Laundry dryer control method
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Solution Overview
Problem
Existing clothes dryers with heat pump systems and auxiliary electrical heating pipes do not significantly reduce drying time due to limitations in load management, leading to inefficient energy use and drying speed when the heat pump system reaches maximum load.
Innovation Solution
A control method that coordinates the heat pump system and electrical heating system to operate cooperatively, using auxiliary condensing and pre-heating techniques to maintain high drying speed and reduce energy consumption by adjusting the compressor frequency and turning on/off the electrical heating pipe based on temperature and load thresholds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the electrical heating pipe is turned on to improve drying speed, then the drying speed is improved during initial heating, but the heat pump system load reaches maximum and the electrical heating pipe must be turned off, causing drying speed to drop
Solution Approach 1:
The auxiliary condensing device is activated in advance to pre-condense water vapor from the exhaust air before it enters the heat pump system. This preliminary action reduces the thermal load on the heat pump condenser, creating headroom for the electrical heating pipe to operate longer without causing the heat pump system to reach maximum load
Solution Approach 2:
The condensing function is segmented into two parts: the main heat pump condenser and the auxiliary condensing device. The auxiliary device handles part of the condensing load separately, allowing the heat pump system to maintain lower operating loads while the electrical heating pipe continues operation
2Power
If the compressor frequency is reduced to lower heat pump system load, then the system load is reduced, but the vapor condensing speed decreases and drying speed is affected
Solution Approach 1:
The auxiliary condensing device acts as an intermediary component that handles excess vapor condensation load. This allows the main heat pump compressor to operate at lower frequencies for reduced system load, while the auxiliary device compensates for the reduced condensing capacity
3Productivity
If the electrical heating pipe operates continuously to maintain high drying speed, then drying speed is improved, but energy consumption increases significantly
Solution Approach 1:
The system dynamically adjusts the operation of the electrical heating pipe based on real-time monitoring of heat pump system load and drying progress. The heating pipe operates at high power when the heat pump has available capacity, and reduces or stops operation when the heat pump approaches maximum load, optimizing the balance between drying speed 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 method enhances clothes drying speed and reduces drying time by maintaining the electrical heating pipe's operation beyond the initial load peak, allowing for multiple modes (fast, energy-saving, and general) to optimize energy use and efficiency.
Implementation Method 1
air about to enter the clothes drying drum is controlled to be firstly heated by the condenser of the heat pump system
Implementation Method 2
further heated by the electrical heating pipe
Implementation Method 3
wet air capturing moisture from the clothes is sent back to an evaporator for dehumidification
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Disclosed is a control method for a clothes dryer and the clothes dryer. The clothes dryer comprises clothes drying drum (6), a heat pump system and an electrical heating system. The heat pump system comprises a compressor (1), a condenser (2), an evaporator (3) and a throttling device (4). The electrical heating system is an electrical heating pipe (5). The clothes dryer also comprises a water condenser (7) and/or an air condenser (11) and/or an auxiliary fan (10). The heat pump system and the electrical heating system are controlled to work cooperatively, thus allowing the clothes dryer to at least comprise a fast mode in which the electrical heating pipe (5) is turned on after the compressor (1) is turned on and operated stably, air about to enter the clothes drying drum (6) is controlled to be firstly heated by the condenser (2) of the heat pump system and further heated by the electrical heating pipe (5), and then to enter the clothes drying drum (6), and the load of the heat pump system is reduced in an auxiliary condensing manner, when the load of the heat pump system is close to the maximum load. Therefore, simultaneous working of the electrical heating system and the heat pump system is ensured, and the clothes drying speed is improved.