JP2014052085A - Thermal output measurement device of boiler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily measure thermal output without using a flow meter, without needing a measurement device for exhaust gas flow velocity and even without knowing the position and type of a fuel control valve.SOLUTION: A thermal output measurement device of a boiler, which measures temporal fluctuation of thermal output from a boiler 2 for combusting a burner 4 at a plurality of combustion stages, includes: a fuel tank 9; first liquid level detection means 19 of detecting change of the liquid level of the fuel tank 9; a feed tank 16; second liquid level detection means 20 of detecting the liquid level of the feed tank 16; and measurement control means 21 of calculating a combustion stage and a fuel flow rate on the basis of the detection liquid levels by the first liquid level detection means 19 and the second liquid level detection means 20, and calculating thermal output.

Description

  The present invention relates to a thermal output measuring device such as a steam amount measuring device for a boiler that measures the amount of steam without using a steam flow meter.

  Conventionally, patent documents 1 and patent documents 2 are known simple steam quantity measuring devices which measure a steam quantity without using a steam flow meter and a fuel flow meter. The apparatus of Patent Document 1 measures the exhaust gas flow velocity in the flue from the difference between the total pressure and the static pressure using a Pitot tube, calculates the fuel flow rate, and estimates the vapor amount using the indirectly calculated fuel flow rate signal. Is.

  Moreover, the apparatus of patent document 2 calculates | requires vapor | steam amount based on the flow volume of the fuel calculated | required from the pulse signal corresponding to the energization state of a fuel control valve.

JP 2010-139207 A Japanese Patent No. 3168717

  Since the apparatus of Patent Document 1 requires a measuring device for the exhaust gas flow velocity, the measuring device is complicated and expensive. Also, if there is no hole to insert the exhaust gas flow velocity measuring device in the flue, it is necessary to make a hole, the measurement workability is poor, and it is easy to be affected by the drift in the flue and the combustion state of the burner. Becomes larger. Moreover, it is necessary to stop combustion when attaching the measuring device.

  Moreover, although the apparatus of patent document 2 is superior to the apparatus of patent document 1 at the point which does not require the measuring apparatus of exhaust gas flow velocity, there exists the following subject. In particular, when measuring steam volume for existing boilers of other companies, the position of the fuel control valve is not known, and the types of control valves such as the low combustion control valve and the high combustion control valve are often unknown. It is difficult to calculate the amount of steam by measuring the valve opening / closing signal (energization signal). In addition, when the combustion load is adjusted with a single fuel adjustment valve, such as a proportional control boiler, there is a drawback that the partial load cannot be calculated.

  The problem to be solved by the present invention is that a flow meter such as a steam flow meter and a fuel flow meter is not used, a measuring device for exhaust gas flow velocity is not required, and the position and type of the fuel control valve are not known. It is also easy to measure the heat output.

This invention was made in order to solve the said subject, and the invention of Claim 1 is the heat output of the boiler which measures the time fluctuation of the heat output from the boiler which burns a burner in a some combustion stage. A measuring device,
A fuel tank for supplying the stored liquid fuel to the burner;
First liquid level detection means for detecting a change in the liquid level of the fuel tank;
A water supply tank for supplying water to the boiler body;
Second liquid level detecting means for detecting the liquid level of the water supply tank;
And a measurement control means for calculating a combustion stage or a fuel flow rate and calculating a heat output based on the detected liquid level by the first liquid level detecting means or the second liquid level detecting means.

  According to the present invention, without using a flow meter such as a steam flow meter or a fuel flow meter, without requiring an exhaust gas flow rate measuring device, and without knowing the position and type of the fuel control valve, the heat can be easily obtained. The output can be measured.

It is a schematic block diagram of 1st embodiment of the thermal output measuring device which implemented this invention. It is a schematic block diagram explaining the principal part detail of the first embodiment. It is a flowchart figure explaining the control program of the first embodiment. It is a schematic block diagram of 2nd embodiment of the thermal output measuring device which implemented this invention.

(Description of the configuration of the first embodiment)
Next, a steam amount measuring device 1 as a heat output measuring device according to a first embodiment of the present invention will be described with reference to FIGS. The steam amount measuring device 1 is used for a boiler 2 that outputs steam, and measures a temporal variation of the steam amount X, which is a heat output from the steam outlet passage 3 of the boiler 2. The boiler 2 is a boiler that burns liquid fuel. In addition, the amount of steam can be rephrased as the amount of steam generated and the steam flow rate.

  The boiler 2 includes a burner 4, a can body 5 for generating steam, an air supply means 7 for supplying combustion air to the burner 4 via an air supply duct 6, a fuel supply means 8 for supplying liquid fuel to the burner 4, and a burner 4, air ratio adjusting means (all not shown) for adjusting the mixing ratio of air and fuel to a predetermined air ratio by a damper or an inverter according to the combustion stage, water supply means 10 for the can body 5, and the can body 5 It has a flue (not shown) that discharges exhaust gas from.

  The air supply means 7 includes a blower 14. The fuel supply means 8 includes a fuel tank 9 that supplies the stored liquid fuel to the burner 4, a fuel supply pump 11, and a fuel valve 17 that controls the supply amount and stoppage of supply of fuel. As shown in FIG. 2, the fuel tank 9 is provided with a first liquid level sensor 19 as first liquid level detection means for detecting a change in the liquid level H. In the first embodiment, the liquid level sensor 19 uses a known reflective liquid level gauge, but is not limited to this. The water supply means 10 includes a water supply path 18 and a water supply pump 20.

  The boiler 2 is configured such that three or more combustion stages of combustion stop, low combustion, and high combustion are performed by a boiler controller (not shown). The amount of fuel supplied by the fuel valve 17 is controlled so as to be small during low combustion and large during high combustion. And it is comprised so that the air quantity for combustion by the air blower 14 may be adjusted by controlling the said air ratio adjustment means according to the change of this fuel supply amount.

The steam amount measuring device 1 includes a measurement control means 21, a liquid level sensor 19, a pressure sensor 23 that detects the steam pressure Ps in the can 5, and a water temperature sensor 24 that detects the feed water temperature Tw of the water supply path 18. It is configured to include. The measurement control means 21 is a recording means 25 for inputting and recording signals from the sensors 19, 22, 23, 24, and a recording medium (not shown), a signal line (not shown), and recording by radio from the recording means 25. And a calculation means 26 for capturing the received signal. The calculation means 26 is composed of a personal computer or the like, and includes a microprocessor (not shown), an input unit 27, and a display unit 28. The calculation means 26 is configured to calculate the steam amount X based on a previously stored control procedure. An example of the control procedure is shown in FIG.

(Description of operation of the first embodiment)
Next, the operation of the first embodiment will be described with reference to the drawings. Now, the equivalent evaporation amount We of the existing boiler 2 and the turndown ratio of low combustion and high combustion (representing the ratio of the minimum combustion amount to the maximum combustion amount) are confirmed from specifications and the like. Assume that the turndown ratio is, for example, high combustion = 100% and low combustion = 50%.

  Referring to FIG. 3, calculation means 26 captures the equivalent evaporation amount We and the turndown ratio at step S <b> 1 (hereinafter, step SN is simply referred to as SN) (by input from input unit 27 by the measurement operator). ). In S2, the feed water temperature Tw from the water temperature sensor 24 and the steam pressure Ps from the pressure sensor 23 are fetched (data fetching from the recording means 25 to the calculating means 26).

  Next, in S3, the liquid level signal detected by the liquid level sensor is first taken into the calculation means 26 from the recording means 25 at a predetermined sampling interval, and the combustion stage is determined by the calculation means 26.

  The determination of the combustion stage at S3 is made from the rate of decrease of the liquid level signal. That is, when the decrease rate of the liquid level signal is equal to or higher than a predetermined value, it is determined as high combustion, when the decrease rate is less than the predetermined value, it is determined as low combustion, and when the decrease rate is zero, it is determined as combustion stop.

Next, the calculation means 26 calculates the actual evaporation amount W of each combustion stage from the equivalent evaporation amount We based on the feed water temperature Tw from the water temperature sensor 24 and the vapor pressure Ps from the pressure sensor 23 in S4.
This calculation method uses the actual evaporation amount W =
Equivalent evaporation amount We x latent heat of saturated steam ÷ (total heat of saturated steam at steam pressure Ps-sensible heat of boiler feedwater)

In S5, the calculation means 26 outputs the calculated actual evaporation amount W to the display unit 26 as an instantaneous value of the steam amount X in each combustion stage as follows.
Instantaneous value of steam amount X during high combustion = actual evaporation amount W x 100%
Instantaneous value of low combustion steam amount X = actual evaporation amount W x 50%

  The steam load of the boiler 2 can be estimated by integrating the steam amount X thus calculated at an appropriate time interval (for example, 10 minutes average or 1 hour average).

  The present invention is not limited to the first embodiment. For example, the second embodiment shown in FIG. 4 is included. In the second embodiment, a water supply tank 16 for supplying water to the can 5 of the boiler 2, a first liquid level sensor 20 as second liquid level detecting means for detecting the liquid level of the water supply tank 16, Measurement control means 21 for calculating a combustion stage or a fuel flow rate and calculating a heat output based on a detected liquid level by a liquid level sensor is provided. The first embodiment differs from the first embodiment in that the first embodiment calculates the heat output based on the change in the liquid level in the fuel tank 9, whereas in the second embodiment, the change in the liquid level in the water supply tank 16. Since the other configurations are the same except that the heat output is calculated based on the same, the same reference numerals are given to the same configurations and the description thereof is omitted. The second liquid level sensor 20 can be the same sensor as the first liquid level sensor 19.

  Further, in the first embodiment, the combustion stage is determined from the change in the liquid level signal of the fuel tank 9 and the vapor amount X is calculated, but from the change in the liquid level signal of the fuel tank 9. The fuel flow rate can be calculated, and the vapor amount X can be calculated from the fuel flow rate as disclosed in Patent Document 2. In addition, since the fuel flow rate can be calculated from the change in the liquid level signal of the fuel tank 9, it becomes possible to analyze the load of a proportional control boiler (a boiler that continuously controls the combustion amount), which is difficult with the conventional method. The present invention can also be applied to a heat output measuring device in which the boiler 2 is a hot water boiler or a heat medium boiler, and the output from the outflow passage 3 is a heat medium.

1 Steam volume measuring device (heat output measuring device)
2 Boiler 9 Fuel tank 16 Water supply tank 19 First liquid level sensor (first liquid level detecting means)
20 Second liquid level sensor (second liquid level detecting means)
21 Measurement control means

Claims (1)

A boiler heat output measuring device for measuring temporal fluctuations in heat output from a boiler that burns a burner at a plurality of combustion stages,
A fuel tank for supplying the stored liquid fuel to the burner;
First liquid level detection means for detecting a change in the liquid level of the fuel tank;
A water supply tank for supplying water to the boiler body;
Second liquid level detecting means for detecting the liquid level of the water supply tank;
Thermal output of a boiler, comprising: a combustion stage or a fuel flow rate based on a detected liquid level detected by the first liquid level detecting means or the second liquid level detecting means, and a measurement control means for calculating a heat output. Measuring device.

Images