A SOLAR HEATED SWIMMING POOL NETWORK FOR GREECE

Objetivo

Demonstration of the use for solar energy for heating open-air swimming pools during the winter in Greece.
Three pools: Xanthi (North), Athens and Heraklion.
Total solar collector area is 3,920 m2. Estimated savings 154 TOE/a.
The collector is an unglazed direct flow type FAFCO.
Ilissia : The two monitoring periods (3/84-12/84) and (10/86-4/87) showed a solar contribution of 139 mWh and 61 mWh. Recalculated on an annual basis, an energy saving of 160 mWh/yr is obtained, corrsponding to 205 kWh/m2 yr, which is half of the design value. It should be noted that the interference of the pool personnel, who kept the pool temperature at early morning at 27 deg.C. through auxiliary heating during the night, prevented the solar system to operate correctly and switched off at the limit of 28 deg.C.
Xanthi : Only very partly performance results are available. The 2 months monitoring period (4-5/1994) gave a solar output of 129 mWh (solar efficiency 43%). Here problems were encountered to balance the hydraulic flow distribution between the collectors which are mounted around the pool on different levels.
Heraklion : Monitoring results were obtained over three peiods in (1984-1985-1986-total 13 months) with a total of 802 mWh, equivalent to 410 kWh/m2 year. This pool,which is exposed to high winds, has a very high specific energy consumption in spite of the use of wind screens.
In summer time, the solar system is switched off due to overheating problems. The experience gained with the operation of the solar system has lead to a change in the controlling of the system in the year 1986.
Furthermore, practical experience was gained in the three swimming pools, regarding the installation and operation of the solar systems. Some of the problems encountered in the hydraulic pipework are cited here :
a) the pressure in the absorbers should be between 0.5 and 1.0 bar. If the pressure is lower than 0.5 bar, the water flowrate through the collectors is insufficient and reduces the efficiency. If the pressure is higher than 1.0 bar, leaks occur in the pipe connections.
b) The pressure in the pipework of the oil-fired heating system was not constant, this was due to changes in the operation of the circulation pumps (two were in operation and one was usedas reserve) and also to the amount of dirt in the sand filters (the pressure drop in the filters was directly proportioned to the amount of dirt). These problems were solved by means of pressure-reducing valves and pressure switches in the solar circuit.
c) There were some leaks in pipe connections fitted with o-ring seals. Better results might have been achieved with a different type of pipe connection; connections might have produced better results, if the swelling problems could have been solved.
The pool covers proved to be awkward to handle and are no longer used regularly. Many of the covers have been destroyed by ultra-violet radiation and wind.
The three swimming pools of olympic size were built by the government. They are supervised by the General Secretary for Sports in Athens. The total number of pools run by the Secretary is 56 all over Greece. The pools are mainly used by sport clubs, schools and the Universities for training purposes. The minimum temperature of the pool's water was reduced from 26 C to 24 C.
The same manufacturer equips all the pools (FAFCO), direct flow through polypropylene pannels on racks. The auxiliary heating is with light oil. Because of the sizes of the pools the handling of the movable covers is problematic especially when it is windy. All the pools have wind brakes as shelters, made of plexiglass.
The control strategy for the operation of the solar collectors includes the condition to switch off the collectors if the pool temperature is 28 C or higher.
1) Xanthi
Sporting center of the University.
Water surface 1,000 m2
Absorber surface 1,410 m2
The pannels are installed on various buildings and beside the pool. The hydraulic distribution is rather complicated. It can get quite good in this region of Greece.
2) Ilyssia (Athens)The pool is in the town beside a gymnasium and well sheltered.The pool serves for training, competitions and water games.
Water surface 1 250 m2
Absorber surface 780 m2
In Summer the hot water is produced with the solar installation.
3) Heraklion (Crete)
The pool is outside the town at a distance of approx. 500 m from the sea.
The pool is very exposed to the wind and therefore consumed in spite of the mild climate up to 2 000 000 l light fuel per year, which is almost ten time more than the well sheltered pool in Athens.
Total solar overcost = 358,000 ECU
Water surface 1,250 m2
Absorber surface 1,730 m2.
The designed energy savings are : 340 mWh for Xanthi, 320 mWh for Illisia and 550 mWh for Heraklion.

Programa(s)

ENG-ENALT 1C - Programme (EEC) of financial support for projects to exploit alternative energy sources, 1979-1984

Tema(s)

3.2 - SWIMMING POOLS

Convocatoria de propuestas

Data not available

Régimen de financiación

DEM - Demonstration contracts

Coordinador

GEN. SECRET. FOR SPORTS PRESID. OF THE GOVERNMEN

Aportación de la UE

Sin datos

Dirección

PANEPISTIMIOU STREET 25
Athens
Grecia

Coste total