JP2659510B2 - Drain detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steam rich system comprising a water injection mechanism for adjusting the temperature or amount of steam superheated by a superheater, and a drain detection mechanism provided in a steam flow path downstream of the water injection mechanism. The present invention relates to a drain detection device in a gasifier.

[0002]

2. Description of the Related Art As shown in FIG. 8, a drain detection device in a conventional steam enrichment device has a drain detection mechanism, and a liquid level gauge 6c is attached to a steam trap 6b of a drain passage 6a provided in a steam flow passage 6. Thus, it is configured to detect the occurrence of drainage.

[0003]

However, in the above-mentioned conventional drain detection device, a liquid level gauge cannot be attached unless a certain large steam trap is used.
Drain generation could not be detected for those that did not have a steam trap mechanism or that could only be attached to small ones. Therefore, when the drain generated in the steam flow path flows into the heat transfer tube of the superheater as a result of being injected by the water injection mechanism, there is a disadvantage that the life of the superheater is shortened due to adverse effects such as thermal stress applied to the heat transfer tube. An object of the present invention is to eliminate the above-mentioned conventional disadvantages.

[0004]

In order to achieve this object, a drain detecting device according to the present invention is characterized in that the drain detecting mechanism comprises a temperature detecting means for detecting a vertical temperature difference in the steam flow path, And a determining means for determining that drain has occurred when the temperature difference detected by the temperature detecting means reaches a predetermined value or more. In addition, it is preferable that the temperature detecting means is constituted by a pair of temperature detecting elements disposed in a vertical direction of the steam flow path, one of which is disposed at a bottom of the steam flow path.

[0005]

The temperature of the steam flowing through the steam flow path is usually superheated to a temperature higher than the saturated steam temperature under a constant steam pressure. Depending on the case, drainage may occur and flow at the bottom of the steam flow path. In such a case, the temperature on the lower side of the steam flow path decreases due to the heat of vaporization of the drain and the like, and a large temperature difference is generated as compared with the temperature on the upper side of the steam flow path in which the steam flows. Therefore, by providing temperature detecting means for detecting a temperature difference in the vertical direction of the steam flow path, and by providing a determining means for determining that drain has occurred when the temperature difference detected by the temperature detecting means reaches a predetermined value or more. It detects the occurrence of drainage.

[0006] The above-mentioned temperature detecting means is constituted by a pair of temperature detecting elements disposed in the vertical direction of the steam flow path, and if one of the temperature detecting elements is disposed at the bottom of the steam flow path, the temperature disposed at the bottom is reduced. The temperature of the drain or the saturated steam temperature is detected by the detecting element,
The temperature of the superheated steam can be detected by a temperature detecting element disposed above the sensor, and when the temperature difference reaches a predetermined value or more, it is determined that drain has occurred.

Here, the predetermined value of the temperature difference is not particularly limited, and is appropriately set according to the pressure, the degree of superheat and the like in the system.

[0008]

According to the present invention, the generation of drain can be easily detected even in a steam enrichment apparatus which does not have a steam trap mechanism or can be mounted only in a small size. By avoiding as much as possible, the life of the superheater can be kept long.

[0009]

Embodiments will be described below. The drain detection device applied to the steam enrichment device is, for example, as shown in FIG. 5, a steam generated by using a waste heat boiler 2 utilizing heat generated in a refuse incinerator 1, and a turbine for power generation. This is used in a garbage power generation device or the like having a combustion type superheater 4 that further superheats in the process of leading to 3, and as shown in FIGS. 2 to 4, regulates the temperature or amount of steam superheated by the superheater 4. Water injection mechanism 5 and a steam flow path 6 downstream of the water injection mechanism 5
And a drain detection mechanism 9 provided in the above.

A water injection mechanism 5 is installed on each upstream side of two steam flow paths 6 interposed in the heat transfer tube 4a in order to guide the steam from the superheater 4 to the outside and further return the steam to the superheater 4. The flow rate sensor (not shown) provided on the upstream side of the superheater 4 detects that the amount of steam generated in the waste heat boiler 2 is insufficient, which is constituted by the water channel 5a and the spray water amount control valve 5b. If the temperature of the steam flowing out of the superheater 4 is detected to be abnormally high by a temperature sensor (not shown) provided on the downstream side of the superheater 4, The water injection operation is performed by computer-based control means (not shown) for adjusting the water amount control valve 5b.

The drain detecting mechanism 9 detects a drain generated in the steam flow path 6 as a result of water being injected by the water injection mechanism 5, and as shown in FIG. It comprises a temperature detecting means 7 for detecting, and a judging means 8 for judging that drain has occurred when the temperature difference detected by the temperature detecting means 7 reaches a predetermined value or more. The temperature detecting means 7 includes a pair of thermocouples attached to a temperature measuring nozzle 6a provided on an upper pipe wall of the steam flow path 6 by temperature detecting elements 7a and 7b.
The upper temperature detecting element 7a is disposed on the upper wall portion of the flow path 6, and the temperature of the upper part of the flow path 6, that is, , Detects the temperature of the superheated steam flowing through the flow path 6, and detects the temperature of the lower temperature detecting element 7b.
Is disposed at the bottom of the flow path 6 to detect the temperature of the drain or the saturated steam temperature. The determining means 8 includes a temperature detecting element 7a,
A subtraction circuit that receives the output value of 7b and takes a difference, and a comparison circuit that compares the subtraction value with a predetermined reference value.
When the temperature difference between the temperature detecting elements 7a and 7b reaches a predetermined value (reference value) or more, it is determined that drain has occurred.

When the drain detection mechanism 9 detects the generation of drain, the control means throttles the spray water amount control valve 5b to stop or restrict the injection of water, thereby avoiding the subsequent generation of drain, and thereby controlling the drain. Is the heat transfer tube 4a of the superheater 4.
And removes adverse effects such as thermal stress that flows into the device.

Here, the predetermined value (reference value) of the temperature difference is not particularly limited.
It is set as appropriate depending on the degree of superheat and the like.

Another embodiment will be described below. In the above-described embodiment, the upper temperature detecting element 7a, which is a component of the temperature detecting means 7, is disposed on the upper wall of the flow path 6. However, the upper temperature detecting element 7a is not necessarily provided with the upper temperature detecting element 7a. Road 6
It is not necessary to dispose it on the upper wall,
If it is arranged above b, it may be arranged at the center of the flow path 6. Further, the upper temperature detecting element 7a, which is a component of the temperature detecting means 7, can also be used as a temperature sensor for detecting the temperature of steam flowing out of the superheater 4 and operating the water injection mechanism 5.

As temperature detecting means 7 for detecting a temperature difference in the vertical direction of the steam flow path 6, thermocouples 7a and 7b are provided above and below the outer wall of a pipe constituting the steam flow path 6, as shown in FIG. As shown in FIG. 7, an infrared camera which is disposed on the side of the tube constituting the steam flow path 6 and detects a temperature difference between the upper and lower portions of the outer wall of the tube may be attached. The determining means 8 for determining that drain has occurred when the temperature difference detected by the detecting means 7 reaches a predetermined value or more is constituted by an image processing circuit for calculating and deriving the temperature difference from the luminance data of the image obtained by the infrared camera. You may.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of the drawings]

FIG. 1 is a schematic side view, partially cut away, of a main part.

FIG. 2 is a schematic plan view, partially cut away, of a main part.

FIG. 3 is a schematic side view of a main part.

FIG. 4 is a schematic front view of a main part.

FIG. 5 is a configuration diagram of a garbage power generation device.

FIG. 6 is an explanatory view of a temperature detecting means showing another embodiment.

FIG. 7 is an explanatory view of a temperature detecting means 7 showing another embodiment.

FIG. 8 is a configuration diagram of a drain detection device showing a conventional example.

[Explanation of symbols]

 4 Superheater 5 Water injection mechanism 6 Steam flow path 7 Temperature detecting means 8 Discriminating means 9 Drain detecting mechanism

Claims (2)

(57) [Claims] A water injection mechanism (5) for adjusting the temperature or amount of steam superheated by a superheater (4), and a drain detection provided in a steam flow path (6) downstream of the water injection mechanism (5). A drain detection device in a steam enrichment device comprising a mechanism (9), wherein the drain detection mechanism (9) detects a temperature difference in a vertical direction of the steam flow path (6). And a determining means (8) for determining that drain has occurred when the temperature difference detected by the temperature detecting means (7) has exceeded a predetermined value. 2. The temperature detecting means (7) is constituted by a pair of temperature detecting elements (7a) and (7b) disposed in a vertical direction of the steam flow path (6), one of which is the steam detecting element (7). The drain detection device according to claim 1, wherein the drain detection device is provided at a bottom of the flow path (6).