Title: Unit 7 Overview
Course: REEC 220 Solar Thermal Systems > Section: REEC 220 Solar Thermal Systems

Unit 7 Overview

Unit 7 Overview

This is a large topic area. The pump needs to be sized correctly to provide the proper flowrate to overcome the head pressure.  All pumps have performance curves and the duty point is used to find the flow at a pressure. Pressure is not produced by a pump.  FLOW is!  The pump over comes opposition in the form of pressure to deliver flow.

The most common type of solar thermal fluid is water with an added antifreeze.  If you are lucky to live in a warm climate then antifreeze is not necessary.  However, the rest of us need to have a portion of antifreeze in our systems.  Generally, a 50% (antifreeze to water) mix is ideal in Illinois.
Important Terms | Definition
Erosion | Flow of the solar thermal system should be fast enough to move the heated water from collectors to the tank but not slow enough to erode or wear away the pipe walls. Velocities over 3 feet per second should be avoided.
Head Pressure | Is the loss of energy to get fluid to travel up elevation or the loss of lift of the pump can overcome. Head pressure is not a critical part of the system in a pressurized system.
Dynamic Loss | All loss in a fluid system. Elbows, pipe size, and length of run are all forms of losses.
PV Pumps | A DC type pump that is directly connected to a small PV module.