Tempco Blog articles

Double wall exchangers and oil hydraulics

18/02/2022

Double wall heat exchangers are a particular kind of exchangers that is also employed in oil hydraulics applications. The main characteristic of these exchangers is to have a double plate, or double wall, to avoid the possibility of mixing between primary and secondary fluid in case of breaking, corrosion or perforation of the plates.

This kind of exchangers is employed in hydraulics plants especially in case of extremely sensitive applications. An example is the cooling of the hydraulic oil of a gearbox in a turbine for power generation, where the mechanical component is a core part of the application. In this case, having the presence of water within the oil leads to irreparable damages.

The most common solution employs tube-in-tube shell and plate exchangers, double tube then, or double wall. These exchangers have special heads that, in case of leakage of fluids, allow the leakage to flow within a special chamber between the two heads. Allowing the detection of the leakage and a prompt repair intervention.

In case of double wall plate heat exchangers, the presence of a double gasket in the nozzle area avoid the possibility of fluid’s mixing. In case of breaking of a gasket, indeed, along the external perimeter of the exchanger or in the nozzle section, the leakage flows towards the outside of the exchanger. In case of cracking of a plate, there is an air chamber passing between the two plates, with therefore a visible leakage of fluids toward the outside, making it easy to repair it.

Advantages and disadvantages of the double wall solution. The advantages are all related to the security, making double wall exchangers a mandatory choice when is strictly necessary to avoid any possible mixing between the primary and secondary fluid, in this case hydraulic oil and water. The disadvantages are many, on the other side, first of all the higher costs due to the fact that the number of plates gets duplicated. Thus increasing the amount and costs of construction materials. In addition, having a higher thickness and an internal chamber air between the two plates, the thermal transfer coefficient rates are lowered. And so, not only a higher amount of construction materials is needed, but also the thermal transfer surface must be increased, in order to achieve the same thermal duty. Anyway, it remains a necessary solution to prevent any possible problem of fluid’s mixing, protecting the oil hydraulic plant from serious issues.

Stay updated on the latest applications and subscribe here to our monthly Tempco Newsletter – Solid Temperature.

Leave a comment

Carbon-ceramic brakes cooling plant revamping

11/02/2022

Carbon-ceramic brakes are with no doubt one of the excellences of the Italian industry and very well recognized all over the world.
From high-performance racing cars, to blazoned hyper cars, through high-speed aircrafts and trains, all of these systems employed in the automotive and aerospace sectors need braking solutions that ensure top-level and best in class performances.

Tempco has realized about 12 years ago a first plant for the cooling of furnaces for high temperature processing of carbon-ceramic discs. Since then, the plant performed flawlessly. By the way, later on we have also implemented a new plant with almost twice the power capacity, updated to the state of the art of technology available today, equipped with efficient control technologies and advanced monitoring systems.

raffreddamento forni freni carboceramici

After two years of operations of the second enhanced plant, the customer wanted to reply the new technologies also on the first plant installed. During the break for the holidays at the end of the last year, we’ve worked providing a deep revamping and boosting, by introducing a new control system equipped with a PLC and an operator panel, adopting the management software and the instruments successfully tested over the last two years.

After 10 days of intensive work, the new enhanced plant has finally been completed with positive start up and testing.

Stay updated on the latest applications and subscribe here to our monthly Tempco Newsletter – Solid Temperature.

Leave a comment

Mechanical and engineering advantages of plate exchangers in hydraulics

04/02/2022

In addition to the thermodynamic advantages offered by plate heat exchangers in hydraulics applications, in substitution of shell and plate exchangers, there are also other main advantages related to mechanical and installation aspects.

In hydraulics, the goal is to maintain at a certain temperature level the oil, which provides mechanical work in operating machines. A plate heat exchanger is much more compact then a shell and plate exchanger with the same thermal capacity, with clearly a direct impact on the size of the hydraulic units within the plant, which will be smaller and more compact.

Another huge advantage is the fact that all of the four nozzles are placed on the same side of the exchanger, two for the water and two for the oil. This allows to build the depth of the exchanger based on the thermal capacity required. It permits machine builders and plant builders to make some standardization, which means that they can adopt a standard layout employing a certain kind of exchanger, and depending on the power capacity of the pumps installed they can increase or decrease the number of plates with no variations to the design of the piping.

 

Moreover, the use of plate heat exchangers instead of shell and plate ones in hydraulics makes maintenance and substitution operations easier: is it indeed sufficient to disconnect the piping located on the same side of the exchanger, extract the old exchanger and insert the new one. In addition, in case of big hydraulic plants, where a switch from brazed plate to inspectable plate exchangers is required, this advantage is even more evident due to the fact that it allows to correct possible mistakes on the engineering, or facing increases in power capacity. This is possible because an inspectable plate heat exchanger can be easily expanded by increasing the number of plates, with no variations on the piping layout and thus offering great flexibility.

To solve a similar issue having a shell and plate heat exchanger on a hydraulic plant leads to great problems instead, because the new exchanger will be longer, or bigger, with a different shell, forcing the machine builder or the plant engineer to revise the overall layout of the piping.

Subscribe here to our monthly Tempco Newsletter – Solid Temperature.

Leave a comment

Heat exchangers super-enabled by additive manufacturing

28/01/2022

The attraction and elective affinities between heat exchangers and additive manufacturing are very strong and getting more and more triggering, as it’s clear to see while reading this interesting article published by All3dp focused on the many advantages that 3D printing brings into the world of heat exchangers. While designing and developing more efficient heat exchangers for cooling and heating tasks in industrial processes, there are indeed two main targets: increasing the thermal transfer surface and reducing at the same time the pressure drops.

The total design freedom offered by additive technologies allows the complete re-imagining the design of heat exchangers.

Tempco scambiatori saldobrasati

The source article mentions the example of a recently developed prototype of heat exchanger realized by GE Research called UPHEAT – Ultra performance heat exchanger enabled by Additive technology: this heat exchanger can handle temperatures up to 900° C, which means 200° C above the maximum level that actual heat exchangers can stand. GE Research says the exchanger could find applications in the energy sector, enabling a more efficient and cleaner power generation.

Metal additive manufacturing is as well the focus of R&D in the aerospace sector, where metal 3D printed single piece heat exchangers are being developed for the NASA and the US Army, also enhanced thanks to topological optimization, using metal 3D printers by Fabrisonic and 3D Systems.

Scambiatori di calore additive manufacturing 3D Systems

3D printing brings indeed a series of main advantages for the production of heat exchangers, allowing to manufacture lighter devices, more compact and performing, while increasing efficiency and reliability. First of all, additive manufacturing could revolutionize the production process of heat exchangers, allowing the manufacturing of the plates pack and the manifold in a single piece, requiring no more extra steps of forming, assembly, brazing or welding. Reducing not only the production cycle time but also increasing the lightness and the robustness of the overall structure.

Using additive manufacturing is furthermore possible to create any imaginable kind of shape and geometry, opening a virtually unlimited design landscape for the creation of unique and customized shapes and internal geometries, also leveraging breakthrough techniques such as generative design. Also heading to the miniaturization of components and devices, aimed for narrow spaces applications which are very often required as we see in Tempco, and not just in the motorsport and aerospace sectors mentioned in the article.

The possibility to create in AM extremely thin thermal exchange walls finally drastically increases the amount of thermal transfer surface, boosting the efficiency of the thermal machines. In addition, AM can create heat exchangers using a wide range of materials, ranging from aluminium alloys to high conductivity copper and copper alloys, and all the way up to high-temperature alloys such as Inconel 718 and Inconel 625. Eventually allowing the manufacturing of multi-material heat exchangers as showcased by the heat exchanger developed by Gen3D, a software developer for AM applications, in collaboration with 3D printers manufacturer Aerosint using laser powder bed fusion technology. This special heat exchanger combines the high-conductivity advantages of a copper alloy employed for the internal surfaces of the exchanger with those of a high strength steel on the outside.

scambiatori di calore additive manufacturing

Subscribe here to our monthly Tempco Newsletter – Solid Temperature.

Leave a comment

Plate heat exchangers and hydraulics

21/01/2022

Here’s a new video rolling out a series of videos dedicated to the mechanical sector, and this new one in particular is about plate heat exchangers in hydraulics applications.

On hydraulics plants, until a few years ago, shell and plate exchangers were commonly employed, or also air cooled exchangers. While there is not very much to say about air cooled exchangers – in fact radiators using electric fans -, an interesting evolution happened on the side of the water cooled process: for hydraulic oil cooling, here shell and plate exchangers were, and still are, a widely employed solution.

But recently, plate heat exchangers became more and more employed for hydraulic oil cooling applications, both brazed plate and inspectable exchangers. The main advantage they offer is the fact that they allow cross temperature, on the contrary of what shell and plate exchangers can do. In hydraulics plants, the oil have to bee cooled at a relatively high temperature, because the hydraulic oil must keep an average temperature of about 40° C, being cooled when it comes back from hydraulic drives.

Therefore, there is no need of a very hard cooling, and thus a plate heat exchanger is a profitable solution because it allows to employ cooling water at higher temperatures. Indeed, there is no need of water at 15-20° C, since it’s possible to have evaporative tower water at the temperature of 30° C available in order to achieve the same cooling task. This is possible thanks to the higher thermal transfer efficiency, and also the possibility to use a lower thermal transfer surface.

In addition, as they permit to cross temperatures, plate heat exchangers allow to use a lower amount of cooling water. Being it an ideal solution wherever there is a lack of cooling water within the facility, allowing to take maximum advantage of the limited cooling water available obtaining anyway a very efficient cooling of the hydraulic oil.

Subscribe here to our monthly Tempco Newsletter – Solid Temperature.

Leave a comment

Infographic from heat to value, energy recovery in industrial processes

14/01/2022

The new Tempco infographic, which has been published at the end of 2021 and with which we are glad to welcome you in the New year, is related to the energy recovery market, a field aimed to maximize the value of heat, in other words thermal energy which is a precious resource widely available within industrial processes; and for Tempco it really means playing at home.

Following the previous infographics that spanned through automation, smart manufacturing in industrial processes and the renewables, finally heat recovery applications in the field of industrial production processes is what really characterizes Tempco’s engineering commitment.

The primary technology here analyzed for energy recovery are heat exchangers, a kind of thermal machines employing the physical effect of thermal transfer between two fluids having a temperature’s gap, allowing an intelligent re-use of thermal energy which is a very abundant form of energy available in a wide variety of industries, that can be re-used as second-level kind of energy in other points of the production process. With no further power consumption required, contributing to increase the energy balance of the process by implementing energy saving and efficiency solutions reducing CO2 emissions and the environmental impact of industrial productions.

A look at other technologies such as dry cooling and cogeneration is included as well, solutions that enable a more efficient and smart use of fuels, reducing energy waste for an increased and more efficient use and deployment of primary resources in cooling and heating tasks involved in any kind on industry, from oil & gas and steel mill to food & beverages and plastics, to chemical and pharmaceutical sectors. The key words of Tempco’s vision for each one of these sectors are energy efficiency and thermal energy recovery.

 

infografica-dal-calore-al-valore-eng thermal energy recovery

Subscribe here to our Tempco Newsletter – Solid Temperature.

Leave a comment

Solid wishes from Tempco!

23/12/2021

Merry thermoregulating units from Tempco!

This year we wanted to wish you a Very Merry Holiday Season with something special, wishing you also that the New Year will bring everyone Joy, Health and Safety, Inspiration and lots of Satisfactions!

And so, Enjoy, and Happy Holidays from all the Tempco Team! #solidtemperature

 

 

Leave a comment

Efficiency and energy saving with SCR relays in electrical heating

17/12/2021

Let’s keep on talking about energy, renewables and energy saving. We’ve already talked on how is it possible to achieve energy saving in refrigerating groups using inverters, and how to increase efficiency in cooling tasks using dry coolers and evaporative towers.

While the use of inverters is quite affirmed on the cooling market, the use of SCR solid state relays with switching control is still not very much widespread on heating tasks. This is in fact a kind of application that we implement on Tempco’s thermoregulating units. When there is the need to heat a fluid, there are two options: a traditional boiler producing vapor, or diathermic oil or pressurized water, thus heated. The second option is to use electrical heaters. The primary energy sources employed are thus fossil fuels, or natural gas in burners, or electricity in the case of heaters.

Modulating burners are already very common in the market, enabling an adjustment of fuel consumption based on the thermal duty required. In case of electrical heating, the goal is to adjust the power capacity of the heaters. This is possibile thanks to SCR (silicone controller rectified) solid state relays. In this case, using a thermoregulating unit with a PID controller (proportional integral derivative controller), we can ask the heaters to provide only the effective power capacity required for the thermal duty needed at a certain step of the production process, in order to reach the temperature set-point or to maintain the temperature level.

The energy saving that can be achieved is really interesting. That’s because when engineering these kind of machines, they are designed to be able to provide the maximum heating capacity required. For example: an application requires to heat a certain amount of product inside a pharmaceutical reactor. The thermal duty is calculated by considering the starting temperature of the product and the final temperature to be reached, and the time lapse to achieve the heating task. With some additional power to the final result in order to also heat the reactor itself, and considering for example possible thermal losses. But once the final working temperature has been reached, the power capacity required becomes very much lower, only aimed to maintain that temperature level. For sure there will be the need to supply some more energy, for example in case of chemical reactions of the product, to compensate thermal dissipation or the heat loss through the coibentation. But, overall, this amount of energy will probably only be 1/10 of the design capacity, or maybe 1/3 or 1/5.

In order to adjust this power capacity, the solution employed in the past was to build multistage machines, equipped with different heating stages obtaining power adjustment using contactors or ON/OFF solid state relays, with the PID regulator switching these devices on and off in function of the heating capacity required.

The thyristor, or SCR solid state relay, allows to adjust the power capacity providing only the effective thermal duty required to maintain the temperature level within the proportional range, thus maintaining the set-point. Two main results are obtained, the first one being a relevant energy saving. While the second one, very important as well, is a much more accurate and fine regulation of the temperature.

Subscribe here to our Tempco Newsletter – Solid Temperature.

Leave a comment

Chillers in special EC motors test bench

10/12/2021

The growing attention on energy saving and efficiency within the industry, even for cooling applications, as we have seen already involves the possibility to implement electronic control motors on machinery such as chillers and evaporative towers. EC motors allow a variable speed control over equipments such as fans, based on the real cooling need of the production process. Even if designed and sized upon the maximum cooling capacity requested, indeed, cooling systems don’t always have to function at maximum capacity, requiring a lower cooling effect during many production steps.

In this context, the trend towards a more smart energy consumption in cooling plants leads to a growing employ of EC motors. This kind of motors have in particular to ensure the correct definition of the power absorbed at various rotation speed levels possible, as well as the evaluation of potential energy savings that can be achieved. The engineering of EC motors therefore requires accurate tests during the design step, in addition to the check of their effective performances: at this purpose, special test benches with a high sophistication level are employed. These test benches require at their turn an extremely accurate control of temperature and flow rate during the cooling/thermoregulation task, in order to guarantee the precision of the test process of EC motors.

Tempco raffreddamento test bench motori EC

The temperature range required in this kind of test benches is between 0° C and +90° C, involving two circuits. The first one is easier to realize, aimed to brakes cooling, while the second one is quite more sophisticated, aimed to the direct cooling/thermoregulation of motors, that undergo strict tests and thermal stresses.

The test bench for EC motors is then served by an air condensed chiller. The chiller provides refrigerated water for a thermoregulating unit, serving the plant water at the required temperature for each of the different steps of the testing. A series of equipments then provide water at the correct flow rate and temperature level as needed by the various components being tested. Finally, the overall system is equipped with instruments with an interface for remote control and monitoring of the plant.

Tempco raffreddamento banchi prova motori EC

Tempco termoregolazione banchi prova motori EC

Tempco raffreddamento banchi prova test motori EC

Subscribe here to our Tempco Newsletter – Solid Temperature.

Leave a comment

Renewables and energy saving in free coolers and evaporative towers

03/12/2021

Back to renewables and energy saving in applications involving second level energy, in other words thermal energy. After the video on refrigerating groups, another field offering important and interesting opportunities in terms of energy saving are free coolers and evaporative towers.

These are cooling systems employed in case of industrial production processes requiring cooled water at temperatures above 30-35° C. With such temperature levels it is possible to avoid the employ of refrigerating groups, and thus eliminating the energy consumption related to compressors and the complicated refrigeration circuit, the use of freon and so on.

Using free coolers, or dry coolers, and cooling towers, every saving can be therefore implemented fans equipped with EC motors, with electronic control and inverters. A sensing probe measures indeed the temperature of the water, and based on a predefined set-point it provides the adjustment of the power required to dissipate the right amount of energy to achieve the cooling task.

In the past, the costs of EC motors and inverters were too high to justify the investment cost. Alternative energy saving solutions were thus employed, such as using multi-fans installments with stepped functioning, partializing the number of functioning fans and limiting the power consumption based on the real demand.

Nowadays, the costs of EC motors allow a very interesting ROI. The solution is indeed more and more often required by our customers, and gladly embraced because it allows the obtain not only significant and effective energy savings, but also a reduction in maintenance costs. It’s clear indeed that the wear of a fan working for six or even nine months per year at a lower speed will be much less than the wear of a fan working at 100% of its capacity.

EC motors and inverter technologies are very much consolidated in the market today, and can thus be widely employed in industrial applications but also in conditioning, plants that have to work 365 days per year. Clearly, if a system works only during the summer, the ROI will probably be longer. But the opportunity is worth to be evaluated anyway, because during the night hours the temperature decreases, leading the an increased efficiency of the exchanger and requiring a less amount of air. So that energy saving can be achieved too.

Subscribe here to our Tempco Newsletter – Solid Temperature.

Leave a comment
About

TEMPCO researches and develops systems and solutions for cooling, heating, control temperature and heat exchange in different industrial processes.

Leggi »

ARCHIVIO

Tutti gli archivi »

CATEGORIE

Tutte le categorie »