Multi-temperature transportation refrigeration system
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Solution Overview
Problem
Existing multi-temperature transportation refrigeration systems require separate refrigeration circuits for each compartment, which increases complexity and reduces efficiency, as they often share a common condenser that may not optimally utilize the air-side heat transfer surface area when one circuit is stopped.
Innovation Solution
A refrigeration system with a staggered arrangement of refrigerant flow passages in a common condenser, where the inlet lines of the two circuits are interspersed perpendicular to the flow direction, allowing for efficient heat transfer and continued operation even if one circuit is stopped, utilizing a microchannel or round tube plate fin heat exchanger design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If separate refrigeration circuits are used for each compartment, then distinct temperatures can be provided, but system complexity increases
Solution Approach 1:
The patent combines two separate refrigeration circuits into a single integrated system that shares a common compressor and a common condenser with staggered flow passages. This merging approach reduces the number of components while maintaining the capability to provide distinct temperatures to different compartments through the staggered circuit configuration within the shared condenser.
Solution Approach 2:
The common condenser is designed with multi-functionality to handle refrigerant from both circuits simultaneously. The staggered flow passages allow the condenser to serve both temperature requirements, making a single component perform the function of what would traditionally require separate dedicated condensers for each circuit.
2Device complexity
If a common condenser is shared by multiple circuits, then component count is reduced, but air-side heat transfer surface area utilization decreases when one circuit is stopped
Solution Approach 1:
The condenser is segmented into multiple flow passages arranged in a staggered configuration, with each passage dedicated to a specific circuit. This segmentation allows independent operation of each circuit's refrigerant flow through the condenser, ensuring that when one circuit is stopped, the other circuit can still utilize the full air-side heat transfer surface area without interference.
Solution Approach 2:
The staggered arrangement of flow passages introduces a spatial dimension to the condenser design, where passages are interspersed perpendicular to the flow direction. This dimensional arrangement ensures that refrigerant streams from different circuits do not interfere with each other's heat transfer efficiency, allowing full utilization of the heat transfer surface area regardless of the operational status of individual circuits.
3Productivity
If staggered flow passages are implemented in the condenser, then heat transfer efficiency is improved, but manufacturing complexity increases
Solution Approach 1:
The staggered flow passage configuration provides local quality optimization within the condenser structure. Each passage is designed with specific geometric characteristics that enhance heat transfer efficiency at its location, while the overall pattern of staggered arrangement ensures uniform utilization of the entire heat transfer surface area across the condenser.
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 enhances efficiency by ensuring the entire air-side heat transfer surface area is utilized, allowing for effective cooling of both compartments with distinct temperatures, and prioritizes heat transfer based on refrigerant inlet temperatures, maintaining efficiency even if one circuit is halted.
Implementation Method 1
a common condenser condensing refrigerant from both the first and second circuits into a high-temperature high-pressure liquid refrigerant
Implementation Method 2
a common condenser condensing refrigerant from both the first and second circuits into a high-temperature high-pressure liquid refrigerant
Implementation Method 3
a first expansion valve for lowering temperature and pressure of refrigerant condensed by the first condenser, a second expansion valve for lowering temperature and pressure of refrigerant condensed by the second condenser
Implementation Method 4
a first evaporator for evaporating refrigerant passed through the first expansion valve, a second evaporator for evaporating refrigerant passed through the second expansion valve
Implementation Method 5
The evaporator cools air to be delivered into an environment to be conditioned
Data Source
Figure 1
Figure 2A~2D
AI summary
A transportation refrigeration system includes an enclosure, and at least two compartments (22,24) within the enclosure to be conditioned to two distinct temperatures. A refrigeration is circuit associated with each of the at least two compartments. A first refrigeration circuit (26) includes a first compressor (32), a first evaporator (30), and a first expansion valve (40). A second refrigeration circuit (28) includes a second compressor (44), a second evaporator (42), and a second expansion valve (52). The first and second refrigeration circuits utilize a common condenser (36), with first inlets into the condenser from the first circuit connected to a first flow passage and second inlets from the second circuit connected to second flow passages. First and second outlets are connected to the first and second flow passages. The first and second flow passages are staggered in a direction perpendicular to a flow passage across the condenser. A heat exchanger is also disclosed.