Turbomachinery Package Specification

Taurus 60 Compressor Set and Mechanical Drive

 

 

11 Compressor Control and Monitoring

11.1General Description

The following sections outline the control and monitoring options available for compressors and mechanical drives.

11.1.1Process Control

The process control options provide unit control based on the gas compressor suction pressure, discharge pressure, and flow (or combinations of these parameters). Local and remote setpoint adjustments are included. If prime, Solar will provide the necessary transmitters. If the driven equipment supplier is prime, the following input signals are required depending on the type of control:

•4-to-20 mA pressure signal

•4-to-20 mA flow element differential pressure

•Temperature at flow element (100-ohm platinum RTD preferred)

11.1.2Suction Pressure, Discharge Pressure, and Flow Shutdowns

The basic package may be supplied with driven equipment suction pressure, discharge pressure, and flow transmitters and associated control system logic to provide for indication, warning alarm, and unit shutdown when the suction pressure, discharge pressure, or flow exceeds a preset value.

•Suction pressure transmitter – shipped separately for installation by purchaser

•Discharge pressure transmitter – shipped separately for installation by purchaser

•Suction flow transmitter – shipped separately for installation by purchaser

11.1.3Gas Compressor Surge Detection System

The surge detection system detects gas compressor discharge pressure pulsations and initiates a gas turbine shutdown if pulsations exceed a preset value within a predetermined time period. For applications without an anti-surge control system supplied by Solar, a gas compressor surge detection system is recommended.

11.1.4Anti-Surge Control

Surge at a given gas compressor speed is caused by excessive head across the gas compressor (isentropic head) for a given suction flow rate. Therefore, surge in the gas compressor may be controlled by decreasing the head across the gas compressor and/or by increasing the flow rate of the gas to the suction side of the gas compressor. The anti- surge control system prevents surge by modulating a surge control (bypass) valve to lower head and increase suction flow. A typical system consists of pressure and temperature transmitters on the gas compressor suction and discharge lines, a flow differential pressure transmitter across the suction flowmeter, an algorithm in the control system, and a surge control valve with corresponding accessories to keep the gas compressor from going into surge.

The following components and information are required from the purchaser in order to facilitate the surge control system design and onsite operation:

•Expected gas compressor operating conditions range for suction pressure (P1), suction temperature (T1), discharge pressure (P2), flow and gas specific gravity

•Flow meter specification sheet

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TPS60CSMD/309

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