Using Setpoint Changes to Defrost Evaporator Coils
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Solution Overview
Problem
Conventional defrosting methods for evaporator coils, such as electric heating elements or hot gas bypass, are inefficient and energy-intensive, leading to reduced refrigeration system efficiency due to ice buildup over time.
Innovation Solution
Implementing setpoint changes to periodically raise the evaporator saturation temperature or pressure above freezing to melt ice buildup, using controllers and algorithms to optimize defrost frequency based on environmental conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional defrost methods (electric heating elements or hot gas bypass) are used, then ice buildup on evaporator coils is removed, but energy consumption increases and system efficiency decreases
Solution Approach 1:
The patent changes the temperature setpoint parameter of the evaporator from a constant low temperature to a dynamically adjusted parameter that temporarily rises above freezing point during defrost cycles. This parameter change allows the evaporator to melt ice buildup using its own refrigeration cycle without requiring external heating elements or hot gas bypass, thereby reducing energy consumption while maintaining defrost effectiveness
Solution Approach 2:
The patent implements periodic defrost cycles by temporarily adjusting the evaporator temperature setpoint above freezing point at scheduled intervals or based on ice detection. This periodic action allows ice to melt during brief defrost windows while the system returns to normal low-temperature operation afterward, eliminating the need for continuous energy-intensive heating or hot gas bypass methods
2Reliability
If defrost is performed on a time-based schedule, then ice buildup is removed, but system efficiency degrades due to longer run times and increased power consumption
Solution Approach 1:
The patent incorporates ice detection mechanisms (such as temperature sensors or cameras) that provide feedback about actual ice buildup conditions on the evaporator. This feedback allows the control system to adjust defrost timing and duration dynamically, performing defrost only when ice accumulation reaches thresholds that would impair performance, rather than following rigid time-based schedules. This optimizes system efficiency by minimizing unnecessary defrost cycles while ensuring ice removal when needed
Solution Approach 2:
The patent transitions from static, predetermined defrost schedules to dynamic defrost control that adapts to real-time operating conditions. The defrost timing, duration, and temperature setpoint adjustments are dynamically modified based on detected ice conditions, ambient temperature, humidity, and system load, allowing the system to maintain optimal efficiency while effectively removing ice buildup
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 minimizes ice buildup and reduces energy consumption by defrosting only when necessary, thereby increasing system efficiency and eliminating the need for traditional defrost methods.
Implementation Method 1
changing the evaporator saturation temperature or pressure to run above freezing and doing this more frequently than a traditional defrost, ice buildup on the evaporator coil can be minimized (or at least reduced) and removed quickly
Data Source
AI summary
Exemplary embodiments are disclosed systems configured for using setpoint changes for defrosting evaporator coils. Also disclosed are exemplary methods of using setpoint changes for defrosting evaporator coils.