Boiler system and method for operating boiler

Abstract

To provide a boiler system capable of operating a boiler, using room-temperature solidification fuel (for example, recycled oil made from beef tallow) that solidifies at room temperature.SOLUTION: A boiler system comprises: an A type heavy oil tank 20 for storing A type heavy oil, which serves as fuel when a boiler 10 is started up and running; a fuel tank 30 for storing fluidized room-temperature solidification fuel; an A type heavy oil fuel supply line 21 for supplying the A type heavy oil to the boiler 10; a fluidized fuel supply line 31 for supplying the fluidized room-temperature solidification fuel to the boiler 10; and a fuel switching valve (first switching valve 22 and second switching valve 32) for switching a supply source between the A type heavy oil fuel supply line and the fluidized fuel supply line. The fuel tank 30 comprises heating means (steam heating device 35) for heating the fluidized fuel with steam from the boiler 10.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a boiler operating system that generates steam using recycled oil, and in particular to a boiler system and boiler operating method that can operate the boiler using room temperature solidifying fuel (e.g., recycled oil using beef tallow) that solidifies at room temperature. [Background technology]

[0002] Heavy oil A is generally used as fuel for boilers. In recent years, in view of rising fuel prices and the need to conserve energy, there has been much research into whether it is possible to use only recycled oils, such as waste oil, as fuel for boilers.

[0003] In this situation, the inventor has proposed the multi-tube once-through boiler described in Patent Document 1, which has a structure that allows recycled oil (waste oil) to be used as fuel for the combustion gas used to generate consumed steam in the boiler.

[0004] According to this structure, the combustion chamber is cylindrical and extends horizontally, and a door (lid) is formed on one end facing the combustion chamber. This allows the interior to be seen by opening and closing the door (lid). This makes it easy to clean the combustion chamber, and makes it possible to use recycled oil (waste oil) as fuel for the combustion gas (see Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 7099864 Summary of the Invention [Problem to be solved by the invention]

[0006] As a result of searching for possible fuels for boilers other than recycled oil (waste oil), the inventor came up with the idea of ​​using beef tallow and waste animal and vegetable oils, which are generated in large quantities as waste during food processing, as fuel.

[0007] However, since beef tallow and waste animal and vegetable oils have the property of solidifying at room temperature, they could not be used as fuel in systems that operate conventional boilers.

[0008] The present invention has been made in consideration of the above-mentioned situation, and aims to provide a boiler system that can operate the boiler using room temperature solidifying fuel (e.g., beef tallow or recycled oil made from waste animal and vegetable oils) that solidifies at room temperature. [Means for solving the problem]

[0009] In order to achieve the above object, the present invention (claim 1) is a boiler system equipped with a boiler (10) that uses fuel that solidifies at room temperature (room temperature solidifying fuel), and the following components are installed in a boiler room (1). An A-heavy oil tank (20) for storing A-heavy oil as fuel for start-up operation of the boiler (10). a fuel tank (30) for storing the room temperature solidifying fuel in a fluid state; an A-heavy oil fuel supply line (21) for supplying the A-heavy oil to the boiler (10); a fluidized fuel supply line (31) for supplying the room temperature solidified fuel to the boiler (10); A fuel switching valve (a first switching valve 22 and a second switching valve 32) for switching the supply source between the A heavy oil fuel supply line (21) and the fluidized fuel supply line (31). The fuel tank (30) is characterized by including a heating means (steam heating device 34) for heating the liquefied fuel with steam from the boiler (10).

[0010] Claim 2 provides the boiler system of claim 1, an outdoor storage tank (50) for fluidizing and storing the room temperature solidified fuel outside the boiler room (1); The outdoor storage tank (50) is a heat retaining means (steam heating device 55) for heating the liquefied fuel with steam from the boiler (10); a carry-in line (53) for carrying the room temperature solidified fuel through a carry-in entrance (a tanker connection portion 51); an oil supply line (60) for supplying the fluidized fuel to the fuel tank (30); a circulation line (70) for circulating the fluidized fuel between the oil supply line (60); a return line (80) for feeding back the fluidized fuel from the fuel tank (30) to the carry-in line (53); The present invention is characterized by being provided with the following:

[0011] Claim 3 provides the boiler system of claim 2, The system is characterized in that a three-way valve is provided in the circulation line (70), which switches the destination of the fuel from the circulation line (70) between the return line (80) side and the oil supply line (60) side, and a circulation pump (61) is provided to circulate the fluidized fuel between the oil supply line (60) and the circulation line (70).

[0012] Claim 4 relates to a method for operating a boiler (10) that includes an A-type heavy oil tank (20), a fuel tank (30), and an outdoor storage tank (50), and uses fuel that solidifies at room temperature (room-temperature solidifying fuel) stored in the fuel tank (30) and the outdoor storage tank (50), comprising: The boiler (10) is started up and operated using the A-type heavy oil supplied from the A-type heavy oil tank (20), The boiler (10) is stably operated by switching from the A-type heavy oil tank (20) to liquefied fuel from the fuel tank (30) equipped with a heating device (steam heating device 34) that heats the fuel using steam from the boiler (10), Just before the operation of the boiler (10) is terminated, the boiler (10) is switched back to the A-type heavy oil tank (20) for operation, During the stable operation, liquefied fuel is sent from the outdoor storage tank (50) equipped with a heating device (steam heating device 55) that heats the fuel with steam from the boiler (10) to the fuel tank (30) via an oil sending line (60); When the boiler (10) is stopped, liquefied fuel from the outdoor storage tank (50), which is equipped with a heating device that heats the fuel using an electric heater (54), is circulated between the outdoor storage tank (50) and the oil supply line (60). Effect of the Invention

[0013] According to the present invention, when the boiler (10) is started up, the A-type heavy oil is used as fuel from the A-type heavy oil fuel supply line (21), so that a smooth start of operation can be achieved. After the boiler (10) is started up, the fuel switching valve (first switching valve 22 and second switching valve 32) is used to switch the supply source from the A heavy oil fuel supply line (21) to the liquefied fuel supply line (32), making it possible to use fuel from the fuel tank (30), which stores liquefied room temperature solidified fuel in advance.

[0014] The fuel tank (30) includes a heating means (steam heating device 34) for heating the fuel liquefied by steam from the boiler (10), thereby making it possible to maintain the fuel in a liquefied state. By equipping the outdoor storage tank (50) with an electric heater (54), the room temperature solidified fuel can be kept liquefied even when the boiler (10) is stopped, and by circulating the liquefied fuel from the outdoor storage tank (50) between the outdoor storage tank (50) and the oil supply line (60), solidification of the fuel in the oil supply line (60) can be prevented. [Brief description of the drawings]

[0015] [Figure 1] 1 is a configuration explanatory diagram of a boiler system according to an embodiment of the present invention. FIG. [Diagram 2] This is a piping flow diagram of the boiler system (when the boiler is started up and when the boiler is stopped). [Diagram 3] This is a piping flow diagram of a boiler system (when the boiler is operating stably). [Figure 4] This is a piping flow diagram of the boiler system (when transporting fuel from the outdoor storage tank to the fuel tank). [Diagram 5] This is a piping flow diagram of the boiler system (when recycled oil is transported to the outdoor storage tank). [Figure 6] This is a piping flow diagram of a boiler system (when the boiler is stopped at night, etc.). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] An embodiment of a boiler system of the present invention will be described with reference to the drawings. The boiler system of the present invention is a system that fluidizes fuel that solidifies at room temperature (room-temperature solidifying fuel), such as beef tallow, which would otherwise be disposed of as waste, and enables it to be used as boiler fuel. In the figure, the thick solid lines represent fuel pipes for transporting boiler fuel, the thin solid lines represent steam pipes for transporting steam, and the arrows of the thick solid lines and the thin solid lines indicate the transport directions of the fuel and steam. Examples of room temperature solidifying fuels include recycled oil made from beef tallow, as well as waste animal and vegetable oils.

[0017] The boiler system is composed of equipment installed in a room in which a boiler 10 is installed (hereinafter referred to as a boiler room) and equipment installed outside the boiler room (outdoors). The boiler room 1 is equipped with a boiler 10 that uses combustion gas from a burner 11 to heat water in water tubes installed inside the boiler 10 to generate steam, an A-heavy oil tank 20 that stores A-heavy oil as fuel for start-up operation of the boiler 10, and a fuel tank 30 that liquefies room temperature solidifying fuel, which solidifies at room temperature, and stores it as fuel for the boiler 10. Fuel oil A is a heavy oil made by mixing residual oil after distillation of crude oil and diesel. It is classified according to kinetic viscosity according to the JIS standard, with diesel components making up 90% of the oil.

[0018] The A heavy oil tank 20 is connected to an A heavy oil fuel supply line 21, and is capable of supplying A heavy oil to the fuel inlet of the burner 11 via a first switching valve 22 and an inlet line 40. The A heavy oil fuel supply line 21 is configured with a double piping structure consisting of an inner pipe that delivers A heavy oil and an outer pipe that keeps the inner pipe warm by passing steam through it.

[0019] The fuel tank 30 is connected to a fluidized fuel supply line 31, and is capable of supplying fluidized fuel to a fuel inlet of the burner 11 via a second switching valve 32 and an inlet line 40. A line heater 33 for maintaining the fluidized fuel at 60 to 70 degrees and a double strainer 34 for filtering out foreign matter in the piping are installed in the fluidized fuel supply line 31.

[0020] A fuel switching valve is formed by the first switching valve (solenoid valve) 22 and the second switching valve (solenoid valve) 32, and by the opening and closing action of each solenoid valve, when the first switching valve 22 is open and the second switching valve 32 is closed, heavy oil A is supplied via the introduction line 40 to the fuel inlet of the burner 11, and when the first switching valve 22 is closed and the second switching valve 32 is open, liquefied fuel is supplied via the introduction line 40 to the fuel inlet of the burner 11.

[0021] The steam generated in boiler 10 is sent to a steam discharge pipe 12 that delivers the steam to a desired supply location, and is also returned to the fuel tank 30 side from a steam branch pipe 13 that branches off from the steam discharge pipe 12 via a pressure reducing valve 14. A steam heating device (heating means) 35 is installed in the fuel tank 30, which uses steam (about 80 degrees) supplied from the steam branch pipe 13 of the boiler 10 to keep the stored fuel warm.

[0022] Heavy oil A is used as fuel when boiler 10 starts operating, and after the generated steam stabilizes at about 80 degrees after 5 to 10 minutes and the fuel in fuel tank 30 becomes liquefied, the liquefied fuel is used as fuel for boiler 10. Burner 11 is also equipped with a pump for introducing fuel, and is configured so that when the vapor pressure reaches or exceeds a set value, the fuel supply to burner 11 is cut off and the fuel circulates through introduction line 40.

[0023] An outdoor storage tank 50 is installed outside (outdoors) of the boiler room 1. In order to fluidize and store the room temperature solidified fuel, the outdoor storage tank 50 is equipped with a carry-in line 53 for carrying the fuel from a lorry connection part (carry-in) 51 for introducing recycled oil to an upper inlet 52 of the outdoor storage tank 50, an electric heater 54 installed at the bottom of the tank, a steam heating device (heat retention means) 55 for keeping the fuel warm by using steam supplied from a steam branch pipe 13, an oil delivery line 60 for sending the fluidized fuel to the fuel tank 30, and a return line 80 for feeding back the fluidized fuel from the lorry connection part (carry-in) 51 side to the carry-in line 53. The delivery line 53 is composed of a double piping structure consisting of an inner pipe for delivering the room temperature solidified fuel and an outer pipe for keeping the inner pipe warm by using steam supplied from the steam branch pipe 13 via an electromagnetic valve.

[0024] A circulation pump 61 is installed in the oil supply line 60, and by connecting the circulation line 70, it is possible to switch between flowing fluidized fuel from the outdoor storage tank 50 via the oil supply line 60 to the fuel tank 30, and circulating the fluidized fuel from the outdoor storage tank 50 via the oil supply line 60 and the circulation line 70, by opening and closing the stop valve 91 and solenoid valve 92 installed in the oil supply line 60 and the solenoid valve 93 installed in the circulation line 70. The oil supply line 60 is configured with a double piping structure including an inner pipe for delivering the fluidized fuel and an outer pipe for keeping the inner pipe warm by using steam supplied from the steam branch pipe 13 .

[0025] Furthermore, a three-way valve 90 is installed in the circulation line 70 to switch between sending the fluidized fuel to the fuel delivery line 60 and sending the fluidized fuel to the return line 80. By installing the three-way valve 90, the fluidized fuel is fed back to the carry-in line 53 side via the circulation line 60 and the return line 80, and the fluidized fuel kept warm in the outdoor storage tank 50 can be kept from solidifying in each line.

[0026] That is, when storing fuel in the fuel tank 30, the lock valve 91 is opened, the solenoid valve 92 is opened, and the solenoid valve 93 is closed, so that the liquefied fuel flows from the outdoor storage tank 50 through the fuel supply line 60 to the upper inlet 36 of the fuel tank 30. When the fuel tank 30 becomes full and it is no longer possible to flow fuel, the stop valve 91 is opened, the solenoid valve 92 is closed, the solenoid valve 93 is opened, and the three-way valve 90 is opened to the return line 80 side, so that the liquefied fuel circulates and flows from the outdoor storage tank 50 to the outdoor storage tank 50 via the fuel supply line 60 and the circulation line 70.

[0027] When liquefied fuel is transported from the rotary vehicle through the lorry connection part (carry-in entrance) 51, the stop valve 91 is opened, the solenoid valve 92 is closed, the solenoid valve 93 is opened, and the three-way valve 90 is opened toward the fuel supply line 60, so that the liquefied fuel transported from the outdoor storage tank 50 is circulated between the fuel supply line 60 and the circulation line 70 and is not returned to the lorry connection part (carry-in entrance) 51. The room temperature solid fuel is liquefied at the delivery destination and is delivered to the outdoor storage tank 50 while still liquefied in the tank of the rotary vehicle. At this time, by flowing only the liquefied fuel from the rotary vehicle through the delivery line 53, the delivery work can be carried out smoothly.

[0028] Next, the operating procedure of the boiler system will be described. The A-type heavy oil tank 20 in the boiler room 1 stores A-type heavy oil, which is used as fuel when the boiler 10 is started up and running. The fuel tank 30 in the boiler room 1 stores fluid fuel made by liquefying room temperature solid fuel, but if time has passed since the boiler was shut down, it is possible that the fuel may have solidified. In that case, the fuel is liquefied by heating the heating device with steam from the boiler 10 after it starts operating using heavy oil A.

[0029] Heavy oil A is supplied to the boiler 10 from the heavy oil supply line via the fuel switching valve (first switching valve 22 is open, second switching valve 32 is closed). In this state, the burner 11 of the boiler 10 is ignited, and the boiler 10 is operated using the heavy oil A as fuel to generate combustion gas (Figure 2).

[0030] A temperature sensor installed in burner 11 checks the temperature (60 to 70 degrees) in the fluidized fuel supply line 31, and the fuel switching valve is switched (first switching valve 22 closed, second switching valve 32 open), allowing the boiler 10 to continue operating using liquefied fuel from the fluidized fuel supply line 31 as fuel to generate combustion gas (Figure 3). The steam generated in the boiler 10 is sent to the steam discharge pipe 12 and used for the desired purpose, and is also used via the steam branch pipe 13 to heat the fuel tank 30, the outdoor storage tank 50, the oil delivery line 60, and the delivery line 53. The steam from the steam branch pipe 13 used for heating is recovered as water (hot water) in each steam trap TR disposed at the tip of the supply destination.

[0031] When the burner is operating stably, liquefied fuel is sent from the outdoor storage tank 50 to the fuel tank 30 via the fuel supply line 60 by driving the circulation pump 61 and opening and closing the solenoid valves (solenoid valve 92 open, solenoid valve 93 closed) (Figure 4).

[0032] Just before the burner 10 is shut down, in order to leave fuel in the burner that is easy to ignite, the fuel switching valve is switched (first switching valve 22 open, second switching valve 32 closed) and heavy oil A is taken into the piping on the burner 10 side from the fuel switching valve via heavy oil A supply line 21 (Figure 2).

[0033] When transporting recycled oil (room temperature solidified fuel) to the outdoor storage tank 50, solenoid valve 92 is closed, solenoid valve 93 is opened, and three-way valve 90 is opened toward the oil supply line 60, thereby circulating fuel from the outdoor storage tank 50 between the oil supply line 60 and the circulation line 70, and only liquefied fuel from the lorry connection part (supply entrance) 51 flows into the supply line 53, making it possible to transport the oil smoothly into the outdoor storage tank 50 (Figure 5).

[0034] In addition, when the boiler 10 is stopped, such as at night, the liquefied fuel in the outdoor storage tank 50 is heated by the electric heater 44 to prevent it from solidifying, and by opening the stop valve 91, closing the solenoid valve 92, opening the solenoid valve 93, and opening the three-way valve 90 to the return line 80 side, the liquefied fuel is circulated from the outdoor storage tank 50 to the outdoor storage tank 50 via the oil supply line 60 and the circulation line 70, thereby preventing the fuel from solidifying in each line (Figure 6). [Explanation of symbols]

[0035] 1. Boiler room 10. Boiler 11…Burner 12...Steam discharge pipe 13...Steam branch pipe 14...Reducing valve 20…A heavy oil tank 21…A heavy oil supply line 22...First switching valve 30…Fuel tank 31...Liquefied fuel supply line 32...Second switching valve 33...Line heater 35...Steam heating device 40…Introduction line 50…Outdoor storage tank 51…Lorry connection (entrance) 52…Upper inlet 53...Loading line 54…Electric heater 55...Steam heating device 56…Lower outlet 60…Oil transmission line 61...Circulation pump 70…Circulation line 80…Return line 90...3-way valve 91...Shut-off valve 92...Solenoid valve 93...Solenoid valve

Claims

1. A boiler system including a boiler that uses fuel that solidifies at room temperature (room temperature solidifying fuel), An A-type heavy oil tank for storing A-type heavy oil as fuel for start-up operation of the boiler; a fuel tank for storing the room temperature solidifying fuel in a fluid form; A heavy oil fuel supply line that supplies the heavy oil to the boiler; a fluidized fuel supply line for supplying the room temperature solidified fuel to the boiler; a fuel switching valve for switching a supply source between the A heavy oil fuel supply line and the fluidized fuel supply line; Installed in the boiler room, The fuel tank is provided with a heating means for heating the liquefied fuel with steam from the boiler. A boiler system comprising:

2. an outdoor storage tank for fluidizing and storing the room temperature solidified fuel outdoors of the boiler room; The outdoor storage tank is a heat retaining means for heating the fluidized fuel with steam from the boiler; a carry-in line for carrying the room temperature solidified fuel through a carry-in entrance; an oil supply line that supplies the fluidized fuel to the fuel tank; a circulation line for circulating the fluidized fuel between the fuel supply line and the circulation line; a return line for feeding back the liquefied fuel from the outdoor storage tank to the carrying-in line; 2. The boiler system of claim 1, comprising:

3. 3. The boiler system of claim 2, further comprising a circulation pump that circulates the liquefied fuel between the oil supply line and the circulation line by providing a three-way valve in the circulation line and switching the destination of the fuel from the circulation line between the input line side and the oil supply line side.

4. A method for operating a boiler in which an A-type heavy oil tank, a fuel tank, and an outdoor storage tank are installed, and fuel that solidifies at room temperature (room temperature solidifying fuel) stored in the fuel tank and the outdoor storage tank is used, comprising the steps of: The boiler is started up and operated using the A-type heavy oil supplied from the A-type heavy oil tank, The boiler is stably operated by switching from the A-type heavy oil tank to liquefied fuel from the fuel tank equipped with a heating device that heats the fuel using steam from the boiler, Just before the boiler is shut down, the boiler is switched back to the A-type heavy oil tank for operation, During the stable operation, the liquefied fuel is sent from the outdoor storage tank equipped with a heating device that heats the fuel with steam from the boiler to the fuel tank via an oil supply line; When the boiler is stopped, the liquefied fuel from the outdoor storage tank, which is equipped with a heating device that heats the fuel by an electric heater, is circulated between the outdoor storage tank and the oil supply line. A method for operating a boiler comprising the steps of:

Images