Systems and methods for indoor air temperature control for heat pump systems
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Solution Overview
Problem
Existing heat pump systems often deliver air at temperatures insufficiently above the indoor temperature, causing occupant discomfort known as 'cold blow', and can overtax the compressor, especially in low outdoor temperatures.
Innovation Solution
A method and system for controlling indoor air temperature in heat pump systems by determining outdoor coil and compressor speeds, adjusting indoor fan speed based on the difference between current and target indoor coil temperatures to maintain a desired temperature rise and avoid compressor overwork.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the heat pump system operates to warm the indoor space, then the indoor temperature is improved, but the air temperature delivered may be insufficiently above the indoor temperature causing cold blow
Solution Approach 1:
The system continuously monitors the outdoor coil temperature and compressor speed, then adjusts the indoor fan speed based on the difference between current and target indoor coil temperatures. This closed-loop feedback control ensures the delivered air temperature remains sufficiently above indoor temperature to prevent cold blow while maintaining heating effectiveness.
Solution Approach 2:
The indoor fan speed is dynamically adjusted based on real-time conditions (outdoor coil temperature and compressor speed) rather than operating at a fixed speed. This dynamic control allows the system to adapt to varying operating conditions and maintain optimal temperature differential to prevent cold blow.
2Temperature
If the heat pump system operates in cold conditions, then heating is provided, but the compressor may be overtaxed
Solution Approach 1:
The system monitors outdoor coil temperature and compressor speed as feedback parameters, using this information to adjust indoor fan speed. This feedback mechanism helps prevent compressor overwork by adapting system operation to actual thermal conditions, especially important in cold environments where compressor stress is higher.
Solution Approach 2:
The system changes the operating parameters of the indoor fan based on outdoor coil temperature and compressor speed. By adjusting fan speed rather than maintaining a constant high speed, the system reduces overall energy consumption and prevents unnecessary compressor strain while still achieving adequate heating in cold conditions.
3Productivity
If the indoor fan speed is increased to improve heating, then the temperature delivery is improved, but the system energy consumption increases
Solution Approach 1:
The indoor fan operates at variable speeds rather than a fixed high speed, dynamically adjusting its operation based on actual system conditions (outdoor coil temperature and compressor speed). This dynamic operation maintains adequate heating performance while minimizing unnecessary energy consumption from the fan motor.
Solution Approach 2:
The system changes the fan speed parameter based on outdoor coil temperature and compressor speed measurements. By using lower fan speeds when conditions permit and only increasing speed when necessary to maintain proper temperature differential, the system optimizes the balance between heating performance and energy consumption.
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 approach ensures comfortable indoor air temperatures while preventing excessive compressor load, optimizing system efficiency and occupant comfort without overtaxing the compressor.
Implementation Method 1
an indoor fan configured to flow air over the indoor coil
Implementation Method 2
indoor heat exchanger comprising an indoor coil to flow refrigerant therethrough
Implementation Method 3
outdoor heat exchanger comprising an outdoor coil to flow refrigerant therethrough
Implementation Method 4
outdoor heat exchanger comprising an outdoor coil to flow refrigerant therethrough
Implementation Method 5
a compressor configured to compress the refrigerant that is to be flowed through the indoor coil and the outdoor coil
Data Source
AI summary
Methods and related systems for controlling an indoor air temperature for a heat pump system are disclosed. In an embodiment, the method includes (a) determining an outdoor coil temperature of an outdoor heat exchanger and a speed of a compressor of a heat pump system. In addition, the method includes (b) determining a target indoor coil temperature of the indoor coil based on the outdoor coil temperature and the speed of the compressor. Further, the method includes (c) adjusting a speed of air flowing across the indoor coil based on a difference between a current indoor coil temperature and the target indoor coil temperature to reduce the difference between the current indoor coil temperature and the target indoor coil temperature.