Thermal storage device with ice thickness detection and control methods

A thermal storage device for generating a thermal storage medium from a fluid, the thermal storage device comprising:

• a storage tank including first and second ports in fluid communication with one another defining a flow path through the storage tank between the first and second ports, the storage tank configured to contain the fluid;
• a refrigeration system including at least one heat exchanger positioned within the fluid in the storage tank;
• a pump fluidly coupled to the first and second ports and operable to pump the fluid through the flow path;
• a storage medium detection device operable to generate a signal corresponding to at least one parameter of the pump;
• and
• a controller in electrical communication with the storage medium detection device and the refrigeration system, the controller operable to control the refrigeration system in one of a first mode and a second mode based on the signal, wherein the at least one heat exchanger removes heat from the fluid to generate the thermal storage medium thereon when the refrigeration system operates in the first mode, and wherein the at least one heat exchanger does not remove heat from the fluid thereby terminating generation of the thermal storage medium when the refrigeration system operates in the second mode.

A method of controlling the generation of a thermal storage medium from a fluid, the method comprising:

• staggering a plurality of heat exchanger plates in an alternating fashion within a storage tank containing the fluid such that the plurality of heat exchanger plates define a serpentine-shaped path within the storage tank;
• pumping the fluid with a pump along the serpentine-shaped path in the storage tank;
• sensing at least one parameter of the pump, wherein the at least one parameter of the pump includes at least one of a pressure difference across the pump and power consumed by the pump while pumping the fluid along the flow path;
• generating a signal corresponding to the at least one parameter of the pump;
• correlating the at least one parameter of the pump to a particular size of the thermal storage medium;
• controlling the refrigeration system in one of a first mode and a second mode based on the signal;
• operating the refrigeration system in the first mode to remove heat from the fluid with the at least one heat exchanger to generate the thermal storage medium on the at least one heat exchanger;
• and
• operating the refrigeration system in the second mode in which heat is not removed from the fluid with the at least one heat exchanger, the second mode for terminating generation of the thermal storage medium on the at least one heat exchanger.