Container Refrigeration Airflow Layout for Accurate CA Gas Control
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Solution Overview
Problem
Existing container refrigeration apparatuses may fail to accurately control the air composition within a container by allowing outside air to be exhausted without sufficient mixing, leading to potential inaccuracies in oxygen and carbon dioxide concentration control.
Innovation Solution
A container refrigeration apparatus with a refrigerant circuit, interior fan, and inside air control system that includes a gas supply device for nitrogen-enriched air, and strategically positioned intake and exhaust passages to ensure outside air is circulated and mixed within the container before being controlled, using a plate member to block airflow at the exhaust passage inlet, preventing outside air from being exhausted without mixing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the exhaust passage inlet is positioned in the second space where air is blown out by the interior fan, then the air circulation function is improved, but outside air may be exhausted without sufficient mixing leading to inaccurate air composition control
Solution Approach 1:
A partition wall is introduced as an intermediary structure between the first space and second space. The partition wall includes a through-hole that allows controlled air passage while preventing direct mixing. This mediator ensures that outside air taken in through the intake passage is properly mixed with container air before being exhausted, thereby maintaining accurate air composition control while preserving air circulation efficiency.
Solution Approach 2:
The internal storage space is segmented into a first space and a second space using a partition wall. The first space receives outside air through the intake passage, while the second space receives air blown by the interior fan. The partition wall with its through-hole creates separate zones that control air flow paths, ensuring proper mixing before exhaustion and preventing premature discharge of unmixed outside air.
2Speed
If the exhaust passage inlet is positioned to allow direct access to blown air flow, then the exhaust function is improved, but the mixing of outside air with container air is insufficient
Solution Approach 1:
The partition wall acts as an intermediary that forces air from the first space (containing outside air) to mix with air from the second space (blown by the fan) through the through-hole. This ensures stable air composition by preventing direct exhaustion of unmixed outside air, while the exhaust passage maintains efficient exhaust speed by providing a dedicated path for the mixed air to be discharged.
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 ensures accurate control of oxygen and carbon dioxide concentrations within the container by ensuring outside air is circulated and mixed before being controlled, reducing the risk of outside air being exhausted without sufficient mixing, thus maintaining desired air composition.
Implementation Method 1
a refrigerant circuit (20) in which a compressor (21), a condenser (22), an expansion mechanism (23), and an evaporator (24) are connected together to perform a refrigeration cycle
Implementation Method 2
an evaporator (24) housed in the internal storage space (S2)... the air in the container guided to the internal storage space (S2) is cooled when passing through the evaporator (24)
Implementation Method 3
an interior fan (26) which is provided in the internal storage space (S2), and circulates air between the interior of the container (11) and the internal storage space (S2)
Implementation Method 4
a gas supply device (30) which supplies nitrogen-enriched air having a higher nitrogen concentration than outside air to the internal storage space (S2)
Implementation Method 5
a plate member (27c) which forms, in the second space (S22), a region where the flow of the air blown from the interior fan (26) is blocked. The exhaust passage (46a) has an inlet at a location where the flow of the air blown from the interior fan (26) is blocked by the plate member (27c)
Data Source
Figure 1
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AI summary
A container refrigeration apparatus (10) includes a CA system (60) which controls the composition of the air in the container (11). The CA system (60) includes a gas supply device (30) which supplies nitrogen-enriched air, an intake duct (47a) which guides outside air to a first space (S21) on a suction side of an interior fan (26), and an exhaust duct (46a) which guides air in a second space (S22) on the blowout side of the interior fan (26) out of a container (11). The exhaust duct (46a) has an inlet at a location where the flow of the air blown from the interior fan (26) is blocked by a fan housing (27c).