Heat Pump Evaporator Temperature Offset to Reduce Defrost Frequency
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Solution Overview
Problem
Ice formation on the evaporator surface of heat pumps reduces efficiency and necessitates defrosting, increasing operational costs due to additional energy consumption and frequent defrost intervals.
Innovation Solution
A controller modifies the set points of heat pump components to operate at a positively offset temperature, extending the heating interval and reducing the frequency and duration of defrost intervals by slowing ice formation, thereby optimizing energy efficiency and cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the evaporator operates at a lower temperature to improve heat pump efficiency, then heat transfer efficiency is improved, but ice formation on the evaporator surface increases
Solution Approach 1:
The patent dynamically adjusts the evaporator temperature setpoint based on outdoor temperature conditions. When outdoor temperature is above a threshold (e.g., 0°C), the evaporator operates at a lower temperature for high efficiency. When outdoor temperature drops below the threshold, the evaporator temperature setpoint is raised to prevent ice formation, thus adapting operating parameters to environmental conditions to balance efficiency and frost prevention.
2Object-affected harmful factors
If defrosting is performed frequently to remove ice from the evaporator, then ice formation is reduced, but operational cost and energy consumption increase
Solution Approach 1:
The patent performs preliminary action by raising the evaporator temperature setpoint before ice formation becomes severe. By proactively adjusting the temperature setpoint based on outdoor temperature conditions, the system prevents ice accumulation that would require frequent defrosting, thereby reducing the need for energy-consuming defrost cycles while maintaining effective ice management.
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 extends the heating interval length, decreases the number and duration of defrost intervals, and lowers the overall operational cost of the heat pump by managing frost formation effectively.
Implementation Method 1
If the temperature of the evaporator is below the dew point of the air, moisture in the air can condense on the evaporator surface
Implementation Method 2
if the air temperature is below the freezing point, the condensed moisture on the evaporator surface can turn to ice
Data Source
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AI summary
Methods, devices, and systems for frost management of an evaporator (106) are described herein. One device includes a memory (318), and a processor (320) configured to execute executable instructions stored in the memory (318) to receive operating information of a heat pump (104), determine a first set point of at least one of a number of components of the heat pump(104) and a first operating temperature, receive a second operating temperature of the evaporator(106) that is positively offset from the first operating temperature of the evaporator (106), determine a second set point of at least one of the number of components of the heat pump(104) based on the second operating temperature, and modify a set point of at least one of the number of components of the heat pump(104) to the second set point such that a heating mode of the heat pump(104) is enabled for a heating interval length of the heat pump(104).