Application Description AG/CP101-EN Temperature measurement in steam pipes of chemical plants Application requirements — Reliable supply with steam as heating medium — Continuous monitoring of steam temperature — Reliable measurement despite high mechanical load Process description In chemical installations, process steam is used to heat processes or as a heat carrier. The steam is generated centrally before being transported via large pipelines to the various parts of the installation, from where it is distributed. To safeguard the processes and production operations that rely on the supply of steam, the temperature of the steam is measured at numerous points in the system. Moreover, the energy consumed by a part of the installation or a process can be recorded by measuring the temperature of the steam upstream and downstream in conjunction with flow measurement and a calculation tool. Description of the measuring task To measure the steam temperature in pipelines with a nominal diameter of DN 200, for example, which are used to transport steam to the various parts of an installation. The pipes carry medium-pressure steam at approx. 25 bar at temperatures in the region of 200 °C. The temperature sensors used to take the measurements must support accurate and rapid temperature measurement at flow rates of 30 m/s in the range from 100 to 300 °C. The majority of the pipelines are fully insulated. At the measuring points, the extension tube of the temperature sensor must be routed outwards through the insulation. Moreover, maintenance-free and trouble-free operation is required to minimize running costs.
Transcript
Application Description AG/CP101-EN
Temperature measurement in steam pipes of chemical plants
Application requirements — Reliable supply with steam as heating medium — Continuous monitoring of steam temperature — Reliable measurement despite high mechanical load Process description In chemical installations, process steam is used to heat processes or as a heat carrier. The steam is generated centrally before being transported via large pipelines to the various parts of the installation, from where it is distributed. To safeguard the processes and production operations that rely on the supply of steam, the temperature of the steam is measured at numerous points in the system. Moreover, the energy consumed by a part of the installation or a process can be recorded by measuring the temperature of the steam upstream and downstream in conjunction with flow measurement and a calculation tool.
Description of the measuring task To measure the steam temperature in pipelines with a nominal diameter of DN 200, for example, which are used to transport steam to the various parts of an installation. The pipes carry medium-pressure steam at approx. 25 bar at temperatures in the region of 200 °C. The temperature sensors used to take the measurements must support accurate and rapid temperature measurement at flow rates of 30 m/s in the range from 100 to 300 °C. The majority of the pipelines are fully insulated. At the measuring points, the extension tube of the temperature sensor must be routed outwards through the insulation. Moreover, maintenance-free and trouble-free operation is required to minimize running costs.
AG
/CP
101-
EN 0
2.20
12
Carrying out the measuring task SensyTemp TSP131 weld-in resistance thermometers are used to carry out the measuring task. The TTH200 or TTH300 transmitter is integrated in the head of the temperature sensor. The process conditions described require high mechanical strength on the part of the temperature sensor. The SensyTemp TSP131 can be relied upon for safe and reliable measurement of steam temperature at measuring points. To meet requirements for measuring accuracy, resistance
thermometers are used instead of thermocouples. On account of the high pressure and high flow rates, Form 4 weld-in resistance thermometers to DIN 43772 should be used. The risk of the thermowell breaking due to vibrations caused by vortex shedding is low with this design. Under the given operating conditions, the stainless steel 1.4571 from which the sheath is made is resistant up to 400 °C. Welded spuds are also used. The SensyTemp temperature sensors described are particularly sturdy. They have been designed for trouble-free operation. Maintenance is not required.
Change from two to one column
Product information SensyTemp TSP131 temperature sensor TTH200 temperature transmitter
for sensor head mounting
TTH300 temperature transmitter
for sensor head mounting
— DIN 43772 design
— Modular design
Measuring inset, thermowell, extension
tube, connection head, transmitter
— Interchangeable measuring insets
— ATEX
— SIL 2
— HART protocol
— Input functionality without redundancy
— Measuring accuracy: 0.1K
— Sensor error adjustment
— Optional: LCD indicators with configuration
function
— ATEX, FM, CSA,
— SIL 2
— HART, PROFIBUS PA,
FOUNDATION fieldbus-H1
— Input functionality with redundancy
— Measuring accuracy: 0.1 K
— Sensor error adjustment
— Sensor drift monitoring
— Sensor redundancy
— Extended diagnostics
— Optional: LCD indicators with configuration
function
— ATEX, FM, CSA
— SIL 2
Contact us ABB Limited Process Automation Salterbeck Trading Estate Workington, Cumbria CA14 5DS UK Tel: +44 (0)1946 830 611 Fax: +44 (0)1946 832 661 ABB Inc. Process Automation 125 E. County Line Road Warminster PA 18974 USA Tel: +1 215 674 6000 Fax: +1 215 674 7183
ABB Automation Products GmbH Process Automation Schillerstr. 72 32425 Minden Germany Tel: +49 551 905-534 Fax: +49 551 905-555 www.abb.com
