Chiller Buffer Storage Using PCM for Compact Design
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Solution Overview
Problem
Conventional chillers with liquid cooling medium buffers require large structural volumes due to the necessary tank size for water or oil, limiting the compactness of the external dimensions.
Innovation Solution
Incorporating a phase change material (PCM) in the buffer storage and using a heat exchanger to thermally couple the chilled liquid cooling medium with the PCM, reducing the cycle rate of the compression refrigerant circuit while maintaining buffer store sizes, thus allowing for a more compact chiller design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a large volume buffer tank is used to store cooled liquid cooling medium, then the cycling rate of the compression refrigerant circuit is reduced, but the external dimensions of the chiller increase
Solution Approach 1:
The invention changes the thermal parameter of the buffer storage by incorporating PCM material with higher heat capacity compared to conventional liquid cooling medium. This parameter change allows the same thermal energy storage capacity to be achieved in a smaller volume, thereby reducing the buffer tank size while maintaining the cycling rate reduction benefit
Solution Approach 2:
The invention uses a composite approach by combining PCM material with the liquid cooling medium in the buffer storage. The PCM material is distributed throughout the buffer storage, creating a composite thermal storage system that leverages the high latent heat of fusion of PCM to reduce the required storage volume while effectively reducing compression circuit cycling
2Volume of stationary object
If the buffer tank volume is reduced to minimize chiller dimensions, then the cycling rate of the compression refrigerant circuit increases, but the service life of compression components decreases
Solution Approach 1:
By changing the thermal storage parameter through PCM material with higher heat capacity, the system achieves the same protective effect on compression components with a smaller buffer tank volume, thus reducing chiller dimensions without compromising component service life
Solution Approach 2:
The invention utilizes the phase transition properties of PCM material (specifically the latent heat of fusion during melting and solidification) to provide efficient thermal energy storage. This phase transition mechanism allows the buffer storage to absorb and release large amounts of thermal energy in a compact form, effectively reducing compression circuit cycling and extending component service life while maintaining compact dimensions
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 reduces the volume of the buffer tank and external dimensions of the chiller while maintaining the usual cycle rates, enhancing the service life of the compression refrigerant circuit components by utilizing the higher heat capacity of PCM materials.
Implementation Method 1
a phase change material, in particular ice, as the heat storage material
Implementation Method 2
utilizes the higher heat capacity of PCM materials compared to these media
Implementation Method 3
the cooled, liquid cooling medium in the buffer storage is passed through a heat exchanger, via which the cooled, liquid cooling medium is thermally coupled to the PCM material
Data Source
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AI summary
The invention relates to a chiller for cooling a liquid cooling medium, wherein the chiller has a compression refrigerant circuit with a compressor (1), a condenser (2), an expansion valve (3), and an evaporator (4), wherein the evaporator (4) is a heat exchanger through which a refrigerant (6) of the compression refrigerant circuit is fluidically separated and thermally coupled to a liquid cooling medium (7) to be cooled, wherein an outlet (8) of the heat exchanger (4) for cooled liquid cooling medium (7) opens into at least one buffer storage tank (9), and the cooled liquid cooling medium (7) is supplied from the buffer storage tank (9) to a cooling medium outlet (11) of the chiller, characterized in that a PCM material (12) is contained in the buffer storage tank (9), and the cooled liquid cooling medium (7) is passed through a heat exchanger (13) in the buffer storage tank (9), through which the cooled,liquid cooling medium (7) is thermally coupled to the PCM material (12).