Parabolic trough collector with loop fixing element and solar field with the parabolic trough collector

BACKGROUND OF THE INVENTION

1. Field of the invention This invention relates to a parabolic trough collector with at least one loop fixing element and a solar field with at least one parabolic trough collector

2. Description of the related art

One of the solutions to connect the rotating parabolic trough collector with the piping system in the solar fields and be ^¬ tween the rows of the collectors is the using of ball joint assembly systems. It can happen that these assemblies tend to move outwards resulting in an arrangement of the ball joint assembly out of the rotation plane. This leads to higher friction within the system and can created problems up to damages of the hardware. Up to now, two different rings have been placed at one ball joint within each assembly to limit the outward movement. This led to high frictions within the assembly system and in some cases to bending of the elbows and / or breakages of system supports.

SUMMARY OF THE INVENTION

It is an object of the invention to reduce the probability of damage of a parabolic trough collector caused by the above described problem. This object is achieved by the invention specified in the claims .

Concerning the invention a parabolic trough collector with at least one loop with at least one tube for pumping heat ther ^¬ mal fluid trough the tube is provided. The parabolic trough collector comprises at least one a loop fixing element for fixing the loop and at least one a counter weight for reduc ^¬ ing a probability for moving of the loop out of a rotation plane.

Preferably, the loop fixing element and the loop are connect ^¬ ed via at least one rope. The intention of the invention is to keep SBJ (single ball joint) assembly within or near the rotation plane.

The single ball joint assembly tends to move outwards its ro ^¬ tation plane due to frictions within the system. The solution is to avoid this outwards movement using counter weights.

Therefore a rope is attached to the piping via a clamp near the middle ball joint or a other adequate place of the assem ^¬ bly. The rope is guided via a ring or similar facility at ^¬ tached to a nearby placed fix installed structure, e.g. the end column of the respective Solar Collector Element. Defined weights are attached to the other vertical end of the rope. The weight shall be defined in a way that the ball joint as ^¬ sembly is kept within its rotation plan. The weights are de ^¬ signed in a way that it can be reduced or increased as the friction within the Ball Joint Assembly can change e.g. by repacking of the ball joints.

The solution is very simple and easy to implement. No cutting of the system is necessary. As it is foreseen that the weights can be changed it is easy to react on changes of friction within the assembly and the ball joints can be kept in or near the rotation plane and with that the fiction of the assembly can be kept at a possible minimum. One of the alternatives is to change the design of the ball joints in a way that the degree of freedom is reduced.

Possible Solution:

Work principle: Keep SBJA in rotation plane by rope and re ^¬ move "Inner ring"

BRIEF DESCRIPTION OF THE DRAWING

The figure shows a solar field 1 with a parabolic trough col lector 2. The trough collector comprises a loop 21 with at least one tube 22 for pumping heat thermal fluid trough the tube .

In addition there is at least one a loop fixing element 23 for fixing the loop and at least one a counter weight 24 for reducing a probability for moving of the loop out of a rota ^¬ tion plane. The loop fixing element and the loop are connect ed via at least on rope 25 which is guided by guided means 26. The fixing element 23 comprises a clamp with which the rope is fixed an the tube 22 of the loop 21.