Complete collector b) Collector without glass plate 2. Illumination with halogen lamp. Water temperature θe ≈60°C.
c) Complete collector d) Complete collector, cold jet of air impinges e) Collector without glass plate f) Collector without glass plate, cold jet of air impinges
INTRODUCTION:
Solar ray collectors transform solar radiation into heat and transfer that heat to water. Then solar heat can be used for heating water, to back up heating systems. The heart of a solar collector is the absorber, which is usually composed of several narrow metal strips. The carrier fluid for heat transfer flows through a heat-carrying pipe, which is connected to the absorber strip. In plate-type absorbers, two sheets are sandwiched together allowing the medium to flow between the two sheets. Absorbers are typically made of copper or aluminum.
CALCULATION:
Important formula for calculating the useful power, PN and efficiency, η:
1. Useful power, PN = c · m · (θo - θi)
where, m = 100 g/min = 1.667 x 10-3 kg/s c = specific thermal capacity of water = 4.182 kJ/kg · K θo = average absorber outlet temperature θi = average absorber inlet temperature
2. Efficiency, η = PN / (qi x A)
where, qi = 1 kW/m2
A = 0.12 m2
Sample calculation:
PART A
I. Complete collector ( t=15 min ) - useful power, PN = c · m · (θo - θi) = (4.182 kJ/kg · K) · (1.667 x 10-3 kg/s) · (32.5 – 28.5) K = 0.0279 kW - efficiency, η = PN / (qi x A) = 0.0279kW / (1 kW/m2 x 0.12 m2) = 0.232
II. Complete without glass plate ( t=15min ) - useful power, PN = c · m · (θo - θi) = (4.182 kJ/kg · K) · (1.667 x 10-3 kg/s) · (35.0 - 30.0) K = 0.0348 kW
- efficiency, η =