Saturday 28 February 2015

Counter Top Water Filters and Air Coolers

Counter top water filtering systems as the simple and fast way to clean your water. You can even take it with you when you travel.
If you are going on vacation, or renting a place for a while, you may want to make sure that your water is just as clean and pure as your home water supply. The perfect solution for this kind of situation is to bring along a counter top water filtering system. Many people also use this type of system if they are unable to install an under the sink system because of space restrictions or your landlord won't allow alterations such as this. A simple counter to systems needs no plumbing yet it offers more filtering power than the small faucet additions that many people use.

A counter top system can be installed by anyone; no plumber is needed since it is simply a matter of using a diverter valve to attach the system to any faucet you like. Using a diverter valve such as this, you can shut it on or off, depending on whether you need the water to be filtered. You filtered water will be cleaner and better tasting, and it does not require a great deal of space on your kitchen counter, Of course, the more compels the filtering system, the larger the unit will have to be. The models also come in a range of finishes and styles the will fit in with the style of your kitchen. Another convenient feature is a decanter you can fill from the filtering system so that you can keep cool, filtered water in the firdge at all times.
A counter top filtering system will remove many unpleasant particles from your drinking water such as calcium, potassium, magnesium, lead, chlorine and other chemicals you prefer not to drink. You may not realize it, but there may be particles of pesticides, herbicides and dirty sediment in your water; a water filtering system, even a fairly simple one such as counter top system, will remove a great deal of these. Just as an air cooler removes impurities from the air, these will remove impurities from the water. If your drinking water tastes orsmalls funny, a water filter system will improve the taste and smell as well. This solution is a great alternative to bottled water, since it only costs about 10 cents a gallon to produce.
Make sure that your system keeps doing its job properly by changing the systems filter according to the manufacturer's instructions, usually twice a year, or after a certain number of gallons have been purified. It is simple enough to change the filter-just open the compartment, remove the old one and slip in a new filter. It is a good idea to run some water through the new filter before you start draining it.
If you want to make sure that you your family drink safe, clean water, a counter top filtering system is the ideal solution.

ASAC REFRIGERATION DIVISION OIL COOLING SYSTEMS



With reference to screw compressor oil cooling systems sales & service engineers should be aware of what methods can be used, how & where to apply & design them. There are three basic oil cooling systems.

•    Water cooled
•    Air cooled
•    Refrigerant cooled

1) Water cooled

Are applicable to systems utilizing Evaporative condensers or cooling towers or where an independent water supply is available.

Water cooled oil coolers are shell & tube or plate heat exchanger design. Generally the oil cooling circuit is on the shell side and the water circuit on the tube side for shell & tube coolers. For PHE's the oil cooler cassettes should be welded & the water side gasketted to facilitate cleaning.

The water circuit on a S&T cooler will normally be 2 pass and the heads or bonnets should be able to be removed for tube cleaning & maintenance purposes. For all applications in Saudi Arabia the tubes + tube sheets should be 90/10 Cu/Ni & the channels or bonnets epoxy coated. Tubes must be straight bore thick wall 0.35" thick, internally enhanced tubes should not be used.

The water circuit can be piped from one end of the pan & back to the opposite end of the pan to ensure thorough mixing of the pan water, using optional extra connections provided by the manufacturer + a separate circulating pump & Y type strainer. Alternatively & probably lower cost option, is to request the condenser manufacturer to provide a "Tee" piece in the spray water pump discharge & uprate the spray pump flow rate + head to accommodate the oil cooler. The water is returned to the spray sparge inlet connection on the condenser. Service stop valves must be included in the flow & return to the oil cooler + a bypass valve between the flow & return located in the standard condenser water pump discharge piping. As the oil cooler circuit will always have the highest pressure drop this bypass valve should be a flow regulating type valve so the flow can be adjusted to the condenser spray manifold with the remainder passing direct to the oil cooler.

Care must be taken in selecting the Evaporative Condenser as the  evaporative condenser or cooling tower sees the oil cooling load as an addition to the compressor THR by virtue of the rise in spray water temperature, unless the water source is independent from the compressor condenser. Generally the rejection capacity will need to be increased by approximately 5% to cover the increase in the spray water temperature. Rather than waste time calculating the rise in spray water temperature just simply include the oil cooling load in the THR figure or select the condenser as normal e.g. evaporator load + shaft power only, but ensure you use a selection with say +10% spare capacity or surface area.

2) Air cooled

Can be utilized on all systems where air cooled condensers are utilized or a water supply is not available. For air cooled systems where the condenser is close coupled to the compressor an additional independent row can be added to the main condenser with its own inlet/outlet header. However sales should contact both the condenser manufacturer to ensure they can provide this facility + the compressor manufacturer to check the engineering & whether a full time lube oil pump is required.

Alternatively a packaged air cooled oil cooler can be mounted on the compressor & the compressor manufacturer should be able to provide a quotation for both the air cooled cooler + mounting & piping.

For all remote air cooled oil cooler applications the oil cooling load is not to be included in the compressor condenser selection. Obviously safety relief valves will be required between any valves in the system & a separate DOL starter contactor or relay, fuse & control circuit will be required for the fans.

3) Refrigerant cooled


Refrigerant cooled oil cooling can be
•    Liquid injection either low or high or automatic low & high Vi into the compressor rotors.
•    Thermosyphon shell & tube or plate heat exchanger
•    Pumped circulation

3.1) Liquid injection oil cooling

In the case of liquid injection the oil cooler load must be included in the THR for the condenser selection. It does provide a low cost means of oil cooling on bare compressor units + chillers. If liquid injection is used, automatic dual Hi/Low injection systems must be used which facilitates injecting earlier or later along the length to the rotors depending upon the operating Vi.
However liquid injection should be avoided wherever possible due to

•    Inability to accurately control the liquid injected at various Vi's & condensing pressures during normal operation.
•    Increase in power + decrease in capacity
•    Problems arising in high back pressure applications where the total mass flow is too high for the radial + axial discharge ports, particularly at pull down.
•    Propensity to cause additional wear in rotors & bearings due to overfeeding or overcooling, causing gas to condense in the discharge ports + oil in the separator.

3.2) Thermosyphon oil cooling

Thermosyphon systems provide the optimum oil cooling system in terms of cost, performance & maintenance. However it is important the system is designed properly and a basic understanding of the system requirements is appreciated. Thermosyphon oil cooling systems may utilize either shell & tube or welded Plate heat exchangers. In all cases the oil cooler load has to be included in the condenser total heat of rejection.

•    Sufficient liquid reserve of 2 minutes must be provided to ensure a continous feed to the oil cooler when the compressor is disabled to allow adequate oil cooling during the motor coast down period.
•    Thermosyphon systems must operate with a liquid overfeed rate of minimum 1.5:1 to 4:1.
•    The liquid feed and wet suction returns have to be very carefully sized to reduce friction losses to a maximum of 0.5pfsi/100' (0.035 kg/cm2) for the liquid feed & 0.2pfsi/100' (0.014kg/cm2) for the return. If the line sizes are too small the friction losses  will increase. As the friction losses increase the circulation rate will reduce; the flow will balance out at a new equilibrium corresponding to the static head minus the system pressure drop.
•    Wherever possible the main system HP liquid receiver should be used rather than using pilot receivers.
•    In terms of static head, the liquid feed static head must be high enough to overcome the pressure drop in the liquid feed + oil cooler + return line. Generally the total pressure drop will be around 1.5pfsi which requires the priority vessel to be mounted at least 2mtr above the TSOC/s.
•    For multi TSOC applications a plug type flow regulating valve must be installed at the inlet to each TSOC to enable proper balancing of the flow. Normal service stop valves or ball valves or butterfly valves are unsuitable for flow regulation & should not be used.
•    Where the main system HP receiver is used or where a priority or pilot receiver is used for single or multi condensers in parallel, the vessel must be installed at a height of at least 6mtrs below the condenser outlet drain in order to ensure free liquid drainage as per the sketch provided to you all previously. The priority or pilot or main HP receiver must be vented back to the condenser inlet connection. To calculate the correct trapping height of the condenser liquid drain lines, the pressure drop must be calculated from the condenser hot gas inlet to the vessel. This averages out at around 5-6psi & @ 40degC liquid temperature (1ft head = 4psi @ 40degC) the drain line trapping height will approximately 6mtr.     Too much height is preferable to little height. If insufficient height is allowed, liquid will back up in the condensers until sufficient static head is available to overcome the drain line pressure drop.
•    Liquid drain service stop valves must be installed in the vertical position above the drain trap into header back to the vessel at a height of at least 1.2mtr above the P trap.
•     Thermosyphon circulation is no different from a mechanically pumped system except that the motive force arises from the conversion of kinetic energy to pressure energy by virtue of the difference between the available static liquid head minus the circuit pressure drop & by the difference in density between the single phase liquid feed & the 2 phase liquid/vapour return. However unlike a mechanically pumped system or pumper drum system, thermosyphon systems are fixed head systems & cannot pump to a height above the available static head except for small differences between the flow and return due to differencies in refrigerant density plus Einstein bubble lift effects where gas bubbles lift the liquid as they rise through the column.

             If the pressure losses through the TSOC + return line are greater than the available liquid feed static             head, then liquid overfeed cannot take place The TSOC will then act as a flooded cooler on a 1:1 basis & a danger of gas binding arises.

             The TSOC/s return line/s must be larger than the liquid feed line by one pipe size to accommodate the vapour return & ensure friction losses are maintained at or below 0.2psig to ensure the design 4:1 recirculation rate is achieved. The vapour is carried back with the liquid by the force exerted by virtue of the static head & refrigerant liquid density difference + Einstein bubble lift flow. The vapour velocity may be greater than the liquid velocity but it is not necessarily the case that the vapour velocity is sufficiently high enough to assist in the liquid return up vertical risers and back to the priority vessel.

             The return flow in a vertical riser on a TSOC is not the same as a wet suction return on a freezer cooler,  where the circulating pump is designed to circulate the design refrigerant mass against the pressure differential between pump suction & surge drum return connection for bottom fed coolers below the surge drum, or to the cooler outlet connection for top fed coolers above the surge drum where gravitational forces

             assist in returning the liquid & vapour.
             The flow regime in a thermosyphon vertical riser or pumped cooler system will be 2 phase Annular, bubble or slug flow depending on the heat flux, liquid/gas velocities, pipe size.
             In case of pumped liquid overfeed systems or gravity flooded systems, the vertical riser pipe size may be smaller than for a TSOC application & the systems must not be confused. In the case of long vertical risers if the pipe size is larger than necessary the static head will increase requiring higher head pumps or in the case of Thermosyphon flow, stalling of the thermosyphon cycle.
•    Where for some reason the TSOC return/s cannot be headered back to the pilot or priority vessel & are taken up to the condenser hot gas inlet pipe, it may be impossible to obtain liquid overfeed or a 4:1 rate of recirculation as there is insufficient static head or kinetic energy to drive the liquid above & beyond the liquid level existing in the priority vessel.

•    The thermosyphon circuit is simply a closed loop U tube, where, when no heat is rejected in the oil cooler, no circulation will take place & the liquid level in the liquid feed & return line will be in equilibrium at the same height, as the pressure above both the feed & return in the priority vessel will be at the same saturated pressure as exists in the condenser. The liquid temperature will be the same as the condenser saturated temperature by virtue of the vent lines from the HP receiver + the priority vessel, back to the condenser inlet.
•    The phase change from liquid to vapour in the TSOC will be at a higher temperature than the condensing temperature due to the submergence effect in the oil cooler due the static liquid head pressure exerted by the liquid feed line + vessel diameter. This provides the difference in refrigerant liquid density due to the difference in temperature. The refrigerant flow rate can be calculated by the TSOC THR divided by the difference in enthalpy between the liquid & vapour at the condensing temperature e.g. 40degC x by the recirculation rate.
•    A common misconception with thermosyhpon oil cooling systems exists in relation to taking the TSOC return back to the priority vessel, where Sabroe recommend against it due a loss of liquid subcooling.
•    They recommend the returns are taken up to the condenser inlet line. The notion of loss of subcooling is incorrect (In Saudi Arabia) as the liquid exiting the condenser & the liquid in the priority vessel + HP receiver  will all be at the same saturated condensing temperature e.g. 40degC by virtue of the gas balance or vent lines.
            Too, as explained above there will be insufficient motive force in the TSOC liquid feed line or liquid density difference to force the liquid refrigerant up the portion of return line above the liquid level in the priority vessel. In most evaporative condenser designs, the hot gas inlet connection will be approximately 1.5mtr above the outlet connection & upto 6mtrs above the priority vessel liquid level.
            If condenser sub cooling is required then the condenser has to be ordered with a separate sub cooling
            section with its own inlet & outlet connections separate from the condenser main inlet & outlet
            connection. The liquid to the system is then fed from the HP liquid receiver through the condenser sub
            cooling coil and from the coil to the system.
•    Priority or pilot receivers are additional expense in terms of the vessel + installation costs. Wherever possible the main liquid receiver should be used to feed the TSOC/s. Generally there is little maintenance required on a receiver & if external liquid level gauge glasses are used there is no reason on any installation why the liquid receiver should not be installed in the plant room, out of the sun, installed at a height of 2 mtrs above the TSOC/s. The receiver should have a priority pot on the outlet sufficient to provide 2 minutes of liquid storage which is the amount of time for the motor/compressor to coast down to zero RPM. As noted above it is very easy to calculate the liquid overfeed flow rate in Kg/s or lbs/min and from that to
            calculate the priority pot capacity in M3 or ft3 by multiplying the 2 minute supply by the density of the
            refrigerant at the condensing temperature.
            If liquid receivers are installed on the roof along with the condenser then insufficient trapping height will be
            available, unless  a bottom inlet surge type receiver is used, plus the receiver will be subject to excessive
            heat ingress due to solar radiation whereby surface temperatures have been logged at upto 80degC.

3.3)  Pumped liquid recirculation oil coolers

           Pumped recirculation oil coolers may use Shell & Tube or Plate heat exchangers. Liquid is circulated using a  mechanical hermetic pump at a rate of  1.5 to 4:1. This system would generally only be used where insufficient static height exists to install a priority or pilot receiver or the main HP receiver cannot for some reason be elevated at least 2mtr above the oil cooler/s & refrigerant cooling is the only option available. Obviously the system is expensive in terms of initial capital costs of the pump, starter, controls, orifices, valves, strainer, relief devices etc, in comparison to a straight Thermosyphon system.
•    The refrigerant mass flow rate is calculated in the same way as detailed above e.g. Oil cooler THR/ enthalpy difference between liquid & vapour @ condensing temperature x the rate of recirculation e.g. x 4.
•    The oil cooler should be selected on whatever rate of flow provides the smallest heat exchanger, commensurate with the lowest pressure drop. If it is the same size cooler or same # of plate cassettes there is no point in selecting a recirculation rate of 4:1 if 1.5: 1 provides an identical cooler.
•    The pump should be connected to an outlet connection on the main system HP liquid receiver ensuring the receiver is mounted at a height sufficient to meet the pump NPSH requirements. The return from the oil coolers can be taken back to a connection at the top of the HP liquid receiver.
A suitably sized vent line based on the mass vapour flow must be installed between the receiver & the condenser inlet. The vent or gas balance line would be selected based on the mass flow rate and pressure drop of less than 0.2pfsi100'.

Friday 27 February 2015

What Pressure Vessels Mean to You

At their most basic, pressure vessels are closed containers used to hold liquids and gases at different pressures. Around the world, pressure vessels are frequently used in both the private sector and for a number of industries for compressed air, water storage, compression chambers, autoclaves, pressure reactors, and much more.
However, Because of the dangerous nature of these vessels, their engineering, development, and construction is dictated by a number of parameters that dictate maximum operating pressure and temperature.


You might wonder, why would anyone even need a pressure vessel? In a number of applications, manipulation of the pressure is essential when it comes to achieving the results needed. For example, one of the most common vessels is the ASME compressed air vessel, used in an almost uncountable number of industries and applications around the world. For instance, compressed air can be used to supply power for a variety of different manufacturing operations, while being much safer and more convenient than using a power source like electricity. At the same time, it can also be used to provide the power for drills, jack hammers, and much more - and it's all made possible because of the vessel that safely and securely contains the air.
However, pressure vessels aren't just for compressed air. In fact, the uses for these vessels range in variety from simple compressed air systems to highly advanced vessels for advanced industrial, scientific, and defense applications.
But how does it work? While the science behind the pressure limits of various styles of vessels can be incredibly complex, the underlying principle at work in a vessel is relatively simple. The pressure within the vessel can be created by a chemical or gas reaction occurring inside the enclosure, or by an external source - such as in the case of a boiler vessel.
As for their construction and design, while vessels tend to be spherical or cylindrical, they can actually be constructed in just about any shape or size. The most common shape is a cylindrical vessel with end caps known as "heads". While the governing authority of pressure vessel design and construction (ASME) allows for a long list of materials to be used, steel (in a number of grades) is the most common.
On the other hand, some vessels are constructed of composite materials while others are constructed out of materials like concrete, with cabling for added tension. In the end, it all depends on the application that calls for the pressure vessel.
Pressure vessels are a relatively new invention. The first pressure vessel was invented during the industrial revolution to be used as a boiler which contained steam for steam engine. The steam was contained inside the pressure vessel, and then expelled into the steam engine as power. However, along with these early vessels also came a number of accidents. Boiler explosions were a common problem, which eventually lead to a system of design, testing, and certification standards.
In 1919, the first high-pressure (10,000 PSI) pressure vessel was constructed as a 6-inch diameter tank. This tank was wound with high-tensile steel to prevent rupturing and reinforced end-caps for additional support. The design for that particular vessel was particularly important in the progression of the technology, and inevitably lead to many of the modern design standards we rely on today.

 For more info , click here.

Trail Bikes Oil Cooler Kit Installation Guide (Part II)

 

Step 3.  Remove the right hand side cylinder head cover (it is the one near the spark plug held in with 3 bolts) The center bolt runs all the way through the head to the other side, hold the cover on the opposite side when removing the long center bolt.

Once the head cover is removed, remove the old gasket and clean off any oil from the sealing surface on the head.

At this time select the new gasket from the two that are provided in the kit.  You need to check the gasket against the head plate to see which one aligns with the holes and passages on your application.
Next, prepare the oil cooler taps to be installed into the new head tap plate provided with the kit.  You will need to use the Teflon tape provided in the kit on the threads to ensure an oil tight seal as the illustration shows below. It is not necessary to use Teflon tape on the compression fitting side of the taps.  Make sure when wrapping the threads with the Teflon tape that you are applying the tape in the same direction as the taps would thread into the new head tap plate.  The tape should cover the threads of the taps but it must not cover the end where oil will flows through.

 

Prepare the new oil cooler head tap plate to replace the right hand side cylinder head cover by installing the oil cooler taps. Pay close attention to the angle you have installed the taps to ensure they are facing in the direction that you selected when “mocking up” the install in Step 1.  Be sure not to over tighten the taps. Make sure that the taps are in such a position that when attaching the oil cooler line that the lines clear the cooling fins on the new head tap plate. Minor adjustments of the taps can be made once everything is in position.



Step 4. Ensure that all sealing surfaces are clean and apply the gasket of choice. Install the head tap plate on the engine and torque the bolts to manufactures specification. The torque rating is 8ft lbs for a factory Honda engine. Once the head tap plate has been installed, proceed to step 5.

 

Step 5. Route oil lines to the oil cooler and head tap plate. At this time only hand tighten the lines and determine what the best routing for your application will be.  You may have to make minor adjustment to the taps to achieve the best routing for you application. It is crucial to ensure that there is no severe bends in the oil lines that could restrict oil flow.  The lines must attach to the cooler at a nearly perpendicular angle (90’ angle) or else the banjo fittings will not form a seal.  If not installed at a perpendicular angle the end of the line will bottom out on the cooler and not the sealing surface for the banjo fitting. Once you have determined the correct routing for your application then tighten all connections.

 

Step 6. Check over complete installation to ensure that all lines are routed without severe bends and that all connections are tight.  Turn the wheel lock to lock and compress the suspension fully making sure nothing will come in contact with the cooler or the lines. Check the oil dipstick to make sure the oil level is full. You are now ready to start your engine.

 Start the engine for a few seconds (10 seconds or so) and inspect all connections for any signs of leakage.  Shut the engine off after the 10 second interval.  Oil pressure should have built up and some of the oil should now be in the cooler causing your crankcase to be low on oil.    If it does not appear that the oil level has decreased any there may be an oil flow problem and severe damage could occur if engine is restarted.  Recheck all connections and installation if the oil level in the crankcase is not dropping.  If the oil level lowered by a few ounces add the necessary oil to bring the crankcase oil level back to full. Once the oil level is back to full and you have made sure that there are no leaks, start the engine and allow it to run for a little longer and then shut off the motor and verify oil level again.  Do this a few times until the oil level stays consistent, resulting in the correct level for the new increased oil capacity with the addition of the new Trail Bikes oil cooler.

Step 7. Recheck all oil connections, mounting bracket of choice, cylinder studs should be re-torque if you chose this mounting method, re-torque cylinder head cover and check for oil leaks once again.  If everything looks good, proceed to start the engine again. After the engine has warmed up you should be able to feel some warmth by touching the oil cooler. At this time rev the engine up a few times and ensure that there are no oil leaks again and again.

If the installation was performed correctly the cooler will provide very reliable service, extend the life of your engine and increase the performance on long or heavy-duty runs that generate a lot of horsepower robbing heat.

IMPORTANT NOTE

If you would like to verify that the installation is correct and that the oil is flowing as it should (highly recommended when installed on non OEM Honda engines such as the popular Chinese produced replicas)  please take the following steps.

You will need to check for oil flow and pressure in some critical areas of the engine.  First check for oil flow through the cooler.  The easiest way is to crack loose the fittings on the cooler, check one at a time and shield the oil from hitting you with a rag as the oil can just squirt out (do this at your own risk)  If there is oil pressure escaping at each end of the cooler then you can be certain that the flow to and through the cooler is good.

Next you want to make sure that the cam is getting oil to it with the new cylinder head cover (this is particularly important to check on Chinese replica engines with the “short” cam as the boss on the Trailbikes cylinder head cover does not extend as far as the factory Chinese cylinder head cover)  You can remove the top cylinder head cover and look for a large amount of oil on the camshaft lobes and rocker arm area.  You can also remove the cylinder head valve caps and see if oil squirts out of the rocker studs (once again, perform this check at your own risk as hot oil will squirt out under pressure if everything is installed correctly)

Recheck the oil level as you are sure to lose some performing these checks and then start enjoying your bike again knowing that the power won’t drop off as much after you ran that motor hard like it did when it was just air cooled.

For more information, click here.

Thursday 26 February 2015

Trail Bikes Oil Cooler Kit Installation Guide (Part I)

The Trail Bikes Oil Cooler Kit is a high quality accessory designed to help your Honda horizontal engine or Honda clone engine keep cooler.  Air-cooled engines run hotter when modified or subjected to heavy loads such as racing use.  This kit will help your engine’s durability and reliability by circulating the engine oil through a cooler reducing the engine’s oil temperature.  It is highly recommend that you completely read through the installation instructions before you begin.

WARNING!!!
The installation of aftermarket accessories such as this oil cooler kit may void your manufacturer’s warranty. Trail Bikes is not responsible in any way for such voids.

WARNING!!!
This guide is for illustration purposes only.  All engine work should be performed by a trained professional mechanic and in accordance to factory recommendations.  Improper installation could result in extensive engine damage.  Use this guide for reference only.  Any and all instructions provided are suggestions for the professional mechanic.

 


Step 1.   Remove oil cooler from box and examine the two mounting brackets included in the kit.  The bracket attached to the cooler is made to slip over your cylinder studs as the illustration shows above.
The other bracket is designed to attach to the frame as the illustration shows below.  The brackets provided in this kit are designed to work on multiple applications and you will need to determine what works best for your application.  If you have the option to use either on your application, we recommend using the frame mounted bracket setup.

 

It is best to locate a spot on the bike that is towards the front of the bike where air will travel across the cooler as the bike is traveling forward.  Once a good spot has been located, attach your mounting bracket of choice. Only hand tighten the cylinder studs or the hose clamp provided for the other mounting bracket.  At this time you will  “mock up” the installation and make sure that the oil cooler lines will be long enough to reach the cooler and that the lines will not have to make any extreme bends which would restrict oil flow. (Please note that the cooler can be installed upside down if necessary, the oil lines can be at the top or bottom of the cooler)
Turn the wheel lock to lock and compress the suspension fully making sure nothing will come in contact with the cooler or the lines.
If everything looks like it is going to clear, proceed to step 2.



Step 2. Mount the oil cooler in the selected location using the mounting bracket of choice.  The illustration above shows the cooler being mounted with the bracket that slips over the cylinder studs.  Be sure to re-torque the cylinder studs to your manufactures specification if you choose this method.  The torque rating is 8ft lbs for a factory Honda engine.

The illustration below shows the oil cooler mounted to the frame using the other bracket provided. This mounting bracket is attached to the frame using a hose clamp and is the better choice if it can be used on your application.  For a stronger and more reliable mount you can also drill and tap a hole in the frame.  The bracket has a clearance hole in it already. This would be the preferred mounting method if applicable.

Friday 6 February 2015

7 Reasons to Purchase an Air Cooler

A. Health Benefits.

Some forms of air coolers, present consolation to individuals with allergic reactions and respiratory issues, in addition to aged individuals and kids. Some swamp coolers are perfect for individuals allergy symptoms and different respiratory circumstances. These such coolers draw exterior air into the constructing. Once inside, the air is cooled by evaporation after which circulated. This exercise gives a continuing provide of filtered, contemporary air. This course of is completely different from air con models, which recirculate outdated air. Air coolers draw moisture into dry indoor air, rising humidity whereas decreasing the air temperature.

B. Environmentally Friendly.

Powered by the pure strategy of evaporation, evaporative coolers don't depend on extraordinarily massive quantities of electrical energy and chemical-based mostly coolants, like Freon. Swamp cooler can present power financial savings and environmental advantages that may probably decrease your indoor air temperature by as a lot as 30 levels Fahrenheit. Swamp coolers use a couple of quater of the power utilized by an air conditioner or central air unit. Even probably the most complicated residential swamp cooler system will makes use of considerably much less vitality than an air-con unit.

C. Save Money on Your Cooling Bill.

If your objective is to save cash in your utility payments and scale back your cooling prices, then an evaporative cooler or swamp cooler could also be for you. An evaporative cooler, such because the Schaefer Waycool S/A HP Oscillating Cooler makes use of solely 1 / 4 of the power utilized by refrigerated air conditioners. the associated fee to function an evaporative air cooler or swamp cooler is comparatively cheaper than different cooling strategies.

D. Affordable.

An air cooler prices solely a fraction of the price of a central air unit, starting from $one hundred for a conveyable unit to $A,000 for a big industrial unit. Additionally,the low price of set up, is about half the price of putting in a central air unit.

E. Easy to Install.

Because of its easy design, it's pretty simple and cheap to put in an evaporative cooler.

F. It's Also a Humidifier.

Evaporative air coolers even have the power to humidify dry air, as moist pads are used to chill the air. With this, you can be glad to know that your furnishings and materials will likely be saved effectively moisturized too. This will certainly assist keep the sturdiness and lifespan of your furnishings.

G. Easy Maintenance.

Easy upkeep is without doubt one of the finest causes for getting an evaporative cooler. All coolers include refillable water tanks that are simply accessible. A full tank lasts about 10 hours. If you require an extended operational interval, think about an cooler with a hose connection which repeatedly provides recent water to the cooler. All air cooler filters may be eliminated and rinsed.

More commercial air cooler for marine industry, visit www.heatecholdings.com

How to Choose a Portable Air Cooler

When seeking to preserve the house cool in summer time many individuals look in direction of the transportable air cooler to realize this, there are various advantages from utilizing an air cooler in comparison with an air conditioner.

One profit is the electrical energy these items really use when working, this may be a lot decrease utilization in comparison with the transportable air conditioner. This means cheaper electrical payments which everyone seems to be searching for as of late, with the price of fueling our houses rising everyone seems to be looking for probably the most economical strategy to warmth and funky their properties.

Another factor to understand in regards to the transportable air cooler is that it'll solely cool a sure space of the room, they don't seem to be designed to chill the entire space like air conditioners are. This is a bonus for the cooler as you'll be able to situate it near an individual to get most cooling, there isn't a level cooling the entire room down when it's you that wants preserving cool.

A lot of individuals today are involved with the hurt to the atmosphere these types of machines really trigger, effectively the air cooler causes no hurt because it doesn't use gasoline or another type of chemical compounds within the cooling course of. It truly makes use of chilly moist pads contained in the machine which sizzling air is drawn over after which blown out as chilly air, this can be a easy course of however very efficient when utilized in dry low humidity areas.

Another side of the moveable air coolers is that they use evaporation to chill the air, this method makes use of far much less electrical energy than different air con models. The coolers are additionally recognized to take away pet dander, mud, and musty smells from the room they're working in, thus making your house a way more pleasant atmosphere to dwell in for all of the household.

A main concern with most individuals is the precise price of those items, they assume they price an unlimited amount of cash to purchase, this isn't the case with the moveable air cooler as they're very fairly priced and the cash you'll save in your electrical energy payments after just a few months of use will nearly cowl the price of the unit.

So if you're on the lookout for an environment friendly technique to maintain your self cool throughout these sizzling summer season months, then go surfing and perform a little research into the various various kinds of moveable air cooler accessible in the present day.

More choice of air cooler for marine services.

Air Cooler - Advantages Versus Portable Air Condition

If you're in search of a room air conditioner however are not sure whether or not a air cooler, also referred to as an evaporative air cooler, or if a correct, transportable air situation unit could be a greater match for you, then on this article we are going to go over a number of benefits of air cooler that make it fairly engaging as in contrast with a daily moveable air situation unit. The benefits are - it's straightforward to grasp how the cooling works, it would cool solely a specific space of the room, and cooling requires no vents or hoses in any respect, and is straightforward and economical to function. For the nice measure, we'll point out the primary disadvantages as properly that are: cooling is not going to work in states with excessive humidity and it'll not cool your complete room.

Advantages

The operation of air coolers is straightforward to know

Indeed, there may be actually not a lot to it. The dry scorching air is blown over the water. Since the method of taking over water requires warmth, the air is cooled and humidified on the similar time. Then the humid air is circulated, and finally blended with the brand new incoming sizzling and dry air, and the method is repeated.

Air cooling will solely cool a specific space of the room

Since there is no such thing as a internet warmth loss, aside from as a lot moist air that manages to flee from the room, the general temperature of the room is just not a lot modified. Only the world the place the moist air is directed from the air cooler will likely be pleasantly cooler, by as a lot as ten to fifteen levels Fahrenheit. This characteristic of a evaporated air cooler can be utilized to your benefit.

Air cooling requires no vents or hoses to function

Due to the simplistic method the evaporated coolers function, and since there is no such thing as a directed warmth transport circuit, there are not any hoses or vents wanted. No must open the home windows both. No want certainly even to have home windows.

Coolers are straightforward and quiet to function

As there are not any compressors, solely the followers, air coolers take up little power, as little as a 60 W mild bulb, and are usually quiet when operating.

Disadvantages

Air con won't work in locations with excessive humidity

Due to the straightforward operation of air coolers described above, they won't work when the humidity of the air is already excessive. The air that blows over the water merely cannot settle for any extra moisture, and due to this fact cannot quiet down. That is why coolers are additionally known as dry air coolers. The common humidity of 38 % is quoted as nonetheless acceptable for the operation of a air cooler. The states that simply meet that restrict are Arizona, New Mexico, Nevada, and Southern California.

Air con won't cool the whole room

We talked about that earlier as a bonus of evaporative cooling. You can cool simply the components of the room the place you're. However, when there are extra individuals within the room, you typically would wish to settle down your entire room. Even the very best evaporative air cooler can't do this. In distinction, a transportable air situation unit is well able to cooling your complete room when its vents are configured as directed.

More air cooler information over here.

Thursday 5 February 2015

Thermal Design specifications and properties of electronic components and materials (Part 2)



The modelling technics currently used have at least two different methods for creating real models for thermal design. One method uses direct geometrical/material analyses to make thermal model for components and the other method uses thermal resistor/capa-citor networks for example the DELPHI-project. Both of these methods should be possible in component level specifications.

The European co-operative project DELPHI /Rosten et al/ is an example of an activity where the responsibility of the thermal design has been attempted to be shared between the supplier of component and the end user.

The specification system for thermal specifications of electronic components and sub-systems and the applicable tests/measurement methods should cover following areas:

- Component specifications
- Interface specimens and materials (heat conducting specimens, thermally conductive insulators) and their specifications and models
- Subsystems (Printed circuit boards, units, rails)
- Heat sinks and fans.
- Material specifications (materials of components and other parts of electronics)

Some guidelines are needed for the thermal specification of PCB and subsystem level. It should be kept in mind that all relevant heat transfer mechanisms are treated, conduction, convection and radiation, when components are positioned on PCB. Monitoring the work of existing groups generating thermal models - DELPHI, SEED, JEDEC; SEMI, and standardising these different methods will be an important task for this research project and CENELEC.

REFERENCE

1. Rosten, H.I. et al. Final report to SEMITHERM XIII on the European-funded project DELPHI - the Development of libraries and physical models for an inte-grated design environment.
Thirteenth Annual IEEE Semiconductor Thermal Measurement and Management Symposium, Austin, TX, USA, 1997. Pp. 73 - 91.
2. Vinke, H. & Lasance, C.J.M. Recent achievements in the thermal characteriza¬tion of electronic devices by means of boundary condition independent compact models.
Thirteenth Annual IEEE Semiconductor-Thermal Measurement and Management Symposium, Austin, TX, USA, 1997. s. 32 - 39

1. ECONOMIC AND SOCIAL BENEFITS

A good thermal design of electronics is crucial on the reliable and safe operation of equip¬ment. The current situation makes it difficult to design electronics effectively because of the lack of standardised thermal specifications of electronic components and heat conducting materials. The ever increasing power density of electronics causes large difficulties for the designers who need more accurate and reliable information of thermal properties. The existence of standards could make it much more economical to make good thermal design.

2. SCIENTIFIC AND TECHNOLOGICAL OBJECTIVES

The RTD work-programme should contain the following tasks:

1. Definition of specifications of the thermal properties of electronic components

1.1 Parameters

Definition of the specific thermal parameters concerning thermal design of components, assembled printed wiring boards, materials and test methods.

1.2 Units

Units (and symbols) of the thermal parameters concerning thermal behavior and also design of components, assembled printed wiring boards and various materials shall be defined.

2. Thermal specifications of electronic components and interface parts

2.1 Evaluation of various package types of electronic components

Evaluation of package types used in electronic components shall cover such packages which probably have use also in the future. Evaluation concentrates on finding possibilities to use some simplified geometric thermal model for these package types. Therefore the project has to find and develop some principles how such simpilification should be done.

2.2. PBGA-package evaluation of simplification of detailed geometric models

The objective is to develop methodology for deciding what level of geometric simplification is practical in modelling thermal properties of Plastic ball grid array packages (PBGA). The project includes comparing the simplified models to accurate geometric model of this package type by using simulations and testing.

2.3 Resistor package geometric model

The effect of mounting method of resistors on temperature of the component itself. Developing description of some standardised mounting methods.

2.4 Description of heat sink thermal properties

Develop a method for describing thermal behaviour of heat sinks by using effective heat transfer surface area  for the component instead of using the thermal model of heat sink. This kind of scaling factor reduces the size of accurate thermal model considerably.

3. Thermal specifications of materials used in electronic components

3.1 Material types

Selection of basic material types, how to manage specification for
- construction materials
- interface materials, glues, adhesives, plates

Metals, plastics, ceramics, adhesives, glues, printed wiring board materials, other conductive materials, powder metals, composites

3.2 Basic properties of various materials

- Standard definition of various properties (use of other standards)
- Description of specification for various basic material types
- Effect of surface contact resistance on thermal properties
Thermal conductivity, thermal resistance, contact resistance at surface, thermal capacitance, specific heat, emissivity, density, coefficient of thermal expansion, surface properties (roughness), etc.

3.3. Test methods of thermal properties of materials

- Comparison and further development of test methods
- Selection of test methods to measure various material types

7. TIME SCALE

Although no rigid time scale requirements apply to this project, based on the described objectives, the whole project should be completed within three years maximum.

8. IMPORTANT ADDITIONAL INFORMATION

To get a reasonable amount of progress in this area, a minimum of three intrested parties is necessary.

Close connections with CENELEC should be demonstrated in the proposal, and ensured during the proposed workplan, in order to properly match the requirements of industry and the evolution of technology.


Wednesday 4 February 2015

Thermal specifications and properties of electronic components and materials (Part 1)

1. CONFORMITY WITH THE WORK PROGRAMME

This topic falls under the Competitive and Sustainable Growth Programme, generic activity Measurement and Testing.  Specifically, it is related to Objective GROW-2000-6.2.1 Methodologies to Support Standardisation and Community Policies for which expressions of interest have been called.

2. KEYWORDS

Thermal specification, thermal design, electronic component, modelling, thermal interface, properties of materials, design rule, test method, standardisation.

3. SUMMARY OF OBJECTIVES AND JUSTIFICATION

Controlled thermal design of electronic equipment is currently a very important area of electronic design. This is because the dissipated power densities of modern electronic chips have now reached such a high level that advanced heat transfer systems are needed. However there currently exists very little standardised information about the thermal properties of various electronic components and materials, or the test methods for verify¬ing these thermal properties.

With the new standardised specifications, models and test methods the users and designers of electronic equipment could get better, compatible and more realistic description of the thermal behavior of electronic equipment. Design time reduction and better accuracy can be achieved by using more effective and harmonized thermal models and specifications of electronic components and of heat conducting materials.

4. BACKGROUND

Controlled thermal design of electronic equipment is currently a very important area of electronic design. This is because the dissipated power densities of modern electronic chips have now reached such a high level that advanced heat transfer systems are needed.
However, there currently exists very little standardised information about the thermal properties of various electronic components and materials, or the test methods for verify¬ing these thermal properties. In CENELEC there are no standards for the thermal design of electronic equipment and components.

With regard to standardisation, the technical development of thermal models for compo-nents, and thermal simulation methods are advanced enough, to be used for better

thermal specifications for electronic components. Recent studies performed in Europe by DELPHI and SEED projects (DELPHI = Development of Libraries of Physical models for an Integrated design environment, SEED = Supplier Evaluation and Exploitation of DELPHI, SEED is European ESPRIT project) and the published documents by JEDEC and SEMI will help when starting specification work at CENELEC. In the International Electrotechnical Commission (IEC) there are not any activities on this area yet.

The information sources of thermal data for the manufacturer of electronic equipment are material suppliers and component suppliers. Using both of these channels the equipment designer should get reasonable thermal data. To improve this data flow from supplier to equipment manufacturer, some standardised specification system is needed. CENELEC is the most suitable organisation to co-ordinate this task.


On the following page there is a key figure illustrating ideas on how to manage the basic thermal design specification parameters which should be addressed when specifying an elec-tronic component. In these specifications it is very important, to cover all the applicable heat transfer mechanisms: thermal conduction, convection and radiation.

It is also important to describe every component type by the actual feasible method (which is also measurable) to be used in verification of given parameter values in various models.


How to manage thermal properties of electronic components?



Click here to find out more about thermal design.

Tuesday 3 February 2015

Thermal Design Objective for Spacecraft




The basic purpose of thermal design is to maintain the temperature of all spacecraft components within desired limits.  We also wish to minimize the temperature fluctuation (thermal cycling) that the spacecraft components are subjected to.  FalconSat-2’s internal components, which are the most thermally sensitive parts of the satellite, are fairly thermally decoupled from the external heat flux the satellite is subjected to.  This is due to the design with the inner column and outer structural shell.  This allows us to control the temperature with a passive thermal design approach.  We will modify the thermo-optical properties (absorptivity and emissivity values) of the external facets of the satellite so that the satellite and all components are maintained within the optimal temperature range.

On FalconSat-2, the operational temperatures are limited by the electronic components within the satellite, and specifically by the battery.  The battery is the most thermally sensitive of the satellite subsystems because it cannot be recharged below 0˚C.  As a result, the nominal temperature range targeted for the batteries and internal components of FalconSat-2 is +5 to +30 deg C.  The other commercial electronics within the satellite have temperature limits of –40 and +85 deg C.  The structural components and solar panels have much more relaxed temperature limits.  Table 1 lists the temperature limits for FalconSat-2.

Table 1 – Temperature limits for FalconSat-2 subsystems


To design the thermal subsystem and ensure that FalconSat-2 will meet these temperature limits, we had to first simulate the thermal behavior of the satellite.  This will allow us to see how the satellite will behave without any thermal control implemented, which will in turn show us what design we must implement to meet the temperature range requirements.  In order to simulate the satellite’s thermal behavior, a model had to be created.

We require a detailed thermal model of FalconSat-2 for several reasons.  Primarily, we need to simulate expected on-orbit thermal behavior of the satellite and ensure that no spacecraft components exceed their maximum or minimum temperature limits.  We also need to ensure that the temperature fluctuation (thermal cycling) of all spacecraft components is minimized.  By simulating varying on-orbit scenarios, including varying attitude modes and varying subsystem operation modes, we can also simulate worst-case hot and worst-case cold temperature scenarios.  Furthermore, we wish to use the thermal model to simulate testing environments that we will subject the satellite to at various phases throughout the development.  Furthermore, we wish to integrate the thermal model into an overall behavioral model of the satellite to assess the interaction of the thermal design with the rest of the satellite.

The inputs to the flux history calculation routine are the satellite’s epoch classical orbital elements, epoch date and Universal Time, the satellite’s attitude control method (Sun-tracking, velocity tracking, tumbling, or quaternions), and the time of flight taken from the simulation clock.  The outputs are insolation, Earth infrared, and albedo fluxes for each face with respect to time for an entire orbit.

The flux history calculation model is broken into five modules within MatLab.  These modules, along with their inputs and outputs, are discussed here:

COE Update--This module updates the classical orbital elements (COEs) from the epoch time to the current simulation time. Inputs are the epoch COEs, the epoch date and time, and the time of flight, taken from the MatLab simulation clock.  This module outputs updated COEs for the satellite and the current Julian date.

Light--This module calculates the sun position vector, the satellite position and velocity vectors, and whether or not the sun currently illuminates the satellite.  Inputs are the current COEs and Julian date.  Outputs are the satellite position vector (R), satellite velocity vector (V), sun position vector (Rsun), illumination flag (Vis) and satellite/sun Beta angle.

Surface Normals--This module calculates the surface normal vectors of each of the six faces of the satellite.  This routine is used if the satellite is sun-tracking, velocity-tracking, or randomly tumbling.  There is a switch where the user can choose which tracking mode to use.  Alternatively, the surface normal vectors can be calculated using quaternions from an interface with Satellite Tool Kit.  There is a switch that allows the user to choose which method of calculating the surface normal vectors they would like to use.  Inputs are the satellite position vector (R), satellite velocity vector (V), sun position vector (Rsun), illumination flag (Vis) and satellite/sun Beta angle.  Outputs from the module are the surface normal vectors for each face of the satellite, the angle from the +K axis to the satellite R vector (phi), and the angle from the +I axis to the satellite R vector (theta).

Insolation--This module calculates the insolation flux on each of the six faces of the.  Its inputs are the surface normal vectors, sun position vector, and illumination flag.  It outputs the insolation flux on each face in Wm-2 in both graphical and matrix form.

Earth Effects--This module calculates the Earth Infrared and Albedo flux on each of the six faces of the satellite.  This part of the model takes the longest time, as there is a double discrete summation to calculate the Earth IR and Albedo view factors for each face of the satellite.  Inputs are the surface normal vectors for each face of the satellite, the satellite position vector (R), the sun position vector (Rsun), the angle from the +K axis to the satellite R vector (phi), and the angle from the +I axis to the satellite R vector (theta).  It outputs the Earth infrared and Albedo flux on each face in Wm-2 in both graphical and matrix form.

You can read more about thermal design here.