Heat Pump Water Heater Control for Cost-Speed Heating Tradeoffs
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Solution Overview
Problem
Conventional heat pump water heaters lack the ability to selectively adjust the trade-off between cost-effectiveness and rapidity of water heating, and there is a need for improved placement and component arrangement of the heat pump portion to suit varying operating environments and hot water demand situations.
Innovation Solution
A liquid heating apparatus that includes a refrigerant circuit structure, such as a heat pump, operatively coupled with an electric water heater and an electric resistance type heating structure, along with a control system that manages the operation of both systems to optimize heating based on user-selectable modes and sensed heating demands, initially utilizing refrigerant heat and then supplementing with electrical heat as needed, while preventing simultaneous operation of both systems during a lockout period.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a heat pump is used to heat water, then energy efficiency and operating cost are improved, but water heating rapidity deteriorates
Solution Approach 1:
The patent combines a heat pump system and an electric resistance heating system into a single integrated water heater unit. The heat pump provides efficient heating during normal operation, while the electric heating element provides rapid supplemental heating when needed, allowing the system to achieve both energy efficiency and fast water heating capability through merging of two different heating mechanisms.
2Device complexity
If conventional heat pump water heaters are designed, then component arrangement is simplified, but adaptability to varying operating environments and demand situations deteriorates
Solution Approach 1:
The patent implements a control system that dynamically adjusts the operation of the heat pump and electric heating element based on real-time conditions. The system can switch between heat pump-only mode, supplemental electric heating mode, and electric heating-only mode depending on the temperature differential, ambient conditions, and hot water demand, providing adaptability to varying operating environments while maintaining a relatively simple physical component arrangement.
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
The solution enhances the operational flexibility and efficiency of the water heating system by allowing users to select modes that balance heating cost-effectiveness and rapidity, optimizing energy usage based on demand, and automatically switching between heat sources to maintain desired temperatures.
Implementation Method 1
a refrigerant circuit structure, preferably a heat pump, operatively coupled to the electric water heater
Implementation Method 2
an electric resistance type heating structure extending through an interior portion of the tank
Data Source
AI summary
A heat pump water heater has a tank portion, an electric heating structure for adding electrical heat to water stored in the tank, and a heat pump for adding refrigerant heat to the tank water. A control system associated with the water heater has three user-selectable heating modes for heating the tank water during a given heating demand cycle—a first mode that initially heats the tank water with refrigerant heat while the electric heat is locked out for a first predetermined period before supplementing the refrigerant heat if necessary, a second mode similar to the first mode but with a longer electric heat lockout period, and a third mode in which only the electric heat is utilized to satisfy a tank water heating demand. Illustratively, the heat pump is disposed in a compact component arrangement on the top end of the water heater tank.