TEMPERATURE CONTROL FOR HEATING SOLUTIONS

Transcription

1 TEMPERATURE CONTROL FOR HEATING SOLUTIONS

2 BACKER CALESCO EVERYDAY EVERYWHERE Our heating products together with our measurement and control devices offer our customers complete solutions. Our engineers will not only suggest solutions, they can also take part in and contribute to your product development by using our advanced technical tools and lab facilities. Our extensive experience and competence as well as our reliable quality and service guarantee your success. Our ambition is to not only be a supplier, but your preferred partner. Together we can make it happen! MEMBER OF BACKER-GROUP Backer develops, produces and sells customized solutions and components for electric heating, measurement and control. The original technology was stainless steel tubular elements. PRODUCTION LOCATIONS Backer Calesco main office and production in Sweden Production facilities in China, Poland & Vietnam Sales office/warehouse in the US However, the constant growth of the Group, both organically and through acquisitions, has enabled the integration of several new technologies. Today the Group offers a far wider product range, with a vast number of technologies for several industry sectors and a large variety of applications. Customized solutions INDUSTRY SECTORS AUTOMOTIVE LIFE SCIENCE RAILWAY BATTERY COMFORT COMMERCIAL EQUIPMENT

3 TEMPERATURE CONTROL FOR HEATING SOLUTIONS Flexible foil heaters provide excellent thermal transfer where you need it most. Heaters are used in thermal control design to protect components under cold-case environmental conditions or to make up for heat that is not dissipated. It is usually necessary to arrange some form of control to ensure that the desired temperature is maintained; accurate temperature control is therefore needed. This can be achieved with electromechanical thermostats of bimetallic type when temperatures and surface ratings are low, while electronic thermostats are preferred when temperatures and surface loads are high. We can fit thermostats, temperature fuses and sensors of thermo element type, thermistors and resistance sensors directly to elements in accordance with customer specifications. This helps to ensure reliable control. Typical applications Thermostat Resistance controlled NTC PTC PT100/PT1000 Thermocouple Overheat protection PRODUCT DEVELOPMENT We work together in a gate model to make sure we reach target in cost and production SOP Evaluation / Design / Development: (A-SAMPLES) Prototype development: (B-SAMPLES) Production development: (C-SAMPLES) Preproduction Testing & validation Approval to start: First serial delivery Specification work Feasibility First proposals Design preparation Prototype design Initial testing Verification and analysis of A-samples Production work / final design Documentation and preparation Functional test and evaluation Production engineering DVP Work PPAP Project management Final report Final design DVP PERFORMANCE TESTING To validate the design, we perform the test needed to fulfill specification Temperature profile (sensor and image) Resistance to climate and environment Electrical durability and resistance Specific customer requirements QUALITY We strive to deliver the highest quality products combined with a flexible way of working. This permeates the whole process including sales, product development, manufacturing, customer service and logistics. Backer Calesco delivers products that meet all relevant standards and tests, certifying products according to customer specifications. We are also able to carry out tests in modern labs, constantly improving our product performance and energy efficiency. CERTIFICATIONS Backer Calesco is certified by Bureau Veritas ISO 9001 ISO Our facilities in China, Poland & Vietnam are certified according to ISO 14001, ISO 9001 and IATF Third-party approvals: VDE / ETL / S / UL Innovations for the future A partnership with Backer Calesco gives you a dedicated team of designers, project engineers and technical experts in the fields of electric heating, measurement and control, ready to provide you with the optimal solutions for your needs.

4 TO GENERATE HEAT Conduction Heat transfer by direct contact to substrate Convection Heat transfer by convection, generally in air, fluid or gas and can be forced (heat pumps or natural convection in ex air) Radiation Energy transfer of to or from a body by emission or absorption of electromagnetic radiation Thermal Conductivity To maintain a desired temperature level heat has to be provided and suitable heat storage capability. Thermal conductivity is the property of a material to conduct heat. Thermal conductivity units are W/(m K) in the SI system and Btu/(hr ft F) in the Imperial system. Thermal conductivity (W/m C) Material At 25 C At 125 C At 225 C Iron Low carbon Stainless steel 16 17,5 19 Tungsten Platinum Aluminium Gold Silver Copper

5 THERMOSTAT SILICONE HEATERS WATER TROUGH HEATERS FOOD HEATERS Thermostat is an example of a closed control loop. This can be achieved with electromechanical thermostats of bimetallic type where temperature and surface ratings are low, while electronic thermostats are preferred where temperatures and surface loads are high. It constantly assesses the current room temperature and controls a heater to increase or decrease the temperature according to user-defined settings. This method is called Proportional control.thermostat (low-cost, cheap) thermostat merely switches the heater on or off, and temporary overshoot and undershoot of the desired average temperature. Thermostat (expensive) the difference between the required temperature (the set point ) and the actual temperature. These minimize over/undershoot. Benefits Low cost Proven technology Note Limited number of cycles RESISTANCE CONTROLLED SURGERY BED HEATERS FLUID HEATERS Resistance controlled temperature controller, this is one of the most accurate ways to measure and control temperature. No moving parts, semiconductors or thermistors to measure temperature. The resistance of the heater is dependence on temperature. This means we are using the heater as a temp sensor to detect temperature change exposure. Benefits The heater is the sensor, no added parts on the heater surface open exposure Robust and exact Quick and easy to regulate Cu, Brass or Al circuit Known technology Constant wattage long life Ω - Change SS321 cu Temperature change C

6 NTC METEOROLOGY HEATERS CAMERA HEATERS ADBLUE Negative temperature coefficient (NTC) Decreases in electrical resistance when their temperature is raised. Negative temperature coefficient (NTC) thermistor is a two terminal solid state electronic component with predictable change in resistance corresponding to changes in absolute body temperature. Thermistor Terminology: Thermistors exhibit a large negative change in resistance with respect to temperature, this relationship between resistance and temperature follows an approximately exponential-type curve. Benefits Surface mounted integrated in circuitry Exact measurement on spot or on surface if mounted right Known technology Constant wattage long life PTC REAR-VIEW MIRROR HEATERS DEFIBRILLATOR HEATERS Negative temperature coefficient (NTC) Decreases in electrical resistance when their Positive temperature coefficient (PTC) Increases in electrical resistance when their temperature is raised. Materials which have useful engineering applications usually show a relatively rapid increase with temperature, i.e. a higher coefficient. The higher the coefficient, the greater an increase in electrical resistance for a given temperature increase. Benefits Self regulating Max. power density 0,25W/sqcm² No added parts Note Aging over time, shorter lifetime

7 PT100/PT1000 PACKAGING MACHINES AUTOCLAVES Negative temperature coefficient (NTC) Resistance thermometers are constructed in a number of forms and offer greater stability, accuracy and repeatability in some cases than thermocouples. Limitations RTDs in industrial applications are rarely used above 660 C. Benefits High accuracy Low drift Wide operating range Suitability for precision applications THERMOCOUPLES MOLDING TOOLS VACUUM TABLE HEATERS Thermocouples are a widely used type of temperature sensor for measurement and control. Commercial thermocouples are inexpensive, interchangeable, are supplied with standard connectors, and can measure a wide range of temperatures. In contrast to most other methods of temperature measurement, thermocouples are self-powered and require no external form of excitation. The main limitation with thermocouples is accuracy; system errors of less than one degree Celsius ( C) can be difficult to achieve. Type K (chromel alumel) is the most common thermocouple. Probes are available in its 200 C to C. Type K is made of magnetic material, and have 2 critical temperature s around 185 C and near 400 C.

8 OTHER TYPES Overheat protection Low resistance resistor that acts as a sacrificial device to provide overcurrent protection, of either the load or source circuit. Its essential component is a metal wire or strip that melts when too much curent flows through it, interrupting the circuit that it connects. Short circuits, overloading, mismatched loads, or device failure are the prime reasons for excessive current. Melt fuse A fuse interrupts excessive current ( blows ) so that further damage by overheating or fire is prevented. Overcurrent protection devices are essential in electrical systems to limit threats to human life and property damage. The time and current operating characteristics of fuses are chosen to provide adequate protection without needless interruption. Slow blow fuses are designed to allow harmless short term currents over their rating while still interrupting a sustained overload. Overheat thermostat Bimetal thermal protector is an overheating protection device for electric appliances and they are reusable parts that are reset when equipment cools. If the fault still exists, the protectors continue to automatically protect the equipment. All systems need limitations and control to guarantee precise heat

9 SOFTWARE PROTOCOLS Can Bus CAN bus (controller area network) is a vehicle bus standard designed to allow microcontrollers and devices to communicate with each other in applications without a host computer. It is a message-based protocol, designed originally for automotive applications, but is also used in many other contexts. LIN (Local Interconnect Network) Serial network protocol used for communication between components in vehicles. RS232 Standard for serial communication transmission of data via a serial port. OBD OBD (On-board diagnostics ) Automotive term referring to a vehicle s self-diagnostic and reporting capability. Modern OBD implementations use a standardized digital communications port to provide real-time data in addition to a standardized series of diagnostic trouble codes, or DTCs. RS485 Digital communications networks implementing the EIA-485 standard can be used effectively over long distances and in electrically noisy environments. Enables local networks and multidrop communications links. It offers data transmission speeds of 35 Mbit/s up to 10 m and 100 kbit/s at 1200 m. Bluetooth Wireless technology standard for exchanging data over short distances (2.4 to GHz) from fixed and mobile devices. Originally invented as a wireless alternative to RS- 232 data cables. It can connect several devices, overcoming problems of synchronization. Wi-Fi KNX KNX defines several physical communication media: Twisted pair wiring (inherited from the BatiBUS and EIB Instabus standards) Powerline networking (inherited from EIB and EHS - similar to that used by X10) Radio (KNX-RF) Infrared Ethernet (also known as EIBnet/IP or KNXnet/IP). Local area wireless technology that allows an electronic device to participate in computer networking using 2.4 GHz UHF and 5 GHz SHF ISM radio bands.

10 THERMAL MANAGEMENT EXAMPLES OF TEMPERATURE REQUIREMENTS Batteries Typically between -5 to 20 C Electrical cabinets Typically between -20 to 40 C Propulsion components Typically between 5 to 40 C Autoclaves Typically between 50 to 250 C Cameras Typically between -30 to 40 C Automotive Typically between -40 to 80 C MOUNTING OF HEATER Overmolded Encapsulated in camera encapsulation or at substrate wall No air bubbles Long life time Robust No open parts exposed to environment Supported (envelope) Heater encapsulated in metal to withstand environment and stress from ice, moisture etc. No parts open to environment Mechanically strong Heater in housing Heats where it s needed Laminated by adhesive or glue to inside of wall

11 CONCERNS TO BE CONSIDERED Application environment Clean air Moisture Environmental exposure Surrounding temperatures Vibration levels Life time of heater Expected life time Performance requirements Max. voltage Min/max. temp / Regulation Time allowed to use Temperature Over-Temp Response (time/temp) Reaction time temp regulation Installation/Mounting Connector Cables vs flex tail Fasteners vs. Integrated Space Available Surrounding Materials Overheat Thermostat/ Melt fuse

12 Backer AB / Div. Calesco Västra Åvägen 11 SE Kolbäck, Sweden Tel: +46 (0) backercalesco.com EVERYDAY EVERYWHERE Backer AB / Div. Calesco rev. 13