Beverage dispensers with heat exchangers

1. A method for cooling a mixed beverage formed with one or more beverage components, the method comprising:

circulating a refrigerant through a heat exchanger having a phase change material to cool a beverage component;

sensing a temperature of the refrigerant;

detecting a first instance when the sensed temperature of the refrigerant equals a threshold refrigerant temperature, the first instance being indicative of the phase change material transitioning from a liquid state to a phase change state;

detecting a second instance when the sensed temperature of the refrigerant equals the threshold refrigerant temperature, the second instance being indicative of the phase change material transitioning from the phase change state to a solid state; and

stopping circulation of the refrigerant when the second instance is detected.

2. The method according to claim 1 , wherein the circulating the refrigerant through the heat exchanger includes continuously circulating the refrigerant after the first instance is detected.

3. The method according to claim 1 , further comprising decreasing or increasing a flow rate of the refrigerant after the first instance is detected.

4. The method according to claim 1 , wherein a compressor circulates the refrigerant, and wherein upon detecting the first instance, the compressor increases a flow rate of the refrigerant circulating through the heat exchanger.

5. The method according to claim 1 , further comprising increasing, with a compressor, a flow rate of the refrigerant when the sensed temperature of the refrigerant is greater than the threshold refrigerant temperature.

6. The method according to claim 1 , wherein the sensed temperature of the refrigerant increases between the first instance and the second instance.

7. A method for cooling a mixed beverage formed with one or more beverage components, the method comprising:

conveying a beverage component through a heat exchanger having a phase change material to cool the beverage component;

sensing a characteristic of the phase change material;

detecting a phase of the phase change material; and

circulating a refrigerant through the heat exchanger based on the phase of the phase change material to thereby cool the phase change material and the beverage component.

8. The method according to claim 7 , wherein sensing the characteristic of the phase change material includes sensing a phase of the phase change material.

9. The method according to claim 8 , wherein an ultrasonic sensor senses the phase of the phase change material.

10. The method according to claim 7 , wherein sensing the characteristic of the phase change material includes sensing a temperature of the phase change material.

11. The method according to claim 10 , wherein the detecting the phase of the phase change material includes comparing the sensed temperature of the phase change material to a threshold phase change material temperature.

12. The method according to claim 11 , wherein when the sensed temperature of the phase change material is equal to a threshold refrigerant temperature, the refrigerant is circulated for a predetermined duration of time to thereby cool the phase change material.

13. The method according to claim 7 , wherein the phase change material has a freezing point that is greater than 32.0 degrees Fahrenheit.

14. A dispenser for dispensing a mixed beverage, the dispenser comprising:

a heat exchanger having a phase change material, the heat exchanger configured to cool one or more beverage components that are mixed to form the mixed beverage;

a refrigeration system configured to cool a refrigerant and circulate the refrigerant through the heat exchanger to cool the one or more beverage components;

a sensor configured to sense a characteristic of the phase change material; and

a controller operably coupled to the refrigeration system and configured to control the refrigeration system to circulate the refrigerant based on the characteristic of the phase change material.

15. The dispenser according to claim 14 , wherein the sensor is a temperature sensor that senses a temperature of the phase change material.

16. The dispenser according to claim 15 , wherein when the temperature of the phase change material is greater than a threshold phase change material temperature, the controller causes the refrigeration system to circulate the refrigerant.

17. The dispenser according to claim 14 , wherein the phase change material has a freezing point that is greater than 32.0 degrees Fahrenheit.

18. The dispenser according to claim 14 , wherein the sensor senses a phase of the phase change material.

19. The dispenser according to claim 14 , wherein the sensor senses a viscosity of the phase change material.

20. A dispenser for dispensing a mixed beverage, the dispenser comprising:

a heat exchanger having a phase change material, the heat exchanger configured to cool one or more beverage components that are mixed to form the mixed beverage;

a refrigeration system configured to cool a refrigerant and circulate the refrigerant through the heat exchanger to cool the one or more beverage components;

a sensor configured to sense a temperature of the refrigerant; and

a controller operably coupled to the refrigeration system and configured to control the refrigeration system to circulate the refrigerant based on the temperature of the refrigerant.

21. The dispenser according to claim 20 , wherein the phase change material has a freezing point that is greater than 32.0 degrees Fahrenheit.

22. The dispenser according to claim 20 , wherein when a temperature of the phase change material is greater than a threshold refrigerant temperature, the controller causes the refrigeration system to circulate the refrigerant.

23. A dispenser for dispensing a mixed beverage, the dispenser comprising:

a heat exchanger configured to cool one or more beverage components that are mixed to form the mixed beverage, the heat exchanger comprising:

a housing defining a cylindrical cavity;

a plurality of tubes disposed within the cylindrical cavity, each of the plurality of tubes filled with a phase change material;

a plurality of baffles disposed within the cylindrical cavity and between the plurality of tubes, the plurality of baffles configured to direct flow of the one or more beverage components through the housing; and

an evaporator coil wound along an exterior surface of the housing, wherein a refrigerant is configured to flow through the evaporator coil to cool the phase change material in the plurality of tubes;

a refrigeration system configured to cool the refrigerant and circulate the refrigerant through the evaporator coil;

a controller operably coupled to the refrigeration system and configured to control a flow rate of the refrigerant through the evaporator coil; and

a valve assembly fluidly coupled to the heat exchanger and configured to dispense the mixed beverage.

24. The dispenser of claim 23 , further comprising a sensor configured to sense a characteristic of the refrigerant or the phase change material.

25. The dispenser of claim 24 , wherein the controller is configured to control the flow rate of the refrigerant through the evaporator coil based on the characteristic of the refrigerant or the phase change material.