Refrigeration loop
The third loop is that the refrigeration loop. Recall that within the chilled water loop, the evaporator allows heat to transfer from the water to cold liquid refrigerant. for instance liquid refrigerant at 38°F(3.3°C) enters the tubes of the shell and tube evaporator. As heat is transferred from the water to the refrigerant, the liquid refrigerant boils. The resulting refrigerant vapor is further warmed (superheated) to 50°F(10°C) inside the evaporator before being drawn to the compressor.
Compressor
The compressor is employed to pump the low refrigerant vapor from the evaporator and compress it to a better pressure. This increase in pressure also raises the temperature of the refrigerant vapor 120°F(48.9°C). common sorts of compressors utilized in HVAC systems include reciprocating, scroll, helical-rotary(screw) and centrifugal.
The refrigeration loop typically responds to changing cooling loads by unloading the compressor. the tactic used for unloading depends on the sort of compressor. Many reciprocating compressors use cylinder unloaders. Scroll compressors generally cycle and off. Helical-rotary compressors use a valve or an identical unloading device. Centrifugal compressors typically use inlet vanes or a variable-speed drives together with inlet vanes.
Condenser
After being discharged from the compressor, the hot, high refrigerant vapor enters a condenser. The condenser may be a device that transfers heat from the recent refrigerant vapor to air, water, or another fluid that's at a colder temperature. As heat is faraway from the refrigerant, it condenses and returns to the liquid phase.
Types of condensers
The condenser shown may be a water cooled condenser that transfers heat from the refrigerant to a separate condenser water loop.
The three commonest sorts of condensers are air-cooled, evaporative, and water cooled. A typical air cooled condenser has the recent , high refrigerant vapor flowing through the tubes of a finned tube device and uses propeller type fans to draw outdoor air over the outer surfaces of the tubes and fins.
The variation of the aircooled condenser is that the evaporative condenser. Within this device, the refrigerant flows through tubes and air is drawn or blown over the tubes by a lover . The difference is that water is sprayed on the outer surfaces of the tubes. because the air passes over the tubes, it causes alittle portion of the water to evaporate. This evaporation process improves when then falls into the sump to be recirculated by alittle pump and used again.
The most common sort of water cooled condenser is that the shell and tube design. With this design, water flows through the tubes while the recent refrigerant vapor fills the space surrounding the tubes. As heat is transferred from the refrigerant to the water, the refrigerant vapor condenses on the outer surfaces of the tubes and therefore the condensed liquid refrigerant falls to rock bottom of the shell.
The three commonest sorts of condensers are air-cooled, evaporative, and water cooled. A typical air cooled condenser has the recent , high refrigerant vapor flowing through the tubes of a finned tube device and uses propeller type fans to draw outdoor air over the outer surfaces of the tubes and fins.
The variation of the aircooled condenser is that the evaporative condenser. Within this device, the refrigerant flows through tubes and air is drawn or blown over the tubes by a lover . The difference is that water is sprayed on the outer surfaces of the tubes. because the air passes over the tubes, it causes alittle portion of the water to evaporate. This evaporation process improves when then falls into the sump to be recirculated by alittle pump and used again.
The most common sort of water cooled condenser is that the shell and tube design. With this design, water flows through the tubes while the recent refrigerant vapor fills the space surrounding the tubes. As heat is transferred from the refrigerant to the water, the refrigerant vapor condenses on the outer surfaces of the tubes and therefore the condensed liquid refrigerant falls to rock bottom of the shell.Expansion device
The liquid refrigerant that leaves the condenser remains at a comparatively heat 110°F(43.3°C) within the example. the ultimate step of the refrigeration cycle is for this hot liquid refrigerant to undergo an expansion device. This device creates an outsized pressure drop that reduces the pressure, and correspondingly the temperature, of the refrigerant. The temperature is reduced to some extent 38°F(3.3°C) during this example-where it's again cold enough to soak up heat inside the evaporator.
An example of refrigeration loop may be a packaged, helical-rotary(screw) water chiller. this instance uses an evaporator to supply chilled water by transferring heat from the water to the liquid refrigerant. The compressor consists of two screw-like rotors to compress the refrigerant vapor, raising its pressure and temperature. A second device is the water-cooled condenser, where refrigerant is condensed inside the shell and water flows through the tubes.
An example of refrigeration loop may be a packaged, helical-rotary(screw) water chiller. this instance uses an evaporator to supply chilled water by transferring heat from the water to the liquid refrigerant. The compressor consists of two screw-like rotors to compress the refrigerant vapor, raising its pressure and temperature. A second device is the water-cooled condenser, where refrigerant is condensed inside the shell and water flows through the tubes.Finned-tube evaporator coil
As we mentioned at the start , not all HVAC systems use all five loops. So far, we've checked out the airside loop, the chilled-water loop, and therefore the refrigeration loop. rather than chilled water flowing through the tubes of the cooling coil, some systems have cold liquid refrigerant flowing through the tubes. during this case, the finned-tube cooling coil is additionally the evaporator of the refrigeration loop. As air passes through the coil, heat is transferred from the air to the refrigerant. This heat transfer causes the refrigerant to boil and leave the evaporator as vapor.
No
chilled water loop
In this arrangement, the chilled-water loop doesn't exist. Heat is transferred from the air side loop to the refrigerant loop.
Packaged
rooftop air conditioner
An example of a system that doesn't use the chilled-water loop is one that uses a packaged rooftop air conditioning . It combines several components of the airsideloop with all the components of the refrigeration loop.
Similar to the central air handler, return air from the space is drawn into the unit and is mixed with outdoor air that enters through a separate damper. This mixed air passes through the filters, the cooling coil (which is additionally the evaporator), and therefore the supply fan before it's discharged from the unit. Packaged inside this same piece of kit are one or more compressors, an aircooled condenser complete with propeller-type fans, and expansion devices.
This is dummy text. It is not meant to be read. Accordingly, it is difficult to figure out when to end it. But then, this is dummy text. It is not meant to be read. Period.
Related Post
Zoned Air Conditioning in HVAC System, Zoning in HVAC System
Zoned Air-Conditioning Systems
The air-conditioning system considered thus far provides on
BASICS OF PSYCHROMETRIC CHART | PSYCHROMETRIC CHART IN HVAC SYSTEM
Psychrometric Chart
Many of the air-conditioning processes involve air that's experienci
What is Heat Rejection loop ? What is Heat Rejection Loop in HVAC system ?
Heat rejection loop, Heat rejection in HVAC system
The fourth loop is the heat rejection lo
Chilled Water system? What is Chilled Water loop in HVAC system? Components of Chilled Water System
Chilled water loop
In the air side loop, a cooling coil is used to cool and dehumidi
ConversionConversion EmoticonEmoticon