Solar collector

Abstract

A solar collector for heating and transferring fluids, having an inlet manifold and an outlet manifold through which fluid is respectively transferred into and out of the solar collector; and a plurality of polymer tubes each connected between the inlet and outlet manifolds, the polymer tubes having co-extruded concentric inner and outer tube layers, wherein the outer tube layer is composed of a harder polymer than the inner tube layer.

Description

[0001]The present invention relates to a solar collector for use in a solar water heater, more particularly in heating pools or spas or for use in water heating applications such as domestic hot water services and horticultural applications, for example, for heating plant root soil.BACKGROUND OF THE INVENTION[0002]Various types of solar water heaters have been known for many years. In one particular type commonly used for pool or spa water heating, water is moved from a source (such as a pool or spa) into a solar collector (also known as a strip collector or a solar absorber), whereby solar radiation from the sun is absorbed by the solar collector and heats the water contained therein. The heated water is then returned back to the source in a closed circuit arrangement.[0003]For domestic hot water applications the solar collector strip is generally contained within an enclosure beneath a clear panel such as tempered glass or plastic sheeting such a polycarbonate Corrlute sheeting. T...

AI Technical Summary

Benefits of technology

The present invention provides a new polymer tube design for use in solar collectors, which has a co-extruded inner and outer tube layer. The outer tube layer is made of a harder polymer than the inner layer. This design allows for better heat transfer and reduces the likelihood of blockages in the tube. The solar collector also includes an inlet and outlet manifold to facilitate fluid transfer. The polymer tubes can be connected using co-extruded webs or separate web polymer. Additionally, the polymer tubes can have a co-extruded strip or be welded to the manifolds for better connection. The use of a cross linked polymer for the inner tube layer further improves the performance of the solar collector.

Problems solved by technology

There are a number of drawbacks with rigid tubes, including possessing little elasticity and unsatisfactory sealing properties, resulting in inadequate retention and sealing when installed onto a manifold barb.

Generally the rigid tubes require special compression fittings to fix and seal the tube onto the barb, or alternatively, the manifold is over-moulded or welded onto the tubes in order to create a welded join at the interface to fix and seal the tube to the manifold, which can cause cracking and water leaks at the weld.

The drawbacks with flexible, plasticised or soft types of solar collectors are that the soft material cannot withstand the regular cycle of high pressure from the fluid therein followed by high vacuum pressure when the tube is drained of the fluid therein, and thus premature stress cracking can occur.

Also, the material can deform easily, thus making installation and retention on the manifold difficult.

Furthermore, the tubes can experience UV and chemical degradation over time, and can easily be damaged by pests or trampling by people during installation or maintenance.

Overall, these drawbacks result in a solar water heater that can be inefficient, costly and laborious to install and maintain, and susceptible to degradation and damage.

Images