Cold-Storage Evaporator Structure for Idle-Stop Vehicle Cooling
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Solution Overview
Problem
In hybrid vehicles, the air conditioner's evaporator experiences temperature increases when the engine is stopped, leading to inefficient refrigerant vaporization and re-compression, resulting in prolonged chilly wind supply and increased energy consumption. Additionally, existing thermal energy storage heat exchangers face issues with coupling defects, reduced heat transfer rates, and complex fabrication.
Innovation Solution
An evaporator design with a cold reserving part integrated between refrigerant passages, where a tank with an inlet and outlet is connected to tubes with laminated plates, and fins are formed between the tubes, allowing for efficient cold storage and rapid reactivation when the engine restarts, with a cold reserving material charged through a hole and discharged of air, optimizing the contact surface area for improved cooling efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the engine is stopped during waiting, then fuel consumption is reduced, but the evaporator temperature increases and refrigerant vaporizes requiring re-compression
Solution Approach 1:
The cold reserving part stores cold energy in advance during engine operation, so when the engine stops and the compressor stops, the stored cold energy can immediately cool the air passing through the evaporator, avoiding the time delay and energy waste of re-vaporizing and re-compressing refrigerant
2Use of energy by moving object
If the engine is stopped during waiting, then fuel consumption is reduced, but energy consumption for re-compression increases
Solution Approach 1:
Cold energy is stored in advance in the cold reserving part during engine operation. When the engine stops, this pre-stored cold energy is used to maintain cooling, eliminating the need for energy-consuming re-compression of vaporized refrigerant
3Reliability
If a dual structural tube is formed by coupling plate materials, then thermal energy storage is achieved, but coupling defects occur frequently and fabrication becomes difficult
Solution Approach 1:
The cold reserving part is integrally formed with the tube in a single piece structure, eliminating the need for coupling multiple plate materials together. This integral structure prevents coupling defects and simplifies fabrication while maintaining thermal energy storage capability
4Reliability
If the heat exchanging medium passage is formed outside the dual structural tube, then cold storage is facilitated, but the heat transfer rate of the heat exchanging medium is lowered
Solution Approach 1:
The cold reserving part is integrally formed with the tube, creating direct thermal contact between the refrigerant passage and the cold reserving material. This integrated structure maximizes heat transfer efficiency while maintaining cold storage capability
5Device complexity
If fins are disposed outside the dual structural tube contacting only the thermal energy reserving material chamber, then structure is simplified, but heat exchange efficiency is lowered
Solution Approach 1:
The fins are integrally formed with the tube, creating direct thermal contact with the refrigerant passage. This integral fin structure efficiently transfers heat from the refrigerant to the cold reserving material and surrounding air, improving heat exchange efficiency while maintaining structural simplicity
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 design prevents rapid temperature increases, enhances cooling performance, reduces energy consumption, and simplifies the structure for easier fabrication, while maintaining a compact size and improving gas mileage by effectively utilizing the cold reserving material.
Implementation Method 1
a cold reserving part 20 for storing a cold reserving material is formed between the refrigerant passages 11a and 11b of the tube 30
Implementation Method 2
an evaporator equipped with a cold reserving part which can prevent sharply increasing of a temperature in a vehicle by using the cold reserved in the cold reserving part
Data Source
AI summary
An evaporator includes a plurality of tubes stacked in a row and each of the tubes has a pair of plates coupled with each other. Each of the pair of plates includes a pair of refrigerant passages in an air flow direction at opposite sides thereof. The evaporator further has a cold reserving part between the refrigerant passages for storing a cold reserving material; a plurality of fins formed between the tubes; a tank including an upper tank respectively communicated with upper portions of the pair of refrigerant passages and a lower tank respectively communicated with lower portions of the pair of refrigerant passages; and an inlet pipe and an outlet pipe formed at the tank.