System and method for detecting stall or surge in radial compressors

An avoidance system for avoiding an impending stall or surge in a radial compressor, comprising:

• a detection system comprising a plurality of detection devices coupled to the radial compressor, at least a portion of each detection device disposed in a diffuser channel of a diffuser of the radial compressor, the plurality of detection devices configured to detect a transition of a low momentum zone of a gas flow through the diffuser from a first location of the different locations in the diffuser channel adjacent a shroud wall of the diffuser to a second location of the different locations in the diffuser channel adjacent a hub wall of the diffuser;
• a control system electrically coupled to the plurality of detection devices and configured to receive a plurality of information signals, each information signal being transmitted by a respective one of the plurality of detection devices and correlating to a location of the low momentum zone, the control system further being configured to process the plurality of information signals and detect the impending stall or surge based on the location of the low momentum zone;
• and
• a bypass valve electrically coupled to the control system and in fluid communication with the radial compressor,
• wherein the control system is further configured to generate and transmit a command signal to the bypass valve based on the location of the low momentum zone, and the bypass valve is configured to receive the command signal and vary the amount of the gas flow into the radial compressor based on the command signal, and
• wherein the bypass valve is directly fluidly coupled to an outlet line of the radial compressor, and wherein the bypass valve is further directly fluidly coupled to an inlet line of the radial compressor, the bypass valve, which is directly fluidly connected to the outlet line and is directly fluidly connected to the inlet line of the radial compressor, allowing for recirculation of the gas flow through the radial compressor.

A method for avoiding an impending stall or surge in a radial compressor, comprising:

• at least partially disposing a plurality of detection devices in a diffuser channel of a diffuser of the radial compressor;
• arranging the plurality of detection devices to measure pressure of gas flow at different locations in the diffuser channel;
• transmitting an information signal from each of the plurality of detection devices to a control system, the information signal correlating to a first location and a second location of the different locations in the diffuser channel;
• processing in the control system the information signal received from each of the plurality of detection devices, such that the control system detects the second location of the different locations in the diffuser channel as being indicative of a low momentum zone proximate a hub wall of the diffuser;
• processing in the control system the information signal received from each of the plurality of detection devices, such that the control system detects the first location of the different locations in the diffuser channel as being indicative of a low momentum zone proximate a shroud wall of the diffuser;
• and
• detecting in the control system the impending stall or surge based on movement of the low momentum zone from the first location to the second location;
• transmitting from the control system a command signal generated by the control system based on the detecting by the control system of the impending stall or surge;
• and
• varying a flow rate of the gas flow in the radial compressor by way of a bypass valve in fluid communication with the radial compressor, the varying of the flow rate of the gas flow based on the command signal generated by the control system;
• directly fluidly connecting the bypass valve to an outlet line of the radial compressor;
• directly fluidly connecting the bypass valve to an inlet line of the radial compressor;
• recirculating the gas flow through the radial compressor by way of the bypass valve, which is directly fluidly connected to the outlet line and directly fluidly connected to the inlet line of the radial compressor,
• wherein at least one first detection device of the plurality of detection devices is disposed in the diffuser channel adjacent the hub wall of the diffuser to detect the second location of the low momentum zone by measuring a first pressure of the gas flow in the diffuser channel proximate mate the hub wall;
• and
• at least one second detection device of the plurality of detection devices is disposed in the diffuser channel adjacent the shroud wall of the diffuser to detect the first location of the low momentum zone by measuring a second pressure of the gas flow in the diffuser channel proximate the shroud wall.