WO2019058829A1

WO2019058829A1 - Control device for centrifuge, centrifuge, maritime exhaust gas scrubber system, and maritime diesel engine

Info

Publication number: WO2019058829A1
Application number: PCT/JP2018/030616
Authority: WO
Inventors: 裕二佐野; 勇治今井; 尚史桶谷
Original assignee: 株式会社ジャパンエンジンコーポレーション
Priority date: 2017-09-20
Filing date: 2018-08-20
Publication date: 2019-03-28
Also published as: KR102358727B1; JP2019055357A; CN111050919B; JP6941519B2; CN111050919A; KR20200014820A

Abstract

This control device (controller 151), which controls the discharge of solid components separated by a centrifuge in order to discharge the solid components from the centrifuge at an appropriate timing, is provided with an exhaust timing control unit that determines the timing to discharge solid components from the centrifuge according to the size relationship between: an allowable accumulation amount for solid components in the centrifuge; and a total accumulation amount of solid components in the centrifuge, which is determined according to the concentration of solid components in a to-be-processed fluid entering the centrifuge, the flow rate of the to-be-processed fluid entering the centrifuge, and the separation efficiency of the centrifuge based on the concentration of the solid components.

Description

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

The present invention is a marine exhaust gas scrubber system equipped with a scrubber for removing SOx, NOx and unburned carbon contained in exhaust gas of a marine diesel engine, and cleaning the circulating water of the scrubber system. The present invention relates to a centrifugal separator, a controller of the centrifugal separator, and a marine diesel engine.

In marine diesel engines and the like, an exhaust gas scrubber system is used to remove particulate matter (solid components) such as unburned carbon contained in exhaust gas. In this exhaust gas scrubber system, solid components are absorbed by scrubber water which is water for dust removal, and then separated from the scrubber water by a centrifugal separator. In the centrifuge, the separated solid components are intermittently discharged at a timing when a predetermined amount is accumulated. If the above-mentioned discharge is carried out before the solid components are sufficiently accumulated, the amount of scrubber water discharged together with the solid components increases, and the degree of concentration decreases. On the other hand, if the solid component is accumulated too much, it solidifies and discharge becomes difficult.

Then, the technique which controls discharge timing using the table created from the initial turbidity of scrubber water discharged from a centrifuge, and the change amount corresponding to the above-mentioned initial turbidity is known (for example, patent) Reference 1.).

JP, 2017-029919, A

However, as described above, when the above-mentioned turbidity is used for control, when the measurement upper limit value of the turbidity measuring instrument is small, etc., it can not follow the change in the amount of generation of solid components accompanying the change in engine load. I tend to be. Moreover, in order to control the solid component density | concentration discharged | emitted from a centrifuge by turbidity, it will detect in the state which the solid component overflowed from the separation chamber of a centrifuge, and will detect indirectly. In such a case, it is not always easy to discharge the solid component from the centrifuge at an appropriate timing.

An object of the present invention is, in view of the above-mentioned point, to make it easy to discharge a solid ingredient from a centrifuge at appropriate timing.

In order to achieve the above objective, the present invention is
A control device for a centrifugal separator that controls the discharge of solid components separated by the centrifugal separator,
Concentration of solid components in the fluid to be treated which flows into the centrifugal separator,
Cumulative deposition amount of solid components on the centrifugal separator obtained according to the flow rate of the fluid to be treated flowing into the centrifugal separator, and the separation efficiency of the centrifugal separator according to the concentration of the solid component;
Deposition capacity of solid components in the above centrifuge,
And a discharge timing control unit configured to determine the discharge timing of the solid component from the centrifugal separator according to the magnitude relationship of the above.

As a result, discharge control is performed according to the accumulated accumulation amount of solid components in the centrifuge, so it is considered with high accuracy about the solid component concentration of the waste liquid containing the solid components discharged from the centrifuge. The solid component can be easily discharged at an appropriate timing.

According to the present invention, solid components can be easily discharged from the centrifuge at appropriate timing.

It is an explanatory view showing a schematic structure of an exhaust gas scrubber system. It is a schematic diagram which shows the structure of the principal part of a centrifuge. It is a graph which shows the example of the separation efficiency of a centrifuge, inflow concentration, and the relationship of the flow volume. It is a graph which shows the example of the relationship between the allowable amount correction value P of a centrifuge, and an inflow rate.

Hereinafter, as an embodiment of the present invention, an example of an exhaust gas scrubber system for removing dust from a diesel engine exhaust gas will be described in detail based on the drawings.

(Schematic configuration of exhaust gas scrubber system)
The exhaust gas scrubber system, as shown in FIG. 1, includes a scrubber device 110 for capturing particulate matter (solid component) such as unburned carbon contained in exhaust gas of the diesel engine 101, and scrubber water in the scrubber device 110. And a centrifugal separator 120 for removing solid components trapped in W (fluid to be treated).

More specifically, the scrubber device 110 has a scrubber 111 and absorbs the solid components in the exhaust gas sent from the diesel engine 101 via the engine exhaust pipe 102 into the scrubber water W in the scrubber 111 to remove dust, Exhaust gas from the external exhaust pipe 103. A portion of the cleaned exhaust gas in the scrubber 111 can be returned to the diesel engine 101 via an exhaust gas return pipe 104 to reduce nitrogen oxides if necessary. The scrubber water W stored in the scrubber 111 is circulated by a pump (not shown) via a circulation pipe 112, and a portion thereof is sent to the centrifuge 131 to be cleaned as described later. The other 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 concentration of the solid component of the scrubber water W is prevented from rising. It is supposed to be.

A part of the scrubber water W circulated through the circulation pipe 112 is sent to the centrifuge 131 through the branch pipe 121 or the concentration meter 122, the flow meter 123, and the flow control valve 124, and solid components are centrifuged. After being removed by the separator 131, it is returned to the circulation pipe 112. The densitometer 122 is adapted to measure the concentration (solid component concentration, SS concentration) of solid components in the scrubber water W. Further, the flow meter 123 measures the flow rate of the scrubber water W flowing into the centrifuge 131, and controls the flow control valve 124 so that the flow rate becomes a predetermined amount. The measurement values of the densitometer 122 and the flow meter 123 are continuously sent to a controller 151 (control device of the centrifugal separator) described later.

(Schematic Configuration of Centrifuge 131)
As shown in FIG. 2, the centrifuge 131 has an inflow pipe 132 into which the scrubber water W flows in from the scrubber device 110, an outflow pipe 133 in which the treated scrubber water W flows out and is returned to the scrubber device 110, and an upper end A rotating body (not shown) having an opening, a rotating body lid 134 fitted to the upper end opening of the rotating body to form a rotating body, and a partition arranged with a gap from the inner surface of the rotating body lid 134 A plate 135, and a main valve 136 which moves up and down as shown by the arrow A in the figure in a state of being inserted into the rotary cylinder to open and close an outlet (not shown) formed on the side of the rotary cylinder. , A separation chamber 137 formed between the main valve 136 and the partition plate 135, a plurality of separation plates 138 stacked and arranged at predetermined intervals in the separation chamber 137 at upper and lower sides, and inflow from the inflow pipe 132 The scrubber water W into the separation chamber 137 And a Ku guide tube 139. The centrifuge 131 also has a chamber 141 formed at the upper end of the partition plate 135, in which the scrubber water W after processing overflowed from the separation chamber 137 is collected, and the scrubber water W accumulated in the chamber 141 is discharged from the discharge pipe 133. And a centrifuging pump 140 for discharging to the outside through the The centrifuge 131 further includes a solid component discharge pipe 142 that discharges the solid component S centrifugally separated from the scrubber water W, and a valve opening / closing mechanism 143 that controls the discharge of the solid component. Here, in FIG. 2, the scrubber water W after the treatment is drawn to be lightly shaded and the solid component S is drawn to be thickly shaded.

The valve opening / closing mechanism 143 receives a valve opening signal from the controller 151, opens a predetermined valve (not shown), supplies opening operation water, moves the main valve 136 downward, and discharges the separation chamber 137. The outlet is opened to discharge the solid component deposited in the separation chamber 137 toward the solid component discharge pipe 142. After that, the valve is closed to stop the valve opening operation water, and then the valve (not shown) is operated based on the valve closing signal to supply the valve opening operation water to close the main valve 136 to close the valve. It is designed to stop working water.

(Solid matter deposition and discharge operation)
The solid component having a specific gravity larger than that of the scrubber water W which has flowed into the centrifuge 131 is centrifugally separated by the separation plate 138 when a centrifugal force is applied in the separation chamber 137 and formed in the largest diameter portion of the separation chamber 137 Deposit in the recess including the outlet (not shown). As deposition progresses with 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 near the interface I move along the flow of the scrubber water W and are discharged from the outflow pipe 133 to the outside.

The solid components deposited in the centrifugal separator 131 as described above are separated by the discharge control formed by the valve opening / closing mechanism 143 as described below, by opening the discharge port formed on the side of the rotary cylinder. The waste water is discharged from the solid component discharge pipe 142 together with a part of the scrubber water W in the above to be waste.

(Configuration of controller 151 and discharge control of solid components)
The controller 151 measures the concentration (inflow concentration) of solid components in the scrubber water W flowing into the centrifuge 131 measured by the densitometer 122 and the scrubber flowing into the centrifuge 131 measured by the flow meter 123. The valve opening / closing mechanism 143 is controlled based on, for example, the flow rate per unit time (inflow rate) of the water W and the deposition allowance β of the solid components that can be deposited on the centrifuge 131, and deposits in the centrifuge 131 These solid components are discharged at a predetermined timing.

More specifically, the controller 151 performs centrifugation on the basis of the separation efficiency calculation unit for determining the separation efficiency η of the solid component based on the inflow concentration of the solid component, the inflow concentration, the separation efficiency η, and the inflow rate. Cumulative accumulation amount calculation unit for calculating the accumulated accumulation amount S of solid components on the machine 131, scrubber water W when the allowable amount of accumulation of solid components set in advance in the centrifuge 131 and the discharge timing are determined Accumulation allowance amount calculation unit for calculating the accumulation allowance amount β of the solid component according to the flow rate of the solid component, the accumulated accumulation amount S calculated by the accumulation accumulation amount calculation unit, and the accumulation allowance calculated by the accumulation allowance amount calculation unit And a discharge timing control unit that controls the valve opening / closing mechanism 143 based on the volume β.

More specifically, the accumulated deposition amount S is calculated, for example, as follows.

Here, the separation efficiency 流出 drains the concentration of solid components in the scrubber water W flowing out of the centrifuge 131. If it is concentration,
Separation efficiency η = (inflow concentration−outflow concentration) / inflow concentration is defined. This separation efficiency may, in fact, vary depending on the inflow concentration and flow rate, for example as shown in FIG. That is, for example, the separation efficiency η increases as the inflow concentration increases. Further, the smaller the inflow rate, the longer the residence time in the centrifuge 131 and the higher the separation efficiency η. Therefore, the separation efficiency calculation unit of the controller 151 sets tables and functions in advance based on experiments with various concentrations and flow rates using real machines such as the centrifugal separator 120, the exhaust gas scrubber system, and the diesel engine 101. These can be used to determine the separation efficiency η. Note that, although the separation efficiency 例えば may further take into account, for example, fluctuations according to the amount of deposition of solid components on the centrifuge 131, the amount of deposition may be 0 if the required control accuracy is obtained. It may be determined based on the actual measurement value of the case.

Further, the deposition allowance β is calculated in more detail, for example, as follows.

Allowable amount of deposition β = preset amount of solid component accumulation × allowable amount correction value P
The allowable amount correction value P is, for example, as shown in FIG. 4, to correct the fluctuation of the allowable amount of deposition of the solid component on the centrifuge 131 according to the inflow rate. That is, when the inflow flow rate is small, the centrifugal force component acting on the solid component becomes relatively large, so the effect of pressing the solid component in the centrifugal direction (compaction effect) becomes large, and It is believed that the capacity that can actually be deposited may tend to be large. On the other hand, when the inflow rate is high, the turbulent elements in the flow of the scrubber water W become large, so the effect of the diffusion of the solid component (the diffusion effect) becomes large, and the sediment is actually deposited on the centrifuge 131 It is believed that the possible allowance may tend to be small. Therefore, like the separation efficiency η, the allowable amount correction value P can be obtained using a table or a function set in advance by an experiment based on a real machine or the like. More specifically, for example, when the maximum water flow rate of the centrifuge 131 is 3000 l / H, 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 in the case of 1500 l / H or more (50% or more), a value in the range of 0.1 ≦ P <1 is set. More specifically, for example, when the solid component deposited in the centrifuge 131 is appropriately discharged to measure the concentration of the solid component, the value is set to a predetermined concentration (for example, 7% by weight). The allowable amount correction value P may be determined so that the cumulative volume amount S becomes the deposition allowable amount β corresponding to the flow rate of the scrubber water W at that time.

When the cumulative deposition amount S of solid components and the deposition allowance β are obtained as described above, the controller 151 compares these values, and when the cumulative deposition amount S becomes the deposition allowance β or more, the valve opening / closing mechanism By controlling 143, the solid component deposited in the centrifuge 131 is discharged.

Since the cumulative accumulation amount S of solid components in the centrifuge 131 and the accumulation allowable amount β are directly integrated, etc. by the above control, it can be determined accurately as compared with the conventional method using turbidity. Since the discharge control is performed, it is possible to easily discharge the solid component at an appropriate timing. In particular, even when the concentration of solid components tends to fluctuate depending on the operating state of the engine, such as a marine diesel engine, the accuracy of the discharge timing can be easily enhanced. Therefore, it is possible to keep the concentration degree high and easily prevent the solid components from being accumulated and solidified or clogged to make it difficult to discharge, to cause vibration or damage.

(Other matters)
The characteristics shown in FIG. 3 and FIG. 4 are an example for the purpose of explanation, and are not limited to the slope of the illustrated curve or the change rate of the slope, etc., and separation according to the actual device etc. The efficiency 設定 and the allowable amount correction value P may be set so as to be obtained.

In the above example, the separation efficiency η and the allowable amount correction value P are obtained based on the measured flow rate of the scrubber water W measured by the flow meter 123. However, the flow rate is controlled by the flow control valve 124 If the flow rate is a constant, the separation efficiency η and / or the allowable amount correction value P may be obtained if the flow rate is kept constant, for example.

Further, although the above calculation example has been described as an example for easily showing the mechanism that can increase the accuracy of the discharge timing, the present invention is not limited thereto, and control may be performed at substantially equivalent timing. Various units such as or units of values may be applied. Further, for example, the present invention is not limited to the determination of the deposition tolerance β by multiplying the preset allowable tolerance of the solid component deposition and the tolerance correction value P, and the correspondence between the flow rate of the scrubber water W and the deposition tolerance β The relationship may be maintained so that the deposition allowance β can be obtained immediately from the flow rate of the scrubber water W. In addition, various methods may be used to obtain various values, such as function calculation including an approximate expression or reference to a value table.

DESCRIPTION OF SYMBOLS 101 Diesel engine 102 Engine exhaust pipe 103 External exhaust pipe 104 Exhaust gas return pipe 110 Scrubber apparatus 111 Scrubber 112 Circulation piping 113 Spray nozzle 120 Centrifugal separator 121 Branch pipe 122 Concentration meter 123 Flow meter 124 Flow control valve 131 Inflow 132 Pipe 133 Outflow pipe 134 Rotator cover 135 Partition plate 136 Main valve 137 Separation chamber 138 Separation plate 139 Guide tube 140 Centrifugal pump 141 Chamber 142 Solid component discharge tube 143 Valve opening and closing mechanism 151 Controller

Claims

A control device for a centrifugal separator that controls the discharge of solid components separated by the centrifugal separator,
Concentration of solid components in the fluid to be treated which flows into the centrifugal separator,
Cumulative deposition amount of solid components on the centrifugal separator obtained according to the flow rate of the fluid to be treated flowing into the centrifugal separator, and the separation efficiency of the centrifugal separator according to the concentration of the solid component;
Deposition capacity of solid components in the above centrifuge,
A control device for a centrifugal separator, comprising: a discharge timing control unit configured to determine a discharge timing of the solid component from the centrifugal separator according to the size relationship of the above.
The control device for a centrifugal separator according to claim 1, wherein
The control device for a centrifugal separator, wherein the separation efficiency of the centrifugal separator is a value further determined according to the flow rate of the processing fluid flowing into the centrifugal separator.
The control device for a centrifugal separator according to any one of claims 1 and 2, wherein
The control device for a centrifugal separator, wherein the deposition allowable amount of the solid component 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.
The control device for a centrifugal separator according to claim 3, wherein
The deposition allowable amount of the solid component in the centrifugal separator is a value determined according to the allowable amount preset in the centrifugal separator and the flow rate of the fluid to be treated when the discharge timing is determined. Control device for a centrifuge characterized by
The control device for a centrifuge according to any one of claims 1 to 4, wherein
The control device of a centrifugal separator characterized in that the discharge timing control unit includes a cumulative deposition amount calculating unit that calculates the cumulative deposition amount by accumulating the product of the concentration, the flow rate, and the separation efficiency. .
The control device for a centrifugal separator according to claim 5, wherein the claim 4 or claim 4 is cited, wherein
The discharge timing control unit multiplies the allowable amount preset in the centrifugal separator by an allowable amount correction value according to the flow rate of the fluid to be processed when the discharge timing is determined, and performs the centrifugal separation. A control device for a centrifugal separator, comprising: a deposition allowance calculation unit for obtaining a deposition allowance of solid components in a separator.
The control apparatus for a centrifuge according to any one of claims 1 to 6.
With the above centrifuge,
A centrifugal separator characterized by comprising.
A centrifugal separator according to claim 7;
A scrubber that absorbs the solid components discharged from the engine into scrubber water;
Equipped with
A marine exhaust gas scrubber system characterized in that the centrifugal separator is configured to remove the solid component contained in the scrubber water.
A marine diesel engine comprising the marine exhaust gas scrubber system according to claim 8.