Why is the maximum possible heat rate for a heat exchanger not equal to Cmax Thi TCI?
Why is the maximum possible heat rate for a heat exchanger not equal to Cmax(Thi-Tci)? Can the outlet temperature of the cold fluid ever exceed the inlet temperature of the hot fluid? No the outlet temperature of the cold fluid can never exceed the inlet temperature of the hot fluid.
Why baffles are used in heat exchanger?
Baffles also serve as support s for the tubes during operation and help in preventing vibration from flow induced eddies. Although heat transfer is increased through the baffle arrangement, the pressure drop of the shell side fluid is also increased due to the decreased flow area, leakage and bypass effects.
Do baffles increase velocity?
Baffles serve two functions: Most importantly, they support the tubes in the proper position during assembly and operation and prevent vibration of the tubes caused by flow-induced eddies, and secondly, they guide the shell-side flow back and forth across the tube field, increasing the velocity and the heat transfer …
What is baffle?
(Entry 1 of 2) transitive verb. 1 : to defeat or check (someone) by confusing or puzzling : to confuse or frustrate completely : disconcert Her behavior baffled her parents. 2 : to check or break the force or flow of by or as if by a baffle (see baffle entry 2) baffle the steam.
How do baffles increase efficiency of heat exchanger?
The use of helical baffles shows a decrease in pressure drop due to the elimination of dead zones. The less dead zones result in better heat transfer. The lower pressure drop results in lower pumping power, which in turn increases the overall system efficiency.
What factors would increase the rate of heat transfer q of an exchanger?
Factors that affect rate of heat flow include the conductivity of the material, temperature difference across the material, thickness of the material, and area of the material. Different materials have greater or lesser resistance to heat transfer, making them better insulators or better conductors.
How can you increase the efficiency of a heat exchanger?
Heat transfer coefficient, pressure drop, baffles and fouling are responsible for the efficiency of the heat exchanger. By increasing the flow resistance the heat transfer rate can be increased by creating the turbulence in the shell side of the heat exchanger.
What is the function of baffles?
The main roles of a baffle in a shell and tube heat exchanger are to: Hold tubes in position (preventing sagging), both in production and operation. Prevent the effects of steam starvation, which is increased with both fluid velocity and the length of the exchanger. Direct shell-side fluid flow along tube field.
What is baffle pitch?
The spacing between segmental baffles is called the baffle pitch. The baffle pitch and the baffle cut determine the cross flow velocity and hence the rate of heat transfer and the pressure drop. These baffle types are typically used for unusual design conditions.
What are the benefits of the baffles in a shell and tube heat exchanger?
What are baffle plates?
baffle plate in British English (ˈbæfəl pleɪt) a plate or mechanical device designed to restrain or regulate the flow of a fluid, the emission of light or sound, or the distribution of sound, esp in a loudspeaker or microphone.
Is a baffle plate necessary?
Without the baffle plate in the way, stoves wouldn’t be able to produce as much heat because all of the warm air would be rapidly lost up the flue. Baffles can also typically be removed from wood burning and multi fuel stoves because they can be damaged over time, causing them to warp and sag.
Where should the baffle plate sit?
The baffle plate sits on two angle brackets towards the top of the firebox. Ensure the tab faces upwards, and runs from side to side. You will need to slide the back edge of the baffle plate onto the brackets and then slide the baffle into position.
Can I use log burner without baffle plate?
Operating a woodburner without a baffle is unlikely to cause any immediate risk of injury. What it does risk is causing irreparable damage to your stove. As we mentioned, the baffle is there to protect the inside of your stove from intense heat. Temperatures inside a stove are incredibly high.
Does my wood burner need fire bricks?
Most stoves have fire bricks up the sides, and up the back if there isn’t a backboiler fitted. The purpose is to protect the stove from the heat of the fire and the bricks will need to be replaced eventually as they degrade with the heat over time. In mine the firebricks are at the back and sides.
What does a baffle plate do in a log burner?
What does a baffle plate do? The simplest way to describe a baffle plate, which is placed at the top of the fire chamber, is a deflector shield which reflects heat back into the combustion chamber. This ensures that as much heat as possible is retained in the stove and emitted into the room in a controlled manner.
Do wood stoves need a grate?
Wood burning stoves are typically designed to be used without the need for a grate. A grate would lift the main bulk of the fire up from the base of the firebox and likely reduce the amount of space available for firewood, which may reduce heat output.
Can I use my fireplace without a grate?
The company says that no grate is the greatest way to go, adding that a grate induces inefficiency, which results in higher wood consumption. Reason: more air gets to the burning wood. The fireplace expert goes on: ”Begin with about one inch of ashes on the fireplace floor. Build up the fire directly on the ash bed.
Is Fatwood bad for your chimney?
If there is too much creosote in your chimney, it can be combustible and create a potential explosive fire in the chimney wall. Chimney fires can create a mess and can be very expensive to clean up.
Are fire starters safe for wood stoves?
Use Fire Starters… Fatwood, fire starter squares, and cedar fire starters are all great kindling replacements to aid you in getting the fire going. If there are leftover ashes in the wood stove don’t clean them out just yet. An ash bed can actually be a good foundation to start a fire in your wood stove.
What is the best kindling for a fire?
Pine cones may be wooden, but they are so abundant that the needles and core make great kindling and tinder. The pine sap ignites with ease, while the woody core provides enough material to keep burning long enough for larger sticks and logs begin to catch fire.
What is the best natural fire starter?
How to Find (and Ignite) Six Natural Fire Starters
- Tinder Fungus. Found under the bark of living birch trees, this is the only natural tinder that will readily glow from a shower of sparks.
- Tree Bark.
- Grass.
- Old Man’s Beard.
- Spruce Tips and Pine Needles.
- Conifer Resin.
What is the best fire starter?
10 Best Fire Starters—Field Tested & Reviewed
| Fire Starter | Score | Rod Material |
|---|---|---|
| Top Pick: UST Strikeforce | 93 | Flint |
| Best One-handed Starter: UST Blastmatch | 91 | Flint |
| Best Sparker: Überleben Zünden | 91 | Ferrocerium |
| Best Value: Survival Spark Magnesium Survival Fire Starter | 89 | Magnesium |
What liquid did Vikings use to start fires?
sodium nitrate
Are pine cones good fire starters?
Pinecones are great for getting a fire started. They’re pretty good on their own, but dipped in candle wax or paraffin, they catch the flame quickly and burn hot, even and steady for use in fireplaces, wood-burning stoves or bonfires.