Dear colleague,

Please clarify your question in more detail.

Regards, Emad

Throttling is a constant enthalpy process.In this process, temperature is constant.Hence there is no question of increase of temperature.

this is constant enthalpy process

In compression refrigeration throttling of the liquid refrigerant changes its high condenser pressure to the low evaporator pressure and the temperature drops significantly while some of the liquid changes into vapour.

Throttling the liquid will change the pressure and velocity and has nothing to do with the temperature, since it is a constant enthalpy process as said by colleagues earlier.

Expansion devices change the pressure without change in enthalpy and I suggest you read any principal refrigeration book.

In a throttling process if there is a change in phase say from liquid to vapor as in refrigeration cycles definitely the temperature will change from condenser temperature to evaporator temperature otherwise refrigeration process will not take place.