JP2014142115A - Drain recovery device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drain recovery device capable of reducing the load of a valve to elongate the service life of the valve.SOLUTION: A drain recovery system 16 includes a flash tank 23, a water level detector 32, a drain discharge line L22, a drain discharge valve V22, and a drain controller 34. The drain controller 34 opens the drain discharge valve V22 when the water level of a drain 22 reaches a water level M and closes the drain discharge valve V22 when the water level of the drain 22 lowers to a water level L, on the basis of the water level in the flash tank 23 detected by the water level detector 32. Also, the drain controller 34 adjusts an opening at the time when the drain discharge valve V22 opens, on the basis of the arrival time from the water level M to the water level L, and discharges the drain 22 from the flash tank 23.

Description

  The present invention relates to a wastewater recovery apparatus that adjusts the discharge amount when recovering and discharging drain discharged from a load device that uses steam as a heat source.

  A drain recovery device that recovers drain discharged from a load device includes a water level sensor that detects the water level of the drain inside the device. The drain recovery device controls the opening / closing of a drain discharge valve for discharging the recovered drain according to the water level of the drain detected by the water level sensor, and discharges the drain. The drain recovery device opens the drain discharge valve when the drain water level reaches the upper limit water level inside the device, discharges the drain, and closes the drain discharge valve when the drain water level drops to the lower limit water level. Is stopped and the drain discharge valve is opened and closed repeatedly. By repeatedly performing the opening / closing operation of the drain discharge valve, the life of the drain discharge valve is shortened. Therefore, it is necessary to reduce the frequency of opening and closing the drain discharge valve and discharge the condensate as continuously as possible. In view of this, a device has been proposed in which the drain discharge amount inside the device is controlled to keep the frequency of opening and closing the drain discharge valve low (see, for example, Patent Document 1).

  The apparatus described in Patent Document 1 detects the water level of the condensate in the condensate tank continuously using a capacitance type water level sensor, and the condensate water level is within the reference range. The degree of opening of the condensate discharged from the condensate tank is controlled by adjusting the opening while keeping the control valve open. Thereby, the device described in Patent Document 1 keeps the frequency of opening and closing the control valve low.

Japanese Unexamined Patent Publication No. 7-317993

  However, since the apparatus described in Patent Document 1 uses a capacitive water level sensor, the processing circuit is complicated and the cost of the apparatus increases. Therefore, there is room for further improvement in reducing the manufacturing cost of the device while reducing the number of times of opening and closing the valve such as the control valve and extending the life of the valve.

  The present invention has been made in view of the above, and provides a drainage recovery apparatus that can reduce the number of times of opening and closing a valve to extend the life of the valve and can be realized with an inexpensive configuration. With the goal.

  The drainage recovery apparatus according to the present invention includes a drainage storage tank that collects drainage, a water level detection unit that is provided in the drainage storage tank and detects the level of the drainage in the drainage storage tank, and the drainage storage tank. A drainage discharge line for discharging the drainage from the drainage storage tank, and a drainage adjustment unit that is provided in the drainage discharge line and adjusts the flow rate of the drainage flowing through the drainage discharge line according to the opening of a valve; Based on the water level in the waste water storage tank detected by the water level detection unit, the valve is opened when the water level of the waste water reaches the upper limit water level, and the valve is closed when the water level of the waste water falls to the lower limit water level. And adjusting the opening when the valve is opened based on the arrival time until the water level of the waste water drops from the upper limit water level to the lower limit water level. A control portion for discharging from the tank, a waste water recovery apparatus characterized by having a.

  As a preferred aspect of the present invention, the control unit sets the opening of the valve that is opened after the valve is closed to be smaller than the opening of the valve that is opened before the valve is closed. It is preferable to discharge the waste water.

  As a preferred aspect of the present invention, when the water level of the waste water in the waste water storage tank becomes higher than the upper limit water level at the time of opening the valve, the control unit sets the opening degree of the valve before the valve closing. The opening is preferably the same as the opening, or the opening between the opening when the water level of the waste water is higher than the upper limit water level and the previous opening before closing.

  As a preferred embodiment of the present invention, the waste water is preferably drain discharged from a load device.

  ADVANTAGE OF THE INVENTION According to this invention, the frequency | count of opening and closing of a valve can be reduced, the lifetime of a valve can be achieved, and it can implement | achieve with an inexpensive structure.

It is a figure which shows schematic structure of the steam system provided with the waste_water | drain collection | recovery apparatus which concerns on embodiment of this invention. It is a flowchart which shows an example of the procedure which controls a drain discharge valve. It is a figure explaining an example of the state of drain discharge. It is a figure explaining an example of the state of drain discharge. It is a figure explaining an example of the state of drain discharge. It is a figure explaining an example of the state of drain discharge. It is a figure explaining an example of the state of drain discharge. It is a figure which shows an example of the time chart of drain discharge | emission control.

  DESCRIPTION OF EMBODIMENTS Hereinafter, modes for suitably carrying out the present invention (hereinafter referred to as embodiments) will be described in detail. In addition, this invention is not limited by the content described in the following embodiment. In addition, constituent elements in the embodiments described below include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those in a so-called equivalent range. Furthermore, the constituent elements disclosed in the embodiments described below may be appropriately combined, or may be appropriately selected and used.

<Steam system>
A steam system including a wastewater recovery apparatus according to an embodiment of the present invention will be described. FIG. 1 is a diagram illustrating a schematic configuration of a steam system including a wastewater recovery apparatus according to an embodiment of the present invention. As shown in FIG. 1, the steam system 10 includes a boiler (steam supply source) 11, a steam header 12, a first load device 13, a water supply tank 14, a second load device 15, and a wastewater collection device 16. It has.

  The boiler 11 is a steam supply source that generates steam 21 by various heat source methods. As the boiler 11, various types such as a combustion boiler and an electric boiler can be used. In the case of the combustion type, the boiler 11 generates steam by heating the can water in the can body using the heat of combustion when the fuel is burned as a heat source. When the boiler 11 is of the combustion type, for example, a gas fuel such as city gas, propane gas, or biogas, or a liquid fuel such as heavy oil or kerosene is used as the fuel. In the case of the combustion type, the boiler 11 includes, for example, a once-through boiler, a furnace tube fired boiler, a water tube boiler, and the like. In the case of an electric type, the boiler 11 generates steam by heating can water in the can body using an electric heater or the like as a heat source.

  The boiler 11 is connected to the steam header 12 by the first steam supply line L11. The first steam supply line L11 is a line that connects the boiler 11 and the steam header 12. The steam 21 is sent from the boiler 11 to the steam header 12 through the first steam supply line L11.

  The steam header 12 is for storing the steam 21. In this embodiment, although one boiler 11 is provided, it is not limited to this, You may provide the several boiler. In this case, steam supplied from a plurality of boilers is collected in the steam header 12.

  The steam header 12 is connected to the first load device 13 through the second steam supply line L12. The second steam supply line L12 is a line that connects the steam header 12 and the first load device 13. The steam 21 is sent to the first load device 13 through the second steam supply line L12. The second steam supply line L12 is provided with a pressure reducing valve V11 and a steam supply valve V12 in the middle of the second steam supply line L12. The pressure reducing valve V11 keeps the pressure (back pressure) of the steam 21 downstream of the pressure reducing valve V11 in the second steam supply line L12 constant. The steam supply valve V12 is provided downstream of the pressure reducing valve V11 in the flow direction of the steam 21. The steam supply valve V12 adjusts the flow rate of the steam 21 supplied to the first load device 13 by adjusting the opening degree.

  The steam header 12 is connected to the steam discharge line L21 through the third steam supply line L13. The third steam supply line L13 is a line connecting the steam header 12 and the steam discharge line L21. The steam 21 is sent from the steam header 12 through the third steam supply line L13 to the steam discharge line L21 and is sent to the second load device 15. The configuration of the steam discharge line L21 will be described later.

  The first load device 13 uses the steam 21 supplied from the steam header 12 as a heating source or a power source. In the present embodiment, the first load device 13 uses the steam 21 as a heating source. When the steam 21 passes through the steam supply passage in the first load device 13, it loses latent heat and partially condenses to become high-pressure and high-temperature drain (condensed water) 22. The first load device 13 includes one or more load devices such as a high pressure steam load device or an intermediate pressure steam load device. Accordingly, the drain 22 is generated from the steam 21 used as a heating source in one or more load devices such as a high pressure steam load device or a medium pressure steam load device.

  The first load device 13 is connected to the flash tank 23 by a drain supply line L14. The first load device 13 uses the steam 21 supplied from the second steam supply line L12 as a heating source, and discharges the drain 22 generated when the steam 21 is used to the drain supply line L14. Further, the drain supply line L14 is provided with a steam trap 24 in the middle of the drain supply line L14. The steam trap 24 allows only the drain 22 discharged from the first load device 13 to pass through. After passing through the steam trap 24, the drain 22 is supplied to the flash tank 23 and collected in the flash tank 23. The configuration of the flash tank 23 will be described later.

  In addition, the drain supply line L <b> 14 is provided with a temperature sensor (temperature measurement unit) 25 between the steam trap 24 and the flash tank 23. The temperature sensor 25 detects the temperature of the drain 22 passing through the drain supply line L14. The temperature sensor 25 transmits an electrical signal corresponding to the detection result to the control device 34.

  In the drain supply line L14, a bypass line L15 is connected between the steam trap 24 and the flash tank 23. The bypass line L15 is a line connecting the drain supply line L14 and the drain discharge line L22. The configuration of the drain discharge line L22 will be described later. The bypass line L15 supplies the drain 22 to the water supply tank 14. The bypass line L15 is provided with an emergency discharge valve V13 in the middle of the bypass line L15. The emergency discharge valve V13 discharges the drain 22 flowing through the bypass line L15. When the water level in the flash tank 23 becomes higher than the normal setting range due to a failure of the drain discharge valve V22 or clogging in the drain discharge line L22, the emergency discharge valve V13 is opened and the drain 22 is The water is supplied to the water supply tank 14 through the bypass line L15 without passing through the flash tank 23.

  In the bypass line L15, a bypass drain discharge line L16 is connected between the drain supply line L14 and the emergency discharge valve V13. The bypass drain discharge line L16 is a line connecting the bypass line L15 and the blow discharge line L23. The bypass drain discharge line L16 supplies the drain 22 to the blow discharge line L23. The bypass drain discharge line L16 is provided with an emergency discharge valve V14 in the middle of the bypass drain discharge line L16. The opening and closing of the emergency discharge valve V14 is controlled based on a control signal sent from the control device 34.

  The water supply tank 14 is for storing the drain 22. The drain 22 in the water supply tank 14 is supplied to the boiler 11 as water 26 for generating steam 21. Further, when only the drain 22 supplied to the water supply tank 14 has insufficient water to be supplied to the boiler 11, the makeup water 27 is supplied to the water supply tank 14 and supplied to the boiler 11 as water 26.

  The third steam supply line L13 is provided with a pressure reducing valve V15 in the middle of the third steam supply line L13. The steam 21 sent from the steam header 12 to the third steam supply line L13 passes through the pressure reducing valve V15 and then becomes the pressure reduced steam 28. The steam 21 flowing from the steam header 12 through the third steam supply line L13 is supplied to the second load device 15 through the steam discharge line L21 as the reduced pressure steam 28 by the pressure reducing valve V15.

  The second load device 15 uses the flash steam 29 and the vacuum steam 28 discharged from the flash tank 23 as a heating source or a power source. The second load device 15 includes one or more low-pressure steam load devices. In the present embodiment, the second load device 15 preferentially uses the flash steam 29 as a heating source or a power source over the decompressed steam 28. The second load device 15 uses the reduced pressure steam 28 as a shortage when the amount of steam used in the second load device 15 is insufficient with only the flash steam 29.

(Drainage recovery device 16)
The drainage recovery device 16 includes a flash tank (drainage storage tank) 23, a pressure sensor (pressure detection unit) 31, a water level detector (water level detection unit) 32, a control device (control unit) 34, and a steam discharge line L21. , Drain discharge line (drainage discharge line) L22, blow discharge line L23, steam control valve (steam control unit) V21, drain discharge valve (drainage control unit) V22, blow discharge valve (blow discharge control unit) V23.

  The flash tank 23 collects the drain 22, and flash vapor 29 is generated from the collected drain 22. Since the pressure in the flash tank 23 is lower than that in the drain supply line L <b> 14, the flash steam 29 is generated from the drain 22 collected in the flash tank 23. The flash tank 23 is provided with a safety valve V24. When the pressure in the flash tank 23 becomes abnormally high, the safety valve V24 is opened to depressurize the flash tank 23.

  The steam discharge line L <b> 21 has one end connected to the flash tank 23 and the other end connected to the second load device 15. The steam discharge line L21 is a line for discharging the flash steam 29 from the flash tank 23. The steam discharge line L21 is provided with a pressure reducing valve V25 in the middle of the steam discharge line L21. The flash steam 29 passes from the flash tank 23 through the steam discharge line L21 and is decompressed by the decompression valve V25, and then is sent to the second load device 15. The second load device 15 uses the decompressed steam 28 together with the flash steam 29 as a heating source or a power source. The second load device 15 preferentially uses the flash steam 29, and uses the reduced-pressure steam 28 as steam that is not sufficient with the flash steam 29 alone. When the steam control valve V21 is closed and the flash steam 29 is not sent to the second load device 15, only the decompressed steam 28 is used as a heating source or a power source for the second load device 15.

  The steam control valve V21 is provided in the steam discharge line L21. The steam control valve V21 adjusts the flow rate of the flash steam 29 passing through the steam discharge line L21. The opening degree of the steam control valve V21 is adjusted based on a control signal sent from the control device 34.

  In the steam discharge line L21, a check valve V26 is provided between the steam control valve V21 and the pressure reducing valve V25. The check valve V26 prevents the reduced-pressure steam 28 from flowing to the flash tank 23 side.

  In the steam discharge line L21, an internal pressure adjustment line L24 is connected between the flash tank 23 and the steam control valve V21. The internal pressure adjusting line L24 discharges a part of the flash steam 29 from the steam discharge line L21 to the outside. The internal pressure adjusting line L24 is provided with an internal pressure adjusting valve V27 in the middle of the internal pressure adjusting line L24. When the pressure in the steam discharge line L21 becomes equal to or higher than the predetermined pressure, the internal pressure control valve V27 opens the internal pressure control valve V27 to release the pressure to the outside, and the pressure in the steam discharge line L21 is higher than the predetermined pressure. It is used to adjust so that it does not become.

  The drain discharge line L22 has one end connected to the flash tank 23 and the other end connected to the water supply tank 14. The drain discharge line L22 is a line for discharging the drain 22 from the flash tank 23. The drain 22 flows from the flash tank 23 into the water supply tank 14 through the drain discharge line L22.

  The drain discharge valve V22 is provided in the drain discharge line L22. The drain discharge valve V22 adjusts the discharge amount of the drain 22 flowing through the drain discharge line L22 according to the opening degree of the drain discharge valve V22.

  In the drain discharge line L22, a check valve V28 is provided between the drain discharge valve V22 and a position where the drain discharge line L22 is connected to the bypass line L15. The check valve V28 prevents the drain 22 from flowing toward the flash tank 23 when flowing into the bypass line L15.

  The drain discharge line L22 is provided with a differential pressure gauge (differential pressure detector) 38 for detecting a differential pressure between the upstream side and the downstream side of the drain discharge valve V22. The differential pressure detector 38 measures the pressure on the upstream side of the drain discharge valve V22 of the drain discharge line L22 and the pressure on the downstream side of the drain discharge valve V22 of the drain discharge line L22. The differential pressure between the upstream side and the downstream side is detected.

  The blow discharge line L23 is connected to the flash tank 23. The blow discharge line L23 is a line for discharging the drain 22 from the flash tank 23 to the outside.

  The blow discharge valve V23 is provided in the blow discharge line L23. The blow discharge valve V23 discharges the drain 22 flowing through the blow discharge line L23.

  The pressure sensor 31 is provided in the flash tank 23. The pressure sensor 31 detects the pressure in the flash tank 23.

  The water level detector (water level detection sensor) 32 is provided in the flash tank 23. In the present embodiment, the water level detector 32 is an electrode type water level sensor. The water level detector 32 includes a first electrode 43A, a second electrode 43B, and a third electrode 43C. The first electrode 43A, the second electrode 43B, and the third electrode 43C are electrode bars. The water level detector 32 is of a contact type that detects whether or not the drain 22 is in contact with the first electrode 43A, the second electrode 43B, and the third electrode 43C. The water level detector 32 measures whether the water level of the drain 22 in the flash tank 23 is above or below the positions of the tips of the first electrode 43A, the second electrode 43B, and the third electrode 43C. That is, the water level detector 32 indicates that the water level of the drain 22 in the flash tank 23 has risen to the positions of the tips of the first electrode 43A, the second electrode 43B, and the third electrode 43C, or the water level of the drain 22 is the first electrode. 43A, the second electrode 43B and the third electrode 43C are measured to descend to the position of the tip. The lengths of the first electrode 43A, the second electrode 43B, and the third electrode 43C are longer in the order of the first electrode 43A, the second electrode 43B, and the third electrode 43C. The tips of the first electrode 43A, the second electrode 43B, and the third electrode 43C are in a position where the water level in the flash tank 23 is low in the order of the first electrode 43A, the second electrode 43B, and the third electrode 43C. Therefore, the drain 22 in the flash tank 23 comes into contact with the first electrode 43A, the second electrode 43B, or the third electrode 43C according to the water level of the drain 22. Therefore, the water level detector 32 determines whether the water level of the drain 22 in the flash tank 23 is the first electrode 43A, the first electrode 43A, and the third electrode 43C, depending on whether the drain 22 is in contact with the first electrode 43A, the second electrode 43B, and the third electrode 43C, respectively. Detecting that the position of the tip of the second electrode 43B or the third electrode 43C has risen, or that the water level of the drain 22 has fallen to the position of the tip of the first electrode 43A, the second electrode 43B, and the third electrode 43C. it can.

  Specifically, when the water level of the drain 22 in the flash tank 23 is rising, when the drain 22 comes into contact with the tip of the first electrode 43A, the second electrode 43B, or the third electrode 43C, the first electrode 43A Since the current flows through the second electrode 43B or the third electrode 43C, the water level detector 32 is located at a position where the water level of the drain 22 is higher than the tip of the first electrode 43A, the second electrode 43B or the third electrode 43C. It can be detected that there is. Further, when the water level of the drain 22 in the flash tank 23 is lowered, if the drain 22 does not contact the tip of the first electrode 43A, the second electrode 43B, or the third electrode 43C, the first electrode 43A, Since the current does not flow to the second electrode 43B or the third electrode 43C, the water level detector 32 indicates that the water level of the drain 22 is lower than the tip of the first electrode 43A, the second electrode 43B, or the third electrode 43C. Can be detected.

  In the present embodiment, the water level of the drain 22 up to the tip of the first electrode 43A is the water level L. The water level of the drain 22 up to the tip of the second electrode 43B is a water level M. The water level of the drain 22 up to the tip of the third electrode 43C is defined as a water level H. In the present embodiment, the water level L is the lower limit water level. The water level M is the upper limit water level.

  In the present embodiment, the water level detector 32 includes three electrodes (the first electrode 43A, the second electrode 43B, and the third electrode 43C), but is not limited thereto. May be two, or four or more.

  The pressure sensor 31 and the water level detector 32 each transmit an electrical signal corresponding to the detection result to the control device 34.

  The control device 34 controls each part of the wastewater collection device 16. The control device 34 is a microcomputer including an input / output unit, a ROM (Read Only Memory), a RAM (Random Access Memory), and a CPU (Central Processing Unit). The output unit manages an interface operation with each of the above components. The ROM stores a control program executed by the CPU such as predetermined data and an arithmetic program. The RAM stores calculation results and is used as a work area. The CPU controls the entire system. In addition, the control device 34 includes a timer (time measuring unit) 35 that measures the opening / closing time of the drain discharge valve V22. The control device 34 is electrically connected to various sensors attached to various portions of the wastewater collection device 16 such as the temperature sensor 25, the pressure sensor 31, the water level detector 32, and the differential pressure detector 38. Electrical signals corresponding to the detection results of these various sensors are input to the control device 34 via an external input circuit. The control device 34 outputs control signals to various valves such as the emergency discharge valves V13 and V14, the steam control valve V21 and the drain discharge valve V22 based on various electrical signals input from various sensors, and controls them. To do.

(Control of drain discharge valve V22)
The control device 34 detects the water level of the drain 22 in the flash tank 23 from the detection result of the water level detector 32. Based on the water level of the drain 22 in the flash tank 23 detected by the water level detector 32, the control device 34 outputs a control signal to the drain discharge valve V22 to adjust the opening of the drain discharge valve V22, The amount of drain 22 discharged to the drain discharge line L22 is adjusted. In the present embodiment, the control device 34 opens the drain discharge valve V22 when the water level of the drain 22 reaches the water level M, and closes the drain discharge valve V22 when the water level of the drain 22 decreases to the water level L. The opening degree when the drain discharge valve V22 is opened is adjusted based on the time (the arrival time) during which the drain discharge valve V22 is open until the water level of the water 22 drops from the water level M to the water level L. To discharge from.

  Further, the control device 34 repeatedly opens and closes the drain discharge valve V22, and the opening degree of the drain discharge valve V22 opened after closing is smaller than the opening degree of the drain discharge valve V22 opened before closing. Thus, it is preferable to drain the drain 22 from the flash tank 23. When opening the drain discharge valve V22, the control device 34 adjusts the opening degree of the drain discharge valve V22 to be smaller than the previous opening degree, and repeatedly opens and closes the drain discharge valve V22, thereby stepping the opening degree of the drain discharge valve V22. Make it smaller. Accordingly, the control device 34 can reduce the number of times of opening and closing the drain discharge valve V22 in order to continuously discharge the drain 22 from the flash tank 23 while maintaining the drain discharge valve V22 at a predetermined opening. it can. For this reason, since the burden on the drain discharge valve V22 is kept low, the life of the drain discharge valve V22 is extended.

  Next, an example when the control apparatus 34 controls the drain discharge valve V22 according to the water level of the drain 22 is demonstrated. FIG. 2 is a flowchart showing an example of a procedure for controlling the drain discharge valve V22. 3-7 is a figure explaining the discharge | emission state of the drain 22. FIG. In Step S11, when the operation of the first load device 13 is started with the drain discharge valve V22 and the blow discharge valve V23 closed, the drain 22 is supplied into the flash tank 23. Since the drain discharge valve V22 and the blow discharge valve V23 are closed, the drain 22 supplied in the flash tank 23 accumulates in the flash tank 23, and the water level of the drain 22 in the flash tank 23 rises. Until the water level of the drain 22 rises to the tip of the first electrode 43A, no current flows through the first electrode 43A, and therefore the control device 34 determines that the water level of the drain 22 has not risen to the water level L.

  As shown in FIG. 3, when the water level of the drain 22 rises to the tip of the first electrode 43 </ b> A, the tip of the first electrode 43 </ b> A comes into contact with the drain 22, so that a current flows through the first electrode 43 </ b> A. The control device 34 determines that the water level of the drain 22 has risen to the water level L by detecting that a current has passed through the first electrode 43A.

  As shown in FIG. 4, when the water level of the drain 22 rises from the position of the tip of the first electrode 43A, and the water level of the drain 22 rises to the position of the tip of the second electrode 43B, as shown in FIG. Since the tips of the two electrodes 43B are in contact with the drain 22, a current flows through the second electrode 43B. The control device 34 determines that the water level of the drain 22 has risen to the water level M by detecting that a current has passed through the second electrode 43B.

  After the drain 22 is supplied into the flash tank 23, the control device 34 shifts the process to step S12. In step S12, the control device 34 determines whether or not a current flows through the second electrode 43B as described above.

  As a result of the determination in step S12, when the control device 34 detects that a current has flown through the second electrode 43B (step S12: Yes), the control device 34 determines the water level of the drain 22 in the flash tank 23. Is determined to have reached the water level M, and the process proceeds to step S13.

  In step S13, the control device 34 opens the drain discharge valve V22 to a predetermined opening (for example, α%). And the control apparatus 34 starts the timer 35, and measures the open | release time of the drain discharge valve V22. Thereafter, the control device 34 shifts the process to step S14.

  In step S14, the control device 34 determines whether or not current stops flowing through the second electrode 43B. As shown in FIG. 6, when the drain discharge valve V22 is opened, the drain 22 in the flash tank 23 is discharged from the flash tank 23 through the drain discharge line L22. As a result, the water level of the drain 22 in the flash tank 23 decreases. When the water level of the drain 22 is lower than the water level M, no current flows through the second electrode 43B. As a result of the determination in step S14, when no current flows through the second electrode 43B (step S14: Yes), the control device 34 determines that the water level of the drain 22 has decreased below the water level M, and the control device 34 Shifts the processing to step S15.

  In step S15, the control device 34 determines whether or not the water level of the drain 22 in the flash tank 23 has further decreased and no current flows through the first electrode 43A. As a result of the determination in step S15, when no current flows through the first electrode 43A (step S15: Yes), the control device 34 sets the water level of the drain 22 to the first electrode 43A as shown in FIG. It is determined that the pressure has dropped to the tip and has fallen to the water level L, and the control device 34 shifts the processing to step S16.

  In step S16, the control device 34 closes the drain discharge valve V22, and shifts the processing to step S17.

  In step S <b> 17, the control device 34 calculates the arrival time T required for the water level of the drain 22 to drop from the water level M to the water level L. Here, the arrival time T means that the drain discharge valve V22 is opened until the current stops flowing to the first electrode 43A in Step 15 after the drain discharge valve V22 is opened in Step 13, and the water level of the drain 22 decreases from the water level M to the water level L. This is the time during which V22 was open. After calculating the arrival time T required for the water level of the drain 22 to drop from the water level M to the water level L, the control device 34 shifts the processing to step S18.

  In step S18, the control device 34 stops and resets the timer 35. Thereafter, the control device 34 shifts the process to step S19.

  In step S19, the control device 34 determines whether or not a current flows through the second electrode 43B. As a result of the determination in step S19, when a current flows through the second electrode 43B (step S19: Yes), the control device 34 determines that the water level of the drain 22 in the flash tank 23 has reached the water level M. Then, the process proceeds to step S20.

  In step S20, the control device 34 opens the drain discharge valve V22 to an opening (for example, β%) smaller than the previous opening (for example, α%). And the control apparatus 34 starts the timer 35, and measures the open | release time of the drain discharge valve V22. Thereafter, the control device 34 shifts the process to step S14.

  As a result of the determination in step S14, when the control device 34 determines that the state in which the current is flowing through the second electrode 43B is continued (step S14: No), the control device 34 It is determined that the water level of 22 is not lower than the water level M, and the process proceeds to step S21.

  In step S21, the control device 34 determines whether or not a current flows through the third electrode 43C. If the water level of the drain 22 does not decrease even after the drain discharge valve V22 is opened to a predetermined opening (for example, β%), it is considered that the water level of the drain 22 has increased. Therefore, when the water level of the drain 22 has not decreased, the control device 34 checks whether or not the water level of the drain 22 has reached the water level H. When the control device 34 detects that a current flows through the third electrode 43C (step S21: Yes), the control device 34 determines that the water level of the drain 22 has risen to the water level H, and the control device 34 performs processing. The process proceeds to S22.

  In step S22, the control device 34 adjusts the opening degree of the drain discharge valve V22 to the same opening degree as the previous opening degree (for example, α%) before the valve closing. After adjusting the opening degree of the drain discharge valve V22 to the previous opening degree (for example, α%), the control device 34 shifts the process to step S14.

  As a result of the determination in step S21, the control device 34 determines that the water level of the drain 22 is between the water level M and the water level H when no current flows through the third electrode 43C (step S21: No). The drain 22 is continuously discharged while maintaining the opening of the drain discharge valve V22 and maintaining the amount of the drain 22 discharged from the flash tank 23.

  In the present embodiment, in step S22, the control device 34 adjusts the opening degree of the drain discharge valve V22 to the same opening degree as the previous opening degree (for example, α%) before closing the valve, However, the present invention is not limited to this. Between the opening when the water level of the drain 22 becomes higher than the water level M (for example, β%) and the previous opening before the valve closing (for example, α%). It is good also as an opening degree.

  Next, an example of control for the drainage recovery device 16 to discharge the drain 22 will be described. Here, a case will be described in which the drain 22 is continuously discharged from the flash tank 23 in four cycles. In one cycle, after the water level of the drain 22 in the flash tank 23 rises from the water level L to the water level M with the drain discharge valve V22 closed, the drain discharge valve V22 is opened and the drain 22 in the flash tank 23 reaches the water level M. It is a period until it falls to the water level L. Further, the drain discharge valve V22 is closed, the drain 22 is accumulated in the flash tank 23 up to the position of the water level L, and the control device 34 detects that electricity is flowing through the first electrode 43A. To do.

(First cycle)
FIG. 8 is a diagram illustrating an example of a time chart of the drain 22 discharge control. As shown in FIG. 8, when the operation of the first load device 13 is started and the drain 22 is supplied into the flash tank 23, the drain 22 is stored in the flash tank 23 (see FIGS. 3 and 4). When the drain 22 is stored in the flash tank 23, the water level of the drain 22 rises to the position of the tip of the second electrode 43B, and current flows through the second electrode 43B. Accordingly, the control device 34 determines that the water level of the drain 22 in the flash tank 23 has risen from the water level L to the water level M (see FIG. 5).

  Next, when the control device 34 determines that the water level of the drain 22 has risen to the water level M (see FIG. 5), the control device 34 controls the drain discharge valve V22 to adjust the opening of the drain discharge valve V22 to be 80% open. . Further, the control device 34 activates the timer 35. Note that the opening degree when the drain discharge valve V22 is fully opened is 100%. By opening the opening of the drain discharge valve V22 by 80%, the control device 34 determines that the water level of the drain 22 has become lower than the water level M by detecting that current does not flow to the second electrode 43B. (See FIG. 6).

  When the water level of the drain 22 gradually decreases from the water level M and the control device 34 detects that no current flows to the first electrode 43A, the water level of the drain 22 decreases to the tip of the first electrode 43A, It is determined that the water level has dropped to L (see FIG. 7), and the drain discharge valve V22 is controlled to close the drain discharge valve V22. Moreover, the control apparatus 34 calculates the elapsed time T1 required for the water level of the drain 22 to fall from the water level M to the water level L (here, 20 seconds).

  When the opening degree of the drain discharge valve V22 is 80%, the control device 34 has an elapsed time T1 from the water level M to the water level L of 20 seconds, so that the drain 22 cannot be continuously discharged from the flash tank 23. Judge that it is necessary to make the opening degree smaller.

(Second cycle)
Next, as shown in FIG. 8, in the control device 34, the drain 22 is accumulated in the flash tank 23 (see FIGS. 3 and 4), and current flows through the second electrode 43B, as in the first cycle described above. When this is detected, it is determined that the water level of the drain 22 in the flash tank 23 has risen from the water level L to the water level M (see FIG. 5). In the present embodiment, the time required for the water level of the drain 22 to rise from the water level L to the water level M is 30 seconds. Thereafter, the control device 34 controls the drain discharge valve V22 to adjust the opening degree of the drain discharge valve V22 to 50%. Further, the control device 34 activates the timer 35.

  When the water level of the drain 22 gradually decreases from the water level M (see FIG. 6) and the controller 34 detects that no current flows through the first electrode 43A, as in the first cycle described above, the drain 22 Is determined to have dropped from the water level M to the water level L (see FIG. 7), and the drain discharge valve V22 is controlled to close the drain discharge valve V22. Moreover, the control apparatus 34 calculates the arrival time T2 required for the water level of the drain 22 to fall from the water level M to the water level L (here, 40 seconds).

  When the opening degree of the drain discharge valve V22 is 50%, the control device 34 has a reaching time T2 from the water level M to the water level L of 40 seconds, so that the drain 22 cannot be continuously discharged from the flash tank 23. Judge that it is necessary to make the opening degree smaller.

(3rd cycle)
Next, as shown in FIG. 8, the controller 34 detects that the drain 22 is accumulated in the flash tank 23 and the current flows to the second electrode 43B, as in the first and second cycles described above. Then, it is determined that the water level of the drain 22 in the flash tank 23 has increased from the water level L to the water level M in a predetermined time (here, 30 seconds) (see FIGS. 3 to 5). Thereafter, the control device 34 controls the drain discharge valve V22 to adjust the opening degree of the drain discharge valve V22 to 30%, and starts the timer 35.

  Next, similarly to the first and second cycles described above, the control device 34 detects that the current has stopped flowing through the first electrode 43A, so that the water level of the drain 22 has decreased from the water level M to the water level L. Judgment is made (see FIGS. 6 and 7). Thereafter, the control device 34 controls the drain discharge valve V22 to close the drain discharge valve V22, and calculates the arrival time T3 required for the water level of the drain 22 to drop from the water level M to the water level L (here, 90 seconds).

  When the opening degree of the drain discharge valve V22 is 30%, the control device 34 has an arrival time T3 from the water level M to the water level L of 90 seconds, so that the drain 22 cannot be continuously discharged from the flash tank 23. Judge that it is necessary to make the opening degree smaller.

(4th cycle)
Next, as shown in FIG. 8, the controller 34 detects that the drain 22 is accumulated in the flash tank 23 and the current flows to the second electrode 43B, as in the second and third cycles described above. Then, it is determined that the water level of the drain 22 in the flash tank 23 has increased from the water level L to the water level M in a predetermined time (here, 30 seconds) (see FIGS. 3 to 5). Thereafter, the control device 34 controls the drain discharge valve V22 to adjust the opening degree of the drain discharge valve V22 to 20%, and starts the timer 35. The control device 34 detects that the current is flowing in the second electrode 43B and that no current is flowing in the third electrode 43C, so that the water level of the drain 22 is at the water level M or above and below it. It is maintained and judged to be stable with almost no decline.

  When the opening degree of the drain discharge valve V22 is 20%, the control device 34 is able to continuously discharge the drain 22 from the flash tank 23 because the water level of the drain 22 is almost stable at the water level M. The opening degree of the drain discharge valve V22 is maintained as it is.

  Thus, the drainage recovery device 16 opens the drain discharge valve V22 when the water level of the drain 22 reaches the water level M based on the detection result of the water level detector 32, and the water level of the drain 22 reaches the water level L. When the drain discharge valve V22 is lowered, control is performed to close the drain discharge valve V22, and the opening degree when the drain discharge valve V22 is opened is adjusted based on the arrival time until the water level of the drain 22 decreases from the water level M to the water level L. The drainage recovery device 16 opens the drain discharge valve V22 and discharges the drain 22 in the flash tank 23 based on the arrival time T required for the water level of the drain 22 to drop from the water level M to the water level L. The opening / closing of the drain discharge valve V22 is repeatedly adjusted by adjusting the opening of the valve V22 to be smaller than the opening when the drain 22 was discharged last time. As a result, the drainage recovery device 16 sets the opening of the drain discharge valve V22 to a predetermined value so that the amount of the drain 22 flowing into the flash tank 23 and the amount of the drain 22 discharged from the flash tank 23 become substantially the same amount. The opening can be adjusted. As a result, the drainage recovery device 16 can continuously discharge the drain 22 from the flash tank 23 in a state where the water level of the drain 22 in the flash tank 23 is substantially maintained at a predetermined water level.

  Accordingly, when the drainage recovery device 16 opens the drain discharge valve V22, the drain discharge valve V22 is gradually drained to reduce the degree of opening of the drain discharge valve V22 so that the drain 22 is continuously discharged from the flash tank 23. Since the opening degree of the valve V22 is adjusted, the number of times of opening / closing the drain discharge valve V22 can be reduced. Thereby, since the waste_water | drain collection | recovery apparatus 16 can suppress the burden which arises with opening / closing operation | movement of the drain discharge valve V22, it can achieve the lifetime improvement of the drain discharge valve V22. Further, since the life of the drain discharge valve V22 is lengthened, the cost required for replacement of the equipment of the drainage recovery device 16 can be reduced. Furthermore, since the use period of the drain discharge valve V22 becomes long, the waste water recovery device 16 can be operated continuously and stably. Further, the drainage recovery device 16 only controls the opening / closing of the drain discharge valve V22 based on the water level of the drain 22 detected using the three electrodes of the first electrode 43A, the second electrode 43B, and the third electrode 43. Therefore, the water level of the drain 22 can be adjusted with an inexpensive configuration. Therefore, according to the waste water recovery device 16, the drain 22 discharged from the first load device 13 can be discharged from the flash tank 23 with a stable and inexpensive structure for a long period of time.

  Further, when the flow rate of the drain 22 discharged from the first load device 13 increases due to a change in the amount of steam used by the first load device 13 due to a change in the load of the first load device 13, the drain 22 in the flash tank 23 The amount increases and the water level in the flash tank 23 rises. When the water level of the drain 22 in the flash tank 23 becomes the water level H, the drainage recovery device 16 controls the control device 34 so that the opening degree of the drain discharge valve V22 becomes large, and the inside of the flash tank 23 The drain 22 is discharged. As a result, the drainage recovery device 16 can discharge the drain 22 from the flash tank 23 while adjusting the water level of the drain 22 in the flash tank 23 so as not to exceed the water level M stably.

  In addition, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the meaning of invention. For example, in the present embodiment, the drain discharge line L22 and the blow discharge line L23 are respectively connected to the flash tank 23, but the present invention is not limited to this, and the blow discharge line L23 is the drain discharge line. It may be provided in the middle of L22, specifically, between the flash tank 23 and the drain discharge valve V22, or the drain discharge line L22 may be provided in the middle of the blow discharge line L23, specifically with the flash tank 23. You may branch and provide from between the blow discharge valves V23.

  Further, in the present embodiment, the drain 22 discharged from the flash tank 23 or the drain 22 passing through the bypass line L15 is supplied to the water supply tank 14 so that the drain 22 is stored only by the water supply tank 14. It is not limited to this. For example, the drain discharge line L22 is on the upstream side of the water supply tank 14, and specifically, a drain tank is provided separately from the water supply tank 14 between the connection point to the bypass line L15 and the water supply tank 14. The drain 22 may be stored in the drain tank.

  In the present embodiment, the case where the flash tank 23 is used as the drainage storage tank using the drain 22 discharged from the first load device 13 is described. However, the present embodiment is not limited to this. A conventionally known drain collection container that does not take out the flash vapor 29 can be similarly applied.

  Moreover, although this embodiment demonstrated the case where the drain 22 discharged | emitted from the 1st load apparatus 13 was collect | recovered, this embodiment is not limited to this, and is discharged | emitted from other than a load apparatus. The same applies to the case of collecting wastewater.

10 Steam system 11 Boiler (steam supply source)
12 Steam header 13 First load device 14 Water supply tank 15 Second load device 16 Waste water recovery device 21 Steam 22 Drain 23 Flash tank (drainage storage tank)
24 Steam Trap 25 Temperature Sensor (Temperature Measurement Unit)
26 Water 27 Makeup water 28 Depressurized steam 29 Flash steam 31 Pressure sensor (pressure detector)
32 Water level detector (water level detector)
34 Control device (control unit)
35 Timer (Time measurement unit)
38 Differential pressure detector 43A 1st electrode 43B 2nd electrode 43C 3rd electrode L11 1st steam supply line L12 2nd steam supply line L13 3rd steam supply line L14 Drain supply line L15 Bypass line L16 Bypass drain discharge line L21 Steam discharge Line L22 Drain discharge line (drainage discharge line)
L23 Blow discharge line L24 Internal pressure adjustment line V11, V15, V25 Pressure reducing valve V12 Steam supply valve V13, V14 Emergency discharge valve V21 Steam control valve (steam control unit)
V22 Drain discharge valve (drainage control part)
V23 Blow discharge valve (Blow discharge control part)
V24 Safety valve V26, V28 Check valve V27 Internal pressure control valve

Claims (4)

A wastewater storage tank for collecting wastewater;
A plurality of water level detection units provided in the waste water storage tank, and detecting a water level of the waste water in the waste water storage tank;
A drainage discharge line connected to the drainage storage tank and discharging the drainage from the drainage storage tank;
A drainage control unit that is provided in the drainage discharge line and adjusts a flow rate of the drainage flowing through the drainage discharge line by an opening degree of a valve;
Based on the water level in the waste water storage tank detected by the water level detection unit, the valve is opened when the water level of the waste water reaches the upper limit water level, and the valve is closed when the water level of the waste water falls to the lower limit water level. A control unit that adjusts an opening when the valve is opened based on an arrival time until the water level of the waste water decreases from the upper limit water level to the lower limit water level, and discharges the waste water from the waste water storage tank When,
A drainage collecting apparatus characterized by comprising: In claim 1,
The control unit discharges the waste water from the waste water storage tank by setting the opening of the valve that is opened after the valve is closed to be smaller than the opening of the valve that is opened before the valve is closed. Wastewater recovery equipment. In claim 1 or 2,
When the water level of the waste water in the waste water storage tank becomes higher than the upper limit water level when the valve is opened, the control unit sets the opening of the valve to the same opening as the previous opening before closing, Alternatively, the waste water collecting apparatus is characterized in that the opening is between the opening when the water level of the waste water is higher than the upper limit water level and the previous opening before the valve closing. In any one of Claims 1 thru | or 3,
A waste water recovery apparatus, wherein the waste water is drain discharged from a load device.

Images