A kind of heat pump-refrigeration unit nitrogen charging and pressure maintaining leak detection equipment and control method thereof

Abstract

The invention provides a heat pump-refrigerating unit nitrogen-charging pressure-maintaining leakage detecting device and a control method thereof and relates to a quality test and control device of a compressing machine, device or system with the low-boiling-point gas being as a refrigerant. The leakage detecting device comprises a high-pressure gas tank, a constant pressure gas tank, a vacuum pump, an expansion gas tank and a control device. A nitrogen-charging pipeline comprises a nitrogen-charging one-way valve, a nitrogen-charging magnetic valve and a nitrogen-charging quick joint which are connected in series, and the pipeline is provided with a first pressure detection element. A high-pressure gas-adding pipeline comprises a gas-adding magnetic valve. The high-pressure gas tank is provided with a third pressure detection element. A vacuum-pumping pipeline comprises an air-pumping quick joint, an air-pumping magnetic valve and an air-pumping one-way valve which are connected in series, and the pipeline is provided with a second pressure detection element. A constant pressure valve is utilized to add gas to the constant pressure gas tank, and the constant pressure gas tank carries out concentrated gas supplying, thereby guaranteeing the stability of the pressure of the high-pressure gas tank and quick charging speed; the pressure detection elements are utilized to detect and control the charging pressure to guarantee small pressure deviation; and the leakage detecting device and the control method can meet the demand of small-amount multi-variety modern flexible production lines.

Description

technical field [0001] The invention relates to a quality detection and control device for compressors, devices or systems in which low-boiling-point gas is used as a refrigerant, and in particular to a nitrogen-filling pressure-maintaining leak detection device and a control method for a heat pump-refrigeration unit. Background technique [0002] In the production process of heat pumps and refrigeration systems, leak detection must be carried out to ensure their quality. Due to the low temperature of liquid nitrogen, easy preparation, low cost, and no pollution, many companies use it in the production process of heat pumps and refrigeration systems. In China, the heat pump-refrigeration unit is leak-tested by nitrogen filling and pressure-holding leak detection method. After the leak detection is completed, the nitrogen gas is directly discharged into the surrounding air without recycling. Dozens of machines are produced every day, resulting in a large amount of waste of nit...

AI Technical Summary

Problems solved by technology

However, in the actual production process, the product models and batches on the production line are constantly changing, especially for modern flexible production lines with small batches and multiple varieties, the systems to be leaked at the same time and the systems that have been leaked often belong to different models or Different batches of products, therefore, the amount of nitrogen discharged from the leak detection system is not equal to the nitrogen filling amount of the leak detection system in most cases. The above-mentioned nitrogen gas discharged from the leak detection system is directly transferred to the leak detection system It is difficult to realize the effective nitrogen recovery and utilization function of the existing technical solutions

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