JP2012063051A - Steam control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steam control device improving system efficiency by maximally utilizing low-pressure steam, while ensuring high reliability.SOLUTION: The steam control device 100 includes a first regulating valve 114, a high-pressure path 112, a first medium-pressure path 116, a boosting device 124, a low-pressure path 122, a second medium-pressure path 126, a drive steam path 118, a second regulating valve 120, a first pressure gauge 132, a second pressure gauge 134, and a control section 136. When a first steam pressure is less than a threshold value, the control section fully closes the second regulating valve and controls the first regulating valve so that a second steam pressure becomes within a predetermined range. When the first steam pressure becomes not smaller than the threshold value, the control section maximally opens the second regulating valve and controls the first regulating valve as a priority so that the second steam pressure becomes within the predetermined range. When the second steam pressure cannot be kept within the predetermined range by only the control of the first regulating valve, the control section further controls the second regulating valve.

Description

  The present invention relates to a steam control device that supplies medium-pressure steam generated by mixing low-pressure steam and high-pressure steam to a production facility.

  When steam is used in production facilities or the like, generally steam is often generated by a combustion boiler or a waste heat boiler (hereinafter collectively referred to as a combustion boiler or the like) using fossil fuel. However, the current unit price of fossil fuels has significantly increased the unit price of steam for combustion boilers and the like, and combustion boilers are also excellent in terms of CO2 emissions, which are greenhouse gases. It's hard to say.

  Therefore, the use of steam generated in flash tanks installed in production facilities and heat pump steam generators (hereinafter collectively referred to as heat pump boilers, etc.) that have become practical due to recent technological advances has been studied. It was. Steam generated by a heat pump boiler or the like mainly uses exhaust heat exhausted from production facilities, and therefore is cheaper by about 20% to 50% in terms of steam unit price than a combustion boiler or the like. Therefore, if steam such as a heat pump boiler can be utilized to the maximum extent, it is possible to reduce the amount of steam generated by a combustion boiler and the like, and hence the amount of fossil fuel used, thereby reducing costs and CO2 emissions.

  However, at present, steam that can be efficiently generated with a heat pump boiler or the like is required in production facilities because the pressure is as low as about 0.1 MPaG and the temperature is about 120 ° C. even when a refrigerant is used. In many cases, conditions of temperature and pressure could not be satisfied (hereinafter, steam generated in a heat pump boiler or the like is referred to as low-pressure steam. On the other hand, steam generated in a combustion boiler is referred to as high-pressure steam). For this reason, in order to use low-pressure steam, it is necessary to increase the temperature and pressure by increasing the pressure.

  Therefore, in Patent Document 1, the steam (high pressure steam) generated in the exhaust heat steam boiler is ejected to the steam ejector, and the inside of the decompression evaporator is decompressed by the ejection action, and heated by the cooling water of the decompression evaporator by this decompression action. The evaporated hot water is evaporated, and the evaporated steam (low pressure steam) is mixed with the steam coming from the steam boiler in the steam ejector, and this is supplied to the steam utilization equipment side. Patent Document 1 states that the overall efficiency is increased by about 30% compared to the conventional example by taking out the steam from the two systems in this way.

  Another problem when using low-pressure steam generated by a heat pump boiler or the like is that the amount of generated steam is not constant (is likely to fluctuate). As described above, since heat pump boilers use exhaust heat exhausted from production facilities, etc., the amount of low-pressure steam generated by heat pump boilers etc. also changes when the amount of exhaust heat generated or temperature fluctuates. End up. Therefore, it is difficult to use a heat pump boiler or the like as a stable steam supply source (low reliability), and it is difficult to effectively use low-pressure steam.

  In order to solve the above problems, in Patent Document 2, an evaporator that evaporates water, a steam compressor that compresses steam generated by the evaporator, and steam that uses the steam compressed by the steam compressor as a steam utilization facility In a heat pump system equipped with a steam supply pipe for supplying to the steam, a steam measuring device is provided between the evaporator and the compressor to measure the state of the steam, and the steam flowing into the steam compressor is based on information from the measuring instrument. Means for adjusting the amount are provided. According to Patent Document 2, when steam is supplied to a factory or the like using a heat pump system, a highly reliable heat pump capable of performing control corresponding to changes in the amount of steam generated due to temperature fluctuations of exhaust heat that is the heat source. The system can be provided.

JP 2002-04943 A JP 2008-57876 A

  However, in the configuration described in Patent Document 1, although the overall efficiency of the system can be improved by using low-pressure steam, how to maintain the reliability of the system when the amount of low-pressure steam fluctuates. Is not specified. Therefore, there are still problems in ensuring the reliability of the system. On the other hand, with the configuration described in Patent Document 2, high system reliability can be obtained, but the efficiency of the system must be sacrificed. Therefore, in the prior art, it has been difficult to achieve both high reliability and improvement in system efficiency in a steam supply system using low-pressure steam in a heat pump boiler or the like.

  In view of such problems, the present invention improves system efficiency by making the best use of low-pressure steam even when both the amount of low-pressure steam generated and the amount of medium-pressure steam consumed in production facilities fluctuate. It aims at providing the steam control apparatus which can ensure the high reliability of the stable supply of the medium pressure steam to a production facility.

  In order to solve the above problems, a typical configuration of a steam control device according to the present invention is to simultaneously pressurize low-pressure steam generated by a low-pressure steam generation source using high-pressure steam generated by a high-pressure steam generation source. A steam control device that supplies medium-pressure steam in a predetermined range to a production facility by depressurizing high-pressure steam and mixing the decompressed low-pressure steam and the decompressed high-pressure steam. A first regulating valve that reduces the pressure to a predetermined range; a high-pressure path that leads high-pressure steam from the high-pressure steam generation source to the first regulating valve; and a first intermediate-pressure path that leads intermediate-pressure steam from the first regulating valve to the production facility A pressure increasing device for increasing the pressure of the low pressure steam to a predetermined range, a low pressure path for guiding the low pressure steam from the low pressure steam generating source to the pressure increasing device, and a first intermediate pressure between the first regulating valve and the production facility from the pressure increasing device. The second that joins the path and guides the medium pressure steam A pressure path, a drive steam path that branches from the high pressure path between the high pressure steam generation source and the first regulating valve and supplies the high pressure steam as drive steam to the booster, and a flow rate of the drive steam provided on the drive steam path A second pressure regulating valve, a first pressure gauge provided on the low pressure path for detecting the steam pressure in the low pressure path, and a junction between the second intermediate pressure path and the production facility on the first intermediate pressure path; A second pressure gauge that detects the steam pressure in the first intermediate pressure path between the junction and the production facility, the steam pressure detected by the first pressure gauge, and the steam pressure detected by the second pressure gauge. And a controller that controls the first regulator valve and the second regulator valve based on the control valve, and when the vapor pressure detected by the first pressure gauge is less than the threshold, the controller fully closes the second regulator valve. The first pressure control valve is controlled so that the steam pressure detected by the second pressure gauge is within a predetermined range, When the steam pressure detected by the gauge exceeds a threshold value, the second regulating valve is opened to the maximum, and the first regulating valve is controlled with priority so that the steam pressure detected by the second pressure gauge is within a predetermined range, When the steam pressure detected by the second pressure gauge cannot be maintained within a predetermined range only by controlling the first regulating valve, the second regulating valve is further controlled.

  According to the said structure, low pressure steam can be pressure | voltage-risen to the pressure suitable for utilization with a production facility with a pressure | voltage rise apparatus. At this time, since the booster uses high-pressure steam as driving steam, power for operating such boosting is unnecessary. Then, by supplying the production equipment with the medium pressure steam generated by mixing the pressurized low pressure steam and the high pressure steam decompressed by the first regulating valve, the steam used in the production equipment is expensive. The proportion of high-pressure steam can be reduced, and the system efficiency can be improved. It is desirable that the pressure of the medium pressure steam generated by mixing the high pressure low pressure steam and the pressure reduced high pressure steam is set to be substantially the same as the upper limit value of the predetermined range of the second pressure gauge. As a result, the control range in which the control of the first adjustment valve can be performed in preference to the control of the second adjustment valve can be widened.

  In particular, in the above configuration, when the steam pressure detected by the first pressure gauge (hereinafter, abbreviated as the first steam pressure) is less than a threshold value, that is, when the low-pressure steam cannot be used, the control unit controls the first regulating valve. The high pressure steam is depressurized to medium pressure steam and supplied to the production facility. Thereby, even in a state where low-pressure steam cannot be used, medium-pressure steam can be reliably supplied to the production facility. Then, in a state where the first steam pressure is equal to or higher than the threshold, that is, the low pressure steam can be used, the control unit opens the second regulating valve to the maximum extent and detects the steam pressure detected by the second pressure gauge by controlling the first regulating valve (hereinafter, Medium pressure steam is generated by adjusting the second steam pressure within a predetermined range. As a result, medium-pressure steam can be generated using the low-pressure steam to the maximum, and system efficiency can be further improved. Further, when the second steam pressure cannot be maintained within the predetermined range only by controlling the regulating valve, such as when the steam consumption fluctuates in the production facility in a state where low-pressure steam is generated, the second regulating valve is further provided. By controlling and adjusting the drive steam volume (high-pressure steam volume) to generate medium-pressure steam, it is possible to stably supply medium-pressure steam whose pressure is maintained within a predetermined range to the production equipment. Reliability can be ensured. Therefore, by utilizing the low-pressure steam as much as possible, it is possible to ensure high reliability while improving system efficiency and achieve both of them.

  The boosting device may be an ejector. The ejector sucks the low-pressure steam from the suction port while the internal pressure decreases in the process in which the high-pressure steam, which is the drive steam, passes from the drive steam port to the discharge port. As a result, the decompression of the high-pressure steam and the pressure increase of the low-pressure steam are performed simultaneously, and as a result of mixing the high-pressure steam and the low-pressure steam, medium-pressure steam in a predetermined range of pressure is generated. It is. Further, since it is driven by high-pressure steam, no power such as a power source is required, and it is possible to reduce power consumption and thus running costs.

  The above-described pressure increasing device may be configured by a turbine that is rotationally driven by high-pressure steam, and a compressor that is coaxially connected to the turbine and compresses the low-pressure steam by using the rotational force of the turbine. Even in such a configuration, the high-pressure steam is decompressed by driving the turbine, and the low-pressure steam is pressurized by the compressor operated by the rotational force of the turbine, so that the decompression of the high-pressure steam and the decompression of the low-pressure steam are performed simultaneously. Therefore, a turbine and a compressor (hereinafter referred to as a turbine compressor) are also suitable as a booster. Moreover, since this turbine compressor is also driven by high-pressure steam, the running cost can be reduced as described above.

  The low-pressure steam generation source may be a heat pump boiler or a flash tank. Heat pump boilers and flash tanks use the heat of the fluid supplied to them to generate steam. In other words, steam is generated without burning fossil fuel like a combustion boiler. Therefore, by using a heat pump boiler or a flash tank as a low-pressure steam generation source, it is possible to promote the reduction of fossil fuel consumption and hence the reduction of CO2 emission, thereby contributing to energy saving and environmental conservation.

  ADVANTAGE OF THE INVENTION According to this invention, the steam control apparatus which can ensure high reliability can be provided, improving a system efficiency by utilizing low-pressure steam to the maximum.

It is a figure which shows schematic structure of the steam control apparatus concerning 1st Embodiment. It is a flowchart explaining control of the steam control apparatus by the control part concerning 1st Embodiment. It is a figure which shows schematic structure of the steam control apparatus concerning 2nd Embodiment.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

(First embodiment)
FIG. 1 is a diagram illustrating a schematic configuration of a steam control apparatus 100 according to the first embodiment. The steam control apparatus 100 shown in FIG. 1 uses the high-pressure steam generated by the high-pressure steam generation source 102 to increase the pressure of the low-pressure steam generated by the low-pressure steam generation source 104 and at the same time depressurize and pressurize the high-pressure steam. Medium-pressure steam having a predetermined range of pressure generated by mixing the low-pressure steam and the decompressed high-pressure steam is supplied to the production facility 108.

  In the following description, high-pressure steam means steam at a pressure higher than the pressure of medium-pressure steam, that is, an upper limit value of a predetermined range, and low-pressure steam means a pressure lower than the lower limit value of the predetermined range. It is steam. In order to facilitate understanding, in the present embodiment, the pressure of the medium-pressure steam (pressure in a predetermined range) is set to 0.18 MPaG or more and 0.22 MPaG or less in terms of gauge pressure, and the high-pressure steam is 0.22 MPaG (the upper limit value of the predetermined range). ) And low-pressure steam are assumed to be steam having a pressure lower than 0.18 MPaG (the lower limit value of the predetermined range). However, the above numerical values are merely examples, and are not limited thereto.

  The high-pressure steam generation source 102 is a device that generates high-pressure steam. An example of such a high-pressure steam generation source 102 is a combustion-type boiler that generates steam (high-pressure steam) by burning fossil fuel. In the present embodiment, it is assumed that the high-pressure steam generation source 102 generates high-pressure steam of 0.6 MPaG, but the present invention is not limited to this.

  The low pressure steam generation source 104 is a device that generates low pressure steam. As such a low pressure steam generation source 104, a heat pump boiler or a flash tank is suitable. Since heat pump boilers and flash tanks generate steam using the heat of the fluid supplied to them, it is not necessary to burn fossil fuel like a combustion boiler. For this reason, by using a heat pump boiler or a flash tank as the low-pressure steam generation source 104, it is possible to promote the reduction of fossil fuel consumption and CO2 emission, thereby contributing to energy saving and environmental conservation. .

  The low-pressure steam generation source 104 is supplied with exhaust heat from the production facility 108 and its associated facilities (not shown). In the present embodiment, the drain steam (or drain water) after being used in the production facility 108 is supplied to the low-pressure steam generation source 104 through the drain path 106. Accordingly, the low-pressure steam generation source 104 can effectively use the heat of the drain steam (drain water) without exhausting it. Note that the present invention is not limited to this, and a configuration in which other fluid is supplied to the low-pressure steam generation source 104 is also possible.

  Next, the configuration of the steam control apparatus 100 according to the present embodiment will be described in detail. In addition, in order to make an understanding easy, in the following description, after explaining the component of the steam control apparatus 100, the control in the steam control apparatus 100 is explained in full detail.

  The high pressure steam generated in the high pressure steam generation source 102 is guided to the first regulating valve 114 through the high pressure path 112. The first regulating valve 114 reduces the pressure of the high-pressure steam guided by the high-pressure path 112 to a predetermined range. As a result, the high-pressure steam becomes medium-pressure steam, and is led from the first regulating valve 114 to the production facility 108 through the first medium-pressure path 116 (supplied to the production facility 108).

  On the other hand, the low-pressure steam generated in the low-pressure steam generation source 104 is guided to the booster 124 through the low-pressure path 122. The pressure increasing device 124 increases the pressure of the low pressure steam to a predetermined range. In the present embodiment, an ejector is used as the booster device 124. A drive steam path 118 branched from the high-pressure path 112 is connected between the high-pressure steam generation source 102 and the first regulating valve 114 to the ejector that is the booster 124. As a result, the high-pressure steam generated in the high-pressure steam generation source 102 is supplied to the booster 124 as driving steam. Further, a second regulating valve 120 is provided on the driving steam path 118, and the flow rate of the driving steam (high pressure steam) supplied to the booster 124 is adjusted thereby.

  When driving steam (high-pressure steam) from the driving steam path 118 passes through the booster 124, the pressure inside the booster 124 decreases, and low-pressure steam from the low-pressure path 122 is sucked into the booster 124. As a result, the booster 124 simultaneously performs decompression of the driving steam (high pressure steam) and boosting of the low pressure steam, and these become medium pressure steam. At this time, since the ejector is driven by driving steam (high-pressure steam) as described above, power such as a power source is unnecessary. Therefore, by using an ejector as the booster device 124, it is possible to reduce power consumption and thus running cost.

  In the pressure increasing device 124, the intermediate pressure steam generated by increasing the pressure of the low pressure steam, reducing the pressure of the high pressure steam, and mixing them is supplied from the pressure increasing device 124 to the first regulating valve 114 through the second intermediate pressure path 126. The first intermediate pressure path 116 joins the production facility 108 and is supplied to the production facility 108 through the first intermediate pressure path 116.

  Further, a first pressure gauge 132 for detecting the vapor pressure in the low pressure path 122 is provided on the low pressure path 122, and the confluence of the second intermediate pressure path 126 on the first intermediate pressure path 116 and the production facility 108. Is provided with a second pressure gauge 134 for detecting the vapor pressure of the first intermediate pressure path 116 therebetween. These pressure gauges (PT: Pressure Transmitter) are connected to the control unit 136. Such a control unit 136 not only controls the operation of the entire steam control apparatus 100, but also in the present embodiment, in particular, the steam pressure (first steam pressure) detected by the first pressure gauge 132 and the second pressure gauge 134 detect. The first regulating valve 114 and the second regulating valve 120 are controlled based on the steam pressure (second steam pressure) (the broken line in FIG. 1 indicates the connection relationship with the control unit 136).

  FIG. 2 is a flowchart illustrating control of the steam control apparatus 100 by the control unit according to the first embodiment. Hereinafter, the control of the steam control device 100, particularly the first regulating valve 114 and the second regulating valve 120 by the control unit 136 will be described in detail with reference to FIG. In FIG. 2, the vapor pressure (first vapor pressure) detected by the first pressure gauge 132 is denoted as PT1, and the vapor pressure (second vapor pressure) detected by the second pressure gauge is denoted as PT2. Further, the values of the pressure, temperature, and steam amount shown in FIG. 2 are all examples, and are not limited thereto.

  Here, as described above, in the present embodiment, the pressure of the intermediate pressure steam (pressure in a predetermined range) is exemplified as 0.18 MPaG or more and 0.22 MPaG or less, and the second pressure gauge 134 is provided in the production facility 108. The steam pressure immediately before the supply is detected. Therefore, the control unit 136 controls the second steam pressure PT2 detected by the second pressure gauge 134 to be within a predetermined range.

  As shown in FIG. 2, if there is no stop signal after activation of the steam control apparatus 100 (NO in step 302), the control unit 136 uses the first steam pressure PT1 that is the steam pressure detected by the first pressure gauge 132 as a threshold value. It is determined whether this is the case (step 304). The threshold value is whether the low-pressure steam generated in the low-pressure steam generation source 104 can be boosted to a predetermined pressure by the booster 124, in other words, the low-pressure steam generated in the low-pressure steam generation source 104 is used as medium-pressure steam. It is a value for judging whether it is possible.

  Specifically, as described above, the low-pressure steam generation source 104 generates low-pressure steam using the exhaust heat from the production facility 108 or the like. Therefore, when the exhaust heat generation source is not operating, for example, immediately after the operation of the production facility 100, low-pressure steam cannot be generated. Even when the production facility 108 is in operation, the pressure of the low-pressure steam is extremely low, and the low-pressure steam cannot be used unless the pressure is raised to a predetermined range by the booster 124.

  Therefore, in the present embodiment, the pressure of the low-pressure steam that can be boosted to a predetermined range by the booster 124 is set as a threshold value, and the control unit 136 determines whether or not the first steam pressure PT1 satisfies the threshold value in step 304. is doing. In the present embodiment, the threshold is exemplified as 0.09 MPaG, but the threshold is not limited to this, and the threshold can be arbitrarily determined according to the processing capability of the booster 124.

  If the first steam pressure PT1 is less than the threshold value (0.09 MPaG) (NO in step 304), the control unit 136 closes the second regulating valve 120 (step 306), and the second steam pressure PT2 Is less than or equal to the upper limit value (0.22 MPaG) of the predetermined range (step 308). During the initial operation of the steam control apparatus 100, the first regulating valve 114 is fully closed and the supply of medium-pressure steam to the production facility 108 has not started, so the second steam pressure PT2 is naturally an upper limit value within a predetermined range. It is as follows (YES in step 308).

  Next, the control unit 136 determines whether or not the second steam pressure PT2 is equal to or higher than a lower limit (0.18 MPaG) of a predetermined range (step 310). Also in this case, for the same reason as described above, the second steam pressure PT2 is naturally less than the lower limit value of the predetermined range (NO in step 310), and therefore the control unit 136 fully opens the first adjustment valve 114. Is determined (step 312). During the initial operation of the steam control apparatus 100, the first regulating valve 114 is fully closed, that is, not fully opened (NO in step 312), so the control unit 136 gradually opens the first regulating valve 114 (step 314). .

  And the control part 136 repeats from step 310 to step 314 until 2nd steam pressure PT2 becomes more than the lower limit of the predetermined range. However, when the second steam pressure PT2 is less than the lower limit value of the predetermined range (NO in step 310) and the first adjustment valve 114 is fully open (YES in step 312), an error is output (step 320). The steam control apparatus 100 is stopped.

  On the other hand, if the second steam pressure PT2 becomes equal to or higher than the lower limit value of the predetermined range by repeating steps 310 to 314 (YES in step 310), the process returns to step 302. In this state, the intermediate pressure steam generated by the pressure reduction of the high pressure steam in the first regulating valve 114 is supplied to the production facility 108 through the first intermediate pressure path 116. In the present embodiment, high-pressure steam generated at the high-pressure steam generation source 102 and having a pressure of 0.6 MPaG, a temperature of 165 ° C., and a flow rate of 4 t / h is passed through the first regulating valve 114 at a pressure of 0.2 MPaG and a temperature of 133 ° C. The pressure steam is adjusted and supplied to the production facility 108 at a flow rate of 4 t / h.

  Then, the control unit 136 again confirms the stop signal in step 302 and determines the threshold value of the first steam pressure PT1 in step 304. Thereby, it is confirmed again whether the low-pressure steam which can be used is generated. If the first steam pressure PT1 is still less than the threshold value (NO in step 304), after step 306, the control unit 136 determines again whether the second steam pressure PT2 is equal to or lower than the upper limit value of the predetermined range (step). 308). If the second steam pressure PT2 is equal to or lower than the upper limit value of the predetermined range (YES in Step 308), Step 310 to Step 302 described above are repeated.

  On the other hand, if the second steam pressure PT2 exceeds the upper limit of the predetermined range (NO in step 308), the control unit 136 confirms whether the first adjustment valve 114 is fully closed (step 316), and the first adjustment valve If 114 is not fully closed (NO in step 316), the first regulating valve 114 is gradually closed (step 318), and the process returns to step 308. And the control part 136 repeats from step 308 to step 318, and controls so that 2nd steam pressure PT2 may be settled in the predetermined range. When the second steam pressure PT2 exceeds the upper limit of the predetermined range (NO in step 308), if the first regulating valve 114 is fully closed (YES in step 316), an error is output (step 316). 320), the steam control device 100 is stopped.

  Even if the first steam pressure PT1 is less than the threshold, such as when low-pressure steam is not generated or the pressure of the low-pressure steam is extremely low by the control in Steps 306 to 318 described above, the control unit 136 controls the first regulating valve 114 based on the second steam pressure PT2 to depressurize the high-pressure steam so as to be within a predetermined range, thereby generating intermediate-pressure steam. This makes it possible to reliably supply the medium-pressure steam to the production facility 108 even when low-pressure steam is not generated.

  Next, the control at the time of generation of medium pressure steam by mixing low pressure steam and high pressure steam, that is, the control at the time of generation of low pressure steam having a pressure equal to or higher than a threshold, which is the most characteristic of the present embodiment will be described. If the first steam pressure PT1 is equal to or greater than the threshold (0.09 MPaG) (YES in step 304), that is, if low-pressure steam that can be boosted to a predetermined range by the booster 124 becomes available in the low-pressure steam generation source 104, control is performed. The unit 136 confirms that the second adjustment valve 120 is fully opened (step 321). When the low-pressure steam becomes available, the second regulating valve 120 is in a fully closed state (NO in step 321), so the control unit 136 gradually opens the second regulating valve 120 (step 322). As a result, the high-pressure steam generated in the high-pressure steam generation source 102 is supplied to the booster 124 through the driving steam path 118 as driving steam. Then, the low pressure steam generated in the low pressure steam generation source 104 is sucked into the booster 124.

  When the second adjustment valve 120 is gradually opened in step 322, the control unit 136 determines whether or not the second steam pressure PT2 is equal to or higher than a lower limit (0.18 MPaG) of a predetermined range (step 324). If the second steam pressure PT2 is less than the lower limit value of the predetermined range (NO in step 324), the control unit 136 determines whether the first adjustment valve 114 is fully open (step 326). When the first adjustment valve 114 is not fully opened (NO in step 326), the control unit 136 gradually opens the first adjustment valve 114 (step 328), and the second steam pressure PT2 becomes equal to or higher than the lower limit value of the predetermined range. Steps 324 to 328 are repeated. Even if the second steam pressure PT2 is less than the lower limit value of the predetermined range (NO in step 324), an error is output (step 326) if the first regulating valve 114 is fully opened (YES in step 326). 320), the steam control device 100 is stopped.

  On the other hand, when the second steam pressure PT2 becomes equal to or higher than the lower limit value of the predetermined range by repeating Step 324 to Step 328 (YES in Step 324), the control unit 136 sets the second steam pressure PT2 to the upper limit of the predetermined range. It is judged whether it is below the value (0.22 MPaG) (step 330). If the second steam pressure PT2 is equal to or lower than the upper limit value of the predetermined range (YES in step 330), the medium pressure steam composed of the high pressure steam decompressed and the decompressed low pressure steam is within the predetermined range. Means. In this embodiment, a pressure of 0.22 MPaG is obtained by a high pressure steam having a pressure of 0.6 MPaG, a temperature of 165 ° C., a flow rate of 3.11 t / h, and a low pressure steam of a pressure of 0.1 MPaG, a temperature of 120 ° C., and a flow rate of 0.89 t / h. The medium-pressure steam at a temperature of 136 ° C. is generated and supplied to the production facility 108 at a flow rate of 4 t / h. Then, the control unit 136 returns to Step 302 and repeats the control after Step 302.

  If the second steam pressure PT2 exceeds the upper limit of the predetermined range (NO in step 330), the control unit 136 determines whether the first adjustment valve 114 is fully closed (step 332). When the first adjustment valve 114 is not fully closed, that is, when the first adjustment valve 114 is open (NO in step 332), the control unit 136 gradually closes the first adjustment valve 114 (step 334), and the second steam Steps 330 to 334 are repeated until the pressure PT2 becomes equal to or lower than the upper limit value of the predetermined range.

  As described above, when the first steam pressure PT1 is equal to or higher than the threshold value in step 304 (a state in which the low pressure steam is available in the low pressure steam generation source 104), the control unit 136 sets the second steam pressure PT2 within the predetermined range. By controlling the first regulating valve 114 with priority, intermediate pressure steam is generated. At this time, unless the second adjustment valve 120 is fully opened (NO in step 321), the second adjustment valve 120 is opened to the maximum by executing the control (step 322) for gradually opening the second adjustment valve 120. Therefore, medium pressure steam can be generated using the low pressure steam to the maximum, and the system efficiency can be further improved.

  On the other hand, as a result of repeating Step 330 to Step 334, the first regulating valve 114 is fully closed although the second steam pressure PT2 exceeds the upper limit of the predetermined range (NO in Step 336). In this case (YES in step 332), the second steam pressure PT2 cannot be maintained within the predetermined range only by controlling the first adjustment valve 114. Therefore, the control unit 136 determines whether or not the second adjustment valve 120 is fully closed (step 336). If the second regulating valve 120 is not fully closed, that is, if the second regulating valve 120 is open (NO in step 336), the control unit 136 gradually closes the second regulating valve 120 (step 338), Steps 330 to 338 are repeated until the steam pressure PT2 becomes equal to or lower than the upper limit value of the predetermined range. Even if Step 330 to Step 338 are repeated, the second steam pressure PT2 exceeds the upper limit value in the predetermined range (NO in Step 336), and both the first adjustment valve 114 and the second adjustment valve 120 are fully closed. In the case (YES at step 332, YES at step 336), the control unit 136 outputs an error (step 320) and stops the steam control apparatus 100.

  As described above, in a situation where low-pressure steam is available, when the second steam pressure PT2 cannot be maintained within a predetermined range only by controlling the first regulating valve 114, the second regulating valve 120 is controlled to control the driving steam amount ( Medium pressure steam is generated by adjusting the amount of high pressure steam. Thereby, even if the amount of low-pressure steam varies, medium-pressure steam can be stably supplied to the production facility 108. Therefore, by utilizing the low-pressure steam as much as possible, it is possible to ensure high reliability while improving system efficiency and achieve both of them.

  Note that, when the stop signal is input from the user during the initial operation of the steam control apparatus 100 or the loop from Step 310 and Step 330 (YES in Step 302), the control unit 136 causes the first adjustment valve 114 to operate. And the 2nd regulating valve 120 is fully closed (step 340), and the steam control apparatus 100 is stopped.

  As described above, according to the steam control apparatus 100 according to the present embodiment, the medium pressure steam generated by mixing the low pressure steam and the high pressure steam by the pressure increasing device 124 is supplied to the production facility 108, so The ratio of cost high-pressure steam can be reduced, and the system efficiency can be improved. Further, the control unit 136 dynamically controls the opening of the first adjustment valve 114 and the second adjustment valve 120 based on the first steam pressure PT1 and the second steam pressure PT2, thereby maximizing the low pressure steam. While being used for a limited time, it is possible to stably supply medium-pressure steam while avoiding the effects of fluctuations in the amount of low-pressure steam and fluctuations in medium-pressure steam consumption in production facilities. Therefore, high reliability can be ensured while improving system efficiency by using low-pressure steam, and both of them can be achieved.

(Second Embodiment)
Next, the steam control apparatus 200 according to the second embodiment will be described. FIG. 3 is a diagram illustrating a schematic configuration of the steam control apparatus 200 according to the second embodiment. In addition, about the element which shows the function and structure substantially the same as the component of the steam control apparatus 100 of 1st Embodiment mentioned above, the same code | symbol is attached | subjected and description is abbreviate | omitted. Further, the operation of the control unit 136 in the steam control apparatus 200 is the same as the control described in the first embodiment, and thus the description thereof is omitted.

  In the steam control apparatus 100 of the first embodiment, an ejector is used as a booster, whereas in the steam control apparatus 200 according to the second embodiment, a turbine compressor is used as the booster 224 as shown in FIG. to differ greatly.

  The booster 224 includes a turbine 226 that is rotationally driven by high-pressure steam, and a compressor 228 that is coaxially connected to the turbine 226 and compresses the low-pressure steam using the rotational force to boost the pressure. In this configuration, when high-pressure steam generated in the high-pressure steam generation source 102 is supplied to the turbine 226 as drive steam through the drive steam path 118, the drive steam (high-pressure steam) is decompressed by driving the turbine 226. Then, the compressor 228 is operated by the rotational force of the turbine 226 driven by the driving steam, and the low-pressure steam is pressurized. Therefore, also in the steam control apparatus 200, the pressure increasing device 224 simultaneously performs the decompression of the high pressure steam and the pressure increase of the low pressure steam.

  As a specific example, when the first steam pressure PT1 is less than the threshold (when the low-pressure steam is not used), the pressure generated at the high-pressure steam generation source 102 is 0.6 MPaG, as in the first embodiment. The high pressure steam at a temperature of 165 ° C. and a flow rate of 4 t / h is adjusted to a medium pressure steam at a pressure of 0.2 MPaG and a temperature of 133 ° C. by the first regulating valve 114 and supplied to the production facility 108 at a flow rate of 4 t / h.

  On the other hand, when the first steam pressure PT1 is equal to or higher than the threshold value (when the low pressure steam is used), the high pressure steam from the high pressure steam generation source 102 at the pressure of 0.6 MPaG, the temperature of 165 ° C., and the flow rate of 2.03 t / h is used as the driving steam. It is supplied to the turbine 226. The driving steam (high-pressure steam) is depressurized by rotating the turbine 226 (the working loses enthalpy and the pressure and temperature decrease), the pressure is 0.22 MPaG, the temperature is 136 ° C., and the flow rate is 2.03 t / h. Becomes medium pressure steam. Then, the low-pressure steam having a pressure of 0.1 MPaG, a temperature of 120 ° C., and a flow rate of 1.97 t / h from the low-pressure steam generation source 104 is pressurized by the compressor 228 operated by the rotation of the turbine 226, and the pressure is 0.22 MPaG, the temperature After it becomes superheated steam at 166 ° C. and a flow rate of 2.2 t / h, it is mixed with reduced-pressure driving steam fed from the junction path 230 to become 0.22 MPaG, 136 ° C. medium pressure steam, and the production equipment 108 To be supplied.

  As described above, the pressure increase device 224 of the steam control apparatus 200 according to the second embodiment can also appropriately reduce the pressure of the high pressure steam and the pressure of the low pressure steam, and suitably generate medium pressure steam obtained by mixing them. Therefore, the same advantages as those of the steam control apparatus 100 can be obtained even with such a configuration. The turbine compressor is also driven by high-pressure steam, so the running cost can be reduced.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this embodiment. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  INDUSTRIAL APPLICABILITY The present invention can be used as a steam control device that supplies medium-pressure steam generated by mixing low-pressure steam and high-pressure steam to a production facility.

DESCRIPTION OF SYMBOLS 100 ... Steam control apparatus, 102 ... High pressure steam generation source, 104 ... Low pressure steam generation source, 106 ... Drain path, 108 ... Production equipment, 112 ... High pressure path, 114 ... First regulating valve, 116 ... First intermediate pressure path, 118 ... Drive steam path, 120 ... Second regulating valve, 122 ... Low pressure path, 124 ... Pressure increasing device, 126 ... Second intermediate pressure path, 132 ... First pressure gauge, 134 ... Second pressure gauge, 136 ... Control unit, 200 ... Steam control device, 224 ... Booster, 226 ... Turbine, 228 ... Compressor, 230 ... Merge path

Claims (4)

Using the high-pressure steam generated in the high-pressure steam generation source, the low-pressure steam generated in the low-pressure steam generation source is pressurized, and at the same time, the high-pressure steam is decompressed, and the pressurized low-pressure steam and the decompressed high-pressure steam are A steam control device for supplying medium-pressure steam in a predetermined range of pressure generated by mixing to a production facility,
A first regulating valve for reducing the pressure of the high-pressure steam to the predetermined range;
A high-pressure path for guiding the high-pressure steam from the high-pressure steam generation source to the first regulating valve;
A first intermediate pressure path for guiding the intermediate pressure steam from the first regulating valve to the production facility;
A booster that boosts the pressure of the low-pressure steam to the predetermined range;
A low-pressure path for guiding the low-pressure steam from the low-pressure steam generation source to the booster;
A second intermediate pressure path that joins the first intermediate pressure path from the booster to the first intermediate pressure path and guides the intermediate pressure steam between the first regulating valve and the production facility;
A driving steam path that branches from the high-pressure path between the high-pressure steam generation source and the first regulating valve and supplies the high-pressure steam as driving steam to the booster;
A second regulating valve provided on the driving steam path for adjusting the flow rate of the driving steam;
A first pressure gauge provided on the low-pressure path and detecting a vapor pressure of the low-pressure path;
On the first intermediate pressure path, provided between the production point of the second intermediate pressure path and the production facility, the vapor pressure of the first intermediate pressure path between the junction point and the production facility is A second pressure gauge to be detected;
A control unit that controls the first adjustment valve and the second adjustment valve based on the vapor pressure detected by the first pressure gauge and the vapor pressure detected by the second pressure gauge;
With
The controller is
If the vapor pressure detected by the first pressure gauge is less than a threshold value, the second adjustment valve is fully closed, and the first adjustment is performed so that the vapor pressure detected by the second pressure gauge is within the predetermined range. Control the valve,
When the vapor pressure detected by the first pressure gauge becomes a threshold value or more, the second adjustment valve is opened to the maximum, and the first adjustment is performed so that the vapor pressure detected by the second pressure gauge is within the predetermined range. The valve is preferentially controlled, and when the steam pressure detected by the second pressure gauge cannot be maintained within a predetermined range only by controlling the first regulating valve, the second regulating valve is further controlled. Steam control device.   The steam control apparatus according to claim 1, wherein the booster is an ejector.   The booster is composed of a turbine that is rotationally driven by the high-pressure steam, and a compressor that is coaxially connected to the turbine and compresses and boosts the low-pressure steam using the rotational force of the turbine. The steam control apparatus according to claim 1.   The steam control apparatus according to any one of claims 1 to 3, wherein the low-pressure steam generation source is a heat pump boiler or a flash tank.

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