Intermittent Pilot Water Heater Control Without Line Voltage
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Solution Overview
Problem
Intermittent pilot systems for gas-powered appliances require line voltage to operate, which is not always available, and they lack a method to store electrical energy generated for later use to reignite the pilot and main burner.
Innovation Solution
Incorporating a rechargeable power storage device that uses energy from a thermoelectric device to store power for the ignitor and controller, allowing the system to operate without line voltage by controlling the pilot and main burner based on water temperature setpoints and charge thresholds, enabling efficient energy use and recharging during low usage periods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If intermittent pilot systems are used to improve energy efficiency, then energy consumption is reduced, but line voltage is required which is not always available
Solution Approach 1:
The system generates its own electrical power through a thermoelectric device that converts thermal energy from the pilot flame into electricity. This self-powered mechanism eliminates the need for external line voltage while maintaining intermittent pilot operation for energy efficiency.
Solution Approach 2:
A rechargeable power storage device serves as an intermediary between the thermoelectric generator and the system components requiring power. It stores electrical energy when available and releases it when needed, enabling operation without direct line voltage connection.
2Adaptability or versatility
If a rechargeable power storage device is added to enable operation without line voltage, then adaptability is improved, but device complexity increases
Solution Approach 1:
The thermoelectric device serves multiple functions: it acts as a heat sink for the pilot flame, generates electrical power through the Seebeck effect, and charges the power storage device. This multi-functionality reduces the need for separate components.
3Power
If the pilot flame is used to generate power continuously, then power availability is improved, but energy efficiency is reduced due to continuous combustion
Solution Approach 1:
The system performs preliminary action by accumulating electrical energy in the rechargeable power storage device during periods when the pilot flame is burning (such as during hot water demand). This stored energy is then available to support system operation during periods when the pilot would otherwise need to remain lit for power generation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables the operation of intermittent flame-powered pilot systems without line voltage, optimizing energy use by storing generated power for later use and maintaining water temperature within setpoints, thereby improving energy efficiency and reducing costs.
Implementation Method 1
a thermoelectric device (e.g., a thermopile) capable of generating electricity using the flame from the pilot burner
Implementation Method 2
a rechargeable power storage device for supplying power to the ignitor and the controller. The rechargeable power storage device may be rechargeable using the energy produced by the thermoelectric device
Implementation Method 3
run the pilot and the main burner to heat the water in the water tank
Implementation Method 4
heat the water in the water tank when the temperature of the water in the water tank falls to a lower temperature setpoint threshold
Data Source
AI summary
A water heater may include a water tank, a burner, a pilot for igniting the burner, an ignitor for igniting the pilot, a thermoelectric device in thermal communication with a flame of the pilot, a controller for controlling an ignition sequence of the pilot using the ignitor, and a rechargeable power storage device for supplying power to the ignitor and the controller. The rechargeable power storage device may be rechargeable using the energy produced by the thermoelectric device. The controller is configured to selectively run only the pilot for at least part of a heating cycle to increase the recharge time of the rechargeable power storage device while still heating the water in the water heater.