压缩机系统的设计首先在过程流程图中概念化或compressor PFD. Subsequently, a more detailed design is created by means of a管道和仪器图或压缩机P＆ID。让我们来看看典型的压缩机P＆ID和进入它的设计考虑因素。
Typical compressor P&ID
Figure 1 - Typical centrifugal compressor P&ID
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- Proper centrifugalcompressor symbolshould be selected first, as shown in figure-1. Normally, acentrifugal compressoris accompanied by a Knock Out Drum (KOD) at the compressor suction and an aftercooler at the compressor discharge, as per atypical compressor PFD.Symbols for these equipments should also be placed on the P&ID before proceeding ahead. All the equipment symbols should be selected from the legend sheets of a particular project.{adinserter 1}
- All the nozzles on the compressor, suction drums and aftercooler should then be correctly represented with size and flanges. This includes inlet and outlet nozzles and equipment drains / vents as shown in the typical P&ID in figure-1.
- Centrifugal compressor suction KOD is intended for removing the entrained liquids before sending gas to the compressor. Demister, mesh pad etc. are used in the knock out drum to efficiently remove the liquid droplets.
- Compressor aftercoolers are generally air coolers and the related fan, motor etc. should be clearly indicated on the P&ID. If cooling water is used, proper symbol for a heat exchanger should be used.
- 入口，用于每个设备的出口线，防喘振线，漏极/通风线，线路到释放阀等是下一步。将正确分配给每个行的行号，材料类，尺寸等。
- 隔离阀，眼镜百叶窗, spacers etc. to be used for maintenance should be drawn up next on various lines between the equipments. Requirement for isolation valves, spectacle blind, spaces etc. depend on the project standards, which should be followed while indicating these on the compressor P&ID. Sometimes, to minimize the number of isolation valves between the equipment, they can be placed only at the suction KOD inlet which is inlet of the centrifugal compressor system and discharge of the aftercooler which turns out to be the outlet of the centrifugal compressor system. Spectacle blinds or spacers can be used for isolation between individual equipments for quick maintenance. This is simply a guideline and project standards need to be followed when indicating the isolation requirements.{adinserter 2}
- 止回阀应在压缩机放电上设置止回阀，以避免泵在操作中时的反向流动。
- 减压阀can be provided on the compressor discharge line, downstream to the check valve, to protect the equipment downstream of compressor.
- 压力gauges should be provided on suction and discharge of the compressor. Level gauges need to be located on the compressor suction knock out drum and temperature gauges on inlet, outlet lines for the aftercooler.
- 应在压缩机抽吸管线上提供压力变送器。压缩机吸入管路应提供流量变送器。来自这些发射机的信号被发送到“抗浪涌控制器”。基于压缩机开发的气流和差压头，防浪涌控制器操作防喘振阀以防止压缩机浪涌健康）状况。
- 应提供来自后加工器排放到吸入kod入口的抗喘振线用于抗浪涌控制。当压缩机接近时surge condition(低流量、高微分头),喘振valves open up to lower the pressure differential and circulate higher gas flow.
- Sometimes, a performance controller can be included in the centrifugal compressor system to control the rotating speed (RPM) of the compressor based on inlet pressure, flow etc. in order to achieve optimum performance. Performance controller will typically adjust the motor/turbine speed.
- 在吸入滚筒上提供的水平发射器负责滚筒中的液位控制。通常为高高的高液位条件提供报警。
- 温度transmitter can be provided on aftercooler for temperature control by sending a signal to adjust the fan speed of the aircooler.{adinserter 1}
- Emergency Shutdown (ESD) valves can be provided on inlet / outlet lines of the compressors system to isolate whole system in case of a shutdown. The inlet line of the suction KOD corresponds to inlet of the compressor system. Aftercooler discharge and liquid outlet of suction knock out drum correspond to the outlet lines of the compressor system. Shutdown valves can be located on these lines as shown in figure-1.
- 用于在吸入/放电线，压缩机壳体，吸入鼓，空气冷却器机体等中提供的漏洞和通风口。用于完全排水/排气压缩机和相关管道，用于维护。
- 为了吹扫压缩机系统，在抽吸kod入口线上的第一隔离阀之后，可以提供氮连接。
- All the guidelines given here are very general and may be modified as per specific requirements of any particular project.
