Why is the pressure and temperature of the refrigerant increased by the compressor?

The refrigerant enters the compressor as a warm, saturated low pressure gas, it is then compressed within the compressor (hence the name). During compression, the quantity of fluid remains the same but the volume decreases, this increases the pressure and temperature.

What happens to the refrigerant pressure when the temperature rises?

The temperature increases as it rises along a constant enthalpy line in the constant quality zone. The pressure of the refrigerant remains the same as the coolant temperature falls to the saturation point in the capacitor depletion section.

What increases pressure of the refrigerant warming it?

In summary, the indoor and outdoor coils (condenser and evaporator) are where the refrigerant changes “phase”, absorbing or releasing heat through boiling and condensing. The compressor and expansion valve facilitate the pressure changes, increased by the compressor and reduced by the expansion valve.

Why must a refrigerant Vapour be increased in pressure after it leaves the evaporator?

Why must a refrigerant vapor be increased in pressure after it leaves the evaporator? The pressure of the refrigerant must be raised.

What causes high suction pressure and high discharge pressure?

Worn compressor rings occur when the discharge gases leak through the compressor’s piston rings. This produces a lower head pressure during the compression stroke in the system. The suction pressure is elevated because the discharge gases have leaked through the rings. The result is higher than normal suction pressure.

What causes high pressure in a chiller?

When an air cooled condenser becomes blocked, there is a reduction in air flow through it. This causes a high pressure condition to exist. The compressor pulls more amps to achieve the same mass flow rate of refrigerant. Also, more fans come on to try and reduce the excessive pressure.

How does pressure affect refrigerant?

As pressure increases, saturation temperature increases. As pressure decreases, so does saturation temperature. In fact, only at saturation are there pressure-temperature relationships for refrigerants.

What happens when refrigerant expands?

As it expands the refrigerant reduces in pressure and temperature, just like if you hold a deodorant spray can and hold the trigger down. The refrigerant leaves the expansion valve at low pressure and temperature then heads straight into the evaporator.

What causes the cooling effect in a refrigeration system?

In general, refrigerators are cooled through the evaporation of a volatile liquid—that is, they use a liquid that evaporates very easily, and this evaporation creates the cooling effect. They then compress the gas into a liquid again, and the whole process starts over.

What happens to the pressure and heat 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.

What causes high suction temperature?

High suction superheat—common system conditions that cause increased suction temperatures are high thermostatic expansion valve superheat settings, ineffective or missing insulation and restricted thermostatic expansion valves.

What causes high suction pressure and high superheat?

Excessive or high superheat is an indication of insufficient refrigerant in the evaporator coil for the heat load present. This could mean that not enough refrigerant is entering the coil or this could also indicate an excessive amount of heat load on the evaporator coil. pressures will be lower than normal.

What happens to the refrigerant when it enters the condenser?

The refrigerant enters the condenser as a superheated (hot) high pressure gas, it dumps its heat into the air being blown across by the fan, this drop in temperature condenses the refrigerant. The refrigerant leaves the condenser as a regular temperature, saturated high pressure liquid.

What happens to the volume of refrigerant during compression?

During compression, the quantity of fluid remains the same but the volume decreases, this increases the pressure and temperature. The refrigerant leaves the compressor as a superheated (hot) high pressure gas.

Why does the condensing temperature of a compressor fluctuate?

The condensing temperature can also fluctuate for various reasons. One reason is that suction pressure differences can affect the pressure ratio of the compressor, which leads to an altered condensation pressure, i.e. a different condensation temperature.

How does condenser pressure affect the performance of a heat pump?

The condenser pressure and temperature affect the performance of the heat pump cycle and the overall system. Figure 3.15 shows the effect of increasing condenser inlet pressure on the exergy efficiency and energetic COP of the heat pump cycle.