JP2022100964A - Steam use system with circulation path - Google Patents

Abstract

To provide a steam use system with a circulation path capable of supplying steam and a low-temperature liquid such as cooling water in simple configuration.SOLUTION: Inside of a circulation path 10, a mixed fluid (steam and warm water, etc.,) is circulated by driving a pump 2, and a steam use device 18 performs predetermined operation with the mixed fluid as a heat source. A control unit 8 supplies steam through a steam supply pipe 31 and maintains the inside of the circulation path 10 at a predetermined reference high pressure. The control unit 8 supplies cooling water into the circulation path 10 through a cooling water supply pipe 32 but since the inside of the circulation path 10 is maintained at the reference high pressure, cooling water cannot be injected in such a state. Therefore, the mixed fluid in the circulation path 10 is discharged from a discharge pipe 34 just for a required quantity. Thus, the pressure in the circulation path 10 is reduced, thereby providing a state where the supply of cooling water is acceptable.SELECTED DRAWING: Figure 1

Description

The steam-using system having a circulation path according to the present application relates to a technique for constructing a system for circulating a target fluid toward a target device such as a steam-using device.

The steam use system is a system that supplies steam generated by a boiler or the like to a steam use device, and the steam use device performs a predetermined operation using the given steam as a heat source. There are various steam-using devices, but depending on the operation of the device, not only steam but also cooling water may be supplied.

As such a steam use system, there is an apparatus disclosed in Patent Document 1 described later. In this heating / cooling device, a steam supply pipe 15 is connected to the jacket portion 2 of the reaction kettle 1 as a steam-using device via a heating fluid tank 24. Further, a cooling vacuum tank 16 is arranged with respect to the jacket portion 2 of the reaction kettle 1 and is connected by a pipeline 14.

Then, one end of the discharge pipe 19 is connected to the lower portion of the jacket portion 2, and the other end is connected to the nozzle portion 12 of the ejector 6. The ejector 6 is provided on the circulation passage 9, and both ends of the circulation passage 9 are connected to the tank 8. A circulation pump 10 is further provided in the circulation passage 9, and cooling water or the like in the tank 8 circulates in the circulation passage 9.

In this heating / cooling device, when switching between heating and cooling, the heating fluid tank 24 and the cooling vacuum tank 16 are switched respectively, so that the heating process and the cooling process can be switched without time delay, and the temperature controllability is improved. ..

Japanese Unexamined Patent Publication No. 2010-151359

However, in the heating / cooling device disclosed in Patent Document 1 described above, a heating fluid tank 24 is provided to supply steam to the jacket portion 2 of the reaction vessel 1 as a steam-using device, and cooling water is further supplied. Therefore, a cooling vacuum tank 16 and a tank 8 are provided. That is, in the heating / cooling device disclosed in Patent Document 1, it is necessary to provide these various tanks, which leads to an increase in size and complexity of the device.

Therefore, the steam use system having a circulation path according to the present application provides a steam use system having a circulation path capable of supplying a low temperature liquid such as steam and cooling water with a simple configuration.

The steam use system having a circulation path according to the present application is
A circulation path in which a target fluid produced by mixing a vapor and a cold liquid circulates inside while maintaining a predetermined high pressure higher than atmospheric pressure.
A target device that receives heat from the target fluid circulating in the circulation path and performs a predetermined operation.
Circulating power means for circulating the target fluid in the circulation path,
A steam supply means that supplies the steam toward the circulation path,
A low temperature liquid supply means for supplying the low temperature liquid toward the circulation path,
A discharge on-off valve provided in the circulation path, which discharges a part of the target fluid circulating in the circulation path to the outside of the circulation path by opening the valve to supply the low-temperature liquid. valve,
It is characterized by being equipped with.

In the steam use system having the circulation path according to the present application, in order to supply the low temperature liquid, the discharge on-off valve discharges a part of the target fluid out of the circulation path to receive the supply of the low temperature liquid to the circulation path. Let me.

That is, the target fluid circulates in the circulation path at high pressure, but the pressure in the circulation path is reduced by discharging a part of the target fluid out of the circulation path through the discharge on-off valve, and the low temperature liquid flows in the circulation path. It can be made easy to supply. Therefore, it is possible to provide a steam use system having a circulation path capable of supplying a low temperature liquid such as steam and cooling water with a simple configuration.

It is a block diagram of the whole which shows the steam use system 1 which is 1st Embodiment of the steam use system which has a circulation path which concerns on this application. It is a flowchart of the program executed by the control unit 8 shown in FIG. It is a graph which shows the relationship between the detection temperature b of the circulation path 10 in the steam use system 1 shown in FIG. 1 and the pressure c to be lowered.

[Explanation of terms in the embodiment]
The main terms presented in the embodiments correspond to the following elements of a steam-using system having a circulation path according to the present application, respectively.

Steam use system 1 ・ ・ ・ Steam use system with circulation path Pump 2 ・ ・ ・ Circulation power means Discharge solenoid valve 4 ・ ・ ・ Discharge switching valve Temperature sensor 6 ・ ・ ・ Temperature measuring means Control unit 8 ・ ・ ・ Control means Circulation path 10 ・ ・ ・ Circulation path Steam use device 18 ・ ・ ・ Target device Steam solenoid valve 21 ・ ・ ・ Steam supply means Cooling water solenoid valve 22 ・ ・ ・ Low temperature liquid supply means Cooling water ・ ・ ・ Low temperature liquid mixed fluid・ ・ ・ Target fluid discharge signal ・ ・ ・ Valve opening signal Temperature signal ・ ・ ・ Detection signal

[First Embodiment]
A first embodiment of a steam-using system having a circulation path according to the present application will be described.

(Explanation of the configuration of steam use system 1)
FIG. 1 shows the overall configuration of the steam use system 1 according to the present embodiment. The steam use system 1 includes a circulation path 10 provided with a pump 2. Then, by driving the pump 2, a mixed fluid such as steam circulates in the circulation path 10. The mixed fluid is a fluid in which steam, hot water, flash steam and drain generated by condensation of steam are mixed. The upstream side of the circulation is the primary side and the downstream side is the secondary side.

A steam-using device 18 is installed on the circulation path 10, and the steam-using device 18 exchanges heat with the mixed fluid circulating in the circulation path 10 and performs a predetermined operation using the mixed fluid as a heat source. The steam use system 1 is a closed system and circulates the mixed fluid while maintaining the high pressure (reference high pressure) in the circulation path 10.

A pressure sensor 7 is provided in the circulation path 10 on the primary side of the steam use device 18, and detects the pressure in the circulation path 10 and outputs a pressure signal. Further, a temperature sensor 6 is provided in the circulation path 10 on the primary side of the pressure sensor 7, and detects the temperature of the circulation path 10 and outputs a temperature signal. Then, the pressure signal and the temperature signal are taken into the control unit 8 through the line L1 and the line L2, respectively.

The pump 2 sends out and circulates the mixed fluid from the primary side to the secondary side, and an ejector 15 driven by the mixed fluid is connected to the circulation path 10 on the secondary side of the pump 2. A steam supply pipe 31 is connected to the suction port of the ejector 15, and steam generated by the boiler is supplied (sucked) into the circulation path 10 through the steam supply pipe 31. The steam supply pipe 31 is provided with a steam solenoid valve 21.

Further, a cooling water supply pipe 32 is connected to the circulation path 10 on the primary side of the pump 2, and cooling water is supplied into the circulation path 10 through the cooling water supply pipe 32. The supplied cooling water is heated by steam and mixed into the mixed fluid as hot water. The cooling water supply pipe 32 is provided with a cooling water solenoid valve 22.

A discharge pipe 34 is connected to the circulation path 10 on the secondary side of the steam use device 18, and the discharge pipe 34 is provided with a discharge solenoid valve 4. Then, the control unit 8 gives a signal to the exhaust solenoid valve 4, the steam solenoid valve 21, and the cooling water solenoid valve 22 through the line L3, the line L6, and the line L7, respectively, and controls the opening and closing of each solenoid valve.

(Explanation of operation of steam use system 1)
Next, the operation of the steam use system 1 will be described. As described above, the mixed fluid circulates in the circulation path 10 by the drive of the pump 2, and the steam use device 18 performs a predetermined operation using this mixed fluid as a heat source.

While the steam use system 1 is operating, the control unit 8 repeats the process of the flowchart shown in FIG. The contents of this process of the control unit 8 will be described based on the flowchart. First, the control unit 8 takes in the pressure signal from the pressure sensor 7 through the line L1, grasps the pressure a in the circulation path 10 (step S2), and determines whether the pressure a is lower than the predetermined reference high pressure. (Step S4).

Then, when the pressure a is lower than the predetermined reference high pressure, the control unit 8 gives a signal to the steam solenoid valve 21 to open the valve, and passes through the steam supply pipe 31 until the pressure a reaches the predetermined reference high pressure. Supply steam into the circulation path 10 (step S6). By opening the solenoid valve 21 for steam, steam is sucked into the ejector 15 and supplied into the circulation path 10.
If the pressure a is higher than the predetermined reference high pressure in step S4, the process proceeds to the process after step S8 as it is, but the steam in the circulation path 10 is condensed by being used as a heat source of the steam use device 18. As a result, drainage is generated, so that the pressure a naturally drops and reaches the reference high pressure.

Next, the control unit 8 takes in the temperature signal from the temperature sensor 6 through the line L2, grasps the temperature b in the circulation path 10 (step S8), and determines whether or not the temperature b is higher than the predetermined reference temperature. (Step S10). The reference temperature is set according to the temperature of the heat source required by the steam-using device 18, but the steam generated by the boiler is generally high in temperature, and the temperature is too high to be used as the heat source of the steam-using device 18 as it is. too high.

Therefore, it is necessary to supply the cooling water into the circulation path 10, but since the inside of the circulation path 10 is maintained at the reference high pressure, the cooling water cannot be introduced in this state. Therefore, in the present embodiment, the pressure in the circulation path 10 is reduced by discharging the mixed fluid in the circulation path 10 from the discharge pipe 34 in a required amount, and the supply of the cooling water is made acceptable.

That is, when the temperature b is higher than the predetermined reference temperature, the control unit 8 proceeds from step S10 to step S12, and obtains the pressure c to be lowered based on the temperature b grasped in step S8. Specifically, the control unit 8 stores the relationship represented by the graph in FIG. 3 in advance, and obtains the pressure c to be reduced from the temperature b. The control unit 8 obtains the amount of cooling water to be supplied from the difference between the temperature b and the reference temperature based on a predetermined mathematical formula stored in advance, and the amount of reduced pressure in the circulation path 10 required to supply this amount of cooling water. May be calculated.

After finding the pressure c to be reduced, the control unit 8 sends a signal to the discharge solenoid valve 4 to open the valve, and circulates through the discharge pipe 34 so that the pressure in the circulation path 10 drops within the range of the pressure c. Drain the mixed fluid in the path 10 (step S14). Since the pressure inside the circulation path 10 is high, the mixed fluid is automatically discharged by opening the discharge solenoid valve 4.
After that, the control unit 8 gives a signal to the cooling water solenoid valve 22 to open the valve, and supplies the cooling water into the circulation path 10 through the cooling water supply pipe 32 (step S16). Since the pressure in the circulation path 10 is reduced by the process of step S12, the cooling water is supplied reasonably. At this time, since the cooling water supply pipe 32 is connected to the circulation path 10 on the primary side of the pump 2 as described above, the cooling water is smoothly drawn into the circulation path 10 by the drive of the pump 2.

If the temperature b is lower than the predetermined reference temperature in step S10, the process is terminated as it is, but since steam is supplied into the circulation path 10 in step S6, the steam is supplied and mixed. The fluid is heated, and accordingly the temperature b gradually rises to reach the reference temperature.

In the present embodiment, the solenoid valve 4 for discharge is exemplified as the discharge solenoid valve 4, but instead of the solenoid valve 4 for discharge, the pressure in the pipe can be controlled proportionally to the input current. It is also possible to use a valve or a pressure reducing valve with proportional electromagnetic relief, which is a combination of a proportional electromagnetic relief valve and a pressure reducing valve.

Further, in the present embodiment, the pressure sensor 7 is provided in the circulation path 10 on the primary side of the steam use device 18, and the pressure in the circulation path 10 is detected. On the other hand, pressure sensors are provided on the primary side and the secondary side of the steam use device 18, respectively, and the pressure to be replenished is grasped by finding the pressure difference before and after the steam use device 18, and the reference height is in the circulation path 10. It may be controlled to maintain the pressure.

[Other embodiments]
In the above-described embodiment, cooling water is exemplified as the low-temperature liquid, but other liquids may be used as long as they lower the temperature in the circulation path. Further, in the above-described embodiment, the discharge solenoid valve 4, the proportional electromagnetic relief valve, or the pressure reducing valve with the proportional electromagnetic relief is exemplified as the discharge on-off valve, but the valve is provided in the circulation path and circulates by opening the valve. Other valves can be adopted as long as a part of the target fluid circulating in the path is discharged to the outside of the circulation path.

Further, instead of the solenoid valve 4 for discharge, a relief valve or a safety valve that does not receive a valve opening signal, opens the valve when the pressure exceeds the set pressure, and closes when the pressure falls below the set pressure can be used as the discharge solenoid valve 4. In this case, the pressure c to be reduced in step S12 is the same as the set pressure (predetermined value).

Further, in the above-described embodiment, the pump 2 is exemplified as the circulation power means, but another configuration can be used as long as a part of the target fluid is circulated in the circulation path. Further, in the above-described embodiment, the cooling water supply pipe 32 is connected to the circulation path 10 on the primary side of the pump 2 so that the cooling water is smoothly drawn into the circulation path 10 by the drive of the pump 2. , An ejector for cooling water may be arranged in the circulation path 10, and the cooling water may be drawn by this ejector.

1: Steam use system 2: Pump 4: Solenoid valve for discharge 6: Temperature sensor
8: Control unit 10: Circulation path 18: Steam usage device 21: Solenoid valve for steam
22: Solenoid valve for cooling water

Claims (3)

A circulation path in which a target fluid produced by mixing a vapor and a cold liquid circulates inside while maintaining a predetermined high pressure higher than atmospheric pressure.
A target device that receives heat from the target fluid circulating in the circulation path and performs a predetermined operation.
Circulating power means for circulating the target fluid in the circulation path,
A steam supply means that supplies the steam toward the circulation path,
A low temperature liquid supply means for supplying the low temperature liquid toward the circulation path,
A discharge on-off valve provided in the circulation path, which discharges a part of the target fluid circulating in the circulation path to the outside of the circulation path by opening the valve to supply the low-temperature liquid. valve,
A steam-based system with a circulation path characterized by being equipped with. In the steam use system having the circulation path according to claim 1.
The discharge on-off valve is configured to open in response to a valve opening signal, and further
A temperature measuring means that measures the temperature of the target fluid circulating in the circulation path and outputs a detection signal.
Based on the detection signal from the temperature measuring means, a valve opening signal is given to the discharge on-off valve to discharge a part of the target fluid out of the circulation path, thereby receiving the supply of the low temperature liquid to the circulation path. Control means,
A steam-based system with a circulation path characterized by being equipped with. In a steam use system having a circulation path according to claim 1 or 2.
The circulation power means is connected to the circulation path, and the target fluid is circulated in the circulation path by passing the target fluid from the primary side to the secondary side.
The steam supply means supplies the steam toward the circulation path on the secondary side of the circulation power means.
The low temperature liquid supply means supplies the low temperature liquid toward the circulation path on the primary side of the circulation power means.
A steam-based system with a circulation path characterized by that.

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