阅读说明：本技术 空气压缩系统 (Air compression system ) 是由 刘雅萍 小泉稔 于 2019-01-16 设计创作，主要内容包括：本发明提供一种空气压缩系统,对于多个终端,能够配合压缩空气的实际使用状态实时地控制空气压缩机。并且,能够基于评价体积响应的时间延迟的预测模型,在压力损失急剧变化的情况下,以没有响应延迟的稳定的动作防止不必要的电力消耗。该空气压缩系统将从空气压缩机排出的压缩空气经由空气罐和配管系统供给至要消耗压缩空气的多个终端,包括：测量空气压缩机的排出压力的压缩机压力传感器；各自测量对多个终端的供给压力的多个终端压力传感器；基于空气罐的容量、配管系统的信息以及排出压力和供给压力来计算偏差量信息的流量差运算装置；和基于偏差量信息控制空气压缩机的动作的控制装置。(The invention provides an air compression system, which can control an air compressor in real time according to the actual using state of compressed air for a plurality of terminals. Further, it is possible to prevent unnecessary power consumption by a stable operation without a response delay when the pressure loss rapidly changes based on a prediction model for evaluating a time delay of the volume response. The air compression system supplies compressed air discharged from an air compressor to a plurality of terminals that are to consume the compressed air via an air tank and a piping system, includes: a compressor pressure sensor that measures a discharge pressure of the air compressor; a plurality of terminal pressure sensors each measuring supply pressure to the plurality of terminals; a flow rate difference calculation device for calculating deviation amount information based on the capacity of the air tank, the information of the piping system, and the discharge pressure and the supply pressure; and a control device for controlling the operation of the air compressor based on the deviation amount information.)

1. An air compression system that supplies compressed air discharged from an air compressor to a plurality of terminals that are to consume the compressed air via an air tank and a piping system, characterized by comprising:

a compressor pressure sensor that measures a discharge pressure of the air compressor;

a plurality of terminal pressure sensors each measuring a supply pressure to the plurality of terminals;

a flow rate difference calculation device that calculates deviation amount information based on the capacity of the air tank, information of the piping system, and the discharge pressure and the supply pressure; and

and a control device for controlling the operation of the air compressor based on the deviation amount information.

2. The air compression system of claim 1, wherein:

the flow rate difference calculating means may calculate the flow rate difference,

calculating the used air amounts of the plurality of terminals and the discharge flow rate of the air compressor based on the capacity of the air tank, the information on the piping system, and the discharge pressure and the supply pressure,

calculating the deviation amount information based on the used air amount and the discharge flow rate.

3. The air compression system as recited in claim 2, wherein:

having an air tank pressure sensor for detecting the air tank pressure,

the flow rate difference calculation device uses the measurement value of the air tank pressure sensor as a correction sensor measurement value,

the used air amount and the discharge flow rate are corrected based on the correction sensor measurement value.

4. The air compression system as recited in claim 2, wherein:

having a current sensor for detecting a current supplied to a motor driving the air compressor,

the flow rate difference operation means calculates the discharge flow rate based on a current measurement value of the current sensor.

5. The air compression system as recited in claim 4, wherein:

the flow rate difference calculation device corrects the used air amount and the discharge flow rate based on a correction sensor measurement value, using the discharge flow rate of the air compressor as the correction sensor measurement value.

6. An air compression system as claimed in claim 3 or 5, wherein:

the flow rate difference calculation means calculates the used air amount and the discharge flow rate based on the measured value of the terminal pressure sensor having no abnormality and the corrected sensor measured value, when it is determined that there is an abnormality in the terminal pressure sensor.

7. The air compression system as claimed in any one of claims 1 to 6, wherein:

the control device increases the amount of compressed air discharged from the air compressor when the deviation amount information indicates a situation in which the amount of compressed air supplied by the air compressor is lower than the amount of compressed air used at the plurality of terminals.

8. An air compression system as claimed in any one of claims 1 to 7, wherein:

the control device increases the amount of compressed air discharged from the air compressor when the deviation amount information indicates a situation in which the amount of compressed air supplied by the air compressor is lower than the amount of compressed air used at the plurality of terminals.

Technical Field

The present invention relates to air compression systems.

Background

An air compression system that supplies compressed air to various locations in a plant is a piping device that temporarily stores compressed air compressed by an air compressor in an air tank, and supplies the compressed air from the air tank to devices (terminals) that consume the compressed air in a production process of the plant, such as cylinders and blowers, in the plant via a piping system and air compression devices (filters, air ducts, control valves, and the like). In an air piping system from a discharge port of an air compressor to a terminal, the pressure loss becomes larger as the pressure loss becomes closer to the terminal, and the pressure loss also changes due to changes in the amount of air discharged from the air compressor and the amount of air used at the terminal. The terminal is not limited to 1 part, and the pressure loss varies greatly due to the fluctuation in the use of the exhaust air.

Therefore, in order to keep the pressure of the compressed air supplied to the terminal at a predetermined pressure or higher, the set value of the discharge pressure of the air compressor is usually set high, including the maximum pressure loss. However, the amount of air used at the end often varies depending on the manufacturing process, and the amount of discharged air and the pressure used per day often differ. When the amount of air used is small, the pressure loss becomes small, and the operation is performed at a high pressure which is useless for the terminal. Meanwhile, when the set value of the discharge pressure of the air compressor is fixed, the discharge pressure is increased more than necessary, which causes a problem of consuming extra electric power.

In order to achieve energy saving and to stabilize the supply pressure, conventionally, constant terminal pressure control is performed in accordance with fluctuations in the amount of air used at the terminal. That is, the discharge pressure of the air compressor is changed so that the supply pressure to the terminal becomes constant. The terminal pressure control method includes two methods of estimated terminal pressure control and measured terminal pressure control. The estimated terminal pressure control is control based on the estimated pressure loss. The estimated value of the pressure loss is controlled by using a piping system model in a steady state and by taking the maximum pressure loss into account.

In the estimated terminal pressure control, when the relationship between the used air amount and the pressure loss of the piping system is not clear, as described in patent document 1, there has been proposed an operation control method in which the pressure loss of the piping system for an arbitrary used air amount is examined in advance and the upper limit and the lower limit set values of the discharge pressure of the screw air compressor at a constant rotation speed are changed.

The measured terminal pressure control is control based on the measured value of the terminal pressure. For example, as described in patent document 2, there is proposed a method in which a pressure detection device is provided in a head (head), a pressure signal is transmitted to a control device of the air compressor, a new set value of the discharge pressure is calculated from a deviation amount between the set pressure and an actually measured terminal pressure, and the rotation speed of a motor of the rotation speed controlled air compressor is changed by an inverter to perform control.

On the other hand, as described in patent document 3, a method is known in which a pressure detection device is provided near each terminal, a new set value of discharge pressure is calculated from a variation amount of a pressure difference from an outlet of the air compressor to each terminal, and the air compressor is controlled.

Disclosure of Invention

Technical problem to be solved by the invention

In the conventional air compression system, since the flow rate detection device is expensive, it is difficult to directly obtain the amount of air to be used, and in the above-described conventional technique, the terminal pressure is measured or predicted, and the discharge pressure of the air compressor is changed so as to reduce the excess supply pressure as much as possible by pressure monitoring.

However, since the piping and the like have different structures for each of the plurality of terminals, a pressure loss occurs from the air compressor to each terminal. Further, since the change in the discharge pressure of the air compressor due to the compression and expansion of the air between the terminals causes a difference in the time delay (for example, several 10 seconds to several minutes) until the change in the terminal pressure, the relationship between the supply pressure to each terminal and the discharge pressure of the air compressor is not clear, and therefore, it is difficult to control the pressure.

A method of preliminarily examining and storing the pressure loss of a piping system using a relatively arbitrary amount of air has been proposed. However, since the pressure loss of the piping system using the air amount is nonlinear and when each condition changes, it is difficult to calculate the pressure loss particularly in a complicated piping system, and thus such preliminary investigation has a problem of generating a large error. In addition, data collection is also time consuming.

Further, there has been proposed a method of controlling an air compressor by providing a pressure detection device at a head, transmitting a pressure signal to a control device of the air compressor, and calculating a new set value of a discharge pressure based on a deviation amount between the set pressure and an actually measured terminal pressure. However, since the pressure loss becomes larger as the distance from the terminal increases, there is a problem that the pressure of the head portion is not equal to the supply pressure to the terminal in general, and if this pressure deviation amount is used as the correction pressure without changing, the control of the air compression system becomes unstable.

Further, a method has been proposed in which a pressure detection device is provided near each terminal, and a new set value of the discharge pressure is calculated from a variation amount of the pressure difference from the outlet of the air compressor to each terminal, thereby controlling the air compressor. However, when the pressure loss changes rapidly, there is a problem that a response is delayed due to the volume of the piping system. Further, the case where the pressure sensor is not provided and the case where the pressure sensor is out of order cannot be dealt with.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an apparatus for controlling an air compressor in real time so as to discharge only a required amount of air in accordance with a used air amount to a plurality of terminals in view of a volume of a piping system and a capacity of an air tank, which are factors of response delay, from the viewpoint of flow control.

Means for solving the problems

In order to achieve the above object, the present invention provides, for example, an air compression system for supplying compressed air discharged from an air compressor to a plurality of terminals that consume the compressed air via an air tank and a piping system, comprising: a compressor pressure sensor that measures a discharge pressure of the air compressor; a plurality of terminal pressure sensors each measuring supply pressure to the plurality of terminals; a flow rate difference calculation device for calculating deviation amount information based on the capacity of the air tank, the information of the piping system, and the discharge pressure and the supply pressure; and a control device for controlling the operation of the air compressor based on the deviation amount information.

Effects of the invention

According to the present invention, it is possible to control the air compressor in real time in a supply method without waste in accordance with the actual usage state of compressed air for a plurality of terminals. Further, it is possible to prevent unnecessary power consumption by a stable operation without a response delay when the pressure loss rapidly changes based on a prediction model for evaluating a time delay of the volume response.

Drawings

Fig. 1 is a schematic configuration diagram of an air compression system according to embodiment 1 of the present invention.

Fig. 2 is a schematic configuration diagram of a flow rate difference calculation device of an air compression system according to embodiment 1 of the present invention.

Fig. 3 is an explanatory diagram showing a processing flow of the flow rate difference calculation device in the air compression system according to embodiment 1 of the present invention.

Fig. 4 is an explanatory diagram showing a specific example of the time-series measurement values acquired from the sensors in embodiment 1 of the present invention.

Fig. 5 shows time-series calculated values of the used air amounts at the terminals 9 to 11 and calculated values of the used air amounts at all the terminals according to embodiment 1 of the present invention.

Fig. 6 is a calculated discharge flow rate of the air compressor according to embodiment 1 of the present invention.

Fig. 7 is a calculated value of deviation amounts of the used air amounts of all terminals and the discharge flow rates of the air compressor according to embodiment 1 of the present invention.

Fig. 8 is a schematic configuration diagram of an air compression system according to embodiment 2 of the present invention.

Fig. 9 is a schematic configuration diagram of a flow rate difference calculation device of an air compression system according to embodiment 2 of the present invention.

Fig. 10 is a diagram showing a process flow of a flow rate difference calculation device of an air compression system according to embodiment 2 of the present invention.

Fig. 11 is a schematic configuration diagram of an air compression system according to embodiment 3 of the present invention.

Fig. 12 is a schematic configuration diagram of a flow rate difference calculation device of an air compression system according to embodiment 3 of the present invention.

Fig. 13 is a diagram showing a process flow of the flow rate difference calculation device of the air compression system according to embodiment 3 of the present invention.

Fig. 14 is a diagram showing a process flow of the flow rate difference calculation device of the air compression system according to embodiment 4 of the present invention.

Detailed Description

An air compression system according to an embodiment (hereinafter, referred to as an embodiment) of the present invention will be described below with reference to the drawings.