JP2022001816A - Management device and biomass power generation facility, and method of calculating moisture content in wood chip being used - Google Patents

Abstract

To calculate a moisture content in wood chips being used.SOLUTION: A management device 55 of a biomass power generation facility 10 comprises a calculation unit 100 which calculates the fuel consumption rate in the biomass power generation facility 10 from the weight of wood chips being used as fuel in the biomass power generation facility 10 and from the electric power generated in the biomass power generation facility 10 to calculate the moisture content in wood chips being used, which are used as fuel in the biomass power generation facility 10, according to the correlation with respect to the fuel consumption rate.SELECTED DRAWING: Figure 9

Description

The present invention relates to biomass power generation.

In order to reduce CO2 to prevent global warming and improve the energy self-sufficiency rate for the realization of a sustainable society, it is expected that renewable energy, especially woody biomass power generation, will be expanded in Japan, which has abundant forest resources. There is. As a patent relating to biomass power generation, there is the following Patent Document 1.

In the following Patent Document 1, a measuring conveyor 13 is provided on the downstream side of the supply hopper 12, and the flow rate of the biomass fuel supplied from the supply hopper 12 to the boiler is measured by the measuring conveyor 13.

Japanese Patent No. 5092222

As a management method for biomass power generation equipment, it is considered effective to manage the power generation efficiency, which is the ratio of the amount of heat input to the boiler and the amount of power generated. However, at present, since the moisture content of the wood chips used as fuel cannot be specified, the amount of heat input to the boiler cannot be calculated, and the power generation efficiency cannot be controlled. In addition, specifying the moisture content of wood chips is considered to be meaningful not only for managing power generation efficiency but also for managing the remaining amount of wood chips.

The present invention has been completed based on the above circumstances, and an object of the present invention is to calculate the moisture content of wood chips used as fuel.

The management device of the biomass power generation facility includes a calculation unit, and the calculation unit is based on the weight of wood chips used as fuel for the biomass power generation facility and the amount of power generated by the biomass power generation facility. The fuel consumption rate is calculated, and the water content used when using the fuel of the wood chips used as the fuel of the biomass power generation facility is calculated based on the correlation with the fuel consumption rate. The moisture content used is the moisture content when wood chips are actually used as fuel (when fuel is used), such as when the hopper is put in. In this configuration, the moisture content of wood chips can be calculated based on the correlation with the fuel consumption rate.

The following configuration may be used as an embodiment of the present invention.
The period from when the remaining amount of chips in the chip storage is zero to when the remaining amount of wood chips received in the chip storage is used up and the remaining amount of chips becomes zero is defined as the zero remaining amount period, and the remaining amount is defined as the correlation. The correlation between the average moisture consumption rate of the wood chips in the zero period and the average fuel consumption rate in the zero remaining period may be used. Since the average moisture content during the zero remaining amount period can be calculated only from the measured values without making assumptions, there is an advantage that the accuracy is high. That is, the average moisture content used can be accurately specified, and a highly accurate correlation can be obtained. Therefore, it is possible to specify the moisture content of the wood chip with high accuracy by utilizing the highly accurate correlation.

The following configuration may be used as an embodiment of the present invention.
The calculation unit calculates the low calorific value of the wood chip based on the calculated moisture content used, calculates the heat input amount of the boiler based on the calculated low calorific value, and calculates the heat input amount and the calculated heat input amount. The power generation efficiency of the biomass power generation facility may be calculated based on the amount of power generated by the biomass power generation facility. With this configuration, it is possible to specify the power generation efficiency of the biomass power generation equipment, which is effective for the management of the biomass power generation equipment.

The following configuration may be used as an embodiment of the present invention.
The calculation unit may calculate the absolute dry fuel consumption rate, which is the ratio of the absolute dry weight of the wood chip to the amount of power generated by the biomass power generation facility, based on the fuel consumption rate and the water consumption rate. The absolute dry fuel consumption rate is an index for evaluating the amount of fuel purchased, and is therefore effective for evaluating business feasibility.

The following configuration may be used as an embodiment of the present invention.
The calculation unit calculates and calculates the dry amount of the wood chips on the day based on the received absolute dry weight of the wood chips on the day, the used dry weight of the day, and the dry amount of the wood chips on the previous day. The remaining amount of wood chips is calculated based on the remaining dry amount of the wood chips on the day of the wood chips and the moisture content of the wood chips used, and the wood chips are calculated based on the calculated remaining amount of the wood chips and the low calorific value of the wood chips. The amount of residual heat of the chip may be calculated. With this configuration, it is possible to accurately estimate the remaining amount of wood chips and the amount of residual heat, and it is possible to sufficiently manage the remaining amount of wood chips.

The following configuration may be used as an embodiment of the present invention.
A display unit may be provided, and the display unit may display at least one calculation result among the calculation results by the calculation unit.

According to the present invention, the moisture content of wood chips used as fuel can be calculated.

Schematic block diagram of biomass power generation equipment according to an embodiment of the present invention Chart summarizing the measurement items of each process Power generation efficiency calculation flow The figure which shows the weight change of the wood chip P Graph showing the relationship between fuel consumption rate and water consumption rate Graph showing fuel consumption rate and moisture consumption rate, power generation efficiency, and time transition of absolute dry HR Graph showing the calculation result of the remaining amount of wood chip P and the annual time transition of the remaining amount inspection Block diagram of management device Block diagram of the first arithmetic unit Block diagram of the second calculation unit Block diagram of the third arithmetic unit

<Embodiment>
1. 1. Explanation of Overall Configuration of Biomass Power Generation Equipment 10 FIG. 1 shows a schematic configuration diagram of the biomass power generation equipment 10 to which the present invention can be applied. The biomass power generation facility 10 includes a boiler 21, a turbine 23, a generator 25, a condenser 27, a water supply pump 29, a bag filter 31, a fly ash silo 33, an exhaust tower 35, and a fuel supply unit. 40 and are provided.

The biomass power generation facility 10 uses the wood chip P supplied from the fuel supply unit 40 as fuel to generate steam in the boiler 21 and supplies the generated steam to the turbine 23. Then, when the turbine 23 is rotated by the supply of steam, the generator 25 directly connected to the turbine 23 generates electricity.

Further, the exhaust gas of the boiler 21 is configured to be discarded from the exhaust tower 35 after the soot dust (fly ash) contained in the gas is filtered and removed by the bag filter 31.

The fuel supply unit 40 includes a chip storage 41 for storing wood chips P, a loading crane 43, a supply hopper 45, and a supply feeder 47.

There are two types of wood chips P, cutting chips and crushing chips. The cutting chip is a chip obtained by cutting wood with a cutter or the like. The crushed chip is a chip obtained by crushing wood with a hammer or the like. The cutting chips are square and thick, while the crushed chips have an elongated shape in the fiber direction, and the shapes of both chips are different.

The chip storage 41 is provided with three types of yards: a cutting yard 41A, a crushing yard 41B, and a mixing yard 41C. The cutting yard 41A is for storing cutting chips, the crushing yard 41B is for storing crushing chips, and the mixing yard 41C is for storing mixed chips in which cutting chips and crushing chips are mixed.

The loading crane 43 can move in the left-right direction in FIG. The wood chips P stored in the chip storage 41 are put into the supply hopper 45 by the crane 43. In this example, a mixing chip is used as the fuel to be charged into the supply hopper 45.

The loading crane 43 is provided with a load meter 43A, and measures the weight [t] of the wood chips P loaded into the supply hopper 45.

When the supply feeder 47 at the lower part of the hopper is driven, the wood chip P, which is fuel, is supplied from the supply hopper 45 to the boiler 21 through the fuel pipe 49.

The supply feeder 47 is a screw type and supplies wood chips P from the rotation of the screw 48. A plurality of screws 48 may be provided in the direction orthogonal to the paper surface in FIG. 1.

Next, the electrical configuration of the biomass power generation facility 10 will be described. The biomass power generation facility 10 includes a crane control device 51 for controlling the input crane 43 and a management device 55.

The management device 55 has a control function of the fuel supply unit 40 and a management function of the biomass power generation facility 10. Specifically, as a control function of the fuel supply unit 40, the supply amount of the wood chip P supplied to the boiler 21 is adjusted so that the difference between the measured value of the generator output and the main steam pressure and the target value becomes small. ..

For example, when the measured values of the generator output and the main steam pressure are lower than the target values, a command to increase the rotation speed V of the supply feeder 47 is sent. As a result, the rotation speed V of the supply feeder 47 becomes high, and the supply amount of the wood chips P to the boiler 21 increases. Therefore, the generator output and the main steam output can be brought close to the target values.

Further, the management device 55 manages the tendency of the power generation efficiency eff0 as one of the management functions of the biomass power generation facility 10. Hereinafter, the management process of the wood chip P, which is the fuel of the biomass power generation facility 10, will be described first, and then the calculation method of the power generation efficiency eff0 of the biomass power generation facility 10 will be described.

2. 2. Wood chip P management process and measurement items <acceptance process>
The receiving step is a step of receiving the wood chips P into the chip storage 41. As shown in FIG. 1, the wood chip P is loaded on a truck and carried to the biomass power generation facility 10. The truck yard 15 of the biomass power generation facility 10 is provided with a truck scale 15A and a moisture content meter 15B as instruments for measuring the wood chips P carried in.

The truck scale 15A measures the weight of a truck loaded with wood chips P. By subtracting the weight of the truck from the measured value of the truck scale 15A, the received weight [kg] of the wood chip P can be measured. Further, the received moisture content [%] of the wood chip P can be measured by the moisture content meter 15B. In this way, in the receiving process, it is possible to measure two items, the "received weight" and the "received moisture content" of the wood chip P.

The received weight is the weight at the time of receiving the wood chip P, and the received water content is the water content at the time of receiving the wood chip P. At the time of acceptance, the wood chips P are received in the chip storage 41.

<Storage process>
The storage step is a step of storing the wood chips P in the chip storage 41. The received wood chips P are roughly classified into cutting chips and crushed chips, stored separately in each yard 41A and 41B, and naturally dried. The wood chips P of the yards 41A and 41B are picked up by the loading crane 43 and loaded into the mixing yard 41C.

At this time, by controlling the number of times of loading by the loading crane 43 and loading into the mixing yard 41C, the ratio of the cutting tip to the crushing tip can be adjusted to the desired ratio.

For example, when the number of times the cutting chips and the crushing chips are input is 1: 1, the cutting ratio (the ratio of the cutting chips in the mixed chips) is 50%. Then, the two kinds of wood chips P thrown into the mixing yard 41C are mixed in the mixing yard 41C before being used.

<Injection process (use process)>
The loading crane 43 randomly grabs the wood chips P from the mixing yard 41C and supplies them to the supply hopper 45. The wood chips P supplied to the supply hopper 45 are then sent to the boiler 21 by the supply feeder 47.

A load meter 43A is installed on the loading crane 43, and the weight [kg] (weight used as fuel) of the wood chips P charged to the supply hopper 45 can be measured. However, since it is difficult to provide a moisture content meter, the moisture content [%] of the wood chip P cannot be measured. The water content used is the water content of the wood chips P when fuel is used (when the hopper is added).

The reason why it is difficult to provide a moisture content meter on the loading crane 43 is that the moisture content needs to be measured by the worker by extracting a sample from the wood chip P, so that the wood chip P is supplied to the supply hopper 45. This is because it is too time-consuming and difficult in reality to perform such work every time it is put in.

Further, as an item accompanying the input process, the power generation amount [kWh] as an output from the chip fuel can be measured by a power meter 25A provided in the generator 25.

The weight of the wood chip P used can be measured by the load meter 43A as described above, and the amount of generated power can be measured by the power meter 25A. Therefore, the fuel consumption rate HR, which represents the weight [kg] used to obtain the power generation amount of 1kWh, can be obtained from the usage weight of the wood chip P and the power generation amount.

<Analysis of chip properties by an external organization>
Wood chips P are sampled regularly, and the absolute dry calorific value and ash content are analyzed by an external organization.

As described above, the management process of the wood chip P includes four processes of a receiving process, a storage process, a charging process, and a property analysis. FIG. 2 shows the measurement items of the wood chip P in each process.

3. 3. Calculation of power generation efficiency eff0 and trend management The power generation efficiency eff0 of the biomass power generation facility 10 can be calculated by three steps S1 to S3 (see FIG. 3).

(S1) Calculation of moisture content Uwout used for wood chip P (S2) Calculation of low calorific value LHVout of wood chip P (S3) Calculation of power generation efficiency eff0

<About S1>
1. 1. Changes in Moisture Weight During Chip Storage Storage The received weight Z1 of the wood chips P received in the receiving step is the sum of the absolute dry weight X and the received water weight W1 as shown in FIG. The absolute dry weight X is the dry weight (weight after drying) of the wood chip P, and the water weight W is the weight of the water contained in the wood chip P.

A part of the water contained in the wood chip P evaporates or absorbs moisture during the storage period from when it is received in the chip storage 41 until it is actually used as fuel. The weight Z2 used for the wood chips P is lighter by the amount of evaporation Q of water or heavier by the amount of moisture absorption than at the time of acceptance.

“Q” in FIG. 4 indicates the amount of water evaporation during the storage period of the wood chip P, and “W2” indicates the weight of water used in the wood chip P. Further, even if the water evaporates, the absolute dry weight X does not change, and the absolute dry weight X is constant.

4. Calculation of used moisture rate Uwout focusing on the zero remaining amount period During the zero remaining amount period, the remaining amount of chips in the chip storage 41 is zero, the wood chips P received in the chip storage are used up, and the remaining amount of chips is zero again. It is a period until it becomes. In other words, the period during which the remaining amount of chips in the chip storage 41 is reduced from zero to zero, that is, after the wood chips P are received in the chip storage 41 having zero remaining chips, all the chips are used up and the remaining amount of chips becomes zero. It is the period until returning. The zero remaining period is, for example, several months to half a year.

Since the weighing scale in the zero remaining amount period is not affected by the remaining amount of chips in the chip storage 41, the following equations 1 and 2 are established for the entire period. The weight scale is the total weight.
Accepted absolute dry weight scale = Used absolute dry weight scale ... (1)
Moisture Weighing Scale used = Weighing Scale Used-Absolutely Dry Weighing Scale = Weighing Scale Used-Accepting Absolute Dry Weighing Scale ... (2)

Then, from the moisture content meter obtained by the second equation, the average moisture content of the wood chips during the zero remaining period can be obtained from the following three equations.
Average moisture content used during the zero remaining period = Moisture content meter / Weighing scale used ... (3)

Since the average moisture content during the zero remaining amount period can be calculated only from the measured values without making assumptions, there is an advantage that the accuracy is high.

FIG. 5 is a graph showing the relationship between the average fuel consumption rate HR in the zero remaining amount period and the average moisture consumption rate in the zero remaining amount period. This graph was obtained by conducting multiple surveys (multiple periods) to investigate the average moisture consumption rate and average fuel consumption rate during the same period, with the zero remaining period as one unit. From the obtained data, if the correlation between the average moisture consumption rate during the zero remaining amount period and the average fuel consumption rate HR during the zero remaining amount period is taken, a correlation straight line (first-order approximate straight line) shown by the solid line shown in FIG. 5 can be obtained. From the correlation straight line shown by the solid line in FIG. 5, the moisture content Uwout of the wood chip P can be expressed by Eq. (4) with the fuel consumption rate HR as a variable.

Moisture content used = 0.4431 x HR-0.1940 ... (4)

The fuel consumption rate HR can be obtained from the weight of the wood chip P that can be measured by the load meter 43A and the amount of power generated by the generator 25 that can be measured by the wattmeter 25A, as shown by the equation 5. That is, it can be obtained using only the measurable amount.
Fuel consumption rate HR = weight used of wood chip P / amount of power generated [kg / kWh] ... (5)

The fuel consumption rate HR changes depending on the power generation efficiency eff0. Since the woody biomass power generation facility 10 for which data was collected is working to improve efficiency, it is grouped into the period during which high-efficiency operation was performed and the other periods, and the average moisture consumption and average fuel consumption during the zero remaining period. When the correlation of the rate HR is taken, the correlation straight line shown by the dotted line in FIG. 5 is obtained, and the correlation is further improved.

The absolute value of the moisture content Uwout used differs by about 1% between the high-efficiency operation period and the other periods, but the amount of change (slope) with respect to the fuel consumption rate HR is almost the same. For the correlation straight line, the characteristics of the solid line may be used without distinguishing between the high-efficiency operation period and the other period, or the characteristic of the broken line corresponding to the high-efficiency operation period and the other period can be used. You may choose and use it.

Further, as shown in the equation (4), the moisture content Uwout of the wood chip P is expressed by a linear equation with the fuel consumption rate HR as a variable. Since the fuel consumption rate HR, which is a variable, can be obtained in real time from the measured values of the weight used and the generated power, the water consumption rate Uwout of the wood chip P can also be calculated in real time.

<About S2>
In S2, the low calorific value LHVout of the wood chip P is calculated by using the moisture content Uwout of the wood chip P calculated in S1. Of the calorific value obtained by burning fuel (wood chips), the calorific value including the latent heat of condensation obtained when the generated steam in the combustion gas is condensed is called the high calorific value, and is condensed as steam. The calorific value that does not include latent heat is called the lower calorific value.

It is known that the following six equations generally hold between the low calorific value LHV of the wood chip P and the water content Uw.
LHV = primary term x Uw + constant term ... (6)

The constant term is the low calorific value LHV when the moisture content is zero, that is, the absolute dry calorific value LHVm of the wood chip P. In this embodiment, a constant term is calculated from the following 7 equations from the analysis data (absolute dry calorific value LHVm, ash content Ua) of the wood chip P measured by an external analysis institution.
Constant term = LHVm / (1-Ua) ... (7)

In the above 6 equations, when Uwout = 100%, LHV = the amount of heat absorbed by water. Therefore, the relationship of heat absorption of water = linear term + constant term is established.

Therefore, the linear term can be calculated by the following eight equations.
Primary term = (heat absorption of water-constant term) ... (8)
The primary term <0.

As the heat absorption amount of water, 539 kcal / kg, which is the latent heat when water is vaporized, is used.

Since the linear term and the constant term can be obtained from the above, the low calorific value LHVout of the wood chip P can be calculated by substituting the moisture content Uwout of the wood chip P obtained in S1 into the equation 6. You can. LHVout is a low calorific value when the wood chip P is used as fuel.

<About S3>
In S3, the power generation efficiency eff0 of the biomass power generation facility 10 is calculated by using the low calorific value LHVout of the wood chip P calculated in S2. The power generation efficiency eff0 is the efficiency of converting the heat energy (heat input amount of the boiler) possessed by the wood chip P into electric energy.

The amount of heat input to the boiler 21 can be obtained from the following nine equations using the weight of the wood chip P used and the low calorific value LHVout.
Boiler heat input = weight used for wood chip P x low calorific value LHVout [kcal] ・ ・ ・ (9)

The power generation efficiency eff0 can be obtained from the following 10 equations using the amount of power generated by the generator 25 and the amount of heat input by the boiler 21.
Power generation efficiency eff0 = Power generation amount [kWh] x 860 / Boiler heat input amount [kcal] ... (10)
In addition, 860 is a unit conversion coefficient.

In the steps S1 to S3, the power generation efficiency eff0 of the biomass power generation facility 10 can be obtained. The power generation efficiency eff0 can be obtained as daily and hourly data. From the change in power generation efficiency eff0, the tendency of power generation efficiency eff0 can be managed.

In the present invention, it is possible to calculate the moisture content Uwout of the wood chip P, which was difficult in the past, so that the low calorific value LHVout of the wood chip P can be subtracted to specify the heat input amount of the boiler 21. It has become possible.

Therefore, the power generation efficiency eff0 can be estimated from the amount of power generated, and the power generation efficiency can be managed in the same manner as the thermal power generation equipment using fossil fuel. From the above, management that is directly linked to business feasibility can be expected, such as equipment deterioration management, early detection of abnormal signs due to changes in operating conditions, and confirmation of equipment operation improvement effects.

FIG. 6 shows the time transition of the fuel consumption rate HR, the water consumption rate Uwout calculated by the steps S1 to S3, and the power generation efficiency eff0 for one year.

5. About the fuel consumption rate ratio The ratio to the standard of the fuel consumption rate is defined as the fuel consumption rate ratio, and its value is obtained.
HRr = HR / HRs ・ ・ ・ ・ ・ ・ ・ ・ (11A)
HRr is the fuel consumption rate ratio, HR is the fuel consumption rate, and HRs is the standard value of the fuel consumption rate.

As the reference value of the fuel consumption rate, it is preferable to use the planned value of the power generation facility 10 or the average value during the zero remaining period. In this example, the reference value of the fuel consumption rate is calculated according to the following equation using the planned value of the power generation amount per day, the planned value of the chip usage weight, and the like.

Uwout is the moisture content used at that time, LHVout is the low calorific value LHV in the moisture content Uwout used, and effs0 is the standard power generation efficiency.

Standard power generation amount Es0 [kWh / d] = Rated output of generator [kW] x 24 [h] ... (11B)
Reference heat input Qs0 [Mcal / d] = Es0 × 860/1000 / effs0 ・ ・ (11C)
Standard weight used Fs0 [t / d] = Qs0 / LHVout ・ ・ ・ ・ ・ ・ ・ ・ (11D)
HRs [kg / kWh] = Fs0 × 1000 / Es0 ・ ・ ・ ・ ・ ・ ・ ・ (11E)

Then, when the fuel consumption rate ratio HRr obtained by the 11A equation is larger than 1, that is, when HR> HRs, it is determined that the fuel consumption is larger than the standard and the power generation efficiency eff0 is worse than the standard power generation efficiency effs0. You can.

On the contrary, when the fuel consumption rate ratio HRr obtained by the 11A equation is smaller than 1, that is, when HR <HRs, the fuel consumption is smaller than the standard, and the power generation efficiency eff0 is better than the standard power generation efficiency effs0. I can judge.

The reference value HRs is a reference value of the weight of the wood chip P required to generate 1 [kWh] of electric power. Since the weight of the wood chip P used will be different if the lower calorific value LHV changes, the reference value HRs needs to be calculated for each LHV.

6. Indicators for evaluating business feasibility There are the following relationships between power generation efficiency eff0, low calorific value LHV of chips, and fuel consumption rate HR.
eff0 x LHV x HR = constant ... (12)
In the unit system of LHV (kcal / kg) and HR (kg / kWh), the constant is 860.

Since the weight used and the amount of power generated by the wood chip P are measurable items in the biomass power generation facility 10, the fuel consumption rate HR can be measured in real time from the equation 5. Therefore, the value of "860 / HR", that is, the value of "eff0 × LHV" can be calculated from the fuel consumption rate HR.

For thermal power generation facilities that use LNG as fuel, the LHV of the fuel is almost constant, so if the HR can be calculated, the power generation efficiency eff0 can be specified in the end.

However, in a woody biomass power generation facility that uses wood chips P as fuel, the LHV changes significantly due to fluctuations in the amount of water retained in the wood chips P during storage in the chip storage, so when the HR changes, the power generation efficiency is eff0. It is difficult to calculate the cause of the change between the low calorific value LHV and the low calorific value LHV.

According to the present invention, the water consumption rate Uwout can be specified from the fuel consumption rate HR, so that the low calorific value LHV can be specified and the power generation efficiency eff0 can also be specified.

In order to evaluate the business feasibility of the biomass power generation facility 10, it is necessary to manage the fuel purchase amount. The fuel consumption rate HR corresponding to the fuel consumption from the 12th formula is expressed by the 13th formula.
HR = 860 / LHV / eff0 ... (13)

In thermal power generation facilities where there is almost no change in LHV, the power generation efficiency eff0 and the fuel consumption rate HR are inversely proportional, and if eff0 is managed, the fuel purchase amount can be managed.

On the other hand, in woody biomass power generation equipment, LHV changes significantly due to fluctuations in the amount of water retained in the wood chip P. Therefore, even if the power generation efficiency eff0 improves, if the amount of decrease in LHV is large, the product of eff0 and LHV becomes small. As a result, HR, or fuel purchase, increases.

From the above, in the woody biomass power generation facility 10, the fuel purchase amount cannot be managed by managing only the power generation efficiency eff0, and the business feasibility cannot be evaluated.

Absolute dry HR (absolute fuel consumption rate) is used as an index for evaluating business feasibility, that is, for evaluating the amount of fuel purchased. The absolute dry HR represents the absolute dry weight (wood weight) of the wood chip P consumed to generate 1kWh, and is defined by the following equation.

Absolutely dry HR (HRz) [kg / kWh] = Absolutely dry weight / generated power
= Weight used x (1-Moisture content used) / Power generation amount
= Fuel consumption rate HR x (1-Moisture consumption rate) ... (14)

Since the absolute dry weight at the time of receiving the wood chip P and the absolute dry weight at the time of use are the same, by using the absolute dry HR, it is possible to control the fuel purchase amount regardless of the water weight of the wood chip P.

For example, assuming that the standard power generation amount per day is Es0 [kWh / d], the absolute dry weight used per day is 15 formulas.
Absolute dry weight used per day = Absolute dry HR (HRz) x standard power generation amount Es0 / 1,000 [t / d] ・ (15)

If the water content used as the standard when purchasing fuel is Uws, the fuel purchase amount can be calculated and evaluated by converting the above-mentioned absolute dry weight into the standard water content Uws using the formula 16.
Standard moisture content Uws equivalent weight = Absolute dry weight used per day / (1-Uws) ... (16)

Figure 6 shows the annual time transition of power generation efficiency and absolute dry HR. The thick line at the top in FIG. 6 shows the time transition of "power generation efficiency", and the thick line at the bottom shows the time transition of "absolute dry HR". If the LHV is constant, the absolute dry HR should decrease if the power generation efficiency eff0 increases, but this is not always the case. This means that it is necessary to manage the dry HR to evaluate the fuel purchase amount.

7. Management of remaining amount of chip storage The absolute dry weight (= wood weight) of the wood chip P is expressed by the formula 17.
Absolute dry weight of wood chips P = weight of wood chips P x (1-moisture content Uw) ... (17)

Since the absolute dry weight is not affected by the water weight, the absolute dry remaining amount on the day is the absolute dry remaining amount on the day before the wood chip P, the received absolute dry weight of the wood chip P, and the use absolute dryness of the wood chip P. From the weight, the remaining dry amount of the wood chip P on the day is calculated based on the following 18 equations.
Absolute dry amount on the day = Absolute dry amount on the previous day + Absolute dry weight received-Absolute weight used ... (18)

Further, the remaining amount of the wood chip P on the day is calculated from the remaining amount of absolute dryness on the day and the moisture content used Uwout based on the following 19 equations.
Remaining amount of wood chips on the day = Absolutely dry amount of the day / (1-Uwout) ... (19)

The residual heat amount of the wood chip P is calculated from the following 20 formulas using the remaining amount of the day and the low calorific value LHV.
Residual heat = remaining amount x lower calorific value LHVout ・ ・ ・ ・ ・ (20)

The storage amount of the chip storage 41 needs to be controlled by the amount of heat. In the past, the volume was visually measured at the end of the month, multiplied by the assumed bulk specific weight, and converted to weight, which required a great deal of labor.

In the present invention, since the used moisture content Uwout of the wood chip P can be calculated, the used absolute dry weight can be calculated from the used weight of the wood chip P and the used moisture content Uwout based on the formula 17. can. Therefore, the remaining amount and the amount of residual heat of the wood chips P on the day in the chip storage 41 can be obtained.

FIG. 7 shows the annual time transition of the remaining amount calculation result according to the present invention and the remaining amount actual inspection result visually measured at the end of the month. The remaining amount calculation result and the remaining amount actual inspection result are almost the same, and it is evaluated that the remaining amount calculation can be used.

In addition, as shown above, the remaining amount is calculated using the water content used Uwout. Therefore, if there is an error in the water content used Uwout, it will be accumulated in the remaining amount calculation result and the error in the remaining amount will increase. In FIG. 7, since the error between the remaining amount calculation result and the remaining amount actual inspection result is small, it can be evaluated that the error of the used water content Uwout calculated in the present invention is small.

From the above, it becomes possible to accurately estimate the remaining amount and the amount of residual heat of the wood chip P, and it is possible to sufficiently manage the remaining amount of the wood chip P. From the above, management that is directly linked to business feasibility, such as fuel procurement management and business feasibility improvement by checking the dryness status in the chip storage, is possible.

8. About the management device 55
As shown in FIG. 1, the management device 55 includes a calculation unit 100, a storage unit 150, a display unit 160, and an input unit 170. The storage unit 150 is for storing data, the display unit 160 is for displaying data, and the input unit 170 is for input by the administrator. The data stored in the storage unit 150 includes various data for calculating the moisture content used Uwout and the power generation efficiency eff0, such as the data of the correlation straight line shown in FIG.

FIG. 8 is a block diagram of the calculation unit 100. The calculation unit 100 includes a first calculation unit 110, a second calculation unit 120, and a third calculation unit 130.

The calculation unit 100 inputs, as calculation signals, the amount of power generated, the weight used by the wood chips P, the received weight of the wood chips P, and the received moisture content of the wood chips P. The amount of generated power can be measured by the power meter 25A of the generator 25. The weight of the wood chip P used can be measured by the load meter 43A of the loading crane 43. The received weight of the wood chip P can be measured by the truck scale 15A. The received moisture content of the wood chip P can be measured with a moisture content meter 15B.

The first calculation unit 110 calculates the moisture content Uwout of the wood chip P based on the calculation signal.

As shown in FIG. 9, the first calculation unit 110 has an HR calculation unit 110A and a moisture content used calculation unit 110B.

The HR calculation unit 110A obtains the fuel consumption rate HR of the biomass power generation facility 10 based on the amount of power generated and the weight used by the wood chip P. Specifically, it is obtained from the above-mentioned five equations.

The moisture content used calculation unit 110B calculates the moisture content Uwout of the wood chip P. Specifically, based on the fuel consumption rate HR of the biomass power generation facility 10, the moisture content Uwout of the wood chip P is calculated from the above four equations.

As shown in FIG. 10, the second calculation unit 120 calculates the power generation efficiency eff0, the fuel consumption rate ratio HRr, and the absolute dry HR based on the water consumption rate Uwout, the weight used by the wood chip P, and the power generation amount. do.

As shown in FIG. 10, the second calculation unit 120 includes an LHV calculation unit 120A, a boiler heat input calculation unit 120B, a power generation efficiency calculation unit 120C, an HR calculation unit 120D, a setting unit 120E, a fuel consumption rate ratio calculation unit 120F, and a fuel consumption rate ratio calculation unit 120F. It has an absolute dry HR calculation unit 120G.

The LHV calculation unit 120A calculates the low calorific value LHVout of the wood chip P from the above 6 equations using the moisture content Uwout of the wood chip P calculated by the first calculation unit 110.

The boiler heat input calculation unit 120B calculates the heat input of the boiler 21 from the above 9 equations based on the low calorific value LHVout of the wood chip P and the weight used by the wood chip P.

The power generation efficiency calculation unit 120C calculates the power generation efficiency eff0 from the above 10 equations based on the amount of heat input of the boiler 21 and the amount of power generation.

The HR calculation unit 120D obtains the fuel consumption rate HR of the biomass power generation facility 10 based on the amount of power generated and the weight used by the wood chip P.

The setting unit 120E calculates the reference value HRs of the fuel consumption rate HR based on the low calorific value LHV of the wood chip P calculated by the LHV calculation unit 120A.

The fuel consumption rate ratio calculation unit 120F calculates the fuel consumption rate ratio HRr from the above formula 11A based on the calculated value of the fuel consumption rate HR calculated by the HR calculation unit 120D and the reference value HRs.

The absolute dry HR calculation unit 120G calculates the absolute dry HR (HRz) from the above 14 equations based on the calculated value of the fuel consumption rate HR calculated by the HR calculation unit 120D and the moisture content used Uwout.

The second calculation unit 120 may display the calculated data of each value on the display unit 160. For example, the power generation efficiency eff0, the fuel consumption rate ratio HRr, and the absolute dry HR may be calculated on a daily basis, and the data may be displayed by a graph or the like with the horizontal axis as the time axis. The calculation cycle and display cycle of these data are not limited to daily units, but may be hour units, half-day units, or several-day units.

As shown in FIG. 11, the third calculation unit 130 includes a receiving absolute dry weight calculation unit 130A, a used absolute dry weight calculation unit 130B, an absolute dry remaining amount calculation unit 130C on the current day, an absolute dry remaining amount storage unit 130D on the previous day, and the current day. It has a remaining amount calculation unit 130E, an LHV calculation unit 130F, and a residual heat amount calculation unit 130G.

The receiving absolute dry weight calculation unit 130A calculates the received absolute dry weight of the wood chip P from the received weight of the wood chip P and the received moisture content Uwin based on the above 17 equations.

The used absolute dry weight calculation unit 130B calculates the used absolute dry weight of the wood chip P from the used weight of the wood chip P and the used moisture content Uwout based on the above 17 equations.

The absolute dry amount calculation unit 130C of the day is based on the above 18 equations from the absolute dry amount of the day before the wood chip P, the received absolute dry weight of the wood chip P, and the used absolute dry weight of the wood chip P. The remaining dry amount of the wood chip P on the day is calculated.

The remaining amount calculation unit 130E of the day calculates the remaining amount of the wood chip P on the day from the absolute dry remaining amount of the wood chip P on the day and the moisture content Uwout used on the day based on the above 19 equations.

The LHV calculation unit 130F calculates the low calorific value LHVout of the wood chip P from the above 6 equations using the moisture content Uwout of the wood chip P.

The residual heat amount calculation unit 130G calculates the residual heat amount of the wood chip P from the above formula 20 by using the remaining amount of the wood chip P on the day and the lower calorific value LHV.

The third calculation unit 130 may display the calculated data of each value on the display unit 160. Specifically, daily data of the remaining dry amount, the remaining amount, and the amount of residual heat of the wood chip P may be displayed by a graph or the like with the horizontal axis as the time axis.

<Other embodiments>
The present invention is not limited to the embodiments described above and the drawings, and for example, the following embodiments are also included in the technical scope of the present invention.

In the above embodiment, the average moisture content during the zero remaining period was calculated from the three equations. The average low calorific value during the zero remaining period may be calculated based on the average moisture content used during the zero remaining period. Further, the average heat input amount of the boiler during the zero remaining period may be calculated based on the calculated average low calorific value. Then, the average power generation efficiency of the biomass power generation facility in the zero remaining period may be calculated based on the average heat input amount of the boiler in the zero remaining period and the average power generation amount in the zero remaining period. In the zero remaining period, each value can be calculated only by the measured value, so that a highly accurate value can be obtained.

In the above embodiment, the correlation between the water consumption rate and the fuel consumption rate was obtained based on the actual data of the average moisture consumption rate during the zero remaining amount period and the average fuel consumption rate during the zero remaining amount period (correlation straight line in FIG. 5). ).
The method of obtaining the correlation between the water consumption rate and the fuel consumption rate is not limited to the method exemplified in the embodiment (method focusing on the zero remaining amount period), and may be obtained from the actual data of other periods. Further, the correlation between the moisture content used and the fuel consumption rate is not limited to linear approximation, but may be curve approximation or the like. Further, the correlation data is not limited to being held as a mathematical formula, and may be held as a reference table.

10 Biomass power generation equipment 21 Boiler 23 Turbine 25 Generator 40 Fuel supply device 43 Crane 45 Supply hopper 47 Supply feeder 48 Screw 51 Crane control device 55 Management device 100 Calculation unit 110 1st calculation unit 120 2nd calculation unit 130 3rd calculation unit

Claims (8)

It is a management device for biomass power generation equipment.
Equipped with a calculation unit
The calculation unit calculates the fuel consumption rate of the biomass power generation facility from the weight of the wood chip used as the fuel of the biomass power generation facility and the amount of power generated by the biomass power generation facility, and uses the fuel consumption rate as the fuel consumption rate. A management device for biomass power generation equipment that calculates the moisture content of wood chips used as fuel for the biomass power generation equipment when using fuel based on the correlation. The management device according to claim 1.
The period from when the remaining amount of chips in the chip storage is zero to when the remaining amount of wood chips received in the chip storage is used up and the remaining amount of chips becomes zero is defined as the zero remaining amount period.
As the correlation, a management device that uses the correlation between the average moisture consumption rate of the wood chips during the zero remaining amount period and the average fuel consumption rate during the zero remaining amount period. The management device for the biomass power generation facility according to claim 1 or 2.
The calculation unit calculates the low calorific value of the wood chip based on the calculated moisture content.
Based on the calculated low calorific value, the amount of heat input to the boiler is calculated.
A management device for a biomass power generation facility that calculates the power generation efficiency of the biomass power generation facility based on the calculated heat input amount and the power generation amount of the biomass power generation facility. The management device for a biomass power generation facility according to any one of claims 1 to 3.
The calculation unit calculates the absolute dry fuel consumption rate, which is the ratio of the absolute dry weight of the wood chips to the amount of power generated by the biomass power generation facility, based on the fuel consumption rate and the water consumption rate of the biomass power generation facility. Management device. The management device for a biomass power generation facility according to any one of claims 1 to 4.
The arithmetic unit
Based on the dry weight received on the day of the wood chips, the dry weight used on the day, and the dry remaining amount on the previous day of the wood chips, the absolute dry weight on the day of the wood chips is calculated.
The remaining amount of wood chips was calculated based on the calculated absolute dry amount on the day of the wood chips and the moisture content of the wood chips used.
A management device for biomass power generation equipment that calculates the residual heat of wood chips based on the calculated remaining amount of wood chips and the low calorific value of wood chips. The management device for a biomass power generation facility according to any one of claims 1 to 5.
Equipped with a display
The display unit is a management device that displays at least one calculation result among the calculation results by the calculation unit. A biomass power generation facility provided with the management device according to any one of claims 1 to 6. It is a method of calculating the moisture content of wood chips.
The period from when the remaining amount of chips in the chip storage is zero to when the wood chips received in the chip storage are used up and the remaining amount of chips becomes zero again is defined as the zero remaining amount period.
Based on the weight scale used for the wood chips during the zero remaining period and the acceptance absolute dry weight scale, the moisture weight scale used during the zero remaining period was calculated.
A method for calculating the moisture content of wood chips, which calculates the average moisture content of wood chips during the zero remaining period, based on the moisture content meter and the weigh scale used during the zero remaining period.

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