Condensation Dryer Heat Pump With Coupled Excess-Heat Exchanger
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Compressor heat pumps in condensation dryers face efficiency deterioration due to high temperatures, especially when supported by additional heaters for faster heating, leading to the need for controlling and reducing refrigerant temperatures.
Innovation Solution
Incorporating an additional heat exchanger between the condenser and evaporator in the heat pump circuit, which is functionally coupled with the air-to-air heat exchanger, allows for excess heat dissipation without impairing the drying process, enabling optimal coolant temperature control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a compressor heat pump is used to heat process air faster, then heating speed is improved, but refrigerant temperature becomes too high causing efficiency deterioration
Solution Approach 1:
The heat pump system is segmented into two independent heating circuits: a first heating circuit (compressor heat pump) for rapid heating, and a second heating circuit (electric heater) for maintaining optimal refrigerant temperature. This segmentation allows each circuit to perform its specific function without interfering with the other, resolving the contradiction between heating speed and efficiency.
Solution Approach 2:
The system dynamically changes the heating parameter by switching between the first heating circuit (when fast heating is needed) and the second heating circuit (when temperature control is needed). The control unit monitors process air temperature and selectively activates either the compressor heat pump or the electric heater, thereby optimizing both heating speed and efficiency based on real-time conditions.
2Power
If additional heater is added to support compressor heat pump, then heating capability is improved, but device complexity increases
Solution Approach 1:
The second heating circuit (electric heater) serves multiple functions: it acts as a supplementary heater to support the compressor heat pump when needed, and simultaneously serves as the primary heating source during periods when the compressor heat pump should maintain optimal refrigerant temperature. This multi-functionality justifies the added complexity by providing versatile heating control capabilities.
3Power
If compressor heat pump operates at high temperature, then heating output is improved, but compressor reliability deteriorates
Solution Approach 1:
The control unit applies preliminary anti-action by preemptively switching to the second heating circuit (electric heater) when the process air temperature approaches the threshold that would cause excessive refrigerant temperature. This prevents the compressor heat pump from operating in a harmful high-temperature condition, thereby protecting compressor reliability before damage can occur.
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 configuration allows for better refrigerant temperature regulation, improving energy balance and protecting the heat pump, while reducing demands on the compressor, thus enhancing overall dryer efficiency.
Implementation Method 1
the warm, moisture-laden process air is cooled essentially in a first heat exchanger of the heat pump, in particular an evaporator, where the transferred heat is used to evaporate a refrigerant used in the heat pump
Implementation Method 2
the moisture contained in the process air condenses as water
Implementation Method 3
Such refrigerant, which has evaporated as a result of the heating, is fed via a compressor to a second heat exchanger
Implementation Method 4
heat is released due to the condensation of the gaseous refrigerant, which in turn is used to heat the process air before it enters the drum
Implementation Method 5
heat is released due to the condensation of the gaseous refrigerant
Implementation Method 6
The liquefied refrigerant returns to the evaporator through a throttle, which reduces its pressure, in order to evaporate there while again absorbing heat from the process air
Implementation Method 7
an additional heat exchanger located in the heat pump circuit between the condenser and the evaporator, with which the excess heat can be dissipated
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a condensation dryer (1) comprising a drying chamber (3) for the articles to be dried, a process air circuit (2) in which a heater (18) for heating the process air is located and wherein the heated process air can be guided across the articles to be dried, using a blower (19), an air/air heat exchanger (11, 12) and a heat pump circuit (13, 14, 15) comprising an evaporator (13), a compressor (14) and a condenser (15), an additional heat exchanger (16) being arranged in the heat pump circuit (13, 14, 15) between the condenser (15) and the evaporator (13), said additional heat exchanger being functionally coupled to the air/air heat exchanger (11, 12). The invention also relates to a method for operating a condensation dryer (1).