DE2741787A1 - Heating swimming pools directly with solar energy - by passing water through black pigmented polyethylene tubing wound as close coil - Google Patents

Abstract

Solar energy is converted directly into thermal energy by using black pigmented polyethylene tube which is filled with water. Water is recirculated swimming pool water and the tube is coiled into an element in a container having a carbon black oil supporting surface. Polyethylene tubing of 25 mm, outer dia. 100 m long provides a surface area of 2.5 m2 and heat gains of 490 Kcal per m2 per hr. have been obtd.

Description

Process for the production of heating energy

direct transfer of the radiated solar energy into the energy to be heated Fluid The present invention relates to a method of utilizing solar anergy for heating purposes, for which fossil fuels or their conversion materials are still used today be used.

Today, fossil fuels are largely used to generate energy. These fossil fuels are not available indefinitely. Especially today Heating oil used in small plants can only be obtained from petroleum, its stocks According to current estimates, they will be exhausted in 25 years.

There is therefore a general attempt to develop other energy sources. For example nuclear power tidal power wind power solar power during tidal and wind energy is only converted solar energy, solar energy is considered to be the energy that is constantly radiated onto the earth, an inexhaustible source of energy.

The amount of energy hitting the upper atmosphere of the earth is according to more recent measurements 1150 Kcal m² / h (solar constant). Lurch scattering and absorption a part of the direct radiation is converted into diffuse sky radiation.

The global radiation (sum of the direct and diffuse radiation) reached With clear skies, in tropical areas a maximum of 960 Kcal / m h and in the area of the 50th parallel 620 Kcal / m2h.

Unfavorable weather conditions - e.g. Clouds, air pollution reflect or absorb part of the radiant energy.

Another problem with the use of solar energy is conversion the radiation energy in thermal energy.

On a soot-blackened surface, isolated from the outside air Air atmosphere with a membrane permeable to radiation can also be used in temperatures of 9o C are measured in our latitudes.

When the sky is overcast, however, only temperatures are measured with this measuring arrangement from 50 ° C - 70 ° C reached.

About the number of hours of sunshine at which a temperature of 9o C is achieved is much debated. Only in these hours of sunshine is there no mirror reflectors a temperature level of 70 C in so-called solar cells without vacuum insulation to reach. In order to achieve a useful temperature level of 70 C in our latitudes, a high level of control effort is required to ensure that the To switch the heating circuit.

For times with low radiation intensity (strong cloud formation) a large supply of heat must be kept.

Solar heating for hot water preparation for a single family house are currently offered for DM 20,000 to DM 30,000.

With a very high demand calculation of 100 1 water at 50 ° C per day and person, results from a water inlet temperature of 8 ° C a temperature difference of 42 C.

This results in a heat requirement of W = loo i 42 cal per day and Person.

For an electrical energy equivalent, this corresponds to a price from DM o, 5.

A very high estimate of 200 sunny days results in a 4 person household a cost saving of DM 2 .-- K 200 = DM 400 .-- per Year.

An investment of DM 20,000 to DM 30,000 is a saving of DM 400 .-- not to be amotized - especially since maintenance and purse costs are added.

Another energy requirement is the heating of swimming pools. For a swimming pool with a water content of 50 m³, an amount of heat is required to increase the temperature by 1 ° C of 50,000 Kcal required. The temperature level of the swimming pool can be between 22 ° C and 28 ° C can be assumed. This temperature level is suitable for solar heating because this temperature level is also reached when the sky is cloudy.

Conventional solar collectors consist of finned or lamellar tubes, Made of sheet steel, copper or mainly aluminum, those with a special color - soot black - Must be colored in order to prevent the radiation reflection that is common with metals Turn off mirroring.

With the usual swimming pool additives, copper salts or chlorine, will the pool water is corosive to aluminum.

For these reasons, there must be a separate circuit for the solar collector be created. For this circuit is a circulation pump, an expansion tank and a heat exchanger is necessary.

To keep the dimensions of the heat exchanger within limits, a must transition temperature gradient of at least 10 ° C are maintained, that means that the solar collector does not water at 22 ° C to 28 C, but at 32 C to 38 ° C needs to warm up.

This cycle increases the investment costs and requires continuous Operating cost.

The task of the invention should be an economical one, if possible maintenance-free solar system for a lower temperature level, such as swimming pool water heating to scilaffen, which fulfills the following properties - As complete a transformation as possible the solar energy in heat - no costly separate heat cycle - none Complicated control system - no separate conveyor systems. Surprisingly it turned out that all of these requirements were met with a standard plastic pipe are realizing. So-called hard polyethylene pipes, which are matt black in substance are colored, guarantee a complete conversion of the radiant energy in plastic in thermal energy.

With a necessary wall thickness of 2, the thermal energy can now be used immediately be absorbed by the water flowing through the pipes.

These pipes are so corrosion resistant that the pool water can be pumped directly through the swimming pool filter pump, as a bypass through the pipes can.

The pipes are temperature-resistant to such an extent that they can also be used without water cooling the achievable temperature remains below the maximum temperature of the pipes. The tubes are so flexible that they can be rolled up in a spiral shape.

A plastic pipe with an outside diameter of 25 mm and a length of 100 m results in an effective area of 2.5 m2.

In a test facility, pipe lengths of 300 m could be achieved with a standard Swimming pool filter pump are operated. there were warming with unthrottled Flow of 5 C to 3 ° C reached.

In the case of a flat, spiral-shaped, without spacing, coiled pipe, was with an irradiation area of 1 square meter, 490 Kcal with full solar irradiation gained per hour.

L e r s e i t e

Claims (6)

PATENT CLAIM 1. Method for generating heating energy by d i r e c t e transfer of the radiated solar energy into the liquid to be heated, d a d u r c h g e k e n n n z e i c h n e t that the radiation energy in one, in der; let black colored plastic pipe, converted into thermal energy and from dcr, liquids flowing through the pipe is absorbed. 2. The method according to claim 1, cl a d u r c h g e k e n n z e i c Note that a polyethylene pipe is used as the plastic pipe. 3. The method according to claim 1 and 2, d a d u r c h g e k e n n -z e i c h no 1, <leave the pipes flat, spirally wound, in a container be protected against atmospheric influences, and the solar energy by a Glass or plastic surface is irradiated. 4. The method according to claim 1 bi. <I 3, d a d u r c h g e k e n Note that swimming pool water is heated. 5. The method according to claim 1 to 4, d a d u r c h g e k e n nz e i c h n e t that this heating system is operated by a conventional filter pump in the bypass will. 6. The method according to claim 1 to 5, d a d u r c h g e k e n nz e i c h n e t that to control these heating devices only a temperature measurement <; iin the air space of the collector is necessary when a temperature is exceeded switch on the swimming pool filter pump from 30 C.