# US 2019/0245222 A1 · Coolant Storage Tank > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0245222 A1 - Document ID: US20190245222A1 - Status: Published application - Kind: A1 - Application number: 16/387,393 - Filed: 2019-04-17 - Published: 2019-08-08 - Earliest claimed: 2014-05-23 - Assignees: Intelligent Energy Limited - Applicants: Intelligent Energy Limited - Inventors: Daniel Ninan; Nathaniel Palmer; Sophie Charlotte Harris; Phillip Wardle; Jonathan Cole; Iain Fraser; Peter David Hood; Paul Leonard Adcock - Web page: https://patentgrep.com/patent/US20190245222A1 ## CPC - H01M 8/04074: {Heat exchange unit structures specially adapted for fuel cell} - H01M 8/04029: Heat exchange using liquids - H01M 8/04253: {Means for solving freezing problems} - H01M 8/04358: {of the coolant} - H01M 8/04723: {of the coolant} - Y02E 60/50: Fuel cells - H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract A coolant storage tank (1) for storing coolant in a fuel cell system (2), the coolant storage tank comprising a plurality of individually controllable heater elements (7, 8a, 8b). A coolant storage tank comprising a first heater element (7) located at a base of the coolant storage tank and a second heater element (8a) is also disclosed. A coolant storage tank comprising a first coolant storage compartment (50) in fluid communication with a second coolant storage compartment (51), the first coolant storage compartment including at least a first heater element (54) and wherein the second coolant storage compartment is unheated is also disclosed. A method of melting frozen coolant in a coolant storage tank is also disclosed. ## Claims ### Claim 1 A method of heating coolant in a coolant storage tank in a fuel cell system, the method comprising sequentially activating via a controller at least two individually controllable heater elements; wherein the controller configured to; activate a first heater element of the plurality of individually controllable heater elements for a first period at a first power level, provide coolant heated by said first heater element, and activate at least one other of the plurality of heater elements for a second period at a second power level; wherein the energy output per unit volume occupied by the first heater element is higher than the energy output per unit volume occupied by the second heater element; and, wherein coolant is supplied to a fuel cell. ### Claim 2 (depends on 1) The method of heating coolant in a coolant storage tank in a fuel cell system of claim 1, in which at least one of the at least two individually controllable heater elements comprises: a heater element located at a base of the coolant storage tank; a heater element extending upwardly from a base of the coolant storage tank; a heater element extending downwardly from an upper surface of the tank; a heater element located along a side of the tank; or a heater element extending from a side of the tank. ### Claim 3 (depends on 1) The method of heating coolant in a coolant storage tank in a fuel cell system of claim 1 in which the two or more heater elements that are spaced in a vertical direction. ### Claim 4 (depends on 1) The method of heating coolant in a coolant storage tank in a fuel cell system of claim 1 in which the coolant storage tank comprises a first coolant storage compartment and a second coolant storage compartment, the second coolant storage compartment in fluid communication with the first coolant storage compartment, wherein the first coolant storage compartment includes the individually controllable heater elements and the second coolant storage compartment is unheated. ### Claim 5 (depends on 4) The method of heating coolant in a coolant storage tank in a fuel cell system of claim 4, in which the second coolant storage compartment is separated from the first coolant storage compartment by a wall, the wall including an aperture therein for providing fluid communication between the compartments. ### Claim 6 (depends on 1) The method of heating coolant in a coolant storage tank in a fuel cell system of claim 1, wherein the controller is configured to monitor fluid delivered from the tank and control the plurality of individually controllable heater elements accordingly. ### Claim 7 (depends on 1) A method of cooling a fuel cell system, the method comprising a fuel cell, the coolant storage tank of claim 1, and a controller, wherein the controller configured to sequentially activate the individually controllable heater elements of the coolant storage tank, and wherein the fuel cell system is configured to drive coolant in the fuel cell system to the coolant storage tank or arranged such that coolant drains to the coolant storage tank at least on shut-down of the fuel cell system. ### Claim 8 A method of melting frozen coolant in a coolant storage tank of a fuel cell system, the coolant storage tank including at least one heater element for melting frozen coolant within said tank, the at least one heater element configured to be powered by the fuel cell during operation, the method comprising the steps of; operating as fuel cell without coolant from the coolant storage tank; operating in a first melt mode comprising activating the at least one heater element to melt at least part of the frozen coolant within the coolant storage tank; supplying the melted coolant to the fuel cell; and operating in a second melt mode different to the first melt mode. ### Claim 9 (depends on 8) A method according to claim 8, in which in the second melt mode at second heater element is activated and the first heater element is deactivated; and more power is supplied to the second heater element from the fuel cell in the second melt mode than the power supplied to the first heater element from the fuel cell in the first melt mode. ### Claim 10 (depends on 8) The method of claim 8, in which the first melt mode is operated for a first period of time and the second melt mode is operated subsequently for a second period of time. ### Claim 11 (depends on 1) The method of claim 1, wherein the first heater element is located at a base of the coolant storage tank; and, wherein the second heater element comprises one of: a heater element extending upwardly from the base; a heater element comprising a plurality of heater sub-elements extending upwardly from the base; a heater element extending downwardly from an upper surface of the tank; a heater element comprising a plurality of heater sub-elements extending downwardly from an upper surface of the tank; a heater element extending along a side of the tank; and a heater element extending from a side of the tank. ### Claim 12 (depends on 8) The method of claim 8, wherein the coolant storage tank comprises a first coolant storage compartment and a second coolant storage compartment, wherein the second coolant storage compartment is in fluid communication with the first coolant storage compartment, wherein the first coolant storage compartment includes the first heater element and the second heater element, and wherein the second coolant storage compartment is unheated. ### Claim 13 (depends on 12) The method of claim 12, in which the second coolant storage compartment is separated from the first coolant storage compartment by a partition wall, the wall including an aperture therein for providing the fluid communication between the compartments. ### Claim 14 (depends on 12) The coolant storage tank according to claim 12, in which the first heater element forms at least part of the base of the first coolant storage compartment.