Heat Pump Dryer Power Control for Refrigerant Temperature Stability
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Solution Overview
Problem
Existing drying machines and processes for humid articles, such as laundry, face limitations in process control and energy consumption, relying on quasi-stationary operations and simple temperature control which are inefficient and unstable, leading to suboptimal energy usage and operational reliability.
Innovation Solution
A machine and process that utilize a heat pump with a controllable compressor, power input control, and temperature sensing to manage energy efficiently, allowing for precise power input adjustments to maintain predetermined temperature thresholds during the drying process, ensuring stable operation and reduced energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If simple temperature control is used in existing drying machines, then the control system is simple, but the process stability and energy efficiency are poor
Solution Approach 1:
The patent implements a feedback control system where a temperature sensor continuously monitors the refrigerant temperature in the heat source, and the operating unit adjusts the compressor power input based on this feedback to maintain the temperature at a predetermined threshold. This closed-loop feedback mechanism ensures process stability while avoiding the complexity of manual control adjustments.
Solution Approach 2:
The patent replaces simple mechanical temperature control mechanisms with an electronic control system that uses a power sensor to measure compressor power input and an operating unit to automatically adjust the power input based on temperature feedback. This substitution enables precise control of the heat pump's thermal output, improving process stability without requiring complex mechanical adjustments.
2Reliability
If compressor power input is not controlled during start-up, then the operation is simple, but the compressor may be overloaded and reliability reduced
Solution Approach 1:
The patent implements preliminary action by having the operating unit monitor and control the compressor power input during the start-up phase before the drying process begins. The system detects when the refrigerant temperature reaches the predetermined threshold before full operation, and only then allows the compressor to operate at full power. This preliminary power control prevents overload during start-up while maintaining ease of operation through automatic control.
3Productivity
If high power input is continuously applied to the compressor, then the drying speed is fast, but energy consumption increases
Solution Approach 1:
The patent implements dynamic power input control where the compressor power is continuously adjusted based on the refrigerant temperature feedback. The operating unit increases power input when the temperature is below the threshold to maintain high drying speed, and reduces power input when the threshold is reached to conserve energy. This dynamic adjustment optimizes both productivity and energy consumption throughout the drying process.
Solution Approach 2:
The patent changes the power input parameter dynamically during operation. The system maintains high power input during the initial heating phase to achieve fast drying speed, then transitions to lower power input once the predetermined temperature threshold is reached, thereby reducing energy consumption while maintaining effective drying performance.
4Use of energy by moving object
If temperature control is not precisely maintained, then the operation is simple, but energy efficiency and process reliability deteriorate
Solution Approach 1:
The patent uses a temperature sensor to continuously monitor the refrigerant temperature in the heat source and feeds this information back to the operating unit. The operating unit compares the measured temperature with the predetermined threshold and automatically adjusts the compressor power input to maintain optimal temperature conditions. This feedback mechanism ensures precise temperature control for energy efficiency while keeping the control logic simple and automated.
Solution Approach 2:
The control system performs self-service by automatically adjusting the compressor power input based on temperature feedback without requiring manual intervention. The operating unit continuously monitors the temperature and autonomously makes power input adjustments to maintain the predetermined threshold, ensuring energy efficiency while simplifying operation for the user.
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 enables improved process stability, energy savings, and efficient drying by controlling power input to maintain specific temperature conditions, avoiding compressor overloading and ensuring reliable operation with finely controlled start-up and cleaning procedures.
Implementation Method 1
heat source is provided for transferring heat from a refrigerant to the process air by liquefying the refrigerant
Implementation Method 2
heat sink is provided for transferring heat from the process air to the refrigerant by evaporating the refrigerant
Implementation Method 3
controllable compressor for compressing and driving the refrigerant through said heat pump
Data Source
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AI summary
The invention relates to a machine 1 comprising a treating chamber 2 for drying humid articles 3 by process air, a process air guide 5 for guiding the process air through the treating chamber 2 in a first circuit closed in itself, and comprising a first blower 6 for driving the process air, a heat source 7 for heating the process air and placed upstream of said treating chamber 2, and a heat sink 8 for cooling the process air and placed downstream of said treating chamber 2. Heat source 7 and heat sink 8 are included in a heat pump 7, 8, 9, 10, 11 wherein the heat source 7 is provided for transferring heat from a refrigerant to the process air, and the heat sink 8 is provided for transferring heat from the process air to the refrigerant. The heat pump 7, 8, 9, 10, 11 further comprises a controllable compressor 9 for compressing and driving the refrigerant through the heat pump 7, 8, 9, 10, 11 for transferring heat from said heat sink 8 to said heat source 7, an expander 10 for expanding the refrigerant, and a refrigerant guide 11 for guiding the refrigerant through the heat pump 7, 8, 9, 10, 11 in a second circuit closed in itself, and an operating unit 12 for operating the process air guide 5 and the heat pump 7, 8, 9, 10, 11. The operating unit 12 includes a power sensor 13 for measuring a power input to operate said compressor 9, and a temperature sensor 14, 14' for measuring a temperature of said refrigerant in a continuous part of said refrigerant guide 11, and is provided to operate said compressor 9 to perform at least one drying process for drying the humid articles 3. The drying process includes the following steps: (a) Initiating operation of said blower 6 to drive the process air through said process air guide 5, initiating operation of said compressor 9 to increase compressing and driving said refrigerant through said refrigerant guide 11; (b) measuring the power input, and measuring the temperature, and operating said compressor 9 at a power input equal to a respective predetermined power input provided that the temperature is lower than a respective predetermined temperature threshold, and operating said compressor 9 at a power input below said respective predetermined power input to keep the temperature at said respective predetermined temperature threshold, and continuing step (b) until the drying of said articles 3 is completed. The invention also relates to a set of drying processes.