AERCO SWDW68 U-Tube Double-Wall Heaters w/ECS - Manual (Page 8)

HE-
111 − GENERAL INFORMATION
Rev B Mar 2013 1-2
AERCO
STEAM INPUT
CONDENSATE OUTPUT
SHELL ENCLOSING THE
TUBE BUNDLE
COLD WATER
INPUT
HOT WATER OUTPUT
CONTROL BOX
RECIRCULATION
PIPING
RECIRULCATION
PUMP
UPPER HEAD ASSEMBLY
CXT-E CONTROL
VALVE
CXT-E ACTUATOR
LOWER HEAD ASSEMBLY
Figure 1-2. Mechanical Overview of the AERCO Double-Wall Steam-to-Water Heat
Exchanger
The DW steam-to-water heat exchanger includes the following principal mechanical parts and
assemblies:
• Shell and upper/lower head assemblies
• Enclosed double-wall tube bundle and tubesheets
• Input/output connections for steam, condensate and hot/cold water
• Control Valve
• Recirculation piping and pump
1.3 ELECTRONIC CONTROL SYSTEM
The Electronic Control System (ECS; illustrated in Figure 1-3) includes the Control Box components and
associated temperature sensors and actuators. The ECS:
• Controls the temperature of the hot water output to within ±4°F of the Control Box setting under
normal, diversified load conditions (load fluctuations of up to 25% of water heater capacity)
• Shuts down the heat exchanger when the maximum safe water temperature is exceeded
• Relays commands and alarms from/to the MODBUS Communication Option
The ECS and its components are described in Chapter 3.