R
2
How It Works
The WhisperGen PPS16 is based on a four-cylinder Stirling-cycle (external combustion) engine
that repeatedly heats and cools a mass of pressurised nitrogen gas. Each time the gas is heated
and cooled, the changing gas pressure causes the pistons to move up and down. This
mechanical motion, via a special mechanism called the “wobble yoke”, rotates an alternator to
generate DC electricity which can be used to charge a lead-acid battery bank.
The nitrogen gas is heated by a continuous-combustion burner, and cooled by coolant circulating
through engine cavities. Heat transferred to the coolant can be used to heat domestic water
cylinders and for space heating.
The burner consumes air and fuel. The flow rate of air and fuel into the burner is optimised by a
microcomputer. This maximises combustion efficiency and minimises exhaust emissions.
The microcomputer automatically controls all WhisperGen functions and displays real-time
information about the system on a control panel from which the user can also alter operating
options.
BATTERY
BANK
AND/OR
ELECTRICAL
DEVICES
HOT WATER
AND/OR
SPACE
HEATING
CONTROL
SYSTEM
BURNER
(Continuous combustion)
STIRLING ENGINE
(Closed thermodynamic cycle)
EXHAUST
HEAT EXCHANGER
ALTERNATOR,
RECTIFIER,
LOAD DUMP (CLAMP)
Oxidant
Heat energy
Heat energy
(as hot exhaust
gases)
Data
Control
Mechanical energy
Recovered heat energy
(as hot coolant)
Electrical energy
Heat energy
(as hot
coolant)
Unused
heat energy
(as cool
exhaust gases)
FUEL
AIR
Control
Data
Data
Data
Data
Control
WTL0002
Chemical energy
