Fuel system of emergency diesel power generator set for nuclear power station

Abstract

A fuel system of an emergency diesel power generator set for a nuclear power station, comprising a diesel engine (1), an internal circulation unit (2), a leakage fuel unit (3), a fuel conveying unit (4), a daily fuel tank (46), a fuel tank truck fuel discharging unit (5), and a main fuel storage tank (53), wherein a fuel inlet pipe (14), fuel injection pump fuel discharging pipes (15), and a high-pressure fuel pipe leakage pipe (16) are provided in the diesel engine (1), and a fuel booster pump (11) and a fuel duplex filter (12) are connected in series on the fuel inlet pipe (14); the fuel injection pump fuel discharging pipes (15) are connected to dirty fuel drums (13); the high-pressure fuel pipe leakage pipe (16) conveys return fuel to the leakage fuel unit (3); the internal circulation unit (2) comprises a standby fuel booster pump (23), a first fuel duplex coarse filter (22), and a return fuel cooler (21); the internal circulation unit (2) achieves fuel supply from the daily fuel tank (46) to the diesel engine (1), and when the return fuel of the diesel engine is cooled, conveys said return fuel to the daily fuel tank (46); the fuel conveying unit (4) is connected to the main fuel storage tank (53) and the daily fuel tank (46), and the fuel tank truck fuel discharging unit (5) conveys, to the main fuel storage tank (53) from a fuel tank truck, the fuel that is filtered. By simplifying the system arrangement, the conveying and recycling functions of the fuel are achieved, and the fuel in the main fuel storage tank is heated to ensure safe and stable operation of the diesel engine.

Description

Emergency diesel generator set fuel system for nuclear power plant TECHNICAL FIELD

[0001] The present application relates to the technical field of diesel generator set for nuclear power plant, in particular to an emergency diesel generator set fuel system for nuclear power plant. BACKGROUND

[0002] The safety of nuclear power plant is very important, so avoiding accidents is an important part of safety design, and the nuclear emergency diesel generator set as a backup power supply is one of the important parts of the safety system.

[0003] The nuclear emergency diesel generator is an important device for protecting related equipment from damage and safely shutting down the nuclear power unit when a major failure occurs in the nuclear power plant. Generally, the performance requirements of the nuclear emergency diesel generator set are very high, and it is necessary to ensure that the diesel engine always maintains a hot standby state, and the nuclear emergency diesel engine needs to be started quickly within 15s and maintain stable operating voltage and frequency. The diesel engine fuel system can provide the fuel supply required for normal starting and stable operation of the diesel engine, thereby ensuring the reliable operation of the emergency diesel generator set. TECHNICAL PROBLEM

[0004] In the design of the existing fuel system of the nuclear emergency diesel generator set, the fuel filter, fuel return cooler, fuel standby booster pump and other devices are relatively scattered in the plant layout, which cannot realize modularization and is not conducive to the layout and installation of the fuel system. On the other hand, in some northern regions, due to the low temperature, the entire fuel system pipeline may freeze and cannot guarantee the normal supply of diesel fuel.

[0005] Therefore, we propose an emergency diesel generator set fuel system for nuclear power plant. TECHNICAL SOLUTION

[0006] In view of the above-mentioned shortcomings in the prior art, the present application provides an emergency diesel generator set fuel system for nuclear power plant, thereby simplifying the system layout and realizing fuel supply and fuel heating.

[0007] The technical scheme adopted by the present application is as follows:

[0008] An emergency diesel generator set fuel system for nuclear power plant, comprising a diesel engine, an internal circulation unit, a leakage oil unit, a fuel delivery unit, a daily oil tank, an oil tank truck unloading unit and a main oil storage tank, the diesel engine is provided with a fuel inlet pipeline, a fuel pump leakage pipeline and a high-pressure oil pipe leakage pipeline, the fuel inlet pipeline is connected with the fuel booster pump and the fuel double filter in series, and the fuel inlet pipeline is connected with the fuel inlet of the internal circulation unit;

[0009] The fuel pump leakage pipeline is connected to the waste oil bucket;

[0010] The high-pressure oil pipe leakage pipeline connects the oil return to the leakage oil unit;

[0011] The inner circulation unit comprises a standby fuel booster pump, a first fuel double filter, and a fuel return cooler. The inner circulation unit realizes oil supply from the daily oil tank to the diesel engine and transports the diesel engine return oil to the daily oil tank after cooling.

[0012] The fuel delivery unit connects the main oil tank and the daily oil tank, and has the functions of delivering fuel from the main oil tank to the daily oil tank and heating fuel in the main oil tank.

[0013] The oil tank truck unloading unit delivers fuel from the oil tank truck to the main oil tank after filtration.

[0014] Further technical solutions are as follows:

[0015] The fuel return cooler is respectively provided with a first ball valve and a second ball valve at two ends thereof. One end of the first fuel double filter is provided with a third ball valve, and the other end of the first fuel double filter is divided into two paths. One path is connected in series with a fourth ball valve, a standby fuel booster pump, a first check valve, and a fifth ball valve. The other path is connected in series with a second check valve and a sixth ball valve.

[0016] The fuel booster pump is connected in parallel with a first safety valve and a third check valve.

[0017] The standby fuel booster pump, the first fuel double filter, the fuel return cooler, and the valves and pipelines are integrated, which is convenient for on-site installation and debugging of the nuclear power station.

[0018] The high-pressure oil pipe leakage pipeline is provided with a high-pressure oil pipe leakage detection box.

[0019] The leakage oil unit comprises a leakage oil tank. The leakage oil tank is connected in series with a first ball valve, an isolation leakage oil pump, a fourth check valve, and a second ball valve through pipelines in sequence. The leakage oil tank is further provided with a first fire-resistant breather valve above.

[0020] When the diesel engine is running, filtered fuel is delivered to the daily oil tank, so that the daily oil tank is always full and sufficient fuel is provided for the diesel engine. When the oil temperature in the main oil tank is lower than the set temperature, the fuel in the pipeline of the main oil tank is heated, so that the fuel temperature is higher than the condensation point.

[0021] The fuel delivery unit comprises a No. 2 fuel double coarse filter, a fuel delivery pump, a fuel electric heater, an oil-water separator, a fuel double fine filter and a daily fuel tank connected in sequence; when the fuel does not need to be heated, the fuel from the main oil tank is filtered through the No. 2 fuel double coarse filter, and then flows through the fuel delivery pump, the oil-water separator and the fuel double fine filter in sequence and enters the daily fuel tank; when the oil temperature of the main oil tank is lower than the set temperature, the fuel electric heater needs to be started to heat the fuel and then deliver the fuel back to the main oil tank, and the fuel electric heater is provided with a No. 2 safety valve to prevent the fuel electric heater from being dangerous due to pressure exceeding the set value.

[0022] The fuel delivery unit controls the final flow direction of the fuel through the first electromagnetic valve and the second electromagnetic valve.

[0023] The oil tank truck unloading unit delivers the fuel of the oil tank truck to the main oil tank through the fueling booster pump and the fueling filter. Advantages

[0024] The present application has the advantages of compact and reasonable structure, convenient operation, simplified system arrangement, simultaneous realization of fuel supply and fuel heating, control of the flow direction of the fuel at the outlet of the fuel delivery unit through the outlet electromagnetic valve, integrated arrangement of the dirty oil drum in the common chassis, simplified field arrangement and installation, integration of the equipment in each unit module (the internal circulation unit, the leakage oil unit, the fuel delivery unit and the oil tank truck unloading unit), facilitated field installation and maintenance of the system and greatly shortened field installation and debugging time. BRIEF DESCRIPTION OF DRAWINGS

[0025] Fig. 1 is a flow diagram of the fuel system of the present application.

[0026] Fig. 2 is a system diagram of the diesel engine and the internal circulation unit in the fuel system of the present application.

[0027] Fig. 3 is a system diagram of the leakage oil unit in the fuel system of the present application.

[0028] Fig. 4 is a flow diagram of the fuel delivery unit of the present application.

[0029] Fig. 5 is a partial view (I) of the fuel delivery unit of the present application.

[0030] Fig. 6 is a partial view (II) of the fuel delivery unit of the present application.

[0031] Fig. 7 is a flow diagram of the oil tank truck unloading unit of the present application.

[0032] Fig. 8 is a partial view (I) of the oil tank truck unloading unit of the present application.

[0033] Fig. 9 is a partial view (II) of the oil tank truck unloading unit of the present application.

[0034] 1 diesel engine; 2 internal circulation unit; 3 leakage oil unit; 4 fuel delivery unit; 5 tank truck unloading unit;

[0035] 11 fuel booster pump; 12 fuel duplex filter; 13 dirty oil drum; 14 fuel inlet pipeline; 15 fuel injection pump leakage pipeline; 16 high pressure oil pipeline leakage pipeline;

[0036] 101 third check valve; 102 first safety valve; 103 high pressure oil pipeline leakage detection box;

[0037] 21 fuel return oil cooler; 22 first fuel duplex coarse filter; 23 standby fuel booster pump;

[0038] 201 first ball valve; 202 second ball valve; 203 third ball valve; 204 fourth ball valve; 205 first check valve; 206 fifth ball valve; 207 second check valve; 208 sixth ball valve;

[0039] 31 leakage oil tank; 32 leakage oil pump;

[0040] 301 first ball valve; 302 fourth check valve; 303 second ball valve; 304 first flame arrestor breather valve;

[0041] 41 second fuel duplex coarse filter; 42 fuel delivery pump; 43 fuel electric heater; 44 oil-water separator; 45 fuel duplex fine filter; 46 daily oil tank;

[0042] 401 first ball valve; 402 second ball valve; 403 fifth check valve; 404 third ball valve; 405 second safety valve; 406 fourth ball valve; 407 fifth ball valve; 408 sixth ball valve; 409 first solenoid valve; 410 second solenoid valve; 411 seventh ball valve; 412 second flame arrestor breather valve;

[0043] 51 fuel refueling filter; 52 fuel refueling booster pump; 53 main oil storage tank;

[0044] 501 ball valve one; 502 sixth check valve; 503 ball valve two; 504 ball valve three; 505 third flame arrestor breather valve. Embodiment of the present application

[0045] As shown in FIG. 1-9, the nuclear power plant emergency diesel generator set fuel system of the present embodiment comprises a diesel engine 1, an internal circulation unit 2, a leakage oil unit 3, a fuel delivery unit 4, a daily oil tank 46, an oil tank truck unloading unit 5 and a main oil storage tank 53, the diesel engine 1 is provided with a fuel inlet pipeline 14, a fuel injection pump leakage pipeline 15 and a high-pressure oil pipe leakage pipeline 16, the fuel inlet pipeline 14 is connected in series with a fuel booster pump 11 and a fuel double filter 12, and the fuel inlet pipeline 14 is connected to the fuel inlet of the internal circulation unit 2.

[0046] The fuel injection pump leakage pipeline 15 is connected to a waste oil drum 13.

[0047] The high-pressure oil pipe leakage pipeline 16 connects the oil return to the leakage oil unit 3.

[0048] The internal circulation unit 2 comprises a standby fuel booster pump 23, a No. 1 fuel double coarse filter 22 and a fuel return cooler 21, and the internal circulation unit 2 realizes the oil supply from the daily oil tank 46 to the diesel engine 1 and the oil return from the diesel engine 1 to the daily oil tank 46 after cooling; the fuel delivery unit 4 connects the main oil storage tank 53 and the daily oil tank 46, and has the functions of delivering fuel from the main oil storage tank 53 to the daily oil tank 46 and heating the fuel in the main oil storage tank 53.

[0049] The oil tank truck unloading unit 5 delivers the filtered fuel from the oil tank truck to the main oil storage tank 53.

[0050] The fuel return cooler 21 is respectively provided at two ends with a first ball valve 201 and a second ball valve 202; one end of the No. 1 fuel double coarse filter 22 is provided with a third ball valve 203, and the other end of the No. 1 fuel double coarse filter 22 is divided into two routes, one of which is connected in series with a fourth ball valve 204, a standby fuel booster pump 23, a first check valve 205 and a fifth ball valve 206, and the other of which is connected in series with a second check valve 207 and a sixth ball valve 208.

[0051] The fuel booster pump 11 is connected in parallel with a No. 1 safety valve 102 and a third check valve 101.

[0052] The standby fuel booster pump 23, the No. 1 fuel double coarse filter 22, the fuel return cooler 21 and the valves and pipelines are integrated, which is convenient for on-site installation and debugging of the nuclear power plant.

[0053] The high-pressure oil pipe leakage pipeline 16 is provided with a high-pressure oil pipe leakage detection box 103.

[0054] The leakage oil unit 3 comprises a leakage oil tank 31, which is connected in series with a first ball valve 301, an isolation leakage oil pump 32, a fourth check valve 302 and a second ball valve 303 through pipelines, and is further provided at the top with a No. 1 fire-resistant breather valve 304.

[0055] When the diesel engine 1 is running, the filtered fuel is delivered to the daily fuel tank 46 to ensure that the daily fuel tank 46 is always full and provides sufficient fuel for the diesel engine 1 to run; when the oil temperature of the main fuel tank 53 is lower than the set temperature, the in-pipe fuel of the main fuel tank 53 is heated to ensure that the fuel temperature is higher than the condensation point.

[0056] The fuel delivery unit 4 comprises a No. 2 fuel double coarse filter 41, a fuel delivery pump 42, a fuel electric heater 43, an oil-water separator 44, a fuel double fine filter 45 and a daily fuel tank 46 connected in sequence; when the fuel does not need to be heated, the fuel is filtered through the fuel double coarse filter from the main fuel tank 53, and then flows through the fuel delivery pump 42, the oil-water separator 44 and the fuel double fine filter 45 in sequence to enter the daily fuel tank 46; when the oil temperature of the main fuel tank 53 is lower than the set temperature, the fuel electric heater 43 needs to be started to heat the fuel before being delivered back to the main fuel tank 53, and the fuel electric heater 43 is provided with a No. 2 safety valve 405 to prevent the fuel electric heater 43 from being dangerous due to pressure exceeding the set value.

[0057] The fuel delivery unit 4 controls the final flow direction of the fuel through the first electromagnetic valve 409 and the second electromagnetic valve 410.

[0058] The fuel tank truck unloading unit 5 delivers the fuel of the fuel tank truck to the main fuel tank 53 through the fuel filling booster pump 52 after being filtered through the fuel filling filter 51.

[0059] The embodiment discloses an emergency diesel generator set fuel system for a nuclear power plant, and specific structures and functions thereof are as follows:

[0060] The diesel engine 1 comprises a fuel booster pump 11, a fuel double filter 12, a waste oil drum 13, a fuel inlet pipeline 14, a fuel injection pump drain pipeline 15 and a high-pressure oil pipe leakage pipeline 16.

[0061] When the fuel booster pump 11 integrated on the diesel engine 1 is normally running, the fuel flows through the No. 1 fuel double coarse filter 22 in the internal circulation unit 2, bypasses the second check valve 207 and the sixth ball valve 208, and then flows through the fuel booster pump 11 to be pressurized, and then flows through the fuel double filter 12, the fuel injection pump, the high-pressure oil pipe and the fuel injector in sequence to enter the cylinder to be combusted.

[0062] When the fuel booster pump 11 fails or the fuel inlet pressure is low, the standby fuel booster pump 23 is started to supply fuel to the diesel engine 1. The fourth ball valve 204 and the fifth ball valve 206 are arranged before and after the standby fuel booster pump 23 to separately isolate the standby fuel booster pump 23 for maintenance.

[0063] At the same time, in this embodiment, the excess fuel in the diesel engine 1 cylinder is cooled by the fuel return cooler 21 in the internal circulation unit 2 and then returned to the daily fuel tank 46 to prevent the fuel from overheating. The fuel return cooler 21 is provided with a first ball valve 201 and a second ball valve 202 for isolation and maintenance.

[0064] At the same time, the fuel injection pump drain line 15 is connected to the sludge tank 13, and the sludge collected in the sludge tank 13 is stored in the common chassis of the diesel engine 1, and the sludge tank 13 integrated in the common chassis is more optimized for the layout of the nuclear power plant site.

[0065] At the same time, the high-pressure oil pipe leakage line 16 connects the return oil to the leakage oil unit 3; if the high-pressure oil pipe is broken, the leaked fuel flows into the leakage oil tank 31 of the leakage oil unit 3 after triggering an alarm by the high-pressure oil pipe leakage box 103;

[0066] In the leakage oil unit 3, when the liquid level of the leakage oil tank 31 reaches a certain value, the leakage oil pump 32 is automatically started to transport the fuel in the leakage oil tank 31 to the main oil tank 53 by control, and when the liquid level of the leakage oil tank 31 is lower than a certain value, the leakage oil pump 32 stops running.

[0067] The first ball valve 301 and the second ball valve 303 are arranged before and after the leakage oil pump 32 for isolation and maintenance of the leakage oil pump 32, and the fourth check valve 302 is arranged to prevent backflow of the fuel; the leakage oil tank 31 is provided with a fire-resistant breather valve 304 to prevent the leakage oil tank 31 from breathing and prevent the leakage oil tank 31 from generating overpressure or vacuum due to the lifting of the liquid in the leakage oil tank 31, causing deformation of the leakage oil tank 31.

[0068] At the same time, the fuel in the main oil tank 53 is transported to the daily fuel tank 46 by the fuel transportation unit 4 to ensure the normal and stable operation of the diesel engine 1.

[0069] Under normal operating conditions, the second ball valve 402 is opened, and the first ball valve 401, the third ball valve 404, the fourth ball valve 406, the fifth ball valve 407, the sixth ball valve 408, and the seventh ball valve 411 are closed; the fuel in the main oil tank 53 is filtered by the fuel transportation pump 42, the second fuel double coarse filter 41, the oil-water separator 44, and the fuel double fine filter 45, and then transported to the daily fuel tank 46;

[0070] When the fuel temperature is lower than the set value, the fuel electric heater 43 and the seventh ball valve 411 are opened by control circuit, the fuel in the main oil tank 53 is filtered by the fuel transportation pump 42, the second fuel double coarse filter 41, the fuel electric heater 43, and the fuel double fine filter 45, and then transported back to the main oil tank 53, and the first solenoid valve 409 and the second solenoid valve 410 control the final flow direction of the fuel.

[0071] The fifth check valve 403 prevents backflow of fuel, and the second safety valve 405 releases fuel when the pressure in the heater exceeds a set value, preventing accidents. The functions of the first ball valve 401, the third ball valve 404, the fourth ball valve 406, the fifth ball valve 407, and the sixth ball valve 408 are sampling or discharging, and they are opened only when needed. The daily oil tank 46 is provided with the second flame arrestor breather valve 412 to prevent overpressure or vacuum.

[0072] Meanwhile, the tanker unloading unit 5, when the main oil tank 53 needs to be refueled, the fuel oil tanker in the tanker unloading unit 5 through the fuel oil filling booster pump 52 to the main oil tank 53, at this time, open the ball valve one 501 and ball valve three 504, the fuel oil tanker after filtering out larger particles through the fuel oil filling filter 51 is delivered to the main oil tank 53, the sixth check valve 502 can prevent backflow of fuel;

[0073] Under normal operating conditions, the ball valve two 503 is in a normally closed state, and when it is necessary to discharge fuel in the tanker unloading unit 5 pipeline or sampling, open the ball valve two 503; the setting of the ball valve one 501 and the ball valve two 503 can ensure that the fuel oil filling booster pump 52 is isolated. The main oil tank 53 is provided with the third flame arrestor breather valve 505 to prevent overpressure or vacuum.

[0074] The above description is an explanation of the invention, not a limitation of the invention, the scope of the invention is defined in the claims, within the scope of the invention, any form of modification can be made.

Claims

1. An emergency diesel generator set fuel oil system for a nuclear power plant, characterized by: The diesel engine (1), the internal circulation unit (2), the leakage oil unit (3), the fuel delivery unit (4), the daily oil tank (46), the tank truck unloading unit (5) and the main oil storage tank (53) are included, the fuel inlet pipeline (14), the fuel injection pump leakage pipeline (15) and the high-pressure oil pipe leakage pipeline (16) are arranged in the diesel engine (1), the fuel booster pump (11) and the fuel double filter (12) are connected in series on the fuel inlet pipeline (14), and the fuel inlet pipeline (14) is connected to the fuel inlet of the internal circulation unit (2); The fuel injection pump leakage pipeline (15) is connected to the waste oil drum (13); The high-pressure oil pipe leakage pipeline (16) is connected to the leakage oil unit (3); The internal circulation unit (2) includes the standby fuel booster pump (23), the first fuel double filter (22) and the fuel return cooler (21), the internal circulation unit (2) realizes the fuel supply from the daily oil tank (46) to the diesel engine (1) and the fuel delivery from the diesel engine (1) to the daily oil tank (46) after cooling; The fuel delivery unit (4) is connected to the main oil storage tank (53) and the daily oil tank (46), and has the functions of delivering fuel from the main oil storage tank (53) to the daily oil tank (46) and heating the fuel in the main oil storage tank (53); The tank truck unloading unit (5) delivers the filtered fuel from the tank truck to the main oil storage tank (53).

2. An emergency diesel generator set fuel system for nuclear power plants as claimed in claim 1, characterized in that: The first ball valve (201) and the second ball valve (202) are respectively arranged at two ends of the fuel return cooler (21); the third ball valve (203) is arranged at one end of the first fuel double filter (22), and the other end of the first fuel double filter (22) is divided into two paths, one path is connected in series with the fourth ball valve (204), the standby fuel booster pump (23), the first check valve (205) and the fifth ball valve (206), and the other path is connected in series with the second check valve (207) and the sixth ball valve (208).

3. An emergency diesel generator set fuel system for nuclear power plants as claimed in claim 1, characterized in that: The first safety valve (102) and the third check valve (101) are connected in parallel on the fuel booster pump (11).

4. An emergency diesel generator set fuel system for nuclear power plants as claimed in claim 1, characterized in that: The standby fuel booster pump (23), the first fuel double filter (22), the fuel return cooler (21) and the valves and pipelines are integrated, so that the nuclear power station site installation and debugging are facilitated.

5. An emergency diesel generator set fuel system for nuclear power plants as claimed in claim 1, characterized in that: The high-pressure oil pipe leakage pipeline (16) is provided with the high-pressure oil pipe leakage detection box (103).

6. An emergency diesel generator set fuel system for nuclear power plants as claimed in claim 1, characterized in that: The leakage oil unit (3) includes the leakage oil tank (31), the leakage oil tank (31) is connected in series with the first ball valve (301), the leakage oil pump (32), the fourth check valve (302) and the second ball valve (303) through pipelines in sequence, and the first fire-resistant breather valve (304) is further arranged above the leakage oil tank (31).

7. An emergency diesel generator set fuel system for nuclear power plants as claimed in claim 1, characterized in that: When the diesel engine (1) operates, the filtered fuel is delivered to the daily oil tank (46), so that the daily oil tank (46) is always in full tank operation, and sufficient fuel is provided for the diesel engine (1) operation; when the oil temperature of the main oil storage tank (53) is lower than the set temperature, the fuel in the pipeline of the main oil storage tank (53) is heated, so that the fuel temperature is higher than the condensation point.

8. An emergency diesel generator set fuel system for nuclear power plants as claimed in claim 1, characterized in that: The fuel delivery unit (4) comprises a second fuel double coarse filter (41), a fuel delivery pump (42), a fuel electric heater (43), an oil-water separator (44), a fuel double fine filter (45) and a daily fuel tank (46) connected in sequence; when the fuel does not need to be heated, the fuel from the main fuel tank (53) is filtered through the second fuel double coarse filter (41), and then flows through the fuel delivery pump (42), the oil-water separator (44) and the fuel double fine filter (45) in sequence and enters the daily fuel tank (46); when the oil temperature of the main fuel tank (53) is lower than the set temperature, the fuel electric heater (43) needs to be started to heat the fuel before being delivered back to the main fuel tank (53), and the second safety valve (405) of the fuel electric heater (43) is arranged to prevent the pressure of the fuel electric heater (43) from exceeding the set value and causing danger.

9. An emergency diesel generating set fuel system for a nuclear power plant as claimed in claim 8, characterised in that: The fuel delivery unit (4) controls the final flow direction of the fuel through the first electromagnetic valve (409) and the second electromagnetic valve (410).

10. An emergency diesel generator set fuel system for nuclear power plants as claimed in claim 1, characterized in that: The oil tank truck unloading unit (5) delivers the fuel of the oil tank truck to the main fuel tank (53) through the fueling booster pump (52) after being filtered through the fueling filter (51).

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