Heat Pump Dryer Compressor Control for Low-Temperature Drying
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Solution Overview
Problem
Driers equipped with heat pump systems face reduced drying performance in low outer temperatures, leading to increased manufacturing costs and power consumption when additional heaters are used, and vibration and noise issues due to limited compressor size.
Innovation Solution
A control unit manages the heat pump system's operation by varying the compressor's driving speed and frequency, using a twin rotary compressor to enhance compression efficiency while minimizing vibration and noise, and automatically switching to a low-speed mode when the outer temperature is low to maintain effective heating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the capacity of the compressor is increased to improve compression performance, then the heating performance is improved, but vibration and noise increase
Solution Approach 1:
The patent applies dynamics by making the compressor speed variable rather than fixed. The control unit adjusts the compressor's rotational speed based on operating conditions (such as temperature and humidity levels), allowing the system to achieve high compression performance when needed while operating at lower speeds to minimize vibration and noise during milder drying conditions. This dynamic adjustment resolves the contradiction between maintaining high power output and reducing harmful vibrations.
2Temperature
If a heater is additionally used together with a heat pump system to improve drying performance in low outer temperature, then the heating performance is improved, but manufacturing cost and power consumption increase
Solution Approach 1:
The patent applies parameter changes by adjusting the compressor's operating parameters (speed, frequency) rather than adding additional heating components. The control unit modifies the compressor speed based on outer temperature conditions, enabling the heat pump system to maintain effective heating performance in low temperatures by optimizing refrigerant compression efficiency. This approach achieves the desired temperature improvement without the increased power consumption and manufacturing costs associated with adding separate heaters.
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 solution ensures sufficient heating performance in low temperatures, reduces the risk of compressor overload, maintains optimal drying performance, and minimizes vibration and noise, thereby enhancing user satisfaction and energy efficiency.
Implementation Method 1
the heat energy of the refrigerant is transferred to the air flowing into the drum through the condenser and thus hot air is generated
Implementation Method 2
the refrigerant circulating through the system heats the air supplied to the drum after collecting the energy of the hot air exhausted from the drum
Data Source
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AI summary
A dryer according to an embodiment of the present invention in which a heat pump system is provided as a heat source for heating air supplied to a drum includes selecting one of a plurality of operation modes in which initial driving frequencies are different from each other and inputting a drying start command to the drier by a user [S10]; checking an outer temperature and comparing the outer temperature with a preset reference temperature T by a control unit [S20]; performing the operation mode selected by the user by the control unit, in a case where the outer temperature is equal to or more than the reference temperature T [S45]; performing an operation mode in which the initial driving frequency of the compressor is the highest of the plurality of operation modes, in a case where the outer temperature is less than the reference temperature T [S50].