Thermal storage device with ice thickness detection and control methods

Abstract

A thermal storage device for generating a thermal storage medium from a fluid and including a storage tank for containing the fluid, a refrigeration system having a heat exchanger positioned in the storage tank, a pump for pumping the fluid through the storage tank, a storage medium detection device, and a controller. The storage medium detection device generates a signal corresponding to at least one parameter of the pump. The controller controls the refrigeration system in one of a first mode and a second mode based on the signal. 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 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.

1 . A method of controlling the generation of a thermal storage medium from a fluid, the method comprising:
 positioning at least one heat exchanger of a refrigeration system within a storage tank containing the fluid;   pumping the fluid with a pump along a flow path in the storage tank;   sensing at least one parameter of the pump;   generating a signal corresponding to the at least one parameter of the pump;   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.   
     
     
         2 . The method of  claim 1 , further comprising:
 directing a cooling fluid of the refrigeration system through one of an evaporator and a chilling device in the first mode to cool the fluid in the storage tank.   
     
     
         3 . The method of  claim 1 , wherein generating a signal includes generating a signal corresponding to a pressure difference across the pump. 
     
     
         4 . The method of  claim 1 , wherein generating a signal includes generating a signal corresponding to power consumed by the pump while pumping the fluid along the flow path. 
     
     
         5 . The method of  claim 1 , further comprising correlating the at least one parameter to a particular size of the thermal storage medium. 
     
     
         6 . The method of  claim 1 , wherein positioning at least one heat exchanger of a refrigeration system within a storage tank includes staggering a plurality of plates in an alternating fashion within the storage tank such that the plurality of plates define a serpentine-shaped path within the storage tank, and wherein pumping the fluid with a pump along a flow path includes pumping the fluid with the pump along the serpentine-shaped path. 
     
     
         7 . The method of  claim 6 , wherein staggering a plurality of plates in an alternating fashion within the storage tank includes arranging every other of the plurality of plates on a first wall of the storage tank, and arranging the remaining of the plurality of plates on a second wall of the storage tank opposite the first wall. 
     
     
         8 . The method of  claim 1 , wherein operating the refrigeration system in the second mode includes operating the refrigeration system in the second mode to prevent the thermal storage medium from closing the flow path. 
     
     
         9 . The method of  claim 1 , wherein pumping the fluid in the flow path occurs during the first mode to improve formation of the thermal storage medium. 
     
     
         10 . 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.   
     
     
         11 . The thermal storage device of  claim 10 , wherein the at least one parameter is indicative of a characteristic of the thermal storage medium. 
     
     
         12 . The thermal storage device of  claim 11 , wherein the characteristic includes a size of the thermal storage medium. 
     
     
         13 . The thermal storage device of  claim 10 , wherein the at least one parameter includes a pressure difference across the pump. 
     
     
         14 . The thermal storage device of  claim 10 , wherein the at least one parameter includes power consumed by the pump while pumping the fluid through the flow path. 
     
     
         15 . The thermal storage device of  claim 10 , wherein the at least one heat exchanger includes a plate heat exchanger. 
     
     
         16 . The thermal storage device of  claim 10 , wherein the fluid includes water and the thermal storage medium includes ice. 
     
     
         17 . The thermal storage device of  claim 10 , wherein the flow path includes a serpentine-shape. 
     
     
         18 . The thermal storage device of  claim 10 , wherein the refrigeration system includes a cooling fluid, and wherein the at least one heat exchanger receives a flow of cooling fluid therethrough in the first mode to cool the at least one heat exchanger. 
     
     
         19 . The thermal storage device of  claim 10 , wherein the storage tank includes a first wall and a second wall opposite the first wall, wherein the at least one heat exchanger includes a first plate heat exchanger and a second plate heat exchanger, and wherein the first plate heat exchanger extends from the first wall and the second plate heat exchanger extends from the second wall and is spaced from the first plate heat exchanger such that a serpentine-shaped path is defined within the storage tank by the first and second plate heat exchangers, wherein the flow path includes the serpentine-shaped path. 
     
     
         20 . The thermal storage device of  claim 10 , wherein the storage medium detection device includes a static pressure switch that generates the signal corresponding to a rise in pressure across the pump. 
     
     
         21 . The thermal storage device of  claim 20 , wherein the rise in pressure across the pump is indicative of a maximum thermal storage medium thickness. 
     
     
         22 . The thermal storage device of  claim 10 , wherein the pump is operable to improve formation of the storage medium during the first mode. 
     
     
         23 . 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.