Refrigeration-type chiller
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing refrigeration-type chillers are not suitable for gradually changing the temperature of a load over a given period of time, which is necessary for processes like craft beer fermentation or aging that require delicate and precise temperature management.
Innovation Solution
A refrigeration-type chiller with a control unit that adjusts the temperature of the coolant and refrigerant flow rates through electronic expansion valves to achieve a target temperature gradient over a specified time, using a tank, pump, temperature sensors, and a heat exchanger to manage temperature changes in the load.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the coolant circulation apparatus maintains constant coolant temperature for constant load temperature control, then the load temperature stability is improved, but the ability to gradually change load temperature over time deteriorates
Solution Approach 1:
The control unit dynamically adjusts the coolant temperature setpoint over time based on a specified temperature gradient, transitioning from static constant temperature control to dynamic time-varying temperature control. This enables the system to gradually change the load temperature while maintaining stability during each incremental phase.
Solution Approach 2:
The system changes the temperature parameter of the coolant from a fixed constant value to a time-varying value that follows a specified gradient. By modifying the temperature parameter dynamically, the system achieves both stability during transitions and adaptability to different temperature profiles.
2Measurement precision
If the refrigeration circuit uses multiple expansion valves for temperature control, then the temperature control precision is improved, but the device complexity increases
Solution Approach 1:
The refrigeration circuit is segmented into multiple parallel paths with separate expansion valves (first and second electronic expansion valves) that can independently control different refrigerant flows. This segmentation enables precise temperature control by selectively adjusting each valve based on the required temperature gradient.
Solution Approach 2:
The multiple expansion valves serve dual functions: they can operate independently for precise temperature control during gradient changes, and they can work together to maintain constant temperature when needed. This multi-functionality increases precision without requiring entirely separate systems.
3Manufacturing precision
If the system cools a high-temperature solution to low temperature over 24-48 hours for craft beer production, then the yeast extraction quality is improved, but the process time increases
Solution Approach 1:
The system pre-calculates and sets the temperature gradient profile before the cooling process begins, determining the optimal rate of temperature change to achieve yeast extraction. This preliminary planning allows the system to execute the gradual cooling efficiently without unnecessary delays.
Solution Approach 2:
The cooling process is divided into periodic phases with different temperature gradients, where the system adjusts the cooling rate at different stages to optimize yeast extraction while minimizing total process time. This periodic adjustment of cooling intensity achieves both quality and time 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
Enables gradual and precise temperature adjustment of the load to a target temperature over a long duration, suitable for processes requiring gradual temperature changes.
Implementation Method 1
a heat exchanger that exchanges heat between the coolant and the refrigerant
Implementation Method 2
exchanges heat between the coolant and the refrigerant
Implementation Method 3
exchanges heat between the coolant and the refrigerant
Implementation Method 4
a compressor that compresses the refrigerant
Implementation Method 5
a condenser that cools a high-temperature refrigerant discharged from the compressor
Implementation Method 6
a second electronic expansion valve that sends to the heat exchanger the high-temperature refrigerant discharged from the compressor
Data Source
AI summary
A refrigeration-type chiller includes a coolant circuit that supplies a coolant to a load, a refrigeration circuit that adjusts the temperature of the coolant, and a control unit that controls the chiller as a whole. The control unit includes a temperature setting unit that sets, as an adjustment target temperature, the temperature of the coolant for causing the load to be at a target temperature, a time setting unit that sets an adjustment time during which to change the temperature of the coolant to the adjustment target temperature, an arithmetic unit that calculates a gradient of temperature change as a target temperature gradient from the adjustment target temperature and the adjustment time, and a temperature control unit that adjusts the opening degrees of first and second electronic expansion valves and so that the temperature of the coolant changes in accordance with the target temperature gradient.