Mollier Diagrams

MOLLIER Diagrams P-h CHART PRESSURE ENTHALPY CHART

WHY IN REFRIGERATION? • To determine accurately what is going on inside a refrigeration system • Visualize the refrigerant behavior • Calculating capacities of refrigeration system • Representing the condition of equipment at any thermodynamic state. • TROUBLESHOOTING…

Classic Refrigeration system

Refrigerant regions

Constant pressure line

Constant temperature line

Enthalpy line

Constant specific volume line

Entropy line

How to plot a P-h chart?

Data From the Unit • • • • • • •

Low pressure P1=3 bar High pressure P2=14 bar Suction temperature T1=0°C Discharge temperature T2=70 °C Condensing temperature T3=40 °C Temperature at TXV T4=10 °C Evaporating temperature T5=-6 °C

P1

P2

T1

T2

T3

T4

T4

Enthalpy

Superheat

Sub cooled

High head • Recycle cooling medium • High cooling medium • Poor cooling medium flow • Fouled condenser • Non-condensable

Over charge

Low charge • System leak • System incorrectly charged

Liquid line restriction • Filter dryer chocked • Blocked particle inside the system

Poor Compressor • Under sized compressor • Unloaded compressor • Wrong compressor pulley sizes • Bad compressor valves, ring or pistons

MOLLIER Calculation Compression ratio=High pressure/Low pressure Flash gas=(h4-h4’)/(h1-h4’) Refrigerating effect=h1-h4 Circulation rate of refrigerant=Refrigerating capacity/refrigerating effect • Power at compressor=circulation rate x (h2-h1) • COP=Refrigerating capacity/power at compressor • • • •

MOTOR SINGLE PHASE

SINGLE PHASE MOTOR

SINGLE PHASE MOTOR

SINGLE PHASE MOTOR

SINGLE PHASE MOTOR

SINGLE PHASE MOTORtesting

SINGLE PHASE MOTORtesting

SINGLE PHASE MOTORtesting

SINGLE PHASE MOTORtesting

SINGLE PHASE MOTORtesting

SINGLE PHASE MOTORcapacitor

SINGLE PHASE MOTORcapacitor • Run (operating) • Starting

- large dimension, low capacitance ± 30µ F - small dimension, large capacitance (can exceed 100 µ F) - 5 seconds, 20 startups/hour

SINGLE PHASE MOTORcapacitor

SINGLE PHASE MOTORcapacitor

SINGLE PHASE MOTORcapacitor

SINGLE PHASE MOTORcapacitor

SINGLE PHASE MOTORcapacitor

SINGLE PHASE MOTORcapacitor • 240V, 2A • Xc =240/2, = 120Ω • C =1/(2*π *Hz*Xc) = 1/(6.28*50*120) = 0.00002652 F = 26.52 µ F

SINGLE PHASE MOTORcapacitor • Normally 14 times of Amperage • 2*14 = 28 µ F, if ± 10% 30.8 µ F or 25.2 µ F • If out of range; change capacitor

THREE PHASE MOTOR- general point

THREE PHASE MOTOR- general point • P =√3*V*I*ϕ =1.732*220*1.7*0.8 =1.732*380*1*0.8

= 520W = 520W

THREE PHASE MOTOR- general point

THREE PHASE MOTOR- general point • 145W loss as heat • 375W/520W= 0.72 • 72% useful • 28% loss

THREE PHASE MOTOR- general point

THREE PHASE MOTOR- general point

THREE PHASE MOTOR- delta ∆

THREE PHASE MOTOR- delta ∆

THREE PHASE MOTOR- star Y

THREE PHASE MOTOR- star Y

THREE PHASE MOTOR- ?

THREE PHASE MOTORconnections

Protection Protection Devices Devices

FUSE FOR DISTRIBUTION

THERMAL OVERLOAD RELAYS

FUSE FOR MOTORS

Thermal Thermal Relay Relay

Combination of a thermal overload relay with a contactor

Electromagnetic ElectromagneticOvercurrent Overcurrent Relay Relay

Contactor Contactor -- Breaker Breaker

Isolator Isolator -- Breaker Breaker

COMBINATIONS COMBINATIONS OF OFPROTECTION PROTECTION DEVICES DEVICES

COMBINATIONS COMBINATIONS OF OFPROTECTION PROTECTION DEVICES DEVICES

COMBINATIONS COMBINATIONS OF OFPROTECTION PROTECTION DEVICES DEVICES

SWITCHES SWITCHES • Manual switch-on pushbutton

S1

• Manual switch-off pushbutton

S2

• Manual on-off pushbutton

S3

SWITCHES SWITCHES • Emergency stop pushbutton • Color: Red – large mushroom head pushbutton

Limit Limit switches switches • •

Normally open contact Operated by mechanical sensor (cam roller)

• •

Normally open contact Operated by level

• • • •

•

Normally open contact Operated by temperature Normally closed contact Operated by pressure

S1 1

S1 1

S1 1

S1 1

θ

S1 P 1

Other Other switches switches • Normally open contact • Operated by electromagnetic • Operating equipment designation: KM (contactor); KA (relay) A1

11

KM1 KM1 A2

14

ELECTRICAL ELECTRICAL DIAGRAMS DIAGRAMS & & WIRING WIRING

DIRECT DIRECT ON ON LINE LINE (D.O.L.) (D.O.L.) • -The stator connected directly to the main supply • -The motor starts with a high peak • -Current peak 4 to 8 times of rated current • -1 to 5 hp

D.O.L. D.O.L. • Main circuit

D.O.L. D.O.L. • Control circuit

D.O.L… D.O.L… forward forward reverse reverse • Main circuit wiring diagram

X1 1

L1 L2 L3

2 3

F1

A1

A1

KM 1

KM 2 A2

A2

F2

U1

V1

X2

M

W 1

D.O.L… D.O.L… forward forward reverse reverse • Control circuit wiring diagram L1

F1 S1 S2

KM1 1

1

KM2

KM1 N

S3

KM2

1

KM1

KM2

D.O.L.. D.O.L..block block diagram diagram

STAR STAR DELTA DELTA (YΔ) (YΔ) • -Motor having both ends of the three stator brought out-6 terminal • -First step with Star- (main voltage/√3) • -Second step with delta-normal voltage

STAR STAR DELTA DELTA (YΔ)..power (YΔ)..power circuit circuit

STAR STAR DELTA DELTA (YΔ).. (YΔ).. Reverse Reverse rotation rotation

STAR DELTA (YΔ)..control circuit

STAR STAR DELTA DELTA (YΔ)..TNB (YΔ)..TNB control control circuit circuit

STAR DELTA (YΔ)..TNB power circuit

AUTO AUTO TRANSFORMER..control TRANSFORMER..control circuit circuit

AUTO AUTO TRANSFORMER..Power TRANSFORMER..Power circuit circuit

SPECIFICATION

POWER SUPPLY

POWER SUPPLY

Connection - fan

Connection - condensing

Connection - condensing

Connection - condensing

That had been…

AC Technology ZULKARNAINI ABDULLAH [email protected] [email protected] 012 913 8059