Water heater with integrated building recirculation control
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Solution Overview
Problem
Traditional hot water storage systems face inefficiencies in energy use and water conservation, as they maintain constant high temperatures, leading to excess heat loss and potential damage from high exhaust temperatures, and require separate controllers for recirculation and recovery operations.
Innovation Solution
A unified recirculation controller manages both recovery and recirculation operations, integrating temperature sensors and error notifications to optimize water circulation between a tankless water heater and storage tank, turning pumps on and off based on temperature differences and error states, thus eliminating the need for separate devices and enhancing control functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a storage tank maintains water at a desired temperature at all times, then hot water availability is ensured, but energy efficiency deteriorates due to continuous heating and excess heat loss
Solution Approach 1:
The recirculation pump operates periodically rather than continuously, circulating water only when temperature differences indicate heat loss is occurring. The controller monitors temperatures and activates the pump intermittently to maintain hot water availability while reducing continuous energy consumption and heat loss from the storage tank.
2Ease of operation
If a separate recirculation pump and controller are used for hot water recirculation, then recirculation control is achieved, but device complexity increases
Solution Approach 1:
The patent combines the recirculation controller with the water heater controller into a single integrated device. This unified controller manages both the recirculation pump and the water heater operations, reducing the number of separate devices while maintaining full recirculation control functionality through integrated temperature monitoring and pump management.
Solution Approach 2:
The integrated controller performs multiple functions: it controls the recirculation pump operation, monitors temperatures in both the storage tank and recirculation lines, manages the water heater, and coordinates recovery operations. This multi-functional approach eliminates the need for separate dedicated recirculation controllers.
3Power
If high current flow or Gas/BTU input is used to heat water instantaneously in a tankless water heater, then heating performance is improved, but energy efficiency deteriorates
Solution Approach 1:
The system uses the recirculation of relatively warm water from the return lines to preheat incoming cold water before it enters the storage tank or water heater. This self-service approach reduces the heating load on the high-power heating elements by recovering thermal energy that would otherwise be wasted, thereby improving energy efficiency while maintaining the high heating capacity when needed.
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
This solution improves energy efficiency by optimizing water circulation and reducing excess heat loss, while preventing damage from high exhaust temperatures and integrating error handling to ensure safe and efficient operation.
Implementation Method 1
The recirculation controller is configured to receive a water heater output temperature of a water heater from a first temperature sensor
Implementation Method 2
The recirculation controller is configured to receive a recirculation temperature of a building recirculation return pipe from a second temperature sensor
Implementation Method 3
The recirculation controller is configured to control a recovery pump for circulating water between the water heater and a storage tank
Implementation Method 4
The recirculation controller is configured to control a building recirculation pump configured to circulate water between the storage tank and the building recirculation return pipe
Implementation Method 5
With the tankless water heater, incoming ground water passes through a component generally known as a heat exchanger and is instantaneously heated by heating elements
Data Source
AI summary
A water heater system includes a controller configured to integrate control of both recovery and recirculation operations of a recovery pump and a recirculation pump. As such, a separate device, installation location, and power source (e.g., available outlet) is not needed with the controller. Because a single controller is configured to control both recovery and recirculation operations, additional control functions are available. The controller may be in communication with an internal controller of the water heater and configured to receive an error notification upon abnormal operation of the water heater. The controller can stop recovery and recirculation operations in response to an error notification, unlike with traditional water heating systems which may otherwise continue to function. The recovery and recirculation operations are based on a setpoint temperature of the water heater such that changes made to the setpoint temperature will automatically adjust in the recovery and recirculation operations.