Laundry Dryer Blower Speed Profiles for Heat Pump Overheating Control
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Solution Overview
Problem
Existing laundry treatment apparatuses, particularly those using heat pump systems, face inefficiencies and prolonged drying cycles due to overheating issues, especially in low process air flow rates and high ambient temperatures, leading to compressor shutdowns and extended drying times.
Innovation Solution
Implementing a method that uses temperature sensors to detect ambient and internal temperatures, allowing for the selection and application of predetermined speed profiles for the laundry treatment chamber and process air blower, optimizing agitation and heat transfer by adjusting motor speeds based on detected temperature signals before and during the drying cycle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the process air flow rate is reduced to save energy, then energy consumption decreases, but the heat pump system temperatures rise too much causing compressor shutdowns
Solution Approach 1:
The patent applies preliminary action by detecting ambient temperature before the drying cycle starts and pre-selecting an appropriate speed profile for the process air blower. This ensures that when the heat pump system operates at reduced air flow rates for energy savings, the blower speed is already optimized to prevent excessive temperature rise in the heat pump components, thereby avoiding compressor shutdowns while maintaining energy efficiency.
Solution Approach 2:
The patent implements dynamics by using variable speed control of the process air blower based on ambient temperature conditions. Instead of operating at a fixed speed, the blower motor speed is dynamically adjusted according to the detected ambient temperature and selected speed profile, allowing the system to maintain reliable heat pump operation across different environmental conditions while optimizing energy consumption.
2Temperature
If the compressor is switched off to cool down the heat pump system, then the heat pump temperatures decrease to normal range, but the drying cycle lengthens considerably
Solution Approach 1:
The patent prevents the need for compressor shutdowns by pre-selecting appropriate blower speed profiles based on ambient temperature detection before the drying cycle begins. This preliminary action ensures that the process air blower operates at optimal speeds throughout the cycle, maintaining adequate heat dissipation from the heat pump system and preventing excessive temperature accumulation that would otherwise require compressor interruptions.
Solution Approach 2:
The patent ensures continuous operation of the compressor throughout the drying cycle by maintaining appropriate process air flow rates through dynamic blower speed control. By continuously adjusting the blower speed according to the selected profile and ambient conditions, the system maintains continuous heat dissipation capability, eliminating the need for intermittent compressor shutdowns and ensuring uninterrupted drying operation.
3Temperature
If the process air blower speed is increased to prevent heat pump overheating, then heat pump temperatures are controlled, but energy consumption increases
Solution Approach 1:
The patent applies dynamics by using variable speed control of the process air blower based on ambient temperature conditions. Instead of operating at a fixed high speed to prevent overheating, the blower motor speed is dynamically adjusted according to the detected ambient temperature and selected speed profile, allowing the system to maintain reliable heat pump operation across different environmental conditions while optimizing energy consumption.
Solution Approach 2:
The patent changes the operational parameters of the process air blower by selecting from multiple predetermined speed profiles stored in memory. These profiles represent different combinations of blower speed and drum rotation speed, allowing the system to optimize the balance between heat dissipation effectiveness and energy consumption by selecting the most appropriate parameter set for the current ambient temperature conditions.
4Productivity
If the drum rotation speed is adjusted to improve drying performance, then drying efficiency increases, but the system complexity increases due to multiple speed profiles
Solution Approach 1:
The patent applies preliminary action by pre-storing multiple predetermined speed profiles in memory that represent optimized combinations of drum rotation speed and process air blower speed for different ambient temperature conditions. When the system starts, it detects the ambient temperature and automatically selects the most appropriate pre-programmed profile, eliminating the need for complex real-time calculations and simplifying the control logic while maintaining optimal drying performance.
Solution Approach 2:
The patent manages system complexity by organizing control parameters into discrete, pre-defined speed profiles rather than requiring continuous real-time optimization. Each profile contains specific parameter settings for drum speed and blower speed that have been predetermined to work optimally together under specific ambient temperature ranges, simplifying the control system's decision-making process while maintaining high drying efficiency.
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 enhances drying performance by regulating heat transfer and process air flow, preventing overheating and reducing drying cycle lengths, thus improving energy efficiency and operational reliability.
Implementation Method 1
detecting by the at least one temperature sensor at least one temperature signal indicative of the ambient temperature of the laundry treatment apparatus
Implementation Method 2
a first heat exchanger (evaporator) for heating a refrigerator fluid, a second heat exchanger (condenser) for cooling the refrigerant fluid
Implementation Method 3
A compressor is provided which is adapted to operate for circulating the refrigerant fluid through the refrigerant loop
Implementation Method 4
an expansion device and a refrigerant loop, in which the refrigerant fluid is circulated through the first and second heat exchangers and the expansion device
Data Source
Figure 1~2
Figure 3~4
Figure 5a~5b
AI summary
The invention relates to a laundry treatment apparatus, in particular a dryer or a washing machine having dryer function, and to a method for operating the apparatus, wherein the apparatus comprises a laundry treatment chamber (18) for treating laundry using process air (A), a blower (8) for circulating the process air (A) within the laundry treatment chamber (18); and at least one temperature sensor (27, 28, 29), the method comprising: detecting by said at least one temperature sensor (27, 28, 29) at least one temperature signal indicative of the ambient temperature of the laundry treatment apparatus, selecting a predetermined speed profile for operating the laundry treatment chamber (18) or the blower (8) in dependency of the at least one temperature signal detected by said at least one temperature sensor (27, 28, 29), and starting to operate the laundry treatment chamber (18) or the blower (8) in a laundry drying cycle by applying or executing the selected predetermined speed profile to the laundry treatment chamber (18) or to the blower (8) during the drying cycle in dependency of the at least one detected temperature signal.