Hermetic Compressor Motor Cooling via Segmented Refrigerant Flow
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Solution Overview
Problem
Transport refrigeration machines for commercial vehicles face challenges in providing reliable cooling and heating while minimizing refrigerant leakage, preventing drive motor overheating, and maintaining cost-effectiveness, as existing designs either suffer from refrigerant leakage or inadequate cooling/heating performance.
Innovation Solution
A transport refrigeration machine with a measuring device to monitor drive motor temperature and a control device to adjust cooling measures based on temperature readings, ensuring the drive motor is cooled only when necessary, and incorporating a hermetic compressor with a refrigerant flow that cools the motor without overheating, along with an economizer for enhanced cooling efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the drive motor is continuously cooled by refrigerant flow, then the drive motor temperature is reduced, but energy consumption increases and cooling efficiency decreases
Solution Approach 1:
The patent implements periodic cooling by controlling the refrigerant flow to the drive motor in cycles rather than continuously. The control device alternates between cooling phases (when motor temperature exceeds threshold) and non-cooling phases, thereby reducing overall energy consumption while still preventing overheating. This is achieved through the control device that regulates the refrigerant flow based on temperature sensor feedback.
Solution Approach 2:
The patent employs a feedback control system where temperature sensors monitor the drive motor temperature and provide signals to the control device. The control device adjusts the refrigerant flow accordingly - increasing flow when temperature rises above a threshold and reducing or stopping flow when temperature is within acceptable range. This closed-loop feedback mechanism optimizes energy consumption by cooling only when necessary.
2Reliability
If a hermetic compressor is used to prevent refrigerant leakage, then sealing is improved, but cooling performance may be compromised due to restricted refrigerant flow
Solution Approach 1:
The hermetic compressor housing is segmented into multiple chambers or flow paths that allow refrigerant to flow around the drive motor while maintaining the hermetic seal. The housing includes specific passages and openings that divide the internal space to enable both sealing and adequate refrigerant circulation for cooling the motor without compromising either function.
3Temperature
If refrigerant flow around the drive motor is increased to improve cooling, then drive motor temperature is reduced, but refrigerant leakage risk increases
Solution Approach 1:
The patent implements preliminary cooling measures by designing the hermetic compressor housing with pre-configured refrigerant passages that guide cooling flow around the drive motor before temperatures become critical. The control device anticipates temperature rise and activates cooling protocols in advance, preventing overheating while maintaining seal integrity through controlled, gradual refrigerant flow increases rather than sudden high-flow conditions that could compromise sealing.
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 solution ensures reliable cooling and heating performance, minimizes energy consumption, prevents drive motor damage, and reduces the risk of refrigerant leakage, thereby maintaining the quality of transported goods while being cost-effective.
Implementation Method 1
the refrigerant flowing around the drive motor at least in sections and compressed by the compressor
Implementation Method 2
heat exchanger for transferring heat between the loading space and a refrigerant flowing through the heat exchanger
Implementation Method 3
compressor for compressing the refrigerant flowing through the heat exchanger and supplying the heat exchanger with refrigerant
Implementation Method 4
heat exchanger for transferring heat between the loading space and a refrigerant flowing through the heat exchanger
Data Source
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AI summary
Described and illustrated is a transport refrigeration machine (10) for cooling and/or heating a cargo space (8) of a box body (1) of a commercial vehicle (N), preferably a truck, trailer or semi-trailer, with a heat exchanger (11) for transferring heat between the cargo space (8) and a refrigerant flowing through the heat exchanger (11), with a compressor (12) for compressing the refrigerant flowing through the heat exchanger (11) and supplying the heat exchanger (11) with refrigerant, and with an electric drive motor (13) for driving the compressor (12).wherein the drive motor (13) and the compressor (12) are housed in a common casing (14) and wherein the casing (14) has at least one refrigerant inlet (15) for the refrigerant flowing through the heat exchanger (11) into the casing (14) and at least one refrigerant outlet (16) for the refrigerant flowing at least partially around the drive motor (13) and compressed by the compressor (12) out of the casing (14). In order to reliably provide the necessary cooling and/or heating capacity with high operational reliability and low costs,A measuring device (31) for measuring at least one temperature measurement value indicative of a motor temperature of the drive motor (13) and a control device (29) for initiating at least one cooling measure cooling the drive motor (13) and terminating the cooling measure are provided, each depending on a temperature measurement value measured by the measuring device (31) and indicative of a motor temperature of the drive motor (13).