Solar Collector Modeling

Abstract

Solar thermal power plants are a key technology for electricity generation from renewable energy resources. Concentrated solar power (CSP) systems collect and concentrate sunlight (solar radiation) to produce thermal energy which can be stored and used to produce electricity in a thermodynamic cycle (Rankine cycle or Brayton cycle). There are several types of concentrating solar power systems.

• Central Receiver Systems (CRSs): CRSs use a field of distributed mirrors—heliostats—that individually track the sun and focus the sunlight on the receiver by concentrating the sunlight 600–1000 times. The wall temperature of the receiver can reach up to 650 °C. Thus, the solar energy is transferred to the working fluid and then used to generate steam to power a conventional turbine.

• Linear Parabolic Trough Collectors (PTSCs): PTSCs concentrate the solar radiation through long rectangular curved mirrors. The mirrors are tilted toward the sun, focusing sunlight on the absorber pipe that runs down the focus line of parabolic trough collectors. The absorber pipes heat up the oil to nearly 400 °C, and a heat exchanger transfers the heat of the oil to a water/steam cycle (Rankine cycle).

• Linear Fresnel Reflectors (LFRs): LFRs concentrate the solar radiation through long parallel rows of flat mirrors. These modular mirrors focus the sunlight onto the receiver, which consists of a system of tubes through which working fluid is pumped.

In this chapter, we present two types of solar collector components, the PTSC and the LFR, and give a detailed description of the physical equations for each of them. We give a test-case for each model that includes the structure of the model, parameterization data, and results of simulation. The full description of the physical equations is independent of the programming languages and tools.