Freezing station liquid ammonia automatic control system

Abstract

The invention discloses a freezing station liquid ammonia automatic control system, and relates to the technical field of freezing station liquid ammonia automatic control. The system is provided with a liquid level sensor, an A / D conversion module, a PLC, a D / A conversion module, an electrically operated valve, a displaying and operating device, an upper computer and an alarming device. The liquid level sensor is used for collecting liquid level height of liquid ammonia in a liquid ammonia separator. The A / D conversion module is connected with the liquid level sensor and is used for converting liquid level simulation signals collected by the liquid level sensor into digital signals. The PLC is connected with the A / D conversion module. The D / A conversion module is connected with the PLC. The electrically operated valve is connected with the D / A conversion module. The displaying and operating device is connected with the PLC and is used for displaying liquid level data of the liquid ammonia and carrying out operation. The upper computer is connected with the PLC and is used for remote control. The alarming device is connected with the PLC. A pipeline provided with a valve is in parallel connection with a liquid inlet pipeline of the liquid ammonia separator, the electrically operated valve is arranged on the pipeline, and a manual switch is connected between the liquid level sensor and the A / D conversion module. The freezing station liquid ammonia automatic control system has the advantages that automatic control over the liquid level height of the liquid ammonia in the liquid ammonia separator in a refrigeration station is achieved, and operation is safe and reliable.

Description

technical field [0001] The invention relates to the technical field of automatic control of liquid ammonia in a freezing station, in particular to an automatic control system for liquid ammonia in a freezing station. Background technique [0002] A lot of equipment is invested in the freezing project construction process, and the liquid ammonia separator in the freezing station is one of the important equipment. At present, the liquid ammonia separator has a low degree of automation and cannot accurately measure the parameters of the ammonia liquid level. The remote headquarters cannot keep abreast of the status of the equipment at the construction site of the project department. It is completely adjusted by the technicians based on experience, so it is difficult to ensure that the equipment is in the best state. Operation, not only wasted a lot of electricity but also failed to achieve the best cooling effect, which brought great inconvenience to the management of daily wor...

AI Technical Summary

Problems solved by technology

At present, the liquid ammonia separator has a low degree of automation and cannot accurately measure the parameters of the ammonia liquid level. The remote headquarters cannot keep abreast of the status of the equipment at the construction site of the project department. It is completely adjusted by the technicians based on experience, so it is difficult to ensure that the equipment is in the best state. It wastes a lot of electricity and fails to achieve the best cooling effect, which brings great inconvenience to the management of daily work and maintenance of equipment.

Due to the relatively large manual measurement error and untimely monitoring, the liquid ammonia separator has potential safety hazards as described below

1. If the liquid level of the low-pressure circulation barrel is too high, it is easy to cause the compressor to absorb liquid and damage the compressor.

2. If the liquid level of the low-pressure circulation barrel is too low, it is easy to cause cavitation of the pump, or due to the gasification of the refrigerant, the pump cannot supply liquid and cool normally, and the ammonia pump will be burned

Images