JPH0417325B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention provides a method for automatically controlling the mixing of two types of fuel oil to a desired mixing ratio. A fuel oil that mixes inferior oil (e.g. C heavy oil) on one side and good quality fuel oil (e.g. A heavy oil) on the other in a desired ratio and continuously supplies it as a mixed fuel to diesel engines, gas turbines, boilers, etc. Concerning the method of mixing.

(Prior Art) Methods for mixing fuel oils of this type for marine diesel engines, boilers, etc. are shown in Figures 1a to 1c, of which a shows a method for mixing fuel oils 1 and 2 for fuel oils A and B.
metering pumps 4 and 5 are arranged in the middle of the pipes 1 and 2 via strainers 3 and 3 (numeral 10 is a Tietsuta valve); The pulse is input to the controller 8, and the output therefrom controls the flow rate control valve 9 arranged in one of the pipes 1 to control the two oils A and B to a predetermined mixing ratio (in addition, 3 is a strainer, 10 is a check valve), and c is a variable speed pump 1 including variable speed motors 11, 11.
2 and 12.

(Problems to be Solved by the Invention) In conventional techniques a to c, the metering pumps 4 and 5, the flow rate transmitters 6 and 7, the flow rate adjustment valve 9, and the variable speed pumps 12 and 12 are all expensive. Maintenance on top
It has the disadvantage that inspection is troublesome.

(Means for Solving the Problems) The present invention focuses on the fact that there is a difference in oil temperature between these two oils A and B when they are stored before mixing, and uses the temperature difference between the two oils to adjust the desired mixing ratio. More specifically, the actual measured temperatures of both fuel oils A and B are set to TA, TB, and the desired mixture ratio (percentage) which is the control target value of both fuel oils A and B.
are respectively MA and MB, and the theoretical oil temperature of the mixed oil under this mixture ratio MA:MB is TM, and the following formula MA/MB=TB-TM/TM-TA...The calculation formula is derived from TM=MA・TA+MB・TB/MA+MB... (However, MA+MB=100) Calculate the TM that satisfies the following by inputting the above-mentioned measured temperatures TA, TB and desired mixture ratio MA, MB into the calculation section, This TM is input as a reference input signal to the adjustment section, and the actual measured temperature TM' of the mixed oil is also input to the adjustment section as a compensation input, and the output signal from the adjustment section is input to the electric/pneumatic positioner for mixing. This is a fuel oil mixing method that controls the opening degree of a valve. Poor quality oil (e.g. heavy oil C) has a high viscosity of 180 to 350 centistokes at 50°C, so it is usually heated to 70 to 85°C in the storage (supply) tank, while good oil A (e.g. heavy oil A) Because it has a low viscosity and some volatile matter remains, the storage tank is kept at room temperature 20-45°C to ensure safety.
It is generally kept at ℃. Therefore, there is a temperature difference of 30 to 50°C between the two. The relationship between this temperature difference and the mixing ratio (proportion) will be explained with reference to FIG. In the figure, the X-axis shows the mixing ratio (percentage) of oil A and oil B, and the Y-axis shows the fuel oil temperature. As an example, oil A is good quality oil, and oil B is poor quality oil. The oil temperature of oil A before mixing is TA, that of oil B is TB, the oil temperature of the mixed oil when both oils are at the desired mixing ratio MA and MB is TM, and the horizontal line containing TA and the vertical line Y' are The intersection is tA, horizontal line and perpendicular line including TM
If the intersection with Y′ is tM, and the intersection of the perpendicular line containing TM and the horizontal line containing the above TA is tAM, then △
TB・TA・tA, △TB・TM・tM and △TM・
TA and tAM are respectively similar right triangles.

Therefore, in △TB・TA・tA and △TB・TM・tM, TB−TA/MB+MA=TB−TM/MA∴MA=(MB+
MA) (TB-TM)/TB-TA In △TB・TA・tA and △TM・TA・tAM, TB−TA/MB+MA=TM−TA/MB∴MB=(MB+
MA) (TM-TA)/TB-TA Mixing ratio of both oils A and B MA/MB=(MB+MA)(TB-TM)/TB-TA/(MB+MA)
(TB-TM)/TB-TA = TB-TM/TM-TA... is obtained.

Therefore, the mixture ratio MA, which is the control target value above,
When performing automatic control of MB, both fuel oils A and B
Detects the temperatures TA and TB of the Rayo controller, calculates the TM that satisfies the above equation in the calculation section of the Rayo controller, uses the calculation result as a reference input to the adjustment section inside the Rayo controller, and adjusts the mixture ratio of the two to be controlled. detects the actually measured temperature TM' of the mixed oil and feeds it back to the control section to achieve automatic control of the mixing ratio. In Figure 3, the oil temperature of oil A is
When changing to TA1, the oil temperature of the new mixed oil is TM1.
However, in this case, TM in the formula can be replaced with TM1. In the above calculation, TM, which is the standard value for control, is obtained as an actual temperature value according to the following formula expanded from the formula.

TM=MATA+MBTB/MA+MB (however, MA+MB=
100)... A specific configuration for implementing the present invention according to the above theory will be described with reference to FIG. 3, and in FIG. 3,
AT and BT are oil tanks for oil A and oil B, respectively.
Oil A is kept at a temperature of 20 to 45°C, and oil B is kept at a temperature of 70 to 85°C. V1, V2, V4 are check valves, S1, S2,
S3 is a temperature sensor for oil A, oil B, and mixed oil A and B.
RC is a ratio controller (calculation section + adjustment section),
Po is an electric/pneumatic positioner V3 is a three-way mixing valve in the operating section, MX is a stirring mixer for mixed oils A and B, M is its motor, PU is a supply pump, H is a heater, St is a strainer, and D is a diesel engine. . In addition, among the detected temperature signals of sensors S1, S2, and S3,
TA and TB are input to the calculation section of the ratio controller RC, and TM' is input to the adjustment section of the same. A.S.
is an air separator.

(Function) With the above configuration, the actual measured temperatures TA and TB of oil A and oil detected by sensors S1 and S2 are calculated as TM=MATA+MBTB/MA+MB in the calculation section of the ratio controller RC. The calculation result is used as a reference input to the adjustment section. The output signal of the adjustment section is an electric/air positioner.
It is input to Po and adjusts the valve opening of the three-way mixing valve V3 in the operating section. As a result, the mixing ratio of oil A and oil B
Controls MA and MB. In this case, mixed oil A, B
The actual oil temperature TM' is detected by the temperature sensor S3 and fed back to the adjustment section of the ratio controller RC. In the adjustment section, the reference input TM is compensated and the final control target values MA, MB are adjusted.
achieve control of Mixed oils A and B may be sent to the load as they are, but as shown in the figure
It is preferable to proceed through this process in order to achieve uniform mixing and uniform temperature. The mixed oils A and B heated by the heater H via the supply pump PU are delivered to the diesel engine D.
Continuously supplied.

(Example) In the equipment shown in Fig. 3, A oil was heated to TA40℃ with A heavy oil.
B oil is C heavy oil, TB80℃, MA40 (%), MB60
(%), the formula TM=MATA+MBTB/MA+MB=(40×40)+(
60×80)/100=64(℃) is calculated and inputted to the adjustment section using TM64℃ as a reference signal. The valve opening degree of the three-way mixing valve V3 of the operation part is adjusted according to the output signal of the adjustment part, and both oils are A oil 40
(%) and B oil 60 (%). Then, the actual mixed oil temperature TM′ is determined by the ratio controller RC.
Continuous mixing of MA/MB = 40/60 is achieved by controlling the temperature at 64°C. If the oil temperature TA of oil A is 40℃ to 30℃
If the target value MA/MB=
Can maintain 40/60.

(Effects of the Invention) As understood from the description, the present invention has the following advantages:
This system automatically mixes and controls the mixing ratio of oils A and B by using only the temperature difference that exists between oils A and B, without using volume or volumetric flow as mixing parameters. There is no need for a transmitter, flow rate adjustment valve, or variable speed pump, and you can use a calculation unit, adjustment unit, positioner, and ordinary valves, so there are no restrictions on the oil flow range.
This not only alleviates problems of clogging and pressure loss and allows for more beneficial mixing, but also simplifies calculation operations and devices because the calculation input data requires only three measured oil temperatures and the desired mixing ratio setting. Done,
Furthermore, the excellent benefits of reducing the cost of equipment for implementing the invention and simplifying maintenance and inspection can be obtained.

Therefore, the present invention can be widely applied not only to mixing poor quality oil and good quality oil, but also to mixing two liquid fuels having different temperatures.

[Brief explanation of drawings]

Figures 1a, b, and c are explanatory diagrams of the conventional fuel oil mixing method, Figure 2 is a characteristic diagram of fuel oil temperature-mixing ratio, which is the principle of the present invention, and Figure 3 is a diagram showing the characteristics of the fuel oil temperature-mixing ratio, which is the principle of the present invention. A diagram of each device is shown. (Explanation of symbols), A, B... Fuel oil, TA, TB
...Actual temperature, MA, MB...Desired mixing ratio, TM
...Reference input.

Claims (1)

[Claims] 1. A method for automatically controlling the mixing of two fuel oils having a substantial temperature difference before mixing to achieve a desired mixing ratio, the method comprising: The actual measured temperature is TA, TB, and the desired mixture ratio (percentage), which is the control target value for both fuel oils A and B, is MA, MB, respectively.
The theoretical oil temperature of the mixed oil under this mixing ratio MA:MB is defined as TM, and the following formula MA/MB=TB-TM/TM-TA... The calculation formula derived from TM=MA・TA+MB・A TM that satisfies TB/MA+MB... (MA+MB=100) is calculated by inputting the above-mentioned measured temperatures TA, TB and desired mixture ratios MA, MB into the calculation section, and this TM is sent to the adjustment section. Input it as a reference input signal, and also input the measured temperature TM' of the mixed oil to the adjustment section as a compensation input, and input the output signal from the adjustment section to the electric/pneumatic positioner to adjust the valve opening of the mixing valve. A controlled method of mixing fuel oil. 2. The mixing method according to claim 1, wherein the calculation section and adjustment section are of a ratio controller, and the mixing valve is a three-way mixing valve operated by an electropneumatic positioner. 3. The mixing method according to claim 1 or 2, wherein fuel oil A is heavy oil A, fuel oil B is heavy oil C, and the temperature is TA 20 to 45°C and TB 70 to 85°C.