JPH0682176A - Device for supplying steam - Google Patents

Abstract

PURPOSE:To carry out quick and appropriate control of the temperature of the water in a drain tank and prevent the suction force from being lowered at an ejector by a method wherein the temperature of the open space inside the drain tank is detected and the temperature of the water in the drain tank is calculated in proportion to the amount of heat carried by condensate based on the detected temperature and the length and the duration time. CONSTITUTION:A device for ejector type vacuum pumping 5 is equipped with an ejector 12 which sucks in, through a pipe 11, the condensate 4a in a steam separator 4, a drain tank 13 which sends the condensate sucked in, a pump 14 which sends to a drain tank 13 the water W in the drain tank 13 in a jet under pressure together with the condensate, and so forth. On the other hand, a controller 10 calculates the amount of heat carried by the condensate on the basis of a detection signal from an atmosphere temperature sensor 19 provided in the upper part of the open space inside the drain tank 13 and the length of time of the continuation of this detection signal and also the temperature of the water inside the drain tank 13 in accordance with the calculated amount of heat. When the calculated temperature of the water has declined below a specified value, the controller 10 opens a cooling-water valve 18 and feeds cooling water CW through a passageway 17 into the drain tank 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention utilizes the latent heat of vacuum steam to generate steam for various types of heating at temperatures lower than 100 ° C., and supplies this to a load that consumes heat of steam. The present invention relates to a steam supply device, and more particularly to a technique for controlling the water temperature in a drain tank into which condensate from the load flows to be maintained below a predetermined value.

[0002]

2. Description of the Related Art In this type of steam supply apparatus, since the condensate is sucked by an ejector that pressurizes the water in the drain tank into a jet flow, the suction force of the ejector is prevented from decreasing. There is a request to keep the water temperature in the water below a specified value. Therefore, Japanese Patent Publication No. 57-322
As disclosed in Japanese Patent No. 40, when the water temperature in the drain tank is detected and the detected water temperature exceeds a predetermined value,
It is known to supply cooling water into the drain tank.

[0003]

However, as described above, in the case of the method for supplying the cooling water into the drain tank based on the detection of the water temperature in the drain tank, the amount of heat carried into the drain tank increases. Since the speed of the water temperature in the drain tank rising to the prescribed value is slower than the speed, there is a time delay in the water temperature control by the supply of cooling water, and as a result, the water temperature in the drain tank becomes excessive. As the temperature rises, there is a problem that the efficiency of the device as a whole is reduced, such as a reduction in the suction force of the ejector.

Further, in the case of detecting the water temperature, the temperature distribution is not uniform not only in the depth direction in the drain tank but also in the horizontal direction, so that the detected temperature itself varies depending on the installation location of the temperature sensor. There is also a problem that the water temperature control by supplying the cooling water is not stable.

The present invention has been made in view of the above situation, and the water temperature is accurately and stably maintained at a predetermined value so that there is no time delay with respect to the increasing rate of the amount of heat brought into the drain tank. An object of the present invention is to provide a steam supply device that can be cooled below and that can maintain a high suction efficiency of an ejector regardless of load fluctuations.

[0006]

In order to achieve the above object, a steam supply apparatus according to the invention of claim 1 is provided downstream of a load that consumes the heat quantity of steam and separates steam and condensate. A steam separator, an ejector that sucks the condensate side of the steam separator and sends it to a drain tank, and pressurizes the water in the drain tank to generate a jet flow of the ejector, and then that water A pressure feeding device for feeding to the drain tank, a cooling water passage for supplying cooling water to the drain tank, a cooling water valve for opening and closing the passage, and an ambient temperature sensor for detecting the temperature of a space above the water surface in the drain tank. And the amount of heat of the condensate that has flowed into the drain tank is calculated based on the ambient temperature detected by the sensor and the duration of the temperature, and the amount of drainage is calculated based on the calculated amount of heat. Water temperature calculation means for calculating the water temperature in the tank, and cooling control means for controlling the cooling water valve to supply cooling water to the drain tank when the water temperature calculated by the water temperature calculation means exceeds a predetermined value. It is equipped with.

Further, the steam supply apparatus according to the second aspect of the present invention includes a steam separator for separating steam and condensate, which is provided downstream of a load that consumes heat of steam, and a steam separator of this steam separator. An ejector that sucks the condensate side and sends it to the drain tank,
After pressurizing the water in the drain tank to generate a shed flow of the ejector, the pumping device that sends the water to the drain tank, a cooling water passage for supplying cooling water to the drain tank, and this passage are opened and closed. A cooling water valve, a trap temperature sensor that detects the temperature of the condensate side of the steam separator as a trap temperature, and the trap temperature detected by the sensor and the trap temperature that flows into the drain tank based on the duration of the temperature. The water temperature calculating means for calculating the amount of heat of the condensed water and calculating the water temperature in the drain tank based on the amount of heat, and the cooling water valve when the water temperature calculated by the water temperature calculating means exceeds a predetermined value Control
Cooling control means for supplying cooling water to the drain tank.

Further, in addition to the structure of claim 2, the steam supply device according to the invention of claim 3 detects the level of condensed water of the steam separator, and the trap temperature sensor sucks the steam. Air / water discrimination means for discriminating whether the temperature of water is detected or the temperature of steam sucked above the condensate, and the water temperature is determined according to the discrimination result of the air / water discrimination means. And a heat quantity calculation adjusting means for changing the amount of heat quantity calculated by the calculating means.

[0009]

According to the invention of claim 1, the steam and the condensate after passing through the consumption load of the calorific value of steam are separated in the steam separator, and the separated condensate is the water in the drain tank. It is sucked by the ejector operated by the jet flow generated by increasing the pressure and sent into the drain tank. As the condensate is sent in, the amount of heat of the condensate is brought into the drain tank and the temperature of the water in the drain tank rises.

According to the above construction, the temperature of the space above the water surface in the drain tank is detected by the ambient temperature sensor. According to the experience of the inventor,
This ambient temperature is in good agreement with the temperature of the condensate (or steam) flowing in. On the other hand, the amount of condensed water flowing into the drain tank per unit time is a known amount determined by the suction force of the ejector. Therefore, the amount of heat of the condensate flowing into the drain tank is calculated by multiplying the detected ambient temperature by the duration. And
The water temperature in the drain tank is calculated based on the calculated amount of heat, and when the calculated water temperature exceeds a predetermined value, the cooling water valve is controlled to open, and the cooling water flows into the drain tank through the cooling water passage. The water temperature in the drain tank is controlled so that the water temperature is controlled to be equal to or lower than a predetermined value.

Here, the atmosphere in the space above the water surface in the drain tank changes in temperature earlier than the water in the drain tank to be cooled and the temperature distribution is averaged. Therefore, by detecting the temperature of this atmosphere and multiplying this by the duration, the calorific value of the condensate introduced into the drain tank can be calculated accurately and quickly without causing a time delay. As a result, the calculation of the water temperature based on the calculated calorific value is performed accurately and promptly, and the water temperature control by the supply of the cooling water based on this water temperature can be performed stably and accurately, which is accompanied by the abnormal rise of the water temperature in the drain tank. Prevents a drop in the suction force of the ejector.

According to the second aspect of the present invention, the trap temperature detected on the condensate side of the steam separator is used as the temperature value for calculating the total amount of heat, and the trap temperature is brought into the drain tank. Accelerate the calculation of the amount of heat of condensate,
The water temperature can be controlled more quickly by supplying the cooling water.

Further, according to the third aspect of the present invention, in calculating the amount of heat by detecting the trap temperature, the level of the condensate in the steam separator is detected and is currently detected by the trap temperature sensor. It is discriminated whether the trap temperature is the temperature of the condensate or the temperature of the steam above the condensate, and the magnitude of the heat quantity is changed according to the discrimination result.

That is, when the fluid brought into the drain tank is condensate, the inflow amount (weight) per unit time
Since the value is large, the calculated value of the amount of heat brought in should also be increased. On the other hand, when the condensate level in the steam separator falls and the steam above the condensate is brought into the drain tank, the inflow of steam per unit time is small, so the calculation of the amount of heat brought in is calculated. Decrease the value. As a result, even when the level of the condensate in the steam separator changes with the change in the load, it becomes possible to calculate the amount of heat adapted to the level change. Therefore, the predetermined water temperature control can be accurately performed regardless of the load change.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a system diagram of a steam supply apparatus according to an embodiment of the present invention, in which 1 is a steam supply pipe,
2 is a vacuum pressure reducing valve, 3 is a steam consumption load for heating an object to be heated, 4 is a steam separator provided downstream of the steam consumption load 3 for separating steam and condensate, and 5 is an ejector vacuum pump A device, 6 is a condensate discharge pipe, 7 is a condensate discharge valve, 8 is a regulating valve provided in a pipe 9 that connects the steam consumption load 3 and the steam separator 4, and 10 is a controller.

As shown in FIG. 2, the ejector type vacuum pump device 5 has an ejector 12 for sucking the condensate side 4a of the steam separator 4 through a pipe 11 and the condensate sucked by the ejector 12. The drain tank 13 and the water W in the drain tank 13 are sucked from the bottom of the tank 13 to increase the pressure, generate a jet flow of the ejector 12, and then send the water to the drain tank 13 together with the condensate. 14 as an engine and an inverter 15 for variably controlling the operating speed of the pump 14.
It has and.

The drain tank 13 of the ejector type vacuum pump device 5 is provided with a water level sensor 16 for detecting the water level in the drain tank 13, and a space above the water surface WL in the drain tank 13. 1
An atmosphere temperature sensor 19 that detects the temperature of 3 A is provided. Further, a cooling water passage 17 for supplying the cooling water CW and a cooling water valve 18 for opening and closing the passage 17 are provided in the drain tank 13.

When the set high water level H is detected, the water level sensor 16 opens the discharge valve 7 to make the drain tank 13
The water W inside is discharged to a recovery tank (not shown) through the discharge pipe 6, and when the set low water level L is detected, the discharge valve 7 is closed. Further, even if the condensed water sucked by the ejector 12 is scattered around the detection end 19a of the atmosphere temperature sensor 19 when being sent into the drain tank 13 via the pump 14, the scattered water is detected. A cover 22 is provided at the end 19a to prevent the vehicle from directly landing.

The controller 10 has a water temperature calculation means 20 and a cooling control means 21 built therein. The temperature detection signal S1 from the ambient temperature sensor 19 is input to the water temperature calculation means 20.
Is the heat quantity Q of the condensate flowing into the drain tank 13 based on the ambient temperature Ta indicated by the temperature detection signal S1 and the duration t of the temperature Ta measured by the built-in timing means. The water temperature T in the drain tank 13 is calculated based on the calculated heat quantity Q. Steam cooling control means 2
1 compares the calculated water temperature T with a preset predetermined value Ts, and when T> Ts, controls the opening of the cooling water valve 18 so that the cooling water CW flows through the passage 17. After that, it is supplied into the drain tank 13.

The tip 23a of the pipe 23 for feeding the condensate sucked by the ejector 12 into the drain tank 13 is opened above the water surface in the drain tank 13 as in this embodiment. In the case of setting to 1, the temperature detection sensitivity by the ambient temperature sensor 19 can be improved, but the tip portion 23a may be deeply inserted into the water in the drain tank 13 and opened.

The method of calculating the water temperature T by the water temperature calculating means 20 is as follows, for example. First, the temperature Ta detected by the temperature detection signal S1 is multiplied by the duration time t of the temperature Ta (Ta × t). On the other hand, the pump 14 is controlled by the inverter 15 to have two rotation speeds, and the rotation speed is known. Therefore, the suction amount by the ejector 12, that is, from the steam separator 4 to the drain tank 13
The inflow rate wi of the condensate flowing into the unit per unit time is also known. Therefore, the inflow amount wi is multiplied by the specific heat c1 of the condensate,
Further, by multiplying this by the above multiplication value Ta × t,
The heat quantity Qi of the condensate that has flowed into the drain tank 13 is calculated (Qi = c1 * wi * Ta * t).

The above calculation is started after the water in the drain tank 13 reaches the set low water level L. That is, from the time when the discharge valve 7 is opened and the water in the drain tank 13 is discharged, the water surface WL reaches the set low water level L in the drain tank 13 and the discharge valve 7 is closed to complete the discharge of water, Calculation is started. On the safety side, the temperature of water below the set low water level L is estimated to be higher than the predetermined temperature Ts, and this Ts is multiplied by the weight Wo of water below the set low water level L and the specific heat c1 to set. The calorific value Qo of water below the low water level L is calculated (Qo = c1 * Ts * Wo).
Next, this heat quantity Qo is added to the heat quantity Qi of the inflowing condensate to obtain the total heat quantity Q of the water in the drain tank 13 (Q = Qi + Qo).

This total heat quantity Q is divided by the total water quantity W (= wi × t + Wo) in the drain tank 13 to obtain the heat quantity q = Q / W per unit weight of water. The water temperature T is calculated by dividing the calculated heat quantity q per unit weight by the specific heat c1 of water. That is, T = q / c1 = Q / (c1 × W) = [(wi × Ta ×
t) + (Ts × Wo)] / (wi × t + Wo)).

The vapor supply apparatus having the above-described structure performs the same basic operation as that of a conventionally known apparatus, but the operation unique to the present invention will be described below. That is, the ambient temperature of the space 13A above the water surface WL in the drain tank 13 is detected by the sensor 19, and the detected temperature signal S1 is input to the controller 10.

With the input of the temperature signal S1, the condensate flowing into the drain tank 13 based on the ambient temperature Ta detected by the water temperature calculating means 20 in the controller 10 and the duration t of the temperature Ta. The heat amount Qi of the water is calculated, and the water temperature T is calculated by the above calculation method based on the calculated heat amount Qi.
Here, according to the experience of the inventor, the ambient temperature Ta is in good agreement with the temperature of the condensate flowing into the drain tank 13. Therefore, using the ambient temperature Ta, the heat quantity Q is calculated.
i can be calculated accurately.

Next, the calculated water temperature T is compared with a preset predetermined value Ts, and when T> Ts, cooling is performed by the control signal S2 output from the cooling control means 21 of the controller 10. The water valve 18 is controlled to open,
Cooling water CW is supplied into the drain tank 13 through the cooling water passage 17, and the water temperature in the drain tank 13 is controlled to be equal to or lower than a predetermined value.

Here, not only does the atmosphere in the space 13A above the water surface WL in the drain tank 13 change in temperature earlier than the water W in the drain tank 13 to be cooled, but also the temperature of the water The temperature distribution is also averaged. Therefore, by detecting the ambient temperature, calculating the amount of heat brought into the drain tank 13 and performing cooling control, no time delay occurs and the control timing does not vary, and the inside of the drain tank 13 does not occur. It is possible to maintain the water temperature of below a predetermined value. Therefore, it is possible to reliably prevent a decrease in the suction force of the ejector 12 caused by the water temperature in the drain tank 13 becoming equal to or higher than a predetermined value.

FIG. 3 is a block diagram of the essential parts of a steam supply apparatus according to another embodiment of the present invention. In FIG. 3, the components corresponding to those of the above embodiment are designated by the same reference numerals. , Their explanations are omitted. In this embodiment, a trap temperature sensor 24 that detects the temperature of the condensed water 4a side of the steam / water separator 4 as a trap temperature, and a level sensor 25 that detects the level of the condensed water 4a in the steam / water separator 4, Based on the level detected by the level sensor 25, it is possible to determine whether the temperature detected by the trap temperature sensor 24 is the temperature of the condensate 4a or the temperature of the steam 4b above the condensate 4a. Means 26 and heat quantity calculation adjusting means 27 that changes the magnitude of the inflowing heat quantity Qi calculated by the water temperature calculating means 20 according to the determination result are provided.

By the way, when the level of the condensate 4a in the steam separator 4 is lowered due to the fluctuation of the consumption load 3, the steam 4b above it is sucked through the pipe 11. Therefore, the sensor tip of the trap temperature sensor 24 is installed at substantially the same level as the suction port 11a of the pipe 11 through which the condensate 4a is sucked out. Detects the temperature of the condensate 4a and the temperature of the steam 4b when the steam 4b is sucked.

According to the embodiment shown in FIG. 3, the temperature of the condensate water 4a of the steam separator 4 on the upstream side of the drain tank 13 is detected by the sensor 24 as the trap temperature Tr. The temperature signal S3 is input to the controller 10, and in response to the input of the temperature signal S3, the water temperature calculating means 20 of the controller 10 determines the drain tank 13 based on the detected trap temperature Tr and the duration t thereof. The heat quantity Qi of the condensate that flows in is calculated, and the water temperature T in the drain tank 13 is calculated based on this heat quantity Qi.

In calculating the water temperature T in the drain tank 13, a time delay dt is set in consideration of the length of the pipe 11 from the steam separator 4 to the ejector 12 and the current operating speed of the pump 14. After the water temperature T is calculated based on the temperature detection signal S3, the control signal S2 is output with a delay of dt and the cooling water valve 18 is opened / closed.
An appropriate water temperature T can be calculated regardless of the length of 1 and the current operating speed of the pump 14.

In the embodiment shown in FIG. 3 as well, since the condensate temperature Tr is detected on the upstream side in the drain tank 13, it is faster than the water temperature in the drain tank 13 is detected.
It is possible to predict the water temperature T and perform cooling control. Therefore, a decrease in suction force of the ejector 12 due to a rise in water temperature is reliably prevented.

Here, when the steam 4b is sucked from the steam separator 4, the suction amount of the steam 4b, that is, the ejector 1
Inflow amount (weight) flowing into the drain tank 13 via 2
Is smaller than that of the condensate 4a. Therefore, the amount of heat carried into the drain tank 13 also decreases. Therefore, the level of the condensate 4a in the steam separator 4 is constantly detected by the level sensor 25, and the condensate 4a in which the trap temperature Tr detected by the trap temperature sensor 24 is sucked based on the detected level. Temperature or the temperature of the sucked steam 4b.
The water determination means 26 determines.

The determination signal S4 from the air / water determination means 26 is input to the controller 10, and the heat amount calculation adjusting means 27 changes the inflow amount per unit time used for calculating the inflow heat amount Qi from wi to wj. , The specific heat is from c1 to c2
It is changed to (specific heat of steam). The air / water discriminating means 26
When it is determined that the detected trap temperature Tr is the temperature of the steam 4b in the determination result by, the inflow heat amount Qi is smaller than that of the condensate 4a because the inflow amount wj of the steam 4b per unit time is small. It will be changed to a smaller value.

Then, the water temperature T in the drain tank 13 calculated on the basis of the inflowing heat quantity Qi adjusted as described above is compared with a predetermined value Ts set in advance,
When T> Ts, the cooling water valve 1 is controlled by the control signal S2 output from the cooling control means 21 of the controller 10.
The valve 8 is controlled to be opened, and the cooling water CW is supplied into the drain tank 13 through the cooling water passage 17, whereby the water temperature in the drain tank 13 is suppressed to a predetermined value or less.

In the above embodiment, the operating speed of the pump 14 of the ejector type vacuum pump device 5 is variably controllable by the inverter 15. However, the operating speed of the pump 14 is constant. Good.

[0037]

As described above, according to the inventions of claims 1 to 3, the water temperature in the drain tank can be calculated without causing a time delay. Therefore, it is possible to quickly perform the water temperature control by supplying the cooling water based on the calculated water temperature, and to prevent the suction force of the ejector from being lowered due to the abnormal increase in the water temperature in the drain tank.

Further, according to the first aspect of the invention, since the ambient temperature above the water surface in the drain tank is detected, the detected temperature is accurate with little spatial variation. It is possible to accurately prevent the decrease in the suction force of the ejector by performing accurate control.

According to the inventions of claims 2 and 3,
By using the trap temperature detected on the condensate side of the steam separator as the temperature value for calculating the amount of heat flowing into the drain tank, calculation of the amount of heat flowing in is accelerated, and the temperature of the water supplied by the cooling water is increased. The control can be further speeded up.

Further, according to the invention of claim 3, even when the level of the condensate in the steam-water separator changes due to the change of the load, the inflowing heat quantity can be accurately calculated by adapting to the level change. The water temperature can be controlled accurately regardless of load fluctuations.

[Brief description of drawings]

FIG. 1 is a system diagram of a steam supply device according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing a main part of the apparatus.

FIG. 3 is a schematic configuration diagram showing the supply device according to another embodiment of the present invention.

[Explanation of symbols]

3 ... Steam consumption load, 4 ... Steam separator, 4a ... Condensate, 4b
… Steam, 10… Controller, 12… Ejector, 13
... Drain tank, 14 ... Pump (pressure feeding device), 19 ... Atmosphere temperature sensor, 20 ... Water temperature calculation means, 21 ... Cooling control means, 24 ... Trap temperature sensor, 25 ... Level sensor, 26 ... Air / water discrimination means, 27 ... Adjusting means for calorific value calculation,
CW ... cooling water.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hiroshi Yado Minami Hiroshi Yado Minami 2-30 Tagawakita, Yodogawa-ku, Osaka-shi, Osaka Unison Co., Ltd. (72) Masakazu Maruoka 2-chome Tagawakita, Yodogawa-ku, Osaka-shi, Osaka No. 30 Miyawaki Co., Ltd.

Claims (3)

[Claims] 1. A steam-water separator provided downstream of a load that consumes the heat of steam and separating steam and condensed water, and an ejector for sucking the condensed water side of the steam-water separator and sending it to a drain tank. The pressure in the drain tank is increased to generate a shed flow of the ejector, and then the water is sent to the drain tank, and a cooling water passage for supplying cooling water to the drain tank and this passage are provided. A cooling water valve that opens and closes, an atmosphere temperature sensor that detects the temperature of the space above the water surface in the drain tank, and the inside temperature of the drain tank based on the atmosphere temperature detected by the sensor and the duration of the temperature. A water temperature calculating means for calculating the heat quantity of the condensate that has flowed in and calculating the water temperature in the drain tank based on the heat quantity, and the water temperature calculating means A steam supply device comprising: cooling control means for controlling the cooling water valve to supply the cooling water to the drain tank when the water temperature exceeds a predetermined value. 2. A steam separator for separating steam and condensed water, which is provided downstream of a load that consumes heat of steam, and an ejector for sucking the condensed water side of the steam separator and sending it to a drain tank. The pressure in the drain tank is increased to generate a shed flow of the ejector, and then the water is sent to the drain tank, and a cooling water passage for supplying cooling water to the drain tank and this passage are provided. A cooling water valve that opens and closes, a trap temperature sensor that detects the temperature of the condensate side of the steam separator as a trap temperature, and the trap temperature detected by the sensor and the duration of the temperature based on the trap temperature The water temperature calculating means for calculating the amount of heat of the condensate flowing into the water and calculating the water temperature in the drain tank based on the amount of heat, and the water temperature calculated by this water temperature calculating means A steam supply device comprising: a cooling control means for controlling the cooling water valve to supply the cooling water to the drain tank when the predetermined value is exceeded. 3. The method according to claim 2, further comprising detecting the level of condensed water in the steam separator to detect the temperature of the condensed water sucked by the trap temperature sensor, or A heat / air discriminating means for discriminating whether or not the temperature of the sucked steam is detected, and a calorific value for changing the magnitude of the calorific value calculated by the water temperature calculating means according to the discrimination result of the steam / water discriminating means. A steam supply device comprising a calculation adjusting means.