Honeywell Experimenting with 3D Printed Heat Exchangers

Recently we have seen a growing demand for additional 3D printed parts in the aerospace industry, and after the announcement that 3D systems and Honeywell International will begin working together, it would seem that the innovative industry may be moving one step closer to gaining those additional components.

The two companies will begin working together to test a new heat exchanger that would be manufactured using 3D printing. If this test proves to be a success, we will see even more 3D printed parts being used in commercial aircraft engines.

3D systems have been awarded the contract worth $1.3 million, they will be responsible for the design, build and test of an aircraft heat exchanger that will be manufactured
using 3D printers.

This partnership also comes with huge perks for the global technology leader Honeywell International. Honeywell now have direct access to 3D systems’ Direct Metal Printing (DMP) technology. They also have the added benefit of gaining access and support from the manufacturing and materials expertise of Penn State’s Center for Innovative Materials Processing through Direct Digital Deposition (CIMP-3D).

Peter Meek director of Engineering Circleregistry of heat exchanger suppliers said; “The joint efforts of Honeywell International and 3D systems will be sure to revolutionise aircraft engine design and manufacture by using 3D printing technology. This collaboration could also introduce 3D printing to the multi billion dollar heat exchanger industry.”

Heat exchangers are currently used in commercial aircrafts to help improve fuel efficiency and reduce the risk of components in the fuel system freezing. It does this by taking heat from the engine’s oil system which can then be used to heat cold fuel.

Honeywell International are not the only industry giant to heavily invest in 3D printing in the aerospace industry. Other players like Lockheed Martin and GE aviation are also investing millions of dollars in additive manufacturing, which is more commonly known as 3D printing.

The Honeywell and 3D Systems project will be administered by America Makes and is due to launch mid year. The funding has been provided by Air Force Research Laboratory.

When explaining the decision John Wilczynski, Deputy Director of Technology for America Makes said, “Additive manufacturing offers design freedoms that are simply not possible when using traditional manufacturing processes.”

John continues; “The teaming by America Makes with industry leaders and researchers that possess substantial experience in heat exchangers and 3D printing will allow us to explore higher performing and lower-cost conformal parts. As a result, both the Air Force and the defense industry are poised to benefit greatly from this directed project.”

America Makes will also gain evaluation data from the development of the 3D printed heat exchangers which they can deliver to all their members. Members currently include all of the major defense and aerospace companies which could help encourage mainstream adoption of 3D Systems’ technology in the defense and aerospace industries. It is also likely that this data will infiltrate into Honeywell’s supply chain.

Checking For Cracked Heat Exchangers

When it comes to checking for cracked heat exchangers we have to start with the bad news first! Unfortunately at the moment there is no perfect technique that will allow you to find every single crack you may have in a heat exchanger.

But there are many techniques that have developed over time that can help. In this article we will take a look at some of the suggested techniques to help you check for cracks in your heat exchangers.

Using your eyes to visually find a crack is probably the best and most accurate way to currently check. But, this is also one of the most difficult and time consuming processes.

A smoke bomb test is another popular suggestion and works by placing a smoke generator in the heat exchanger. By doing so you can then visually check the outside of the heat exchanger to see if any smoke passes through any cracks.

The salt test comes next and consists of spraying a salt solution in the combustion chamber. You are then advised to drill a hole in the supply ducting and hold a torch over the section where the air blows out to see if the colour changes. If the salt has come into contact with the flame the flame will change colour.

In our opinion the next suggestion is slightly easier than the last. With the blower in operation, wintergreen oil can be sprayed in the combustion chamber. To inspect for cracks you can then place yourself at the supply registers and see is the smell is still present.

Up next is one of our favourite suggestions the pressure test. The pressure test requires all of the openings in the heat exchanger to be sealed, with the blower energised a pressure sensor should be inserted into the heat exchanger. This will then check if a crack or hole allows air to blow into the heat exchanger.

A bit more on the complicated side is the tracer gas test. Like the pressure test, all openings in the heat exchanger need to be sealed. A methane tracer gas should then be inserted into the heat exchanger. You can then use a gas leak detector to look for areas where the gas is found to be escaping.

However we do need to stress that most of the above suggestions make lots of fatal assumptions and as we already stated there is no known test that works.

The first assumption we can see is to do with the temperature of the heat exchanger. The assumption is that the crack will be open when the metal from the heat exchanger is at room temperature. Many cracks will only open when the metal is hot.

Secondly there is the assumption that a leak is going to be from the flame side to the distribution side. Yes, this is the case if the vent system is not drafting and the blower is switched off but if the blower is on there is little to no chance that smoke or gasses etc will pass through a crack. When the blower energises it is likely to produce a lot of pressure outside the heat exchanger so there is a good chance that the air will be blown fire side not distribution side.

Then, there is the question of how we suspect there is a crack in the first place. Does the technician have the time, experience or is there a reason behind the assumption? There are many more assumptions that we could list but if anyone tells you a way to test for cracks that works 100 percent of the time, take it from us, they’re wrong!

How Do Heat Exchangers Work?

Quite simply, a heat exchanger is a piece of equipment that transfers heat between two fluids. The fluids can either be in the form of a liquid or a gas and must be at different temperatures.

Where can we find heat exchangers?

One of the most common heat exchangers is found in most homes across the country, can you guess what it is? That’s right it’s a radiator.

Radiators work when hot water heats cold air which then provides enough heat to make the room in your house warm.

There are over 35 million of the second most common heat exchanger in the UK alone and you can find this heat exchanger in your car. The way that this heat exchanger works is the radiator cools the water coming from the engine with air from the atmosphere.

But heat exchanges can be found in a variety of different products and industries including factories, planes and ships.

But how do heat exchangers work exactly?

Generally all heat exchangers will work by passing fluid through tubing or piping, all whilst another fluid or gas flows around the tubes or pipes. The fluids will never come into direct contact with each other but will allow heat to be transferred. This process is what is known as a heat exchanger.

Like anything else, there are several ways to make heat exchangers work far more efficiently. For example, you can add an appliance that will increase the surface area, but by adding extras to the product you will be adding weight. Another option is to decrease the size of the tubing or piping. If you can then make thin walls you will not be adding a weight penalty.This also means you have a much lighter and more compact heat exchanger.

By having smaller piping or tubing means that you can have many more tubes or pipes. This means that you have more surface area which you can use to transfer the heat in a given volume.

There are two common types of heat exchanger which are called the shell and tube and plate and fin. In the shell and tube version, fluid will pass through a set of tubes, all while the other fluid flows through a sealed shell that surrounds the tubes. The second version, the plate and fin, contains lots of thin metal plates or fins that make up a large surface area.

The fluids can also flow in many different directions. There is parallel flow which is where the fluids flow in the same direction, there is counterflow which is where the fluids flow in opposite directions, or finally there is cross flow, this is where the fluid flows at right angles.

Even though you will find heat exchangers in so many different products and they all work in many different ways, there is one thing you should take away from this article and that is the realisation that all heat exchangers do the same thing, essentially they all pass heat from one fluid to another.

Common Heat Exchanger Problems

Unfortunately heat exchangers aren’t exempt from problems. Like any other product out there, they can attract a range of issues which can result in either; a poorly performing heat exchanger or a heat exchanger that just doesn’t work at all.

If regularly working with heat exchangers it would be a good idea to familiarise yourself with some of the most common problems, so you know what to expect if it should ever occur.

In this post we’ve taken a look at one of the most common problems found in heat exchangers and where possible we have thrown in a few simple solutions to help you fix the problem.

Heat Exchanger Fouling

Fouling is the buildup of debris and dirt on the surface area of a heat exchanger and is the most common problem encountered with heat exchangers. Fouling prevents heat from transferring, increases the pressure drop and can obstruct fluid flow. As such, regular maintenance to remove any dirt or debris is highly recommended and will benefit your heat exchanger in the long run.

There are numerous fouling types and each will depend on the fluid used and conditions of the heat exchanger. We’ve listed the more common fouling types below and the common ways to treat them.

Crystallization
Natural waters contain certain salts and these salts have a lower solubility in warm water than cold. This means than during the cooling process dissolved salts will crystallize on the surface.

A common way to avoid this happening is to reduce the temperature of the heat transfer surface.

Sedimentation

Another problem that can occur when using fresh water is sedimentation. Dirt, sand and rust can be commonly deposited in the tubes.

Increasing velocity will help to flush the particles off the surface.

Biological Organic Growth

Chemical reactions can cause biological organic growth material and when left to build up can cause a serious amount of damage.

When this type of fouling happens it would usually be removed by either a chemical treatment or mechanical brushing processes.

Chemical Fouling

This will happen when hydrocarbon deposits in a high temperature. It can be avoided by simply reducing the temperature between the fluid and the heat transfer surface.

Again, like biological organic growth fouling, if this type of fouling occurs, it must be removed by chemical treatment or mechanical descaling processes.

Other things to watch out for are corrosion and freezing fouling. Many people will understand that corrosion can destroy surface areas, it works exactly the same way in a heat exchanger. Freezing fouling happens when the heat transfer surface has been overcooled. This causes the solidification of some of the fluid stream components. Avoid costly damage and reduce the temperature gradient between the fluid and the heat transfer surface.

Be warned, if you fail to treat fouling you could be increasing your chance of attracting other major heat exchanger problems.

Heat Exchanger Market Worth £13,420.30 Million by 2019

MarketsandMarkets recently released a report about the future of the heat exchanger market. One of the predictions in the report suggests that the heat exchanger market will be worth over £13 million by 2019.

The report divides the market into easily identifiable sectors in order to examine the market better and make more accurate predictions. The report segments the market into the following categories; by type (plate and frame, shell and tube, printed circuit, air cooled), application (oil and gas, chemical, Petrochemical, Food and beverage, pulp and paper, HVACR, power generation), classification ( temperature range and fluid type, MoC), and geography.

The report analysed the trends recently witnessed in the market and makes a number of predictions on what will happen in the heat exchanger market by 2019. In this article we’ve picked out some of the key points mentioned in the report.

Asia Pacific has been declared the fastest growing heat exchanger market globally and is estimated to grow at a compound annual growth rate of 10.7% for the next five consecutive years. Currently Asia Pacific is experiencing a high industrial growth rate which according to MarketsandMarkets will have a huge impact on the heat exchanger market. With high industrial growth there will be an increasing demand for heat exchangers in a diverse range of applications.

China in particular dominates the heat exchangers market as it is a major consumer and is the fastest growing country in terms of heat exchanger demand.

It has also been stated that an increasing number of heat exchanger manufacturers from Asia are increasing its efforts to develop a stronger share of the heat exchanger market. It has been suggested that the region has a target to reduce the number of heat exchanger imports.

Europe is also expected to experience growth in the heat exchanger market.

MarketsandMarkets predict a compound annual growth rate of 4.81% from 2014 to 2019. The European region has always had a strong heat exchanger market share and has been a global leader with it comes to demand and production capacity. This is enhanced by the fact that Europe has the presence of nearly every leading manufacturer of heat exchangers from across the globe in its continent.

The demand in Europe is predicted to increase due to the increased replacement demand for heat exchangers.

But, Europe will experience a much slower growth rate than Asia because the area already has a dominant market size and is currently experiencing slow economic activity when compared to other areas. At the moment, Europe holds more than 30% of the entire heat exchanger market globally.

The final factor that will impact and drive the heat exchanger market is the number of emerging Eastern European manufacturers. It is expected that manufacturers from this region will reduce import dependence of various countries.

The full report was produced by MarketsandMarkets to provide apt business insight into the heat exchanger market.

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Southern hospitality and Tajik traditions have joined together in Greenwood, South Carolina on the campus of Lander University, where 2012-2013 JFDP Fellow Munavar Zaripova is not only representing her native country of Tajikistan, but also serving as a prime illustration of how scholarly exchange impacts participants, host institutions and communities alike. Ms. Zaripova is an American Studies and TESOL scholar currently enrolled in two U.S. history classes, a course on modern China and a business English communication class. The Lander University community, from host university coordinators, faculty advisors and senior executive staff, Dr. Ball, President of Lander University and Dr. Sung-Jae Park, Dean of International Programs, has graciously welcomed and supported her during her fellowship.