A.O. Smith SGS - 100, Инструкция по установке, эксплуатации и обслуживанию

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Instruction manual SGS 13
gis
2 Working principle of
the water heater
2.1 Introduction This chapter covers the following topics:
•
General working principle of the water heater;
• Water heater operating cycle;
• Protection for the water heater;
• Safety of the installation;
• Protection for the solar heating system;
• Safety of the solar heating system.
2.2 General working
principle of the water
heater In this water heater, the cold water enters the bottom of the tank through the cold
water inlet (14).
Once the water heater and the storage reservoir are completely filled with water,
they are both constantly under mains water pressure. When hot water is drawn
from the water heater, it is immediately replenished with hot water from the
storage tank, which in turn is replenished with cold water. The water in the
storage tank is heated by a heat exchanger which is connected to the solar
heating system.
The water heater is fitted with a modulating premix burner system with 1:1 gas-
to-air ratio regulation. The air required for combustion is delivered by the fan
(18). The gas is supplied via the gas control valve (16) and the venturi (30) on
the intake side of the fan. The 1:1 gas-to-air ratio always guarantees the most
efficient gas/air mixture.
The heated tap water leaves the tank through the hot water outlet (2).
The special design of the heat exchanger (11) ensures that the flue gases are
first led downwards via the combustion chamber, then upwards via the heat
exchanger, and downwards again alongside the water in the tank. The flue
gases gradually become cooler in the process. Because the cooled flue gases
flow alongside the cold water lower down in the tank, they start to condense.
This condensation causes latent heat energy to be transferred to the cooler
water, thereby increasing the performance of the unit. The condensate yielded
by this process is discharged via the condens trap (23).
Heat losses are prevented by the insulating layer (24) in both the storage tank
and the water heater itself. Both are enamel-coated on the inside to protect
against corrosion. The anodes (9) provide extra protection against corrosion.
Both are fitted with an inspection and cleaning opening (12) for maintenance
purposes.