Control method and control device for variable-frequency and variable-capacity heat pump hot-air drying system
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Solution Overview
Problem
Existing heat pump-type hot-air drying systems face challenges in efficiently supplying high-temperature hot air, leading to frequent starting and stopping of heat pump units, increased energy consumption, and variations in drying room temperature, which affect the quality of finished products.
Innovation Solution
A heat pump-type double-circulation hot-air drying system with a control method that dynamically adjusts the operation mode based on temperature control curves, utilizing a hot-air double-circulation loop with adjustable air valves and condensers to produce high-temperature air, and a control device with a micro-processor for intelligent temperature control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If heat pump units are frequently started and stopped to meet varying heat demand, then the system can adapt to drying requirements, but energy consumption increases and temperature stability deteriorates
Solution Approach 1:
The patent applies variable frequency technology to the compressor, allowing it to operate continuously at different speeds rather than starting and stopping. The compressor speed is dynamically adjusted according to heat demand, enabling the system to adapt to varying drying requirements while maintaining continuous operation and temperature stability, thereby reducing energy consumption.
2Adaptability or versatility
If heat pump units are frequently started and stopped to meet varying heat demand, then the system can adapt to drying requirements, but temperature stability deteriorates
Solution Approach 1:
The variable frequency compressor enables continuous operation with dynamically adjustable speed, maintaining stable temperature by avoiding frequent start-stop cycles. The system adjusts compressor frequency according to heat demand while ensuring continuous heat supply, thus preserving temperature stability during the drying process.
3Temperature
If multiple heat pump units are used in parallel to meet high heat demand, then high-temperature hot air supply is improved, but equipment investment and maintenance complexity increase
Solution Approach 1:
The patent applies a single heat pump unit with variable frequency capability and dual-circulation configuration that can operate across a wide range of temperatures. The system uses a first circulation path for high-temperature conditions and a second circulation path for low-temperature conditions, allowing one unit to perform multiple temperature supply functions, thereby avoiding the need for multiple parallel units and reducing equipment complexity.
Solution Approach 2:
The patent introduces a dual-circulation configuration with different circulation paths. The first circulation path is used when high-temperature hot air is needed, and the second circulation path is used when low-temperature hot air is needed. This dimensional change in system configuration allows a single heat pump unit to achieve variable temperature output without requiring multiple parallel units.
4Temperature
If traditional coal furnaces are used for direct heat supply, then high-temperature hot air can be supplied, but coal consumption increases and environmental pollution worsens
Solution Approach 1:
The patent replaces the traditional coal-fired heating system with a heat pump-based heating system. The heat pump uses electrical energy to drive a refrigeration cycle that transfers heat to the drying room, eliminating direct coal combustion. This substitution reduces coal consumption and associated environmental pollution while still achieving the required hot air temperature for drying.
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 system ensures reliable high-temperature air production, improves energy efficiency, and maintains precise temperature and humidity control, reducing energy consumption and ensuring product quality.
Implementation Method 1
the refrigerant circulation pipeline sequentially passes through an evaporator, a compressor, a condenser and a vapor-liquid separator
Implementation Method 2
the refrigerant circulation pipeline sequentially passes through an evaporator, a compressor, a condenser and a vapor-liquid separator
Implementation Method 3
the refrigerant circulation pipeline sequentially passes through an evaporator, a compressor, a condenser and a vapor-liquid separator
Data Source
AI summary
A control method and control device for a heat pump-type double-circulation hot-air drying system, relating to a device for supplying or controlling air or gas for drying solid materials or products, and in particular to a control method and control device for a heat pump-type hot-air drying system. The method comprises: configuring a temperature control parameter, and saving a preset temperature control curve parameter; detecting and monitoring an outlet air temperature, and the temperature and humidity of a drying room; dynamically adjusting a set temperature according to a preset temperature control curve; and selecting, according to a current set temperature, a double-circulation dynamic operation mode of a system. The control device uses a micro-processor to realize program control. By building an inner circulation loop for large-volume air circulation, the latent heat of condensation in a refrigerant is fully absorbed, to improve the basic air temperature.