Heat Pump Control System

Control system introduction

Control mode 1

The system can use Deutsch blown steam (steam is passed into the dryer, part of it is condensed, and part of it is not condensed, this uncondensed steam is called blown steam.) This control is different from the general differential pressure control, which is obtained by blowing steam through both sides of the orifice plate to maintain a fixed pressure drop. The blow through steam control system can operate at very high or very low pressures without generating excessive blow through steam, providing rapid feedback to load changes and maintaining optimal dryer drainage. When the paper is broken, the blow through steam control automatically adjusts the blow through steam to be equivalent to the blow through steam (ratio) during normal operation, thus avoiding a large amount of steam loss. A standard heat pump group control system in this system includes two control loops, one is a blowthrough control loop and the other is a pressure control loop. The inlet and outlet pressure difference of the dryer group is only used for measurement and indication, and is not adjusted for observing the operation of the system.

Control system introduction

Control mode 1

The system can use Deutsch blown steam (steam is passed into the dryer, part of it is condensed, and part of it is not condensed, this uncondensed steam is called blown steam.) This control is different from the general differential pressure control, which is obtained by blowing steam through both sides of the orifice plate to maintain a fixed pressure drop. The blow through steam control system can operate at very high or very low pressures without generating excessive blow through steam, providing rapid feedback to load changes and maintaining optimal dryer drainage. When the paper is broken, the blow through steam control automatically adjusts the blow through steam to be equivalent to the blow through steam (ratio) during normal operation, thus avoiding a large amount of steam loss. A standard heat pump group control system in this system includes two control loops, one is a blowthrough control loop and the other is a pressure control loop. The inlet and outlet pressure difference of the dryer group is only used for measurement and indication, and is not adjusted for observing the operation of the system.

Control mode 2

The system can directly control the heat pump steam intake through pressure regulation to meet the requirements of drying cylinder steam. The pressure difference at both ends of the drying cylinder can be adjusted by the automatic valve on the pipeline to automatically form a reasonable pressure difference setting value, generate the maximum drainage differential pressure, provide as large as possible flash capacity, realize the normal production of the paper machine, energy saving and consumption reduction.

The above two control modes can be switched on the software.

Heat pump

The characteristic of the heat pump is that the heat pump itself is equipped with a regulating mechanism and a regulating valve core of the heat pump nozzle section, and there is no need to set a regulating valve on the working steam pipeline of the heat pump inlet. By adjusting and changing the effective section area of the nozzle through the steam, the working state of the heat pump is adjusted to meet the requirements of steam. During the adjustment process, the steam pressure in front of the nozzle is kept unchanged, but the steam flow through the nozzle is changed, that is, the work capacity of working steam per unit flow is unchanged. Therefore, the adjustable jet heat pump has good adjustment performance and high efficiency, and overcomes the lack of work capacity of working steam caused by changes in working conditions of the non-adjustable heat pump. The disadvantages of the non-adjustable heat pump injection coefficient are reduced to improve the speed of the paper machine, increase the output, reduce the energy consumption and optimize the operation of the paper machine.

Flash tanks are equipped with liquid level automatic control devices

The purpose is to ensure that the liquid level in the tank is stable, to ensure that there is enough condensed water to continuously flash out secondary steam, and to have enough space for secondary flash use.

The condensate tank is equipped with level control

Its purpose has two: first, to prevent the condensate pump to evacuate and shorten the service life of the pump; The second is to play the role of water seal, so that the condensing water tank to maintain a certain vacuum, real-time discharge of non-condensing gas in the system, help the low-temperature section drainage, while keeping the condensate water can flow back to the condensing water tank.