KR102358727B1 - Control device for centrifugal separator, centrifugal separator, marine exhaust gas scrubber system, and marine diesel engine - Google Patents

Abstract

In order to discharge the solid component from the centrifugal separator at an appropriate timing, the control device (controller 151) that controls the discharge of the solid component separated by the centrifugal separator is a solid component in the fluid to be treated flowing into the centrifugal separator. In the centrifugal separator, the cumulative accumulation amount of solid components in the centrifuge obtained according to the separation efficiency of the centrifuge according to the concentration of the centrifugal separator, the flow rate of the fluid to be treated flowing into the centrifugal separator, and the concentration of the solid component, and a discharge timing control unit that determines the discharge timing of the solid component from the centrifugal separator according to the magnitude relation of the allowable amount of the solid component to be deposited.

Description

Control device for centrifugal separator, centrifugal separator, marine exhaust gas scrubber system, and marine diesel engine

The present invention relates to a marine exhaust gas scrubber system in which a scrubber for removing SOx, NOx, and unburned carbon contained in exhaust gas of a marine diesel engine is mounted, a centrifugal separation device for purifying the circulating water of the scrubber system, centrifugal separation It relates to a control device of the device, and to a marine diesel engine.

In marine diesel engines, etc., an exhaust gas scrubber system is used in order to remove particulate matter (solid components), such as unburned carbon, contained in exhaust gas. In this exhaust gas scrubber system, after making a solid component absorb into the scrubber water which is water for vibration removal, it isolate|separates from the scrubber water with a centrifugal separator. In the centrifugal separator, the separated solid component is intermittently discharged at a timing in which a predetermined amount is stored. If the discharge is performed before the solid component is sufficiently stored, the amount of scrubber water discharged together with the solid component increases and the degree of concentration decreases. On the other hand, when a solid component is stored too much, it hardens and discharge|emission becomes difficult.

Therefore, the technique of controlling the discharge timing using the table prepared with the initial turbidity of the scrubber water discharged|emitted from a centrifugal separator, and the change amount corresponding to the said initial stage turbidity is known (for example, refer patent document 1).

Patent Document 1: Japanese Patent Laid-Open No. 2017-029919

However, as described above, when the turbidity is used for control, when the upper limit of the measurement of the turbidity meter is small, it is easy to keep up with the change in the amount of solid component generated according to the engine load change. In addition, since the concentration of the solid component discharged from the centrifuge is controlled by the turbidity, the detection is performed in a state in which the solid component overflows from the separation chamber of the centrifugal separator, so that the detection is indirectly. In such a case, it is not always easy to discharge the solid component from the centrifuge at an appropriate timing.

In view of the above, an object of the present invention is to make it possible to easily discharge a solid component from a centrifuge at an appropriate timing.

In order to achieve the above object, the present invention,

A control device for a centrifugal separator for controlling discharge of solid components separated by the centrifugal separator, comprising:

the concentration of the solid component in the fluid to be treated flowing into the centrifugal separator;

The flow rate of the fluid to be treated flowing into the centrifugal separator, and

Separation efficiency of the centrifuge according to the concentration of the solid component

The accumulated amount of solid components in the centrifugal separator obtained according to the

Allowable amount of solid component deposition in the centrifugal separator

It is characterized in that a discharge timing control unit for determining the discharge timing of the solid component from the centrifugal separator according to the magnitude relation of .

As a result, discharge control is made according to the accumulated amount of solid components in the centrifuge, so that the solid components can be easily discharged at an appropriate timing in consideration of the solid component concentration of the waste liquid including the solid component discharged from the centrifuge with high accuracy. have.

ADVANTAGE OF THE INVENTION According to this invention, a solid component can be easily discharged|emitted from a centrifugal separator at appropriate timing.

BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing which shows the schematic structure of an exhaust gas scrubber system.
It is a schematic diagram which shows the structure of the principal part of a centrifugal separator.
3 is a graph showing an example of the relationship between separation efficiency, inflow concentration, and flow rate of a centrifugal separator.
4 is a graph showing an example of the relationship between the allowable amount correction value P of the centrifugal separator and the inflow flow rate.

EMBODIMENT OF THE INVENTION Hereinafter, as embodiment of this invention, the example of the exhaust gas scrubber system which dusts the exhaust gas of a diesel engine is demonstrated in detail based on drawing.

(Schematic configuration of exhaust gas scrubber system)

As shown in FIG. 1, an exhaust gas scrubber system is the scrubber apparatus 110 which capture|acquires particulate matter (solid component), such as unburned carbon, contained in the exhaust gas of the diesel engine 101, and the said scrubber apparatus 110. A centrifugal separation device 120 for removing solid components trapped in the scrubber water W (fluid to be treated) in the interior is provided.

The scrubber apparatus 110 has the scrubber 111 more specifically, The scrubber number (W) in the scrubber 111 for the solid component in the exhaust gas sent from the diesel engine 101 via the engine exhaust pipe 102. The dust is removed by absorbing the dust, and the exhaust gas after the vibration is discharged from the external exhaust pipe (103). A part of the exhaust gas purified in the scrubber 111 can return to the diesel engine 101 via the exhaust gas return pipe 104 in order to reduce nitrogen oxides as needed. The scrubber water W stored in the scrubber 111 is circulated by a pump (not shown) through the circulation pipe 112, and a part of it is sent to the centrifugal separator 131 so that it may mention later, and it is purified. Another part of the circulated scrubber water W is sprayed into the scrubber 111 through the spray nozzle 113 together with the cleaned scrubber water W, so that the increase in the concentration of the solid component of the scrubber water W is prevented. has been

A part of the scrubber water W circulated through the circulation pipe 112 is a centrifugal separator 131 through a branch pipe 121 or a densitometer 122 , a flow meter 123 , and a flow control valve 124 . ), and after the solid component is removed by the centrifugal separator 131 , it is returned to the circulation pipe 112 . The said density meter 122 measures the density|concentration (solid component density|concentration, SS density|concentration) of the solid component in the scrubber water W. In addition, the flow meter 123 measures the flow rate of the scrubber water W flowing into the centrifugal separator 131, and controls the flow control valve 124 so that the flow rate becomes a predetermined amount. The measured values of the densitometer 122 and the flow meter 123 are continuously sent to a controller 151 (control device of a centrifugal separation device) described later.

(Schematic configuration of the centrifuge 131)

As the centrifugal separator 131 is shown in FIG. 2, the inflow pipe 132 into which the scrubber water W flows in from the scrubber apparatus 110, and the scrubber water W after a process flow out, and the scrubber apparatus 110 An outlet pipe 133 returning to the The partition plate 135 arranged with a gap to the 136), a separation chamber 137 formed between the main valve 136 and the partition plate 135; A guide tube 139 for guiding the scrubber water W introduced from the inlet pipe 132 into the separation chamber 137 is provided. The centrifugal separator 131 further includes a chamber 141 formed at the upper end of the partition plate 135 and in which the scrubber water W after overflow from the separation chamber 137 is stored, and in the chamber 141 . A centripetal pump 140 for discharging the stored scrubber water W to the outside through the outlet pipe 133 is provided. The centrifugal separator 131 further includes a solid component discharge pipe 142 for discharging the centrifuged solid component S from the scrubber water W, and a valve opening/closing mechanism 143 for controlling discharge of the solid component. be prepared Here, in FIG. 2, the number of scrubbers W after a process is drawn with the light halftone dot, and the solid component S is drawn with the dark halftone dot.

The valve opening/closing mechanism 143 receives the valve opening signal from the controller 151, opens a predetermined valve (not shown), supplies the opening valve operating water, moves the main valve 136 downward, and separates The discharge port of the chamber 137 is opened to discharge the solid component accumulated in the separation chamber 137 toward the solid component discharge pipe 142 . Further, after that, the valve is closed to stop the open valve operating water, and then, based on the valve closing signal, a valve (not shown) operates to supply the closing valve operating water to close the main valve 136, thereby operating the closing valve The number is to be stopped.

(Solid component deposition, and discharge action)

The solid component having a larger specific gravity than the scrubber water W introduced into the centrifugal separator 131 is centrifuged by the separation plate 138 when centrifugal force is applied in the separation chamber 137 , and the maximum It is deposited in a recess including an outlet (not shown) formed in the neck. As the deposition proceeds with the lapse of time, the interface I between the solid component and the scrubber water W moves toward the center of the separation chamber 137 . Some solid components in the vicinity of the interface I move along the flow of the scrubber water W, and are discharged from the outlet pipe 133 to the outside.

The solid component deposited in the centrifugal separator 131 as described above is the number of scrubbers in the separation chamber 137 by opening the discharge port formed on the side of the rotary cavity by discharge control by the valve opening/closing mechanism 143 as described below. It is discharged from the solid component discharge pipe 142 together with a part of (W) and becomes waste.

(Configuration of controller 151, and control of discharge of solid components)

The controller 151 is a centrifugal separator measured by the concentration (inflow concentration) of the solid component in the scrubber water W flowing into the centrifugal separator 131 measured by the densitometer 122 and the flowmeter 123 . Based on, for example, the flow rate per unit time (inflow flow rate) of the scrubber water W flowing into the 131 and the allowable amount of solid components to be accumulated in the centrifugal separator 131 (β), the valve opening/closing mechanism 143 control to discharge the solid component deposited in the centrifugal separator 131 at a predetermined timing.

More specifically, the controller 151 includes a separation efficiency calculator for calculating the separation efficiency η of the solid component based on the inflow concentration of the solid component, and the inflow concentration, separation efficiency η, and the inflow flow rate. A cumulative deposition amount calculating section that calculates the cumulative deposition amount S of the solid component into the centrifugal separator 131 based on the scrubber when the predetermined allowable amount of solid component deposition in the centrifugal separator 131 and the discharge timing are determined A deposition allowance calculating unit for calculating the allowable amount of solid components β according to the flow rate of water W, the accumulated deposition amount S calculated by the cumulative deposition amount calculating unit, and the allowable deposition calculation unit and a discharge timing control unit for controlling the valve opening/closing mechanism 143 based on the calculated allowable deposition amount β.

The cumulative deposition amount S is more specifically calculated, for example, as follows.

The integral or cumulative value of the accumulated accumulation amount (S) = (influent concentration Х influent flow rate Х separation efficiency (η))

Here, the separation efficiency (η) is, when the concentration of the solid component in the scrubber water (W) flowing out from the centrifugal separator 131 is the outflow concentration,

Separation efficiency (η) = (inlet concentration - outlet concentration) / inlet concentration

is defined as In practice, this separation efficiency may fluctuate depending on the inflow concentration and flow rate, for example, as shown in FIG. 3 . That is, for example, the higher the inlet concentration, the higher the separation efficiency (η). In addition, the smaller the inflow flow rate, the longer the residence time in the centrifugal separator 131, the higher the separation efficiency (η). Therefore, the separation efficiency calculation unit of the controller 151, based on experiments on various concentrations or flow rates using actual devices such as the centrifugal separation device 120, the exhaust gas scrubber system, the diesel engine 101, etc., in advance a table or function set, and using this, the separation efficiency (η) can be obtained. In addition, the separation efficiency η may further take into account, for example, fluctuations depending on the amount of solid components deposited in the centrifugal separator 131, but when the required control accuracy is obtained, the amount of deposition is zero. It may be calculated|required based on an actual value, or you may do it.

In addition, the allowable deposition amount β is more specifically calculated, for example, as follows.

Sedimentation allowance (β) = preset allowance for sedimentation Х allowance correction value (P)

The allowable amount correction value P corrects, for example, variations in the allowable amount of solid components to be deposited into the centrifugal separator 131 according to the inflow flow rate, as shown in FIG. 4 . That is, when the inflow flow rate is small, since the centrifugal force component acting on the solid component becomes relatively large, the effect of pressing the solid component in the centrifugal direction (consolidation effect) increases, and the allowable amount that can actually be deposited in the centrifugal separator 131 increases. It seems that there is an easy case. On the other hand, when the inflow flow rate is large, the effect of the diffusion effect (diffusion effect) of the solid component increases because the turbulence factor in the flow of the scrubber water W becomes large, and the allowable amount that can actually be deposited in the centrifugal separator 131 is small. It seems that there are cases where it is easy to lose. Therefore, similarly to the separation efficiency (η), the allowable amount correction value (P) can be obtained by using a table or a function preset by an experiment based on an actual device. More specifically, for example, when the maximum water flow rate of the centrifugal separator 131 is 3000 l/H, and when the water flow rate is 1500 l/H or less (50% or less), a value in the range of 1≤P≤3 is set, and when it is 1500 l/H or more (50% or more), a value in the range of 0.1≤P<1 is set. The setting of these values is more specifically, for example, by appropriately discharging the solid components deposited in the centrifugal separator 131, measuring the concentration of the solid components, and reaching a predetermined concentration (eg, 7% by weight). What is necessary is just to calculate|require the allowable amount correction value P so that the accumulated deposition amount S at the time may become the deposition allowable amount beta corresponding to the flow volume of the scrubber water W at that time.

When the cumulative deposition amount S and the allowable deposition amount β of the solid component are obtained as described above, the controller 151 compares these values so that the cumulative deposition amount S is equal to or greater than the allowable deposition amount β. When done, the valve opening/closing mechanism 143 is controlled to discharge the solid component accumulated in the centrifugal separator 131 .

By the control as described above, the cumulative deposition amount (S) and the allowable amount (β) of solid components in the centrifugal separator 131 are directly integrated, etc., so compared to the conventional method using turbidity, and discharge is controlled, so that the solid component can be easily discharged at an appropriate timing. In particular, it is possible to easily increase the accuracy of the discharge timing even when the concentration of the solid component tends to fluctuate depending on the operating state of the engine, such as in a marine diesel engine. Therefore, while maintaining a high degree of concentration, it is possible to easily prevent the solid component from being excessively stored and hardened or clogged, making it difficult to discharge, or from generating vibration or damage.

(Other matters)

In addition, the characteristics shown in FIGS. 3 and 4 are examples for explanation, and are not limited to the slope of the curve shown or the rate of change of the slope, and the separation efficiency (η) or allowable amount correction value (P) according to the actual device, etc. It should be set to be saved.

In addition, in the above example, the separation efficiency η and the allowable amount correction value P are obtained based on the actually measured flow rate of the scrubber water W measured by the flow meter 123, but the flow control valve 124 ), the separation efficiency η and/or the allowable amount correction value P may be obtained when the flow rate is kept constant within a predetermined accuracy or the like.

In addition, although the above calculation example has been described as an example for easily showing a mechanism capable of increasing the accuracy of the discharge timing, the present invention is not limited thereto, and the control may be performed at a substantially equivalent timing, and the parameter acquisition method or unit of value etc. may be applied in various ways. Further, for example, it is not limited to obtaining the allowable deposition amount β by multiplying the preset allowable amount of solid components by the allowable amount correction value P, but the relationship between the flow rate of the scrubber water W and the allowable amount of deposition β may be maintained so that the allowable deposition amount β can be obtained immediately from the flow rate of the scrubber water W. In addition, you may use various methods, such as a function calculation including an approximate expression, and a value table reference, also for the calculation method of various values.

101 diesel engine
102: engine exhaust pipe
103: external exhaust pipe
104: exhaust gas return pipe
110: scrubber device
111: scrubber
112: circulation pipe
113: spray nozzle
120: centrifugation device
121: branch pipe
122: densitometer
123: flow meter
124 flow control valve
131 centrifuge
132: inlet pipe
133: outflow pipe
134: rotating body cover
135: partition plate
136: main valve
137: separation room
138: separator
139: guide box
140: centripetal pump
141: chamber
142: solid component discharge pipe
143: valve opening and closing mechanism
151 : controller

Claims (9)

A control device for a centrifugal separator for controlling discharge of solid components separated by the centrifugal separator, comprising:
the concentration of the solid component in the fluid to be treated flowing into the centrifugal separator;
the flow rate of the fluid to be treated flowing into the centrifugal separator, and
Separation efficiency of the centrifuge according to the concentration of the solid component
The accumulated amount of solid components in the centrifugal separator obtained according to the
Allowable amount of solid component deposition in the centrifugal separator
A control device for a centrifugal separator, comprising: a discharge timing control unit that determines the discharge timing of the solid component from the centrifuge according to the magnitude relationship of the centrifugal separator. The method of claim 1,
Separation efficiency of the centrifugal separator is a control device for a centrifugal separator, characterized in that the value is further determined according to the flow rate of the fluid to be treated flowing into the centrifugal separator. 3. The method of any one of claims 1 or 2,
The centrifugal separator control device, characterized in that the allowable amount of solid component deposition in the centrifugal separator is a value determined according to the flow rate of the fluid to be treated when the discharge timing is determined. 4. The method of claim 3,
A control device for a centrifugal separator, wherein the allowable amount of solid components in the centrifugal separator is a value determined according to a preset allowable amount in the centrifugal separator and a flow rate of the fluid to be treated when the discharge timing is determined. . 4. The method of claim 3,
The discharge timing control unit includes an accumulation accumulation amount calculation unit configured to calculate the accumulated accumulation amount by accumulating a product of the concentration, the flow rate, and the separation efficiency. 5. The method of claim 4,
The discharge timing control unit multiplies the allowable amount preset in the centrifugal separator by the allowable amount correction value according to the flow rate of the fluid to be treated when the discharge timing is determined, to obtain the allowable amount of solid component deposition in the centrifugal separator A control device for a centrifugal separator comprising a sedimentation allowance calculation unit. A control device for the centrifugal separator according to claim 1;
the centrifuge
A centrifugal separation device comprising a. The centrifugal separation device according to claim 7;
A scrubber that absorbs the solid components discharged from the engine into the scrubber water.
to provide
The centrifugal separation device is an exhaust gas scrubber system for ships, characterized in that it is configured to remove the solid component contained in the scrubber water. The marine diesel engine provided with the marine exhaust gas scrubber system of Claim 8 characterized by the above-mentioned.

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