Constant-Volume Fuel Supply Chamber Using Cyclic Diaphragm Pumps
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Solution Overview
Problem
Liquid fuel fireplaces face unstable fuel supply and short service life due to aging rubber tubes in constant displacement pumps, leading to unstable combustion and high maintenance costs.
Innovation Solution
A device comprising a constant amount chamber, diaphragm pumps, liquid level detection probes, and a controller, which operates cyclically to maintain a constant liquid volume between high and low levels, using inexpensive diaphragm pumps and an overflow system to stabilize fuel supply and prevent pressure buildup.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a constant displacement pump is used to supply liquid fuel, then a stable supply of liquid fuel is achieved, but the rubber tube ages due to stress under cyclic pressing, resulting in a small flow rate and unstable combustion
Solution Approach 1:
The system is divided into two separate pumps: an input pump that fills the constant amount chamber and an output pump that supplies liquid fuel to the burner. This segmentation allows each pump to operate independently, with the input pump refilling the chamber after the output pump has delivered a precise amount of fuel, thereby reducing cyclic stress on any single pump's tubing and extending service life.
Solution Approach 2:
The input pump and output pump operate in periodic cycles controlled by liquid level detection probes. The output pump operates until the liquid level drops to a low threshold, then stops and allows the input pump to refill the chamber until a high threshold is reached. This periodic operation reduces continuous cyclic stress on the rubber tubes compared to constant displacement pumping.
2Reliability
If a constant displacement pump is used, then liquid fuel is supplied at a constant rate, but the pump is expensive and troublesome to maintain
Solution Approach 1:
The constant displacement pump is replaced by two simple diaphragm pumps working in sequence. The input pump fills a constant amount chamber to a predetermined level, and the output pump delivers the fuel. The constant amount chamber itself acts as a flow regulator, ensuring constant fuel delivery without requiring a complex constant displacement pump mechanism.
Solution Approach 2:
The system uses inexpensive diaphragm pumps instead of expensive constant displacement pumps. While the pumps themselves are simpler and cheaper components, the overall system achieves reliable constant flow through the constant amount chamber design, making the system more cost-effective and easier to maintain.
3Measurement precision
If the liquid level fluctuates during feeding or discharging, then the detection of liquid level is affected, but the liquid inlet and outlet positions need to be optimized
Solution Approach 1:
The liquid inlet and outlet are positioned below the low liquid level detection probe to ensure that during normal operation, the liquid level remains above these openings. This preliminary positioning prevents liquid level fluctuations from affecting the detection probes, as the probes detect levels well above the inlet and outlet positions where liquid movement occurs.
Data Source
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AI summary
Disclosed are a device for supplying liquid at a constant amount and a method for controlling the same, and the device for supplying liquid at a constant amount comprises a constant amount chamber, an input pump, an output pump, a liquid level detection device, and a controller; the constant amount chamber is provided with a liquid inlet and a liquid outlet; the input pump is provided with an input pump liquid feeding pipe and an input pump liquid discharging pipe; the output pump is provided with an output pump liquid feeding pipe and an output pump liquid discharging pipe; the liquid inlet is in matched connection with the input pump liquid discharging pipe; the liquid outlet is in matched connection with the output pump liquid feeding pipe; the liquid level detection device is provided with a high liquid level detection probe and a low liquid level detection probe; the input pump, the output pump, and the liquid level detection device are each in matched connection with the controller. In the present invention, by cyclic operation, a liquid volume between a high liquid level and a low liquid level is delivered at a constant amount in each cycle, so that liquid fuel is supplied at a constant amount. The present invention features simple structure, low cost, and convenient application.