Manual CWD 2005
Introduction
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Manual CWD2005.doc
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2.
Introduction
Combustion calorimeters have been an important part of the process industry control
scene for a number of years. Some units are valued for their low maintenance
requirement, rugged durability and ability to understood and serviced quickly by just
about anyone without needing any special tools. Combustion calorimeters burn a
small sample of gas and measure the temperature rise of a fluid (usually air) through
the system and report this as heat release. The goal of a few manufactures has been
to improve response speed of these online units. Over the years, technical progress
and the embodiment of smart design strategies have improved response times from
around 5 minutes for the old mechanical water bath based units down to just a few
seconds for the newly introduced CWD 2005 series.
The CWD 2005 is the successor to the CWD 2000, CW95, CW85, CW71 and all
previous models (about 10,000 units supplied) during more than 85 years service to
the gas industry.
The CWD 2005 is a high-speed combustion calorimeter with a small industrial PC
and large digital display, mounted with the combustion chamber, thermopile and
other vital components in a custom wall mounted enclosure. A small amount of
process gas is measured continuously and the temperature rise from heat of
combustion is transferred from the burner to the thermopile, via the cooling air supply
and is measured by its thermopile sensor as heat rise.
Measurement is based on the real time Wobbe Index and Specific Gravity values of
the gas (a specific gravity sensor is built into the calorimeter). The PC based
microprocessor calculates Calorific Value using the following formula:
Gravity
Specific
Index
Wobbe
value
Calorific
The W 2005 model measures Wobbe Index values of process gas and is supplied
without a Specific Gravity sensor.
Most of the CWD 2005 units are supplied to customers that need to measure the
Calorific Value of their process gas and simultaneous outputs are available for both
upper and lower Calorific Values as well as Wobbe index and Specific Gravity.
The CWD 2005 is a high-speed combustion calorimeter and is usually preferred in
control applications as the response time is fast, the measurement is direct and is
simple to maintain online by Gas, Industrial, Steel and Petrochemical companies.
Petrochemical industries often need to measure flare gases with many unknown gas
components and need to meet the uptime requirements of tough environmental
regulations. The CWD 2005 combustion calorimeter responds to all unknown
components in the process gas and reports them as heating value or Wobbe index.
2.1.
Output values
The output values depend on the model (CWD 2005 or W 2005) and these values
can be shown on the instruments alphanumeric display. The connection board PCB