Following the administration last year of the Covrad company, a historical manufacturer of cooling systems and heat transfer equipment based in Coventry, UK, recently in Tempo we have received several requests from manufacturers that are looking for similar solutions to those once supplied by the British company.
In particular, the company used to provide thermal modules to be combined with power generation groups for cooling of jackets and after coolers, radiators, heat exchangers, engine cooling modules and remote cooling kits in a near-to monopoly regime of the market.
Since a few months now, in Tempco we are therefore working to develop similar solutions to those that Covrad provided since last year, opening the opportunity to offer systems aimed for this kind of application. Three first projects are already being defined, in an advanced engineering step in order to further optimize the construction and quotation of the solutions.
Another interesting use of TCOIL dimple jacket exchangers, of which we often talk about for immersion cooling applications, is using them for contact cooling applications, as if they were a jacket. A very interesting characteristic of TCOIL exchangers is in fact the capacity to be shaped to fit the shape of the equipment to be thermoregulated.
It is then possible to use TCOIL dimple jacket exchangers for application on the outside of equipments employed in the chemical industry, such as mixers and reactors, or generally on the outside of tanks or furthermore on the outside of electric batteries. The metal sheets of the plates of a TCOIL exchanger are in fact easily made into a cylindrical shape, to fit the shape of cylindrical objects to be cooled or heated. Otherwise, it is also possible to use flat plates to cover the external surface of a machinery.
In order to increase the thermal transfer efficiency of a TCOIL exchanger in contact cooling applications, it is therefore necessary to have a flat sheet on the side at direct contact with the equipment. This is achieved using metal sheets having different thickness. When inflating the plates of the TCOIL exchanger, only the external sheet with lower thickness will blow up, taking the typical dimpled look of a TCOIL exchanger, while the internal side with greater thickness, aimed for direct contact with the object to be cooled or heated, will remain flat.
A further trick to increase even more the thermal transfer rate in TCOIL exchangers contact cooling applications is to rub a thermal conductive paste on the flat side aimed for direct contact with the outside of the equipment to be thermoregulated.
This kind of contact cooling application of TCOIL dimple jacket exchangers is triggering a high interest for employ in electric battery cooling, as well as for cooling of electrical and electronics machinery that clearly cannot be cooled using a direct flow of cold water.
We’ve been recently involved in a very peculiar and complicated project for a temperature regulation unit aimed to an automotive test bench for radiators and fans, which required quite a huge deployment of resources. It is enough to say that the whole development and commissioning took 18 months.
The unit works using water/anti-freeze solution in a temperature range between 20° C and 130° C. The power capacity of the system is 240 kW, with an adjustable flow rate between 10 and 200 lt/min, with cooling capacity of 120 kW.
The complexity of the plant is in the fact that it can work at 130° C, thus with pressurized water. And the customer need to avoid leakages of non-freezing solution inside the tunnel test during the substitution of parts. Therefore we’ve had to install a system with quick connections on the mounting/dismantling section of the tested parts. The substitution is made prior the complete draining of both the radiator and the related pipes, using actuated valves and logic managed through a PLC.
Each time a radiator has to be replaced, the plant gets cooled, de-pressurized and secured for the operators, in order to proceed with the draining of the pipes connected with the radiator.
When mounting a new part for the testing procedure, the plant has to be re-filled and pressurized, always through logic, automated valves and pressure transducers.
The overall plant is managed by a dedicated software developed in close collaboration by Tempco and the customer, leveraging both expertise in respective fields of activity. Code writing and the test procedures of the PLC alone took several days.
The evaluation of the thermal duty to be dissipated is fundamental in order to properly size both heat exchangers and chillers and other cooling systems employed to achieve cooling and thermostatation of the anodic oxidation bath.
Anodic oxidation is an electro-galvanic event, which means it involves a direct current at a certain voltage that passes through the anodizing bath. The evaluation of the amount of kW to be dissipated is therefore easy to do, being it directly proportional to the current employed to achieve the anodic oxidation and the voltage of it.
Temperature levels of the galvanic bath then vary depending on the kind of anodic oxidation. In case of hard anodic oxidation plants, the required temperatures are quite low, between 10° C and 15° C. Traditional anodic oxidation processes require instead temperatures between 20° C and 25° C.
Cooling at these temperatures, unless huge amounts of artesian well water at temperatures of 10-12° C are available, leave not too many options. Chillers and refrigerating groups are indeed required, even because the secondary circuit of the exchanger must be fed with water at a temperature of 10-15° C, depending on the type of anodic oxidation.
Among our customers in Tempco, in addition to the CERN in Geneva with the supply of a cooling system for the testing of IGBT equipments, we’ve also had the pleasure to collaborate with the LNGS-INFN Gran Sasso Laboratories in nuclear physics.
Once again, the provided solution consists in a cooling system, in this case complete with a temperature control module. Quite important for this prestigious commission was the flexibility and the rapidity during the deployment and the commissioning of the system to the customer, which is actually involved in a series of activities requiring a very high precision levels of temperature control.
Eventually, in just 10 days we’ve then been able to supply the integrated solution.
Anodic oxidation, or anodizing, is a treatment employed for aluminium, a material that is very light, strong and quite resistant to corrosion. Among the many applications of aluminium, one of the best known is its use for extruded parts in windows. Here, the exposition to external atmospheric agents can degrade the look of the material, damaging it over time.
In order to make aluminium resistant to corrosion, the material thus undergoes a treatment in anodic oxidation baths, which generates a sort of chemical coating that makes it resistant to atmospheric agents corrosion. This is achieved using electro-chemical or electro-galvanic baths, where a direct current passes through. Thanks to an electrolytic process, a hard layer of anodic oxidation is deposited on the external surface of the aluminium.
There are different types of anodic oxidation processes, and the field of expertise in Tempco is to ensure the cooling of these baths. Indeed, the direct current that passes through them generates heating, and the temperature of the baths must be maintained at a temperature of approximately 20-25° C, depending on the kind of anodic oxidation process involved.
The application is simple, but there is a problem: usually, these baths don’t contain water, but a solution of sulphuric acid, in a low concentration of about 20%, depending on the type of anodic oxidation process. Cooling can then be achieved using chillers or main water with heat exchangers.
But heat exchangers have to be manufactured using special materials, in order to ensure resistance to corrosion by sulphuric acid. Therefore, for the cooling of anodic oxidation baths we supply traditional plate heat exchangers using materials such as titanium or high alloy stainless steel. We also employe immersion TCOIL dimple jacket exchangers, still being manufactured using high alloy stainless steel.
Cooling in anodic oxidation is also challenging on another prospect, which is the evaluation of the thermal duty of these exchangers. We will soon dedicate another video to this theme.
We’ve successfully deployed an energy efficiency improvement project for a customer in the mechanical and engineering components sector. The customer employs a cooling plant for the forge and the thermal treatments equipped with evaporative towers and pumps.
The forge cooling plant includes in particular 4 pumps of 75 kw each, 4 pumps of 30 kw each and four evaporative towers of 22 kw each. The energy efficiency improvement intervention involved the implementation of inverters on the 75 kw pumps, which are managed by a pressure gauge that allows to contain the power consumption based on a reduced demand of water within the utilities.
Inverters have been implemented as well on the engines of evaporative towers, managed by the measurement of water temperature. The system allows to adapt and reduce the power consumption based on the thermal energy required and the ambient conditions.
Finally, the overall management of the system is ensured with a PLC , using a management software developed and engineered by Tempco in order to make the management very flexible, tailored to meet the high demanding process quality requirements of the customer.
Cogeneration plants are becoming very much employed, aimed to the combined generation of heat and power using biogas. The biogas is a particular source or renewable energy, generated by the breakdown of organic matter or farm animal waste. Due to its characteristics, biogas is very rich in humidity, which makes it impossible to directly use it into engines, because the content of humidity would seriously damage them.
Biogas is a natural fuel, but in order to be employed in cogeneration plants it requires a special dehumidification treatment. This is achieved using systems composed by a chiller and shell and tube exchangers, especially engineered for this kind of application, which cool and dehumidify the biogas using a very cold mix of water and glicol.
In fact, biogas coming from digesters enters the system at temperatures of 35-40° C, and must be cooled at temperatures of approx. 4-5° C, eliminating the maximum possible amount of humidity contained. At this purpose, chillers at very low temperatures are employed, near the freezing point, at +1° C or +2° C.
On the outlet of the exchangers the biogas will then have a relative humidity of 100%, but with an extremely low absolute content of humidity. Installed on the outlet of the exchangers there are also condense separators, big tanks aimed to collect the condenses. Furthermore, on the output of the systems there are also additional filters, providing a further filtration of the biogas, which then is finally ready to enter the engines.
We’ve just completed an interesting supply in the biotechnology sector, for a manufacturer of fermenters, bioreactors, FTT (tangential flow filtration) and bioprocessing systems. Aimed for thermostatation of his equipments, the customer selected our brazed plate heat exchangers Tempco T PLATE B, in a special version with tri-clamp fittings suitable for applications in pharma production.
Tri-clamp fitting is very common and classic connection type on pharma and food processes, due to the fact that they allow easy connection in assembly and disassembly operations of equipments. At the same time, they prevent pressure drops and ensure easy cleaning operations, without gaps where sediments and production waste could deposit, leading to bacteria growth. Products are in direct contact with stainless steel, and with a gasket which is FDA compliant, suitable for contact with food and drugs.
We supply the same kind of fitting also on heat exchangers employed in beer production, wine and beverages in general. Similar brazed plate exchangers and thermoregulating units are also employed by another Tempco customer, who use them on his pharma equipments thus requiring the same kind of execution.
I’m making available also here the presentation I did for the recent online edition of mcTER event, last November, dedicated to smart efficiency. Back then I took the opportunity to speak about energy savings and efficiency advantages that can be achieved with immersion TCOIL dimple jacket exchangers.
In the video, you can see a more in depth explanation of the project we deployed for the Marina di Loano seaport, in the Liguria Region. The direct immersion of dimple jacket exchangers in the seawater allowed to eliminate almost completely the pumping and suction systems of seawater that previously served traditional heat exchangers. The exchangers serve in turn a network of heat pumps, distributed all over the wide area of the seaport. The cut of electricity consumes have thus been really interesting.
TCOIL exchangers have been realized using a special material, super-duplex stainless steel, in order to ensure corrosion resistance against chlorides in the brackish water. After two years of operations by immersion, the exchangers naturally showed a certain level of biological and organic growth on the surfaces. That’s the reason why a special support structure has been designed, equipped with lifting hooks allowing to pull out the exchangers from the seaport to proceed with cleaning and washing operations using a pressure washer. This operation is much more easy with this kind of exchangers, compared to traditional heat exchangers, and doesn’t require any specific expertise thanks to the high mechanical resistance of TCOIL exchangers.
Furthermore, the video also tells about another similar installation we did in Tempco, for the Ispra Research center of the European Commission. Here, TCOIL exchangers have been immersed inside the water of an artificial drain, using its water to feed heat pumps. Fresh water entails here less material problems, which was here AISI 316. Anyway, the customer wanted an electropolished stainless steel, a special finishing that reduces the deposition and growth of algae and other organisms above the exchangers surfaces, reducing the maintenance needs.
At last, there is also a quick mention of another very interesting application of TCOIL immersion cooling exchangers, having a huge potential. That is the liquid cooling of data centers, of servers and electronic equipments. In this sector is indeed possible as well to take advantage of these exchangers by direct immersion in cold water, providing the cooling of IT devices.
