Ejector and refrigerating system
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Solution Overview
Problem
In commercial refrigeration systems, reverse flow between high-pressure and suction fluids in ejectors leads to significant compressor efficiency loss, especially when multiple ejectors are connected in parallel or downstream pressures are uneven, causing system inefficiency and potential shutdown.
Innovation Solution
An ejector design featuring a mixing chamber with a thermal bulb and elastic diaphragm in the suction fluid passage, which automatically adjusts valve positions to prevent reverse flow through pressure difference sensing, using mechanical structures without external electronic control, ensuring stability and preventing reverse fluid flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If an ejector is used to improve compressor efficiency by pressurizing suction fluid, then compressor capacity requirements are reduced and system efficiency improves, but reverse flow between high-pressure fluid and outlet fluid causes significant loss of compressor efficiency
Solution Approach 1:
The patent applies preliminary anti-action by positioning a blocking member in the suction fluid passage upstream of the mixing chamber. This blocking member prevents reverse flow of mixed fluid back into the suction fluid passage before the reverse flow can occur and cause damage to compressor efficiency. The blocking member is strategically placed to intercept and stop the harmful reverse flow in advance.
Solution Approach 2:
The patent uses a blocking member as an intermediary element between the suction fluid passage and the mixing chamber. This blocking member acts as a mediator that physically separates the suction fluid flow from the mixed fluid flow, preventing direct interaction that would cause reverse flow. The blocking member transfers the function of protecting compressor efficiency without requiring modification to the compressor itself.
2Quantity of substance
If multiple ejectors are connected in parallel to handle larger refrigeration loads, then system capacity increases, but uneven downstream pressures cause reverse flow and system shutdown
Solution Approach 1:
The patent applies segmentation by dividing the suction fluid passage into separate sections for each ejector, with individual blocking members in each suction fluid passage. This segmentation allows each ejector to operate independently with its own reverse flow protection, preventing uneven downstream pressures in one ejector from causing reverse flow and shutdown in other ejectors connected in parallel.
Solution Approach 2:
The patent implements preliminary action by pre-positioning blocking members in each suction fluid passage before reverse flow can occur. These blocking members are arranged to automatically prevent reverse flow based on pressure differential, ensuring system stability before uneven pressures can cause shutdown. This preliminary protective measure allows multiple ejectors to operate in parallel reliably.
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
The solution effectively prevents reverse flow, enhancing compressor efficiency and system stability by automatically adjusting valve positions in response to pressure changes, thereby reducing the risk of system shutdown and improving overall refrigeration system performance.
Implementation Method 1
an elastic diaphragm is disposed in the suction fluid passage, the suction fluid passage is on a first side of the elastic diaphragm, and a closed cavity is on a second side of the elastic diaphragm; the thermal bulb is in communication with the closed cavity, and the thermal bulb and the closed cavity are filled with fluid; and the elastic diaphragm is arranged such that the first valve is opened when a superheat degree of a refrigerant in the suction fluid passage at the thermal bulb increases, or closed when a superheat degree of a refrigerant in the suction fluid passage at the thermal bulb decreases, in response to a change in a pressure difference across two sides of the elastic diaphragm
Implementation Method 2
a thermal bulb arranged in the suction fluid passage downstream of the first valve; wherein an elastic diaphragm is disposed in the suction fluid passage, the suction fluid passage is on a first side of the elastic diaphragm, and a closed cavity is on a second side of the elastic diaphragm; the thermal bulb is in communication with the closed cavity, and the thermal bulb and the closed cavity are filled with fluid
Data Source
Figure 1~2
AI summary
An ejector and a refrigeration system are provided. The ejector includes: a high-pressure fluid passage (1) extending from a high-pressure fluid inlet (11) to a mixing chamber (8); a suction fluid passage (2) extending from a suction fluid inlet (21) to the mixing chamber (8), a first valve being disposed in the suction fluid passage (2); the mixing chamber (8), which includes a mixed fluid outlet (84); and a thermal bulb (75) arranged in the suction fluid passage (2) downstream of the first valve; wherein an elastic diaphragm (47) is disposed in the suction fluid passage (2), the suction fluid passage (2) is on a first side of the elastic diaphragm (47), and a closed cavity (73) is on a second side of the elastic diaphragm (47); the thermal bulb (75) is in communication with the closed cavity (73), and the thermal bulb (75) and the closed cavity (73) are filled with fluid; and the elastic diaphragm (47) is associated with the first valve so that the first valve is opened or closed in response to a change in a pressure difference across two sides of the elastic diaphragm (47). The ejector can effectively prevent an occurrence of a reverse flow.