Why boiling point of refrigerant should be low?

It is very important that the refrigerant has a low boiling point, that is it should have the ability to turn into gas easily when it absorbs heat. If it has a high boiling point, the compressor will have to create too much of a vacuum in order to lower the pressure to make vaporization happen.

What should be the boiling point of refrigerant?

For example the refrigerant commonly used in refrigerators boils between 40° and 50°F as compared to water's boiling point of 212°F.

What happens when refrigerant boils?

The refrigerant will boil. It takes heat to boil it and the heat comes from the remaining liquid refrigerant when you remove vapor. This is why when you charge vapor refrigerant into a system, the cylinder temperature begins to drop. If you keep taking vapor from the cylinder, the cylinder will start frosting.

Why critical pressure of refrigerant should be high?

The critical temperature of the refrigerant should be as high as possible above the condensing temperature in order to have a greater heat transfer at a constant temperature. If this is not taken care of, then you will have excessive power consumption by the air conditioning or refrigeration system.

Why is refrigerant high latent heat?

A refrigerant should have high latent heat of vaporization at the evaporator pressure. The high latent heat results in a high refrigerating effect per kg of refrigerant circulated. The refrigerant should have a low boiling point and low freezing point. It must have low specific heat and high latent heat.

Why water and refrigerants boil when they do.

Why vapour pressure of refrigerant should be higher than atmospheric pressure?

Why do we keep condenser pressure higher than the evaporator pressure in the refrigerator? .. Heat moves from hot to cold, In order to get heat from your house to flow into the evaporator and cause the refrigerant to evaporate/boil, the refrigerant must be at a lower temperature than the air.

What causes the boiling point of water and all other refrigerants to change?

As air passes over the evaporator coil, the refrigerant absorbs heat. The absorbed heat causes the refrigerant reach its saturation or boiling point.

Which refrigerant has lowest freezing point?

Among the given options, R-22 has lowest freezing point.

Which refrigerant has highest freezing point?

R-12:- 252. These are the freezing points of the four refrigerants in deg. celsius, so we can say that carbon dioxide has highest freezing point. High freezing point means it freezes at a higher temperature.

Why refrigerants boils or evaporate in the evaporator?

When the liquid refrigerant reaches the evaporator its pressure has been reduced, dissipating its heat content and making it much cooler than the fan air flowing around it. This causes the refrigerant to absorb heat from the warm air and reach its low boiling point rapidly.

Where does refrigerant boil?

An expansion valve is shown in Figure 2.6. The simplest refrigeration system therefore consists of an evaporator, a compressor, a condenser and an expansion valve (see Figure 2.7). The refrigerant boils in the evaporator at a constant low pressure and temperature. Heat is removed from the fluid being cooled.

Why does refrigerant get cold?

When the Freon gas is compressed, its pressure rises, making it very hot. Next, the hot Freon gas moves through a series of coils, which has the effect of lowering its heat and converting it to liquid. The Freon liquid then flows through an expansion valve, which causes it to cool down until it evaporates.

Why do we need to increase the pressure temperature of the low pressure low temperature refrigerant vapor from the evaporator coil?

The lower the pressure of the coil the lower the temperature and the higher the pressure the higher the temperature. For the evaporator we want low pressure so that its at a low temperature that will absorb heat.

What happens to refrigerant heat in the condenser?

What happens to refrigerant heat in the condenser? The refrigerant heat is absorbed into the coil and through forced convection push to the outside air.

How does refrigerant absorb heat?

The evaporator consists of finned tubes, which absorbs heat from the air blown through a coil by a fan. Fins and tubes are made of metals with high thermal conductivity to maximize heat transfer. The refrigerant vaporizes from the heat it absorbs heat in the evaporator.

Is refrigerant gas or liquid?

The refrigerant, a chemical compound that changes easily from liquid to a gas. When the refrigerant is pushed into the compressor, it is a low pressure gas.

What is freezing point of R-22?

The R22's freezing point is -160C.

At what point in the refrigeration cycle does refrigerant lose the most heat?

At what point in the refrigeration cycle does the refrigerant lose the most heat? In the middle of the condenser where it changes from a gas to a liquid.

What causes low suction pressure in refrigeration?

Many reasons can cause low refrigerant suction pressure, i.e.: low indoor temperature, dirty filters, restricted ducts, undersized ducts, closed dampers, frosted coils, restricted refrigerant line, restricted piston, incorrect piston, restricted strainer, bad indoor blower motor ect.

What removes moisture from a refrigerant?

Detailed Solution. Drier is used to remove the moisture from the refrigerant. Sometimes it is also referred as dehydrator or dryer.

What is the disadvantage of using a pressure greater than one atmosphere?

At such high elevations, it is often necessary to follow special instructions for cooking and baking, as the water temperature is not high enough to cook food. Conversely, if the atmospheric pressure is greater than one atmosphere, liquids will boil at higher temperatures than their normal boiling points.

Which of the following statement is wrong a refrigerant should have?

Solution(By Examveda Team)

- It must have low specific heat and high latent heat. Because high specific heat decreases the refrigerating effect per kg of refrigerant and high latent heat at low temperature increases the refrigerating effect per kg of refrigerant.

What is the pressure inside the evaporator?

Evaporator refrigerant side: 23.8 psig (38.5 psia). This corresponds to a boiling or evaporating refrigerant temperature of the required 10°F.