RU152514U1 - DIESEL-GENERATOR PLANT FOR RESERVE POWER SUPPLY OF NPP SAFETY SYSTEMS - Google Patents

Abstract

Diesel generator set for backup power supply of nuclear power plant safety systems, consisting of a diesel engine, alternator, start-up, cooling, lubrication, air inlet, exhaust and automatic control systems, characterized in that it has two air compressors at least two compressed air cylinders, two pneumatic start valves and redundant pressure relief valves in the start-up system, two pumping units, dual coarse filters and onkoy cleaning fuel in the fuel system, two electric pump unit in the lubrication system, two electrically driven pump in the circuit of cooling the hot standby system, a two turbocharger air intake system.

Description

The proposed utility model is intended for the field of diesel engineering in order to meet the needs of nuclear power plants (NPPs) for backup power supply of safety systems.

Known utility model "Single-cylinder experimental setup for researching the working process of a diesel engine", patent No. 136859. The installation consists of a single-cylinder engine and systems providing engine operation: start-up, fuel supply, lubrication, cooling, an automated measurement system and an alternator.

A disadvantage of the known utility model is the impossibility of meeting the requirements for diesel generator sets for backup power supply of NPP safety systems, due to the lack of duplication of the most important plant functions necessary for NPP safety.

Based on studies conducted on the well-known single-cylinder plant, a utility model of a diesel-generator set with a twenty-cylinder diesel engine 20CHN20.5 / 31 was developed for backup power supply of nuclear power plant safety systems.

The fundamental difference of the proposed diesel generator set is that it consists of a twenty-cylinder diesel generator, which includes a diesel engine and an alternator,

and is equipped with start-up, cooling, lubrication, air inlet, exhaust gas and automation systems designed to duplicate functions to increase the reliability of start-up and automatic operation by using two air compressors, at least two compressed air cylinders, two pneumatic start-up valves and duplication of pressure-reducing valves in the start-up system, two pumping units, dual filters for coarse and fine cleaning of fuel in the fuel system, two electrical units waist in the lubrication system, two electric pumps hot standby, two turbochargers in the air intake system.

A general view of the diesel generator is shown in FIG. one.

The start-up system is shown in FIG. 2.

The start-up system is designed to start the diesel generator set with compressed air and ensure the operation of the pick-up system.

The starting system consists of two compressors 11, 14, at least 2 cylinders with a valve head 16, 21 filled with compressed air, valves: two pneumatic (main starting) 26 and 28 connected in parallel, one pneumatic 29, pressure reducing 1, 24 , 27, safety 4, 8, 25, trigger valves 2 and trigger spools 3.

Compressed air from the starting cylinders through shut-off valves 6, 10, check valves 5, 9, pressure reducing valves 1, 24, flows to pneumatic valves 26 and 28, connected in parallel, then to the spools of starting 3 and starting valves 2 installed in the cylinder covers.

Safety valves 4, 8, 25 are designed to limit the air pressure behind the pressure reducing valves and in the starting cylinders. Filling of cylinders with compressed air is carried out from electric compressors through check valves 13, 19 and shut-off valves 12, 20.

Pressure reducing valves are duplicated and it is possible to turn them off by shut-off valves.

Air pressure in the cylinders is controlled by pressure sensor 7. To increase the likelihood of starting, the system provides for duplication of pneumatic valves 26 and 28.

The system has two electric compressors connected in parallel. In the event of a malfunction of one of the electric compressors, the inclusion of the other electric compressor is automatic.

To ensure the specified loading characteristics of the diesel generator set during power surges, the circuit provides for additional air supply to the engine through a pressure reducing valve 27 and a pneumatic valve 28.

The diesel fuel system is shown in FIG. 3.

The fuel system is designed to supply fuel from the fuel tank to the diesel cylinders and spray it in the combustion chambers of the cylinders.

Fuel is supplied from the fuel storage tank by pump 40 or, in case of malfunction, by pump 41 through fuel pre-filters 35, 36 to fuel tank 31. Fuel is supplied from fuel tank to fuel pumps 47 by a fuel priming pump 44. Fuel is filtered by coarse filters purification 34, 35, 36, 37,

included in the suction pipe line, and a fine filter 50 included in the pressure pipe line.

Filter contamination is monitored by differential pressure sensor 32.

Excess fuel supplied by the fuel priming pump is discharged through the drain pipe back to the supply tank. To create fuel pressure at the inlet to the fuel pumps, an overflow valve 45 is built into the drain pipe.

Fuel pumps 47 take fuel from the low pressure system and through the high pressure pipe 48 and nozzles 49 mounted in the cylinder covers inject it into the diesel cylinders.

Fuel leaked through leaks in nozzles is diverted to the supply tank 31.

High pressure fuel pipelines are made with double walls to prevent fuel from entering the room if the pipeline is damaged. The fuel leaked during the depressurization of the high pressure fuel lines is diverted through the pipeline to the fuel and oil leak collection tank 43.

Pressure sensors 46 are designed to detect the presence of fuel leaks during depressurization of high pressure fuel lines.

A pump 33 is provided for starting the system with fuel.

If the leakage collection tank 43 is full, the pump for pumping 42 is automatically turned on.

To ensure operation in the system, shut-off valves and a check valve 39 are provided.

The fuel level in the tank 31 and 43 is monitored by sensors 30.

The pressure in the low pressure fuel line is monitored by sensors 46.

The lubrication system is shown in FIG. four.

The lubrication system is designed for:

a) oil supply to the rubbing surfaces of diesel parts for their lubrication and cooling;

b) piston cooling.

The lubrication system provides diesel pumping with oil in the “Standby” mode and oil circulation in the system during the start-up and operation of the diesel engine under load.

Refueling of a diesel engine oil is carried out by an electric pump unit 57, the same pump is used to pump oil from a diesel engine.

Monitoring the oil level in the bath is done by the sensor through the fitting 58.

In standby mode, diesel pumping is carried out by an electric pump unit 54; when it malfunctions, standby unit 55 is automatically turned on with a fault signal. Also, the electric pump unit 54 with an integrated bypass valve is switched on when the oil temperature is below 313K (40 ° C) to ensure the heating of the oil by pumping hot water through water-oil coolers 56 and 61.

The oil circulation in the diesel system during the start-up and operation of the diesel engine is carried out by an oil pump 67, which is equipped with an integrated bypass valve.

From the oil bath of the subframe, through the mesh intake 59, the oil enters the suction cavity of the pump 67. During the operation of the diesel engine, the oil pump 67 delivers the oil to the oil coolers, to the automatic oil filter 62 and then to the internal oil system of the diesel engine 60 and through the pressure reducing valve 66 to the turbochargers 64 and 65.

To collect oil leaks, under the electric pump units 54 and 55 and unit 57, leaking collection trays 53 are installed.

The oil pressure at the inlet to the diesel is monitored through sensors connected to the fittings 63. These sensors provide continuous diesel protection by oil pressure and operate on the principle of “two out of three”.

The receiver is purged and contaminated fuel and oil are drained from the shelves of the unit through the valves to the dirty fuel and oil collection tank 53.

The temperature of the oil at the inlet to the diesel engine and at the outlet of the diesel engine is controlled by temperature sensors mounted on fittings 52.

To compensate for thermal expansions and vibration loads from the diesel engine, compensators 51 are provided in the system.

Refueling and pumping oil from the diesel engine is carried out by pump 57.

The cooling system is shown in FIG. 5.

The diesel generator set uses a dual-circuit cooling system (cold cooling circuit and hot cooling circuit), in which coolant is circulated in two water pumps of the same design.

Cold cooling circuit

Coolant from the radiator sections of the modules of the cooling device of the cold circuit 76, connected in parallel, bypassing the modules of the cooling device, through the thermostat 74 enters the suction cavity of the pump water 78 of the cold circuit.

With a water pump 78, coolant is supplied to the charge air cooler 71, water-oil coolers 56 and 61, after which the coolant is discharged to the temperature controller 74.

Hot cooling circuit

Coolant from the radiator sections of the module of the cooling device of the hot circuit 81, bypassing the module of the cooling device, through the temperature controller 80 enters the suction cavity of the water pump 82 of the hot circuit.

With a water pump 82, coolant is supplied to the manifolds arranged in rows of cylinders, then through the channels it enters the cooling of the bushings and cylinder covers, exhaust manifolds, after which part of the coolant enters the cooling of the turbochargers, from which all the coolant, together with the remaining fluid in the manifolds, is discharged to the temperature controller 80.

In the ready-to-start mode, the coolant is heated by the heating boiler 84. The diesel engine is pumped with coolant by an electric pump 73. If the pump 73 fails, the standby pump 75 is automatically turned on and the pump 73 is faulty. The oil is heated by pumping.

To create a constant back pressure on the suction of the water pumps replenishing the circuits with coolant, water pumps are provided from the expansion tank 69.

Coolant is drained from the system into the water treatment tank 86.

Air and steam generated in the system during the operation of the diesel generator set is discharged into the expansion tank 69 with a safety valve 70 installed on it.

Filling the expansion tank 69 and the cooling system with coolant from the water treatment tank 86 is carried out by an electric pump 87.

The control of the coolant level in expansion tanks 69 and water treatment 86 is carried out by level sensors connected to fittings 68 and 85.

The coolant pressure of the hot and cold circuits is controlled by pressure sensors connected to fittings 83 and 88, respectively.

The coolant temperature of the hot and cold circuits is controlled by temperature sensors installed in the fittings 72 and 79, and in the boiler-heater 84, by a temperature sensor installed in the fitting 77.

The air intake and exhaust system is shown in FIG. 6.

The system is used to clean the air entering the diesel engine from dust and moisture particles, and to prevent wear of the assembly units and diesel parts, as well as exhaust gas removal and reduction of exhaust noise.

The system consists of an air filter 89 with connecting pipes 90, two turbocompressors, an exhaust pipe 91 and a muffler 92.

The automated control system (ACS DGU) provides automation of the DGU in the third degree in accordance with GOST R 50783-95 and the fourth degree in accordance with GOST 14228-80 and GOST 10032-80 with a maintenance-free time of at least 250 hours, provides autonomy of the ACS of DGU - independent of NPP systems, the basic functions of a diesel generator set with uninterrupted automatic transition to power from built-in rechargeable batteries (AB) when the main power supply of the automatic control system of the diesel generator disappears.

SAU DGU provides:

a) constant readiness for automatic start;

b) remote automated start and stop from the block control panel (BPU), the backup control panel (RPU) of the power unit, from the local control panel (PUM) of the DGU;

c) the formation of a pulse to turn on the switch of the generator of the diesel generator set when the voltage and speed of rotation of the generator set is not less than 95% of the nominal values in all modes;

d) test (technological) start-up from the local diesel control panel (PUM) to test the functioning and testing of diesel generator sets under load;

d) automatic maintenance of water and oil temperature by the heating system;

f) automatic maintenance within the specified limits of the generator output voltage at all operating modes of the diesel generator set;

g) the power supply for the start-up, control, protection, signaling and regulation circuits is autonomous for each diesel generator set;

i) maintaining a constant (within the regulatory characteristics) frequency of rotation of the shaft of the diesel generator;

j) warning signaling in case of deviation of the operating parameters from the set;

k) generator protection;

m) emergency shutdown of a diesel generator set operating in the standard (stand-alone) mode when the power is off at the NPP with the load disconnected and the sound and light alarm turned on when the controlled parameters deviate from the set;

m) stable operation with a given speed.

The manufacture of a diesel generator, including systems, was made in 2014. Testing confirmed the achievement of the declared results of the utility model for technical and economic indicators in full.

Claims (1)

Diesel generator set for backup power supply of nuclear power plant safety systems, consisting of a diesel engine, alternator, start-up, cooling, lubrication, air inlet, exhaust and automatic control systems, characterized in that it has two air compressors at least two compressed air cylinders, two pneumatic start valves and redundant pressure relief valves in the start-up system, two pumping units, dual coarse filters and onkoy cleaning fuel in the fuel system, two electric pump unit in the lubrication system, two electrically driven pump in the circuit of cooling the hot standby system, a two turbocharger air intake system.

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