Data center, how liquid cooling is gaining ground

Let’ start the New year on the sign of continuity within innovation… We further go on indeed on the topic of cooling in data center, that we have already covered in our last year’s post. And we welcome you in the 2019 with a new Tempco logo, to be properly focused on in a future post of our blog.

data center cooling

Talking about cooling in data centers, we recently found an interesting article online that explains how the power increase in data center’s racks is becoming a problem for traditional air cooling systems, promoting the growth of liquid cooling, a topic we’ve already faced in the past months. A Gartner statement reported affirms that the air cooling is no more able to achieve the necessary heat dissipation in data centers where the electrical consumption is increasing by 16 up to 20 kilowatt for each rack. An increase in energy intensity that affects all data centers around the world, with liquid cooling solutions growing at a rate of 25%.

The higher efficiency ensured by liquid cooling solutions is naturally due to the fact that fluids can carry heat better than air, offering an efficiency in heat transfer 50 to 1.000 times higher. Liquid cooling offers a range of solutions, including water and special non-conductive fluids, and also the new groundbreaking innovations in nanofluids, special thermal fluids on which R&D around the world is very committed, able to increase conductivity and heat transfer capacity of common thermal fluids by the addition of metallic nanoparticles.

raffreddamento a liquido data center

In liquid cooling for data centers, heat exchangers can be installed on the rear of the racks or by direct contact with hardware components, properly using non conductive fluids. A trailblazing and growing application is the direct immersion of racks in dielectric fluids, or even the construction of underwater data centers, such as the Natick project of Microsoft or the data center Green Mountain as well.

The trend raises new challenges for IT staff, traditionally scared by possible leaks of water and fluids in the presence of electrical devices. Elsewhere, the increase in computational power required from data centers is forcing to find new cooling solutions for servers and racks, employing water and liquids that are developed offering high security and protection for electrical components. A cultural change is thus necessary for IT administrators, with training programs aimed to prepare them to the technical transformation happening in the cooling systems for IT infrastructures.

Happy Holidays warmly by Tempco!

We would like to wish you all Happy Holidays, a Warm and Merry Christmas and a Joyful and Thrilling New 2019, from all the Tempco team!

Looking forward for all the new and challenging applications related to thermal energy management, and to the many news and innovations we’re working on… soon to be revelead! But in the meantime, Merry Christmas and Happy New Year to Everyone!

 

Tempco - Best wishes

 

 

 

Dimple jacket and free cooling in data center against global warming

Cooling in data centers is often achieved by direct expansion chillers. This kind of systems, in addition to being highly energy-intensive, employ refrigerants that are pollutants, and thus more and more banned or limited by regulations. The increase in the computational power, due to the global adoption of artificial intelligence, big data analytics and cloud computing, machine learning and blockchain, has an effect increasing the impact of data centers upon the global warming.

If actually the increase of working temperatures of computers is reducing the need of mechanical cooling in data centers, regulations are pushing to a drastic reduction in the employ of refrigerants, responsible of greenhouse gas emissions.

Data center cooling green

 

Different HFC (hydro-fluorocarbon) refrigerants are employed in data centers, the most commonly being the R13a (in big plants) and the R410A (in small-medium size data centers). Their control imposed by regulations around the world is making their prices getting higher, pushing operators to find out new technologies and green cooling strategies for data centers.

Among green solutions for data centers, there is the employ of TCOIL dimple jacket exchangers for liquid cooling of the servers. Possibly also leveraging cold water available in the environment (as achieved in the Green Mountain installation in Norway). Getting rid of chillers, in addition to eliminating the use of HFC refrigerants, also would allow low energy consumption in data center operations.

Data center cooling free

 

Free cooling is another green cooling strategy for data centers, that stands out, as well as dimple jacket exchangers, for cooling efficiency and sustainability. The free cooling employs cold environmental air where it’s available, representing an efficient solution combined with cold water cooled systems. Moreover, the option of an adiabatic boost, which extends the dissipation efficiency of the free cooling systems, makes this green cooling solutions feasible in a wider range of geographical areas.

Evolving electrical thermoregulation in pharma industry

Leveraging a solid know-how built by Tempco in more than 15 years in thermoregulation applications in the pharma sector, we are introducing an improvement in the engineering of our TREG thermoregulating units.

termoregolazione pharma TREG

The new electrical heating units dedicated to chemical, industrial and pharma fields meet the need of these sectors to regulate the temperatures in their processes, with increasing precision and programming functionalities.

In addition the pharma sector requires a constant monitoring of all process’ steps, thus including a continuous monitoring of temperatures and cycle times of all the heating/cooling/temperature maintaining cycles.

termoregolazione settore farmaceutico TREG

These requirements must be fulfilled providing compact machinery, ensuring easy and fast installation and commissioning. Tempco’s solutions portfolio offers a broad constructive range of power capacities, with different temperature control levels.

termoregolazione pharma Tempco TREGOn the side of equipments we held our decisions, at the beginning not always accepted but nowadays representing a very appreciated and required standard:

  • Stainless steel heating armored resistances
  • Stainless steel internal pipings
  • Stainless steel plate heat exchangers
  • Flanged connections
  • Process and utilities connections on the upper side, making installation easier
  • Electrical panel in watertight box with thermoregulation unit interface and remote set point
  • ALL-IN execution complete with fairing, allowing a ‘clean’ installation without external components

Norbornadiene, thermal fluid for solar energy storage

Coming from Sweden is a new thermal fluid for solar energy storage, called Norbornadiene. The innovation arrives from a study of the Chalmers University of Technology in Göteborg, Sweden, dedicated to a new solar thermal fuel mostly composed by carbon, hydrogen and nitrogen molecules.

The Norbornadiene solar thermal fuel is indeed able to capture solar radiation, and to storage solar energy at low cost for years, without discharging in opposition to what happens with traditional batteries. The stored energy can be released on demand in form of heat, by activating the fluid through a catalyst.

Norbornadiene stoccaggio solare termico

When hit by the sunlight, the molecules of Norbornadiene get excited so that some of the bonds between atoms are rearranged to a higher energy level structure (quadricyclane). The energized version of the molecule is stable, with strong chemical bonds, enabling the molecule to sit for nearly two decades without losing the stored energy.

Passing through a catalyst, the chemical bonds are rearranged releasing quite a lot of heat. By inserting a heat exchanger between the thermal fuel and water in the circuit, is it possible to transfer the thermal energy to heat the water at a temperature of approx. 65° C, to be employed for domestic heating or to obtain sanitary hot water.

stoccaggio solare termico norbornadiene

The researchers are actually further developing and optimizing the process, aiming to lower the costs of both materials and the process to take the norbornadiene-based solar thermal storage technology to the market within the next 8-10 years.

Thermal energy and industrial processes, a guide

Tempco operates since many years in the field of thermal energy management in industrial processes, with a solid know-how and expertise and several applications in all kind of industrial sectors. Every day we are committed in solving heating, cooling, dissipating, thermoregulating and heat recovery matters.

We wanted to collect and share our know-how in a Manual, Energia termica and industrial processes (Italian language only), aiming to offer a first guide to engineers and designers helping them in the choice of the best suitable thermal machine for their specific application.

Energia termica e processi industriali Tempco

The Manual offers a wide description of all the main thermal machines, heat exchangers, chillers, cooling towers, thermoregulating units, dissipators and free coolers. Each solution is described in its characteristics and related advantages, completed with a series of case histories developed by Tempco along the way.

 

manuale Tempco energia termica indiceA section is in particular dedicated to the evaluation of thermal capacity of a machine, essential step in order to choose the machine itself and the kind and dimensions of heating/cooling components.

Flexibility and customization capacity complete the ability to suit the best thermal energy management solution in order to fit any customer’s production process need and requirements.

Pipe expansion in exchangers connection pipes

Following last week’s post about the function and importance of expansion tanks in thermal oil equipments, when working with high temperature fluids is also important to take account of thermal expansion coefficients of pipes.

allungamento tubazioni espansione termica

Here is a technical table reporting the values of thermal expansion of pipes for different metals, to be used during the design and engineering of heat exchangers connections.

Pipe thermal expansion

Employing thermal expansion joints can help compensate and absorb the dimensional variations on connection pipings, that can be important due to the high temperatures achieved by the diathermic oil in the plant.

Function and capacity of expansion vessels

Heat transfer fluids employed in thermal machines increase their volume while being heated. This effects in particular heat transfer oil that have a high expansion coefficient, thus requiring to provide the plant with an expansion tank.

vaso espansione olio diatermico

 

The presence of an expansion tank allows not to exceed design pressure values on the system. In order to maintain the mechanical and chemical properties of the diathermic oil, some measures can be adopted to avoid the oxidation of the fluid in contact with air in the tank. It can be achieved with a proper piping connection and leaving a minimum surface in contact with air, by using a vent. The air remaining inside the vessel generates a layer that gives up a limited oxygen quantity to the oil, becoming inactive.

This is a simple and cost-effective solution compared to the cooling of the expansion tank, and by far less complicated than pressurizing the vessel with nitrogen.

 

 

 

Expansion tank capacity evaluation
The capacity of expansion tank must be calculated based on two main factors:
– The high expansion coefficient of the thermal fluid
– The overall capacity of the system

Considering a temperature of 300° C, the capacity of the expansion tank must be approximately 30-50% of the overall volume of the cold transfer fluid employed to be heated. This evaluation allows a quiet fair margin of safety.

The diameters used on the relief piping are also important, based on the plant potential, in order to avoid accidental over-pressure that can occur hampering the natural expansion flow of the oil.

Here is a simple technical table with some recommendations:

expansion tank heat transfer oil

Another important factor to be accounted is the pipe length changes due to thermal variations within the system, which will be properly treated in a future article.

Power transformers and cooling fluids

Transformers work as oil-immersed electrical equipments.
The transformer oil is a special kind of oil aimed to both cool and insulate the windings of the power transformer, and must be maintained at a proper temperature using oil/air heat exchangers.

trasformatori di potenza olio raffreddamento

The cooling oil employed in transformers is a highly refined mineral oil with high dielectric strength, thermal conductivity and chemical stability, and its formulation contains pollutants so that it must be carefully contained and monitored.
Exposed to high electrical and mechanical stresses, and also subject to chemical contamination due to interaction with windings at high temperatures, the transformer oil can loose its properties and there are many companies specialized in the analysis and testing ensuring the right management and monitoring the life expectancy of this kind of special cooling fluids.

scambiatori di calore recupero energetico rigenerazione olio trasformatoriIn collaboration and supporting the main Italian company in this sector, Tempco developed plate heat exchangers dedicated to the energy recovery combined to oil regeneration for electrical equipments.
The exchangers hava some special features:

  • Special multi-pass execution ensuring maximum heat recovery efficiency
  • Gaskets in special material resistant to electrical machine oils
  • Plates with chevron angle design suitable for high viscosity oils, optimized in order to avoid pressure drops and maximizing thermal efficiency

Thermoregulation in critical pharma application

We recently supplied a number of thermoregulating units to a leading pharmaceutical company, aimed to regulate temperature on a series of reactors employed in a strategic production process.
The production presents some very critical temperature regulation requirements.

Termoregolazione farmaceutico

The criticality is not depending on the temperature levels, as the thermoregulation unit works on a set-point between +15 and +75° C.
Working fluids are warm water coming from a boiler and from a chiller, already in use in the production facility for other technical purposes.
The specific pharma application is critical because the thermoregulation must be constant and ensured upon any circumstance. This mandatory requirement led to a special design with a double automatic stand-by pump, in order to ensure in any case the constant temperature regulation.

pharma temperature regulation Tempco

 

termoregolazione settore pharma Tempco

The system also features two modulating control valves managed by a thermoregulator, respectively employed on the cooling and heating circuit, maintaining a constant temperature in a range of +/-1°C referred to the current set-point.
After the setting phase, the production in series will start, also including an additional variant with electrical heating.