The 1heat exchanger.

Plate heat exchanger is composed of a series of corrugated metal sheet laminated into a kind of new type high efficient heat exchanger. A variety of plates to form a thin rectangular channel, through half a piece of heat exchange. It is with the conventional shell and tube heat exchanger is compared, in the same flow resistance and pump power consumption condition, the heat transfer coefficient is much higher, the applicable range is to replace the trend of shell and tube heat exchanger.

Heat exchanger type main frame type ( detachable ) and brazing type two kinds big, plate is the main form of herringbone corrugated board, corrugated board and the tumor shape horizontal flat plate three.

1.1the basic structure of plate heat exchanger

Plate heat exchanger is mainly composed of a frame and a sheet of two parts.

Plate made of a variety of materials made of thin plate with various Abrasives pressed into shapes of corrugated plates, and in the four corners of the open angle hole, for the medium flow passage. Plate and angle around the rubber gasket to seal the hole.

The frame consists of a fixed pressing plate, movable pressing plate, upper and lower guide rod and a clamping bolt.

Plate heat exchanger is a plate to overlay the form is arranged on the fixed plate, movable pressing plate, and then use the clamping bolt clamping and.

1.2characteristics of plate heat exchangers ( plate heat exchanger with shell and tube heat exchanger for comparison)

A. The heat transfer coefficient is high due to the different corrugated plates are inverted, constitute a complex flow passage, the fluid in the corrugated plate passage in a rotary flow, at low Reynolds number ( Re = 50~ 200) under turbulent flow, so the heat transfer coefficient is high, is generally considered a shell and tube type3~5 times.

B. Log mean temperature difference is big, small temperature difference at the end of shell and tube heat exchanger, two kinds of fluid in tube side and a shell side flow in the whole flow, is wrong, logarithmic mean temperature difference correction coefficient is small, and the heat exchanger is shed or countercurrent flow patterns, the correction coefficient is usually in the 0.95so, in addition, cold, hot fluid in a plate heat exchanger flow parallel to the heat transfer surface, no flow, so that the heat exchanger end temperature of small, on the water heat exchanger can be lower than 1 DEG C, and the shell and tube heat exchanger is generally 5degrees.

C. Covers an area of small plate heat exchanger has the advantages of compact structure, the heat exchange area in unit volume for the tube shell type2~ 5 times, also unlike the tube shell type that must be reserved spare bundle inspection places, thus to achieve the same heat exchange, heat exchanger area approximately for shell and tube heat exchanger is a1/ 5 ~1/ 10.

D. Easy to heat transfer area or process, as long as the increase or decrease in a few panels, can increase or decrease the heat exchange area; change plate arranged or replaced several piece of plate, can achieve the requirement of process, to adapt to the new conditions, and the shell and tube heat exchanger heat transfer area is almost not may increase.

E. Light weight plate heat exchanger of the plate thickness is 0.4~ 0.8mm, and the tube shell type heat exchanger tube thickness is 2~ 2.5mm, shell and tube type heat exchanger shell than the frame much heavier, plate heat exchanger in general only shell and tube type weight1 /5.

F. Low price with the same material, the same heat exchange area, price than the tube shell type heat exchanger for about 40% ~ 60%.

G. Convenient manufacturing plate heat exchanger heat transfer plate by stamping process, a high degree of standardization, and can be mass production, shell and tube heat exchanger by handmade.

H. Easy cleaning frame type plate heat exchanger as long as loosening bolts can be loosened, plate beam, unloading plate mechanical cleaning, the need for regular cleaning equipment in the heat transfer process is very convenient.

I. Small heat loss heat exchanger heat transfer plate shell plate is exposed to the atmosphere, thus heat loss is negligible, also does not need heat preservation measures. While the tube shell type heat exchanger heat loss is big, need thermal insulation layer.

J. A smaller capacity is a shell and tube heat exchanger is10% ~ 20%.

K per unit length of the pressure loss due to heat transfer between the surfaces of the gap is smaller, a heat transfer surface is convex, so than conventional smooth pipe pressure loss.

L. Not easy to fouling due to internal fully turbulent, so it is not easy to fouling, fouling coefficient only for shell and tube heat exchanger is a1 /3~ 1 /10

M. Working pressure should not be too large, medium temperature is not too high, is likely to reveal heat exchanger using gasket seal pressure, generally not more than2.5MPa, medium temperature should be below 250DEG C, or there may be leakage.

N. Easy blockage due to plate channel is very narrow, generally only2 ~ 5mm, when the heat exchange medium containing large particles or fibers, easy blocking plate channel.

The 1.4heat exchanger applications

A: as the condenser and the evaporator of refrigeration.

B. HVAC: with boiler using intermediate heat exchanger, high-rise building intermediate heat exchanger.

C chemical industry: soda ash industry, synthetic ammonia, alcohol fermentation, cooling and other synthetic resin.

D. Metallurgical industry: aluminate liquor heating or cooling, cooling and so on steelmaking process.

E. Machinery Industry: all kinds of quenching liquid cooling, reducer for cooling lubricating oil etc..

F Power Industry: high voltage transformer oil cooling, generator bearing oil cooling.

G paper-making industry: bleaching technology of heat recovery, heat washing slurry etc..

H. Textile industry: Viscose alkaline solution cooling, boiling nitrocellulose cooling.

I. Food industry: fruit juice sterilization cooling, heating and cooling, plant and animal oil.

J: soap grease process of drying, heating or cooling of various process with liquid.

K. Central heating: heat and power plant waste heat for district heating, heating water to take a shower.

L. Other: petroleum, medicine, shipbuilding, desalination of sea water, geothermal energy utilization.

The 1.5heat exchanger selection should pay attention to the problem

1.5.1type selection

Plate type heat exchanger occasions or corrugated type should be based on the actual needs of the. The large flow pressure drop is allowed in the situation, should choose small resistance plate, and selection of resistance of large plate. According to the fluid pressure and temperature conditions, determine the choice of detachable, or soldering type. Determine the type of unfavorable choose single plate area is too small to avoid the plate, plate number is overmuch, plate velocity is small, the heat transfer coefficient is too low, the larger the heat exchanger more attention should be paid to this problem.

1.5.2 process and channel selection

Process of plate heat exchanger in a medium with a flow direction of a group of parallel channel, and channel refers to a plate heat exchanger, two adjacent plates formed of medium flow channel. In general, a plurality of channel according to the parallel or series fee that is connected, cold, heat medium passage to form different combinations.

Process combination should form the basis of heat transfer and fluid resistance calculation, to meet the requirements of the technological process of determining the. Try to make the cold, hot water in the flow passage of the convective heat transfer coefficient is equal or close to, in order to get the optimal heat transfer effect. Because the heat transfer surface on both sides of the convective heat transfer coefficient equals to or is close to obtain a larger value of heat transfer coefficient. Although the heat exchanger between the various boards velocity varies, but in heat transfer and fluid resistance calculation, still with average velocity calculation. As a result of" U" type single flow pipe are fixed on the pressing plate, convenient disassembly and assembly.

1.5.3pressure check

In the design of the plate heat exchanger selection so that, generally on the pressure drop of certain requirements, so it should be check. If the check pressure drop exceeds the allowable pressure drop, the need to design and lectotype calculation, until meet the technological requirements.

Zibo Taylor limited heat transfer equipment of plate heat exchanger overview

I plant the production of BR type plate heat exchanger, has high heat exchange efficiency, material flow resistance loss of small, compact structure, sensitive temperature control, flexible operation, convenient assembly and disassembly, long life and other characteristics, is currently the most advanced energy efficient heat transfer equipment.

I plant the production of plate heat exchanger products, disposable material is very wide, from the ordinary industrial water, high viscosity liquid, from the health requirements of high food, medicine liquid material to a certain corrosive acid from liquid, containing granular powder containing a small amount of liquid material to the fiber suspension liquid can be used in plate heat exchanger device processing. Can be used for heating, cooling, evaporation, condensation, sterilization, heat recovery and so on. Such as cooling generator and rectifier internal circulation; used in metallurgical and mining machinery lubrication oil; hydraulic station, eggs, edible oil sterilization, beer, wine and sterilization treatment; used in textile industry, papermaking industry in the waste heat recovery; collecting condensed water, central heating; steam to water heating boiler deaerator system; intermediate heat exchanger and so on. It has been widely used in metallurgy, mining, petroleum, chemical, electric power, pharmaceutical, food, chemical, textile, paper making, shipbuilding and central heating and other industrial sectors.