What does a refrigeration cycle do in a heat pump? As we know, the refrigeration is the reverse of heat pump. They are both two different cycle where one is used for cooling and other is for heating. I dont understand, how can we integrate the refrigeration cycle in a heat pump for cooling? Even in case of heating, how can we create this configuration?
Thanks
 A: They are not different cycles. Think in terms of a heat pump and air conditioner (which is essentially the same a refrigerator except it keeps people cool and not food). Both devices transfer heat from one area to another. If you are in the area where heat is transferred out of, it is an air conditioner. If you are in the area where heat is transferred to, it is a heat pump. What role the device plays depends on the environment you are in.
Hope this helps.
A: Most practical heat pumps have a "working fluid" that moves around a circuit. The fluid, in liquid form under relatively high pressure, enters through a small orifice into a region of low pressure (a heat exchanger, known as the "evaporator") where it absorbs heat from the air (or whatever) and it changes to vapor. The vapor flows to a compressor that raises it back to high pressure, and causes it to get hot as a consequence. The hot vapor then enters  another heat exchanger (the condenser) where it gives up heat to the air (or whatever else) and condenses back to liquid form, ready to go 'round the cycle again.
If we use the "condenser" to remove heat from a living space, we call it an "air conditioner." If we use the condenser to remove heat from an insulated box, we call it a "refrigerator" or a "freezer." If we use the evaporator to warm a living space, we call it "heat pump."*

* But see my comment on your question about when physicists say "heat pump."
