Calentamiento de piscinas

Ed. 20071123

PLATE HEAT EXCHANGERS

SWIMMING POOL WATER HEATING

TECHNO SYSTEM S.r.l. - 50052 CERTALDO (Firenze) - Via Toscana 160/162 - Tel +39 (0)571 667229 (6 lines) - Fax +39 (0)571 664414 http://www.techno-system.it - e-mail: info@techno-system.it

INDEX
SWIMMING POOL WATER HEATING SYSTEMS...............................................................................................2 EXAMPLE OF CALCULATION FOR SELECTING A HEAT EXCHANGER .........................................................2 HYDRAULIC DIAGRAM ....................................................................................................................................3 TABLE N°. 1.......................................................................................................................................................4 TABLE N°. 2 (INDOOR SWIMMING POOL) ..............................................................................................................4 TABLE N°. 3 (OUTDOOR PROTECTED) ...........................................................................................................5 TABLE N°. 4 (PARTIALLY PROTECTED)............................................................................................................5 TABLE N°. 5 (OUTDOOR AIRED) .....................................................................................................................6 CONVERSION TABLE ........................................................................................................................................7

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SWIMMING POOL WATERHEATING SYSTEMS
As things stand today, current technology prefers utilizing plate heat exchangers for this type of duty. This is because since swimming pool water is rather aggressive, it is compulsory to use materials that can provide a positive response to the related needs. Use of AISI 304 or 316 stainless steel for the heat transfer plates and for the connectors, gives an absolute guaranteeof long life and hygiene. For all of these reasons, it is imperative that the system designer consider the plate heat exchanger in place of the traditional shell and tube exchanger for this type of application. Since the passages in the plate exchanger are normally narrower with respect to the shell and tube type, it is practically compulsory to install a bypass (see diagram) on the secondarycircuit (pool side). This is necessary in order to avoid having to over-dimension the exchanger to cope with flow rate and pressure drop problems.

EXAMPLE OF CALCULATION FOR SELECTING A HEAT EXCHANGER
We will examine the case of a 1.000 m2 outdoor, partly-wind-protected swimming pool. The time required to achieve the desired temperature (25°C) is 24 hours. Table 1 shows that the heat dispersal, inthis case, amounts to 750.000 kcal/h. Table 4 instead shows that 1.000.000 kcal/h will be required in order to bring the pool water to standard temperature in 24 hours. Thus, both the boiler and the heat exchanger must be dimensioned on the basis of this second value. For a boiler delivery temperature of 75°C, the table 4 shows that the most suitable heat exchanger for the purpose is a TS 1401 P93. If, instead, the time to standard temperature can be extended to 36 hours, 791.666 kcal/h will be sufficient; in this case the most suitable exchanger is a TS 1401 P 75 (see Table enclused). NOTE For making best use of the tables, it is essential to correctly identify the type of swimming pool; it is of course the system designer’s responsibility, above all in the case of outdoor pools, tocarefully consider the position of the pool for correct evaluation of heat dispersal. For example, it is good practice to consider an indoor pool located at high altitude as an “outdoor partially protected” pool, in order not to risk underestimating heat dispersal. The tables below are clearly intended only for rapid consultation by the system designer for preliminary dimensioning and are in no way...