Bài giảng chapter 6 condenser

AIR COOLED CONDENSER- The condenser is a heat exchanger that rejectsheat from the refrigerant to air water or some otherfluid.. AIR COOLED CONDENSER- A typical air-cooled condenser uses

CHAPTER 6: CONDENSER

Lecturer : ThS.Nguyễn Duy Tuệ

In this chapter st dent can

In this chapter, student can:

-Understand principle of some kind of condensers-Calculate and chose the condenser met theCalculate and chose the condenser met therequired capacity

[1] Trane doc ment

[2] Kỹ thuật lạnh cơ sở - Nguyễn Đức Lợi

AIR COOLED CONDENSER

- The condenser is a heat exchanger that rejectsheat from the refrigerant to air water or some otherfluid

- The three common types of condensers are air-The three common types of condensers are aircooled, water-cooled, and evaporative

AIR COOLED CONDENSER

- A typical air-cooled condenser uses type fans to draw outdoor air over a finned tubeheat transfer surface

propeller The temperature difference between the hotThe temperature difference between the hotrefrigerant vapor and the cooler outdoor air inducesheat transfer The resulting reduction in the heatcontent of the refrigerant vapor causes it tocondense into liquid

Withi th fi l f l th f d t bi

- Within the final few lengths of condenser tubing(the subcooler), the liquid refrigerant is furthercooled below the temperature at which it wascooled below the temperature at which it was

AIR COOLED CONDENSER

AIR COOLED CONDENSER

Air cooled condenser without fan

AIR COOLED CONDENSER

+ Advantage :

It requires very little maintenance and does not

- It requires very little maintenance and does notrequire the freeze protection and water treatmentthat is necessary with a water-cooled condenser

- It is favored in areas that have an inadequate orcostly water supply, or where the use of water for airconditioning is restricted

+ Disadvantage : High condensing pressure

water to evaporate This evaporation processabsorbs heat from the coil, causing the refrigerantvapor within the tubes to condense The remainingwater then falls to the sump to be recirculated andused again

used again

EVAPORATIVE CONDENSER

We can subcool the liquid by using some length

of pipe submerged in the water sump or on thepath of air flow

EVAPORATIVE CONDENSER

+ Evaporative condenser without fan :

Water poured from the top to the surface oftube; then evaporate by adding heat fromcondenser Hot water drop to the sump; and drainp p;out partly; then it is compensated by cool wate

EVAPORATIVE CONDENSER

WATER COOLED CONDENSER

- The shell-and-tube is the most common type

of water-cooled condenser With this design, water

is pumped through the tubes while the refrigerantvapor fills the shell space surrounding the tubes

vapor fills the shell space surrounding the tubes

- As heat is transferred from the refrigerant tothe water the refrigerant vapor condenses on thetube surfaces The condensed liquid refrigerantthen falls to the bottom of the shell

WATER COOLED CONDENSER

+ Shell-tube water cooled condenser

WATER COOLED CONDENSER

- After the warm water leaves the condenser, itmust either be disposed of (as in the case of usingwater from a well) or it must be cooled before itcan be reused by the condenser In this example

can be reused by the condenser In this example,the condenser brings in [29°C] water and warms it

up to [35°C] Before this water can be used again

up to [35 C] Before this water can be used again,

it must be cooled back down to [29°C]

WATER COOLED CONDENSER

WATER COOLED CONDENSER

WATER COOLED CONDENSER

+ Vertical shell-tube condenser :

WATER COOLED CONDENSER

+Vertical shell-tube condenser:

WATER COOLED CONDENSER

+ Tube in tube water cooled condenser:compact but it is difficult to clean out scale inside

WATER COOLED CONDENSER

+ Plate condenser :

- The refrigerant enters at top left of theexchanger as hot gas and starts to condense on thesurface of the channels until fully condensed, and isy ,then slightly subcooled The process is called "freecondensation"

- In the enclosed condenser picture the lightand dark blue arrows show the location of the brineconnections The refrigerant flows counter current inthe opposite channel and is cooled The light anddark red arrows indicate the locations of thedark red arrows indicate the locations of the

WATER COOLED CONDENSER

WATER COOLED CONDENSER

+ Advantage of PHX:

- Compact and high efficiency

- Easy to increase capacity by inserting platesinto that; and vice versa;

+ Disadvantage :

- Not easy to clean out water scale

CONDENSER CALCULATION

1/ Condenser heat transfer area calculation:

Energy balance equation:

∆T=tk-tw

CONDENSER CALCULATION

2/ Experience of heat transfer coefficience table

CONDENSER CALCULATION

Example: Gao Xiang condenser catalogue

http://www zjgaoxiang com/en/productsd php?pid=463

CONDENSER CALCULATION

CONDENSER CALCULATION

CONDENSER CALCULATION