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The secret behind wide temperature technology
Wide temperature technology has enabled system integrators to deploy industrial computers in a greater range of indoor and outdoor environments. For example, an industrial-grade embedded computer may be deployed in a factory where it is constantly exposed to high temperatures. If it is deployed in a remote outdoor location, the computer would need to be able to operate under extreme cold or heat, depending on the climate. As a result, industrial computers are often designed to operate reliably in temperatures ranging from -40 to 75°C. One of the lasting benefits of wide temperature technology is to make computers particularly reliable and less prone to failure over long periods in harsh environments. But how do manufacturers develop computers suitable for such extreme temperatures and conditions? |
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Thermal placement of components
Designing a wide temperature industrial computer requires a full understanding of the product’s thermal gradient in order to optimize the placement of components. Several factors need to be considered with regards to the thermal placement of components inside the computer.
First of all, hardware engineers need to identify the main heat sources and hot spots so layout designers can optimize the component placement on the motherboard. Basically, the closer a component is to the main heat source, the more durable it needs to be. Designers can also reduce the number of heat sources by using components that generate less heat and arranging the components in the most optimal positions.
The chassis and total system power consumption should also be considered when developing a wide temperature computer. For example, using a larger chassis or reducing the system’s power consumption can help dissipate the heat generated by the computer.
It is also crucial for engineers to determine a main direction for heat transmission. This involves a sophisticated understanding of the component placement and a technical arrangement of the components to dispel the heat via a specific transfer route. Understanding the system’s thermal gradient is essential to optimizing the thermal placement of components and designing wide temperature computers
Natural-convection thermal chambers
Environmental test chambers are an important way to determine if a product can be used in harsh surroundings. Most manufacturers use forced-convection thermal chambers for testing. However, results from these tests are usually unreliable as the environments they create are generally inconsistent with actual environmental conditions found in industrial applications. Using a natural-convection thermal chamber allows engineers to establish a windless environment that more closely resembles actual industrial application settings.
Wide temperature components
Using wide temperature components is the most direct way to produce wide temperature computers. To make is easier to find and deploy wide temperature components, hardware and layout designers should construct a database of components that meet the rugged requirements for use in wide temperature environments. Testing components, materials, and products in a natural-convection thermal chamber first makes it easier to determine which ones are suitable for the wide temperature database. This database is extremely important and helpful should you decide to convert a standard temperature product into a wide temperature one. Designers can easily choose the components from the database and deploy them in the product, which accelerates product development and shortens time-to-market.
Optimal heat transfer methods
There are a number of heat transfer methods available including heat pipes and heat sinks. Choosing the most appropriate method for your solution is essential.
- Heat pipes—One method is to use a heat pipe to direct the heat out of the computer. This solution employs specific materials and instruments to transfer heat via the thermal cycle. It is particularly suitable for board-based products that contain CPUs and chipsets as the primary heat sources.
- For example, silicon thermal pads can be used to directly cover the onboard CPU and chipsets, which are then covered by aluminum heat absorbers located on the slat where one or more bronze heat pipes are affixed. The heat pipes are hollow but lined with a wick containing a working fluid, such as water, that can absorb the heat from the heat sources. The pipes are often led to a location where it is easy to dissipate the heat, such as a plate at the front of the computer. In addition, the main function of the heat pipes is to transfer heat from one side of the computer to another via the thermal cycle.
How does the thermal cycle work in the heat pipe?
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| A. |
Fluid evaporates into vapor to absorb thermal energy |
| B. |
Vapor migrates along the cavity to the end at a lower temperature |
| C. |
Vapor condenses back to fluid and is absorbed by the wick, releasing thermal energy |
| D. |
Fluid flows back to the end at a higher temperature |
 Heat sink—Heat sinks are another solution that can be used for transferring heat. The heat sink is usually made of bronze or aluminum, materials that can easily dispatch heat from one side to another. For example, a heat sink made of aluminum may be used to directly cover the component and absorb the heat to transfer it out of the computer.
This method is widely used and can serve as the cooler for the CPU or the entire computer. It usually has a fin-shaped design to maximize the surface area and speed up the heat transfer. When a heat sink is used, the size makes a big difference since the designer needs to optimize the sink to maximize the heat transmission effect.
Self-warming systems
The methods mentioned above are all geared towards heat transmission and only apply to high temperature environments. However, different technology is required to ensure reliable operation for the computers used in cold climates and settings. Balance heaters that automatically start working when the exterior temperature drops too low can be used to warm the interior of the computer. However, this method requires precise and accurate temperature configuration to ensure that the resistors start operating when needed.
Summary
Wide temperature models present a much more reliable and affordable alternative to using regular industrial-grade devices. They are an ideal solution for any application involving harsh industrial environments, such as power substation automation, oil and gas production, intelligent transportation systems, environmental monitoring, factory automation, and other related systems. But developing wide temperature computers is not easy and manufacturers need to address issues related to fanless system design, tolerance for both high and low temperatures, and production cost. To overcome these challenges, manufacturers should
- Optimize the thermal placement of components,
- Use natural-convection thermal chambers,
- Establish a wide temperature component database,
- Deploy optimal heat transmission methods for high temperature, and
- Install a self-warming system for low temperature.
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