Finned Tube----Hair Pin Type Heat Exchanger

Finned Tube----Hair Pin Type Heat Exchanger

http://www.ts-aceroinoxidable.com/html/down/finnedtube15.html

The Hair pin Type Heat Exchanger is a true counter-current flow and are especially suitable for extreme temperature crossing, high pressure, high temperature, and low to moderate surface area requirements. Hairpin heat exchanger designs can increase heat transfer coefficients in single-pass process streams with high temperature differentials.Heat exchanger consists of a pair of concentric tubes. One of the fluids used for heat exchange flows in the inner tube, and the other in the annular space between the two tubes.Our Hairpin Exchangers are available in single tube (Double Pipe) or multiple tubes within a hairpin shell , bare tubes, finned tubes, U-tubes, straight tubes, fixed tube sheets and removable bundle. Hairpin heat exchangers utilize true counter-current flow. When a process calls for a temperature cross, a hairpin heat exchanger is the most efficient design, with fewer sections and less surface area. Hairpin heat exchangers offer the mechanical and maintenance engineer advantages inherent with their design.

Hair Pin Type Heat Exchanger Advantages

• Lower cost
• Mobile exchanger
• Small size and good position in the vat
• Good heat exchange coefficient
• Little fur deposit thanks to the polished finish
• Good fluid circulation in the tube
• Vinification of reds or whites
• Independent tubesheets for high terminal temperature differences.
• Thermal shock.
• Cycling.
• Long radius U-bends for effective thermal expansion.
• High temperature differences.
• Ease of cleaning.
• All-welded baffle cages for durability.
• High pressure closures for pressures
• No internal bolting.

Hair Pin Type Heat Exchanger Applications

• Temperature Cross
• High Tubeside Pressure
• Low Flowrates
• Cyclic Service
• Dirty Service
• Heating or Cooling Vapors
• Slurry applications with minimum velocity requirements and no "dead space" velocity reductions.
• Complete Vaporization Requirements
• Exchangers subject to Thermal Shock
• High Terminal Temperature Differences
• System requiring a moderate quantity of heat exchange with low flow rates
• System with temperature ranges requiring a perfect countercurrent flow.
• 
  

Finned Tube----Screw thread tube heat exchanger

Finned Tube----Screw thread tube heat exchanger

http://www.ts-aceroinoxidable.com/tsaceroinoxidablecom/html/down/finnedtube14.html

Screw thread tube heat exchanger is a new energy-efficient heat transfer equipment  introduced  in recent years, which is designed to completely break through the traditional shell and tube heat exchanger design ideas, choose from materials to structure, shape size, etc. with the traditional shell and tube heat exchanger has a substantial change compared to a number of technical innovations so that heat from the exterior to the various aspects of performance significantly beyond the traditional shell and tube heat exchangers , heat exchanger has changed the traditional simple structure , bulky , rough shape , inefficiency features, is the traditional heat exchanger replacement products.

1. Screw thread tube heat exchanger technology advantages

At present, heat transfer equipment industry technology updates slower, longer product replacement cycle , the manufacturers have generally invested in R & D is low , the manufacturers of the product are mostly imitate each other , resulting in product homogeneity is more prominent.

Screw thread tube heat exchanger heat transfer coefficient from the most important feature of its ultra-high, generally 2-3 times that of conventional shell and tube heat exchanger , along with better energy efficiency , with the traditional shell and tube heat exchangers is compared to more than 10% energy saving .

Outside screw thread tube heat exchanger also changed the image of the traditional extensive heat exchanger shell from the cylinder to the flange , all made ​​of stainless steel material , the outer surface of the heat exchanger to make mirror polished , beautiful and greatly improved .

Screw thread tube heat exchanger advantage also comes from its size and weighs only a fraction of the traditional shell and tube heat exchanger , the installation process is no longer the need for complex tools and lifting equipment, labor to complete.

The heat resistance due to the larger tube is not suitable for low pressure steam source and water / water heat exchanger conditions.

2. Screw thread tube heat exchanger structure

Screw thread tube heat exchanger consists of two parts consisting of a core and a shell , the core is mainly composed of tubes , shell composed by the barrel and closed top , head down , each with two openings , with the head of an center opening angle of 90 ° , so that all involved in heat exchanger , no dead zone .

3. Screw thread tube heat exchanger applications

Screw thread tube heat exchanger with high efficiency heat transfer performance, steam - water heat exchanger excellent field performance , widely used in HVAC and domestic hot water side, while on the cryogenic unit also has outstanding performance in the chemical and pharmaceutical and achieved a wide range of applications .

4. Advantages of screw thread tube heat exchanger

( A ) high- thread spiral tube heat exchanger thermal efficiency , more energy ( steam ) savings :

Internal unique reverse winding, spiral coil structure to countercurrent heat exchanger , the steam is condensed in the tubes can be fully beam , without going through a secondary heat exchanger , it can save a lot of steam ;

(B ) screw thread tube heat exchanger is stainless steel welding , high temperature high pressure :

As the screw thread tube bundle heat exchanger tubes and all stainless steel casing , with a uniform coefficient of expansion , its highest pressure 1.6MPa, the maximum temperature of 400 ℃, not due to pressure and temperature instability caused by heat 's deformation ; without pressure reducer .

The general volume of heat exchanger is generally made ​​of carbon steel shell , copper tube . Because the material is not the same so different coefficients of expansion , with the expansion and contraction easily crack in the weld of the tube . Coupled with mostly floating coil type , coil constant vibration , more broken pipe . Cause great trouble for the post- overhaul. Another low volume heat exchanger pressure , high temperature and pressure reduction pressures need to install the device , not only the initial investment cost increases , while the steam temperature and pressure reduction device will heat wastage.

(C ) screw thread tube heat exchanger compact, easy to install , small footprint

Screw thread tube heat exchanger small, save infrastructure investment ; light weight, ease of installation , the device can be directly connected to the pipeline , reducing installation costs.

Common bulky volume heat exchanger , typically 10 times the spiral tube heat exchanger thread , a larger area ; install complex and require prefabricated foundation, higher installation costs.

(D ) screw thread tube heat exchanger long life :

The use of screw thread tube heat exchanger Owen (OWEN) turbulence buffeting frequency standards principles, using the smallest gap beam tubes designed to effectively eliminate the turbulence buffeting phenomenon , extending the service life of the heat exchanger , spiral ribbed tube heat exchanger design life of up to 40 years under normal conditions of use , quality problems exchanger 8 year free repair or replacement.

While The general volume of the heat exchanger can only use about five years.

(E ) screw thread tube heat exchanger fouling tendencies low , low maintenance costs

Screw thread tube heat exchanger unique internal structure , unique countercurrent heat exchange surface treatment technology and media on both sides , at the same time improving the overall heat transfer coefficient to ensure that the heat exchanger has a self-cleaning function , low fouling tendency . Also, to ensure the stability of the system , our company with a stainless steel heat balancer , can ensure that the temperature is stable. Even after long-term use of fouling phenomenon , we only use chemical cleaning methods to clean the heat exchanger , time-saving , labor-saving , low cost , good effect .

In contrast, volume heat exchanger requires periodic inspection , conduct a visual inspection at least annually , at least once every three years, internal and external inspection, maintenance workload, high maintenance costs. Especially when the tubes appear broken crack pipes and tubes , the tubes need to be drawn overhaul , which must provide space for a large overhaul tube out . Causing great inconvenience for the overhaul .

( Six ) screw thread tube heat exchanger can be adjusted according to actual usage temperature, and volumetric heat exchanger temperature not higher than the limit value terminal , otherwise it will accelerate the scaling, increase the maintenance workload.

( Seven ) screw thread tube heat exchanger energy saving and environmental protection:

Screw thread tube heat exchanger tube heat medium walk , walk refrigerant shell , cold pack to maintain the flow of heat exchanger itself is dry, does not affect the ambient air . Coupled with heat exchangers and heat balancers are made ​​of stainless steel sanitary grade high temperature sterilization regularly .

Volumetric heat exchanger is because both the water storage tank , and its warm, moist environment to create the conditions for microbial growth , easy to produce a large number of bacteria that can cause infection and inflammation , causing indoor secondary pollution, the threat of human health.

Finned Tube----High Pressure Air Cooler

Finned Tube----High Pressure Air Cooler

http://www.ts-aceroinoxidable.com/tsaceroinoxidablecom/html/down/finnedtube13.html

( A ) High-pressure air coolers work expertise and material selection

( 1 ) High-pressure air coolers function and work environment characteristics

After the hydrogenation reaction products by high-pressure heat exchanger 3-5 from the reactor effluent reaches the high pressure air cooler, where it is further cooled , the temperature is lowered to about 50 ℃. Then enters the high pressure separator liquid separation .

Work is characterized by high-pressure air cooler : normal operating temperature is not high (200 ℃ or less ) , but in cases of emergency venting , there will be a lot of hot gas without adequate heat (> 200 ℃) in a short time through the air cooler . Thus requiring finned tube air cooler has good impact resistance.

( 2 ) Material selection high-pressure air coolers

When the media into the air cooler temperatures generally has dropped below 200 ℃ . At this temperature , the hydrogen has no significant corrosion of carbon steel for general effect , so most of the high-pressure air cooler tubes are carbon steel timber . Hydrogen corrosion is hydrogen at high temperatures cause long-term damage accumulation process of steel. So even if there are short-term high-temperature ( > Red D ℃) and gas through the air cooler ( emergency venting ) , nor will it pose a threat to carbon steel tubes . But some hydrogenation process there will be some action in warm air cooler , its normal operating temperature greater than 240 ℃. At this point can not resist hydrogen corrosion of carbon steel . Thus should be selected anti- corrosive hydrogen to produce better CrMo steel tube box and base tube . But in the harsh conditions of the air-cooled tube boxes and tubes , some foreign companies , such as the use of duplex stainless steel or corrosion Incolloy825 stronger material.

(B ) The characteristics of finned tube air cooler and Scope

Five typical finned tube shown in Figure 5-4-6 . Due to the different processing methods of these five finned tube , so that the extent of snapping finned tubes with different groups , resulting in different gap thermal resistance , resistance to thermal fatigue is different , the ultimate long- term operation of the heat transfer performance is decreased after different degrees . To make the finned tube heat transfer performance can still maintain good long-term use , countries regulate temperature limit use different kinds of finned tubes made ​​provision . China's " air-cooled heat exchanger " standard GB 15386 finned tubes specified in the maximum temperature in Table 5-4-3 .

Table 5-4-3 maximum temperature of various forms of finned tubes 

Form of Finned tube	L type finned tube	LL type finned tube	KL type finned tube	Bimetallic extruded finned tube	G type embedded finned tube
Maximum temperature/℃	150	170	250	280	350

The so-called thermal fatigue is what we often see the fins loose on the base tube . Air cooler fins to increase the surface area for heat transfer tubes and settings. Finned aluminum for good heat transfer performance is because of aluminum , and has good ductility , ease of molding . As the name suggests , wound finned tube is wrapped around the aluminum fins on the outside pipe. In order to further strengthen the snapping of the aluminum fins and base pipe and aluminum fins wrapped roots in extrusion knurled to form a knurled wound finned tubes (KL type ) . The aluminum cover on the base tube , aluminum tube from the outside with a mechanical compression methods , while forming fins , while the aluminum rolling on the base tube , rolling it into a bimetallic finned tubes . On the base of the groove pipe processing , and then the aluminum fins inserted and fixed in the recess , the finned tube can be obtained mosaic . This manufacturing process requires special equipment .

 

Aluminum fin molding process is relatively simple, cost is not expensive. However, due to the expansion coefficient of steel is larger than that of aluminum (150 ℃ , the carbon steel as 11.88x10-6mm/mm ℃; aluminum 23.94x10-6mm/mm ℃). When the heated aluminum fins , aluminum fins expanded volume, and a relatively small amount of expansion of steel , which makes the aluminum fins and a gap between the base steel pipe to increase . Ideally, after cooling aluminum fins and the gap between the steel substrate tube should be restored to its original working state. However, research and practice show that this gap can not be fully restored to its original working state. Especially after repeated thermal cycling , which is opened after several stoppages , aluminum fins with large gaps between the base steel pipe will be retained. Especially when an emergency venting device , there will be a lot of high temperatures without adequate heat and gas (> 200 ℃) quickly through the air cooler , the greater the impact of this heat to harm finned tubes , aluminum fins and steel the gap between the rapidly expanding base tube (resulting gap increased thermal resistance ) , and even loose , so that the heat transfer efficiency. If a finned tube after repeated thermal cycling , thermal gap decreased much , then it 's a good thermal fatigue resistance .

Thermal fatigue performance of the best mosaic finned tube , followed by : Bimetallic rolling finned tubes with knurled wound finned tubes, double L-shaped wound finned tubes, finned tubes ordinary wound . Due to the different processing techniques and costs, which are five common finned tubes finned tubes mosaic is also the most expensive , while the cheapest is the common wound finned tubes . Therefore, you should use the occasion , to select the appropriate operating temperature , more economical finned tubes .

Air-cooled with a high-pressure hydrogenation unit 's normal operating temperature is about 150 ℃. But when an emergency venting device , there will be a lot of high temperatures without adequate heat oil ( greater than 200 ℃) huge thermal shock quickly through the air cooler, to the finned tubes . Coupled with the annual open stoppage caused great impact on the gap finned tube heat resistance . If you use an ordinary wound finned tubes, after several cycles of operation , will produce the phenomenon of cold is not down , as well as affect the operation of downstream equipment . Therefore, the current high-pressure air coolers generally use double metal rolling finned tube . This is because the bimetallic finned tube rolling long-term operation in the following 200 ℃, maintain good heat transfer performance , but also short-term resistance higher than 200 ℃ thermal shock , and affordable , ranging from wound finned tubes and mosaic between finned tubes .

Tests show that the thermal fatigue properties of extruded bimetallic finned tube significantly better than LL -type wound finned tubes . That is, after a few stoppages or emergency vent opening , the contact resistance bimetallic finned tube rolling increment is small, the heat transfer performance degradation is small. Therefore , bi-metal rolling finned tubes in the reaction product of hydrogenation unit air cooler , you can make use of the device after a long period can still maintain good heat transfer performance. 

Finned Tube----Heat pipe heat exchanger

http://www.ts-aceroinoxidable.com

What is a heat pipe heat exchanger

A heat pipe is a heat transfer element having a high thermal conductivity , which is enclosed by the inner tube evaporation and condensation of the working fluid to transfer heat , with a high thermal conductivity, good heat transfer isothermal hot and cold sides of the area can be arbitrarily changed , remote heat , temperature controlled series of advantages.

Heat pipe heat exchanger refer to using heat pipe or finned tube to achieve heat exchange.  There are a number of heat pipes consisting of tubes within the housing constructed by the beam separator is placed , the heat pipe heat exchanger is the use of heat pipe heat exchanger principle to achieve exchange. A number of heat pipes are composed of heat transfer tubes within the housing configured by the beam separator is placed , and the heat pipe is heated in the separator section , cooling section and the corresponding housing bore are formed hot and cold fluid passage , hot and cold fluid passage application ACROSS achieve a continuous flow of heat transfer tubes . Used for waste heat recovery projects.

Heat pipe heat exchanger involved improved heat exchanger structure , especially to improve the structure of the heat exchanger on the flue ; solve previous low flue heat transfer efficiency problems ; the heat pipe heat exchanger is determined by the furnace , set the ash pond walls, partitions, wall panels, tubes , flaps , into the outlet structure, which constitutes a major improvement is set in the lower ash pond , water storage tank installed above the retaining plate ; its advantage is the elimination of direct thermal media phenomenon, so that the heat medium heat evenly , improving heat transfer efficiency , coupled with a set of gray in the lower pool is set to make tubes reduce the deposition of dust and improve the heat transfer efficiency ; the heat pipe heat exchanger can be placed in a wide range of heat flue , especially recycling placed in the furnace flue effect is obvious in the use of waste heat , heat the medium can be warm , you can bath .

What is a heat pipe heat exchanger?

Heat pipe is a heat transfer element having a high thermal conductivity , it is through the closed vacuum evaporation and condensation of the working fluid to transfer heat , with a high thermal conductivity , good isothermal , hot and cold sides of the heat transfer area can be arbitrarily changed , remote heat , temperature controlled series of advantages. ? Heat pipe heat exchanger : the principle is the use of heat pipe heat exchanger for heat exchange to achieve . There are a number of heat pipes consisting of tubes within the housing constructed by the beam separator is placed , the heat pipe heat exchanger is the use of heat pipe heat exchanger principle to achieve exchange. A number of heat pipes are composed of heat transfer tubes within the housing configured by the beam separator is placed , and the heat pipe is heated in the separator section , cooling section and the corresponding housing bore are formed hot and cold fluid passage , hot and cold fluid passage application ACROSS achieve a continuous flow of heat transfer tubes . Used for waste heat recovery projects.

Relates to an improved heat pipe heat exchanger heat exchanger structure , especially to improve the structure of the heat exchanger on the flue ; resolve past flue low heat transfer efficiency problems ; the heat pipe heat exchanger is determined by the furnace , set ash pond walls , partitions, wall panels, tubes , flaps , into the outlet structure, which constitutes a major improvement is set in the lower ash pond , water storage tank installed above the retaining plate ; its advantages DC is to eliminate the phenomenon of heating medium , so that the heat medium heat evenly , improving heat transfer efficiency , coupled with a set of gray in the lower pool is set to make tubes reduce the deposition of dust and improve the heat transfer efficiency ; the heat pipe heat exchanger can placed in a wide range of hot flue , especially placed in the furnace flue effect is obvious in recycling waste heat , heat the medium can be warm, you can bath .

Construction principle of heat pipe heat exchanger : A heat pipe is a highly efficient heat transfer components , the heat capacity than the metal hundreds of times to thousands of times higher . Heat pipe also has a mean temperature characteristics, heat flux adjustable, reversible direction of heat transfer characteristics . Use it not only has the heat exchanger consisting of a large amount of heat pipe inherent temperature difference is small , light weight, small size, rapid thermal response characteristics, but also has easy installation, simple maintenance, long life , low resistance loss , intake and exhaust airflow Road to facilitate the separation, and do not leak and so on. A heat pipe is formed with the inner wall of the channel ends sealed aluminum ( rolled ) and the finned tube by pumping into the cleaning liquid injected into the working fluid from the top of high vacuum , and the proportion of the different components with the injection of liquid refrigerant is divided into KLS low temperature heat pipe heat exchanger , GRSC-A in the hot tube heat exchanger , GRSC-B high temperature heat pipe heat exchanger. One end of the tube when the heat pipe heat vaporized working fluid to absorb heat from the heat of vaporization , the vaporization of the steam flow to the other end and cold condensation latent heat released to the cooling zone . Condensate by capillary action and the gravity return and continue to heat of vaporization , so that a large number of reciprocating cycles to transfer heat from the heating zone to the cooling zone .

Heat pipe heat transfer working fluid through the process of phase transition . The heat pipe element arranged at a certain distance between the ranks , mounted bunched within the framework of the shell , with the middle section of the heating and cooling baffle section of the heat pipe separated form the heat pipe heat exchanger . A heat pipe is by the American invention , was originally used in aerospace technology and nuclear reactors , in order to solve the sunny side and the shady side of uneven heating . 1990s were used for civilian air conditioning , due to its superior thermal conductivity, being more widely appreciated , is widely used in high-tech fields of computer , radar.

Heat pipe heat exchanger main features:

a. heat pipe heat exchanger can make through the heat exchanger in the hot and cold fluids completely separate partition , running alone in the heat pipes because of wear , corrosion, damage occurs over temperature and other reasons , it is only a single heat pipe failure , rather than hot and cold fluids doping will occur. So heat pipe heat exchanger for Yi Ran , explosive, corrosive , such as heat transfer fluids occasions with high reliability.

b cold heat pipe heat exchanger , the hot fluid is completely separate from the flow , it is easier to achieve cold , completely countercurrent heat exchanger fluid ; while both hot and cold fluid flow in the tube , because the heat transfer coefficient is much higher flow tube heat transfer coefficient in the flow tube , and the heating surface can be employed on both sides of the extended surface . For low -grade heat recovery is very economical.

c. For high dust content of the fluid , heat pipe heat exchanger by heat pipe structure size , extended surface forms to solve the heat exchanger wear ash fouling problems.

d. heat pipe heat exchanger when used with corrosive flue gas heat recovery , you can adjust the evaporator heat transfer area of ​​the condenser section to adjust the heat pipe wall temperature , so as to avoid the greatest heat pipe corroded areas .

Finned tube : To improve heat transfer efficiency, typically in the heat exchanger finned tube by the addition of a surface , increasing the external surface area of the heat exchanger tube (or inner surface ) , so as to improve heat transfer efficiency purposes, such as for finned tube heat pipe called .

Finned tube according to the shape and structure is divided into: square finned tube , spiral finned tubes, longitudinally finned tubes, spiral serrated finned tube, finned tube ;

Finned tube Material is divided into: single metal finned tube , double metal composite finned tube

Finned Tube----Finned tubes in the condenser Application

Finned tubes to improve heat transfer efficiency, typically in the surface of the heat transfer tubes by the addition of fins to increase the area of heat transfer tubes of the outer (or inner surface ) , so as to improve heat transfer efficiency purposes, such a heat exchanger tube . Condenser is a mechanical air-conditioning system can heat the tube , a rapid manner , spread around the air tube , the tank is placed in front of the majority of automobiles . The gas or vapor into a liquid means . Many power plants use the turbine condenser exhaust steam is condensed ; refrigeration plant used in the condenser to condense the vapor of ammonia and freon refrigeration and the like . Petrochemical industry using the condenser so that hydrocarbons and other chemical vapor condensation . In the distillation process, the vapor into a liquid device called condenser. All the heat of the condenser is a gas or vapor and away operation .

1. A common type and characteristics of the condenser

Condenser known as " liquefaction " is that the vapor is liquefied therein releasing heat exchanger . Depending on the cooling medium and cooling methods, can be divided into water-cooled condensers , air-cooled , evaporative three types.

 1 ) water-cooled condenser

Water-cooled condenser is water as a cooling medium , taken away by the water temperature condensation heat. Water-cooled condenser has a high heat transfer efficiency , compact structure . Currently, due to the shortage of water resources , water-cooled condenser cooling water used widely recycled, its main drawback is the need to set up a dedicated cooling water systems, high initial investment, a large water treatment costs . Commonly used water-cooled shell and tube condensers are horizontal , vertical shell and tube type and tube type and other types .

Water-cooled condenser

In medium-sized industrial refrigeration and air conditioning and refrigeration equipment generally used in water-cooled condensers , among the most commonly used shell and tube condensers . In the shell and tube condenser , the refrigerant tube usually condensed water flowing in the pipe . Currently used shell and tube condenser tube bundle and roll down light finned tubes ( ie spiral ) two. In general, ammonia horizontal shell and tube condenser tube bundle to use more light , multi-use roll down freon condenser finned tubes .

2 ) air-cooled condenser

Also known as the air-cooled condenser air-cooled condenser , the refrigerant condensed in the tube , the refrigerant discharged air heat is taken away . This condenser has a natural convection air -cooled condenser and forced convection air-cooled condenser. Since the convective heat transfer coefficient of air is very low (25 ~ 35 W / m · 2K), air-cooled heat transfer efficiency is not as water-cooled condenser , the condensing temperature and the condensation pressure was high . In addition, the heat load under certain circumstances , the required air-cooled condenser heat transfer area larger than a water-cooled condenser, and therefore the device size and quality are huge , covering large . But be hot and cold dual-use, low initial investment, maintenance and management system is relatively simple. Air-cooled condensers used in engineering practice is very widespread , both for the cooling system, but also widely used in air conditioning systems. Its biggest advantage is that without cooling water , it is particularly suitable for dry areas or where the water supply difficulties in the field of small-scale refrigeration and air conditioning applications particularly extensive.

3 ) evaporative condensers

Evaporative condenser is condensed and evaporated to sensible heat exchange , based on the heat released while the refrigerant away from the cooling water and air. The refrigerant flowing in the pipe , the cooling water absorbs the latent heat of vaporization in the evaporator spray tube , the tube is cooled and condensed refrigerant . Evaporative condensers , cooling water was omitted in the condenser heat transfer stage , the closer to the condensation temperature of the wet bulb temperature of the air , water-cooled condenser system lower than 3 ~ 5 ℃, thereby greatly reducing the compressor power consumption, water consumption is only water-cooled condenser system about 1/3 . Development and application of evaporative condenser is lagging behind in the past and more used in large ammonia refrigeration system. In recent years , due to the scarcity of water and power resources strained , evaporative condensers as an energy -saving type of heat transfer equipment, which has been widely studied and applied importance to promote the maturation and further application of evaporative condenser technology products . Currently, there are a number of manufacturers in the structure of its perfect , making used in central air conditioning units .

For those who need to be harsh precisely controlled refrigeration and air conditioning systems and operating environment occasions , evaporative condensers easier to meet process control requirements. Engineering applications show that the product instead of the traditional " water-cooled condenser cooling tower + " mode , the increase is generally to recover the initial investment in about a year , the economic benefit.

2 , Commonly used in the condenser finned tube heat transfer enhancement

Heat from the heat transfer process is the process of a fluid to pass through the solid wall of another fluid. Engineering practice , and strengthen the performance of the main heat exchanger with tubes from the media on both sides to strengthen the convective heat transfer process between the starting wall . Heat transfer enhancement techniques commonly used are:

    ( 1 ) surface coating ;

    ( 2 ) a rough surface ;

    ( 3 ) Extended surface ;

    ( 4 ) a variety of internal and external threaded pipe ;

    ( 5 ) the mixing element ;

    ( 6 ) additives ;

    ( 7 ) the impact of heat . In a variety of enhanced heat transfer technology , the installation of the fin on the wall , as a primary means of enhancing heat transfer , has been widely used in engineering. Finned -tube heat exchanger with high efficiency , compact structure , etc. , have been widely used in refrigeration and air conditioning equipment , various fields of aerospace equipment, solar collector and electronic equipment and the like. Applications are particularly common in the condenser .

Many types of finned tubes , but also the emergence of new varieties, research in this area is greater [ 4-6 ] . Process according to several aspects of general , fin shape, material , and other uses of finned tubes classification. In the condenser, finned tubes commonly used are the following form .

1 ) Inner grooved pipe

The female is a common good and efficient heat transfer characteristics of tubes . Water-cooled condenser is generally used in air conditioning systems R22 , commonly used in the threaded tube , the heat transfer coefficient of up to 930 ~ 1 600 W / m · 2K, in turn, can reduce the condensation temperature , the cooling capacity of the unit energy consumption of the compressor chiller less. In addition, the water-cooled condenser, especially large chiller condenser cooling water is generally taken directly from the river water, sediment particles suspended in water and microbial fouling materials such as dirt is easy to form the inner wall of the tubes , so that the effect of the heat exchanger greatly weakened . Studies have shown that : condenser tube thread selection , the cooling water flow rate υ there is a critical threshold , when the flow rate υ <υ critical , no matter how long the unit operation , with respect to the light pipe can be realized in terms of economic operation ; If the cooling water flow rate υ> υ critical , then there must be a critical time t critical , when total running time t ≤ t the critical condenser still has the choice of the female economy . So long as the critical time for the regular cleaning of the condenser reference point , we can maintain the unit economy running .

2 ) the overall spiral finned tube

Overall shaped finned tube is shaped by special equipment --- overall disposable spiral finning molding equipment , spiral fins . Whole -fin tube can be divided into two bimetallic finned tube pipe and single metal fins . Bimetallic finned tubes made ​​of metal pipe composite of two different materials, rolling, there are aluminum composite pipe and steel and aluminum composite pipe ; single metal tube consists of a finned aluminum or copper rolling, because they do not contact resistance problems exist , can greatly improve the performance of finned tube heat exchangers . The basic structure of the overall shape of spiral finned tube shown in Figure 2 .

Overall shape finned tube heat exchange equipment as an important heat exchanger components , have been widely used in condenser heating and cooling systems , while also widely used in petroleum , chemical, electric power, metallurgy , baking, heat recovery , etc. a variety of industrial and agricultural production with heat exchange process , areas of life .

3 ) spiral grooved tube；spirally corrugated tube

Spiral groove tube that is threaded grooved tube is machined on a spiral groove from the base tube , shown in Figure 3 . Its mechanism of enhanced heat transfer boundary layer separation flow generated by the heat transfer boundary is destroyed. A single spiral groove tube head and long points, taking into account the combined effects of heat transfer and resistance factors engineering generally use a single head . Practice has proved that : the spiral groove tube of liquid - liquid, liquid - gas, gas - gas heat transfer process between both strengthening effect , compared with fluorescent tubes , the overall heat transfer coefficient can be increased by 20 % to 40 %, can be used in various forms heat exchangers , waste heat boilers.

Spiral groove tube,Thread class finned tube, plate finned tubes , bellows , spiral twisted tubes , spiral wound pipe pieces , such as efficient heat transfer components have been widely used in the condenser , the heat transfer effect has been improved significantly. In addition , the new tooth heat transfer tubes are still emerging. Compared with the light pipe , which has the following common characteristics :

    ( 1 ) can make different shapes of fin heat transfer wall becomes rough, thereby undermining the stationary laminar boundary layer , enhance the convective heat transfer coefficient , so that the heat exchanger to be strengthened to varying degrees ;

    ( 2 ) under certain load conditions , the required condenser area can be greatly reduced ;

    ( 3 ) the knowledge of the majority of people , the rough surface of the finned tube prone to fouling ; Indeed , the turbulence caused by the destruction of the rough surface of the stationary boundary layer of dirt is difficult to make the attachment ; if dirt is attached , dirt also showed discrete scaly , equipment operation temperature changes occur so that the tube expansion and contraction due to differential expansion between the dirt and the wall material is huge and debonding, under the impact of the media off on their own . The light pipe scale layer of the cylinder , without any self- de-force . Therefore , fouling finned tube is not much serious than fluorescent tubes .

Condenser very broad range of applications , especially in the refrigeration and air conditioning systems. As one of the main condenser heat transfer equipment , and its performance has a direct impact on the overall job performance of the device . Therefore , strengthening the condenser heat transfer process has been more widely appreciated . In order to improve the overall performance of the condensing device , by modifying the shape or the surface properties of the tube to enhance the heat transfer process to improve the efficiency of the condenser , the condenser and abroad has become a developing trend . Compact series chip segment Byrne finned tube heat exchanger system used , it is a novel and efficient heat transfer components . Its unique structure and process flow sheet , making the air cooler products with more compact dimensions, higher heat transfer efficiency and lighter important. 

Made to serve offshore: Titanium finned-tube heat exchangers

http://www.ts-aceroinoxidable.com
 

Corrosive offshore platform, marine, and power generation applications and environments are served by newly available titanium finned-tube heat exchangers.

Especially applicable when seawater is used as the working fluids through the tubes, SRC titanium versions exchange heat between air or other gases on the fin-side and a fluid on the tube-side. Because of titanium tube strength, higher velocities for seawater inside them are allowed - as increased heat transfer rates achieved, it's declared.

All exchanger coils are custom configured to your dimensional and heat-transfer requirement. The titanium tubes are welded to headers or manifolds in an inert environment by ASME-certified welders. Tube orientation on a header can be staggered or inline to accommodate any air-side pressure drop requirements. The fins are from heavy-gage aluminum or copper. They can vary in density from 4 to 16 fins/inch. The fin-to-tube bond is strong.

Air Fin Cooler

http://www.ts-aceroinoxidable.com


Air fin cooler is the kind of heat exchanger to take ambient air as cooling medium and make the hot fluid in the tube cool or condense through finned tube.It is applied in many industries such as petroleum,chemical industry,pharmacy,electric power,metallurgy,Refrigeration,heat exchanger surface is made of round finned tubes,fed by an inlet steam duct and manifold,condensates are drained down into bonnet header boxes.They are blown by fans and drivers electrically driven.

It can be named Forced draft,Induced draft and A frame by structure;Forced draft and Induced finned tube bundles are installed flat on a structure,with forced draft,fan is under bundles;with induced draft,fan is top of finned bundle;A frame structure is a slanting finned tube bundles.           

The air fin cooler essentially consists of fin tube bundles, fan rings,axial fans with suitable drive units and a supporting structure. It can be equipped individually with maintenance platforms, louvers and other equipment as requested by the customer.

Main components:

Finned Tube Bundles:

Header_boxes:

Tube material:Carbon steel, Aluminum,Copper

Fin material:Aluminum

Finned tubes:

Fin Tube

http://www.ts-aceroinoxidable.com/


Fin tubes are used wherever efficient cooling or heating is required. These kind of extended surface tubes are used for the production of shell and tube heat ex-changers, air-cooled heat ex-changers  condensers and even convection coils used in furnaces.

Fins are basically external and extended surfaces located or inserted on outside of tubes and or pipes in order to increase the total surface area and thermal efficiency, resulting in compact heat transfer equipment.

The method of attaching the fins over the tube is very important, since any slightness, air gap between the tube and fins may create an additional resistance to heat flow. When the heat transfer coefficient on the outside of the tube is significantly lower than the heat transfer coefficient on the inside of the tube, there is a major advantage to incorporate fins on the outside tube surface to take full advantage of the high heat transfer rate on the inside of the tube.

If the fin and tube have different thermal coefficients of expansion, the bond may loosen due to a differential movement between them. The loosening effect will increase as the bond temperature increases and consideration must be given to the bond temperature which be attained should the fan fail. The bond may loosen due to the weakening effect of thermal and pressure cycling and also because of corrosion at the fin-base tube junction. Operating temperature limits for the various types of fin-tubes.

Finned tubes are used in applications involving the transfer of heat from a hot fluid to a colder fluid through a tube wall. The rate at which such heat transfer can occur depends on three factors: (1) the temperature difference between the two fluids; (2) the heat transfer coefficient between each of the fluids and the tube wall; and (3) the surface area to which each fluid is exposed. In the case of a bare (unfinned) tube, where the outside surface area is not significantly greater than the inside surface area, the fluid with the lowest heat transfer coefficient will dictate the overall heat transfer rate. When the heat transfer coefficient of the fluid inside the tube is several times larger than that of the fluid outside the tube (for example steam inside and oil outside), the overall heat transfer rate can be greatly improved by increasing the outside surface area of the tube. In mathematical terms, the product of heat transfer coefficient for the outside fluid multiplied by outside surface area is made to more closely match the product of the inside fluid heat transfer coefficient multiplied by tube inside surface area.

So the whole concept of finned tubes is to increase outside surface area. As an example, a common finned tube configuration of 2″ (nominal) pipe with 3/4″ high welded helical solid fins of 12 gauge thickness with 6 fins per inch has an outside surface area of 8.23 sq. ft. per linear foot; whereas the same bare pipe has an outside surface area of only 0.62 sq. ft. per linear foot. (See Design Info for extensive tables of surface areas and fin weights.)

The advantage of finned tubes is that by increasing overall heat transfer rate, the total number of tubes required for a given application is reduced, thereby also reducing overall equipment size and decreasing the cost of the project. In many application cases, one finned tube replaces six or more bare tubes at less than 1/3 the cost and 1/4 the volume.

Finned Heat exchangers designed to save energy

The current environment of high and continuously rising energy costs sees an increasing demand for heat recovery from existing processes, in a bid to reduce energy consumption. Waste streams of liquids or gases may contain sufficient energy to financially justify the installation of a purpose designed heat exchanger.

Traditionally these were made of carbon steel materials, but to reduce costs and increase the life of heat exchangers, We introduced higher specification materials, such as stainless tubing and aluminium fins.

Developing expertise with these materials opened up opportunities for expansion into general heat exchanger work, such as spray drier heat exchangers in the dairy industry and heat dumps and recuperators for solid fuel heatplants.

Finned tubing has a unique application in heat exchanger design. The transfer of heat to air is not easy. Air is an excellent insulator, and notoriously difficult to get to conduct heat. It is an oxidising medium, readily coating heat transfer surfaces with insulating deposits. It requires vigorous turbulence to absorb heat from a hot surface and distribute it amongst itself.

To overcome this limitation it is necessary to increase the surface area of the side of the heat exchanger in contact with the air. This is the so called finned tube; a fin is wound onto the outside surface of a tube in a continuous helix. This fin can take many forms, ranging from an interference fit (L and LL fin), through a grooved and swaged fixing (G fin), to a continuously welded form. The fin can be in a range of materials. Fin fixing generally makes little difference to thermal efficiency (unless it has a poor or non-continuous attachment to the tube) but places strict limits on the maximum temperature the fin can be used at.

For industrial applications Windsor uses almost exclusively an aluminium G fin. This ensures the aluminium fin will not come loose on the base tube in service, and provides a high fin efficiency (a measure of the variation in fin temperature) leading to a smaller, less costly exchanger.

Most heat exchangers are purpose engineered by Windsor for the particular application. There are important issues with construction - in particular with the stainless steel welding and the differential thermal expansion of components in the heater. Lifting, transportation and support of the heat exchanger also require careful attention.