Dual-Fuel HVAC System Using Ejector and Pump to Reduce Compressor Load
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Solution Overview
Problem
Existing dual fuel systems for heating are expensive due to the need for both a furnace and a heat pump, and heat pumps become inefficient in colder temperatures.
Innovation Solution
A thermally enhanced heating system using an indoor HVAC unit with multiple heat exchangers and an outdoor HVAC unit with a pump and ejector to circulate refrigerant, combining heat from a fuel source and outdoor air, reducing the need for a compressor and electricity consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a dual fuel system uses both a furnace and a heat pump, then heating capability in cold temperatures is improved, but system cost increases
Solution Approach 1:
The patent combines the furnace and heat pump into a single integrated unit with shared components including heat exchangers, fans, and control systems. This merging reduces overall system cost while maintaining the dual-fuel capability to operate in both cold and moderate temperatures effectively.
Solution Approach 2:
The integrated system performs multiple functions through a single device: it can operate as a heat pump in moderate temperatures and as a furnace in cold temperatures. The system universally handles both heating modes with shared components, eliminating the need for completely separate systems.
2Use of energy by moving object
If a heat pump is used to supply heat, then efficiency is improved, but performance in cold temperatures deteriorates
Solution Approach 1:
The system dynamically switches between heat pump mode and furnace mode based on outdoor temperature conditions. When temperatures are moderate, the heat pump operates for high efficiency. When temperatures drop below a threshold, the system transitions to furnace operation to maintain reliable heating performance.
Solution Approach 2:
The system changes operational parameters based on temperature conditions, switching between different heating mechanisms. The control system monitors outdoor temperature and adjusts the operating mode to optimize both efficiency and performance across different temperature ranges.
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 system increases efficiency and reduces costs by utilizing waste heat from the indoor HVAC unit and minimizing electricity use, enhancing heating performance in colder conditions.
Implementation Method 1
an indoor HVAC unit with multiple heat exchangers and an outdoor HVAC unit with a pump and ejector to circulate refrigerant, combining heat from a fuel source and outdoor air
Implementation Method 2
an ejector including a first inlet, a second inlet, and an outlet, wherein the first inlet is operably coupled to the outdoor heat exchanger, the second inlet is operably coupled to the third heat exchanger, and the outlet is operably coupled to the first heat exchanger
Data Source
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AI summary
A thermally enhanced heating system (100) and a method for thermally enhancing a HVAC system are provided. The thermally enhanced heating system (100) preferably includes an outdoor HVAC unit (200) and an indoor HVAC unit (300). The indoor HVAC unit (300) includes a first heat exchanger (310) for transferring heat from a refrigerant, a second heat exchanger (320) for transferring heat from a fuel source, and a third heat exchanger (330) for transferring heat to the refrigerant. The outdoor HVAC unit (200) includes an outdoor heat exchanger (210) for transferring heat from an outdoor air to the refrigerant, a pump (220) configured to circulate the refrigerant, and an ejector (230) configured to combine the refrigerant from the outdoor heat exchanger (210) and the third heat exchanger (330). Preferably the outdoor HVAC unit (220) is operated to circulate the refrigerant through a first refrigerant circuit (500) and a second refrigerant circuit (400), and combine refrigerant in the first refrigerant circuit (500) and the second refrigerant circuit (400).