数字式低温液位测量系统

Digital measurement system for cryogenic liquid level

液体火箭发动机试验中,低温推进剂(液氢、液氧、液态甲烷等)的稳态流量是发动机设计的重要参数。目前用自主研制的分节式电容液面计、电容变换仪、采集设备和计算机组成流量测量系统,实现氢氧发动机高空模拟试验及校准试验中高精度稳态流量的测量和实时液位监测。为了提高电容式液位计的测量精度和可靠性,对变送仪表的性能进行了改进。研制了基于FPGA的数字式液位测量仪,测量系统仅由分节式液位传感器、数字式液位测量仪和计算机构成一套完整的解决方案,实现了仪器的智能化和数字化。

In liquid rocket engine test, steady-state flow rate of cryogenic propellants （such as liquid hydrogen, liquid oxygen, liquid methane, etc.） is an important parameter of the engine design. Currently, the flow measurement system consists of self-developed sub-section capacitive liquid level gauge, matching capacitance meter, acquisition equipment and computers. It can implement high：precision steady-state flow measurement and real-time liquid level monitoring in altitude simulation test and calibration test of a hydrogen oxygen engine. In order to improve accuracy and reliability of capacitive liquidometer, the performance of transmission instruments was improved and the FPGA-based digital liquidometer was developed, so that a complete set of solutions could be constituted by only the section level sensor, digital level measuring instruments and computers to achieve intelligentization and digitization of the instrument.