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Sealing oil system

key word:Heat exchange element


Product description

Sealing oil system of QFSN-2 and THDF water hydrogen cooled steam generator

 

1. Introduction

1.1. Purpose

The main functions of the sealing oil system are: to provide sealing oil source to the sealing pad to prevent hydrogen from overflowing along the rotating shaft in the generator; during operation, the sealing oil system maintains the sealing oil pressure higher than the hydrogen pressure by a given value through its own differential pressure regulating valve, and its fluctuation is within an allowable range; through the oil filter, the impurities in the oil are removed to ensure the cleanliness of the sealing oil; The sealing oil is cooled by the heat exchanger to take away the heat generated by the friction loss between the sealing pad and the shaft; the system is equipped with multiple standby oil sources to ensure the safe and continuous operation of the generator; the operation of the sealing oil system is automatically monitored by using the differential pressure controller, pressure controller and differential pressure transmitter. It is easy to install and repair the oil supply system.

The seal oil system can be divided into double flow seal oil system and single flow seal oil system.

1.2. System composition

1.2.1. Double flow seal oil system. The double flow seal oil is divided into two oil circuits on the air side and the hydrogen side to supply oil to the two annular oil distribution grooves on the shaft seal bush (see Fig. 20-1 for the structural diagram of the seal Bush), and the oil flows out along the axial direction of the shaft through the gap between the inner circle of the seal Bush and the shaft. If the oil supply pressure of the two oil circuits is exactly equal at the sealing pad, the oil will not flow in the gap between the two oil distribution grooves, so as to prevent air and moisture from invading into the generator and hydrogen from overflowing through the sealing oil. Usually, as long as the seal oil pressure is always higher than the gas pressure in the generator, hydrogen can be prevented from overflowing from the generator. The oil supplied by the oil circuit on the hydrogen side flows to the hydrogen side along the gap between the shaft and the sealing pad and flows to the defoaming box, while the oil supplied by the oil circuit on the air side flows to the bearing side along the gap between the shaft and the sealing pad and enters the air side oil return sealing box together with the bearing oil return.

 

The schematic diagram of double flow seal oil system is shown in Figure 20-2.

 

1.2.2. Single flow seal oil system. Single flow means that there is only one oil flow entering the sealing ring for sealing, as shown in Figure 20-3. The seal oil flows from the seal ring to the air side and the hydrogen side respectively. The hydrogen side oil flows through the defoaming tank or the oil-gas separation tank and then joins with the air side oil to flow to the oil return port of the seal oil system device. Because part of the oil flow through the seal ring flows to the hydrogen side, that is, through the generator, there is no air in the seal oil, so as to avoid the air volatilizing from the oil and polluting the power generation The hydrogen in the engine affects the purity of hydrogen; in addition, part of the air side oil has to be mixed with the bearing oil, which may bring hydrogen to the main oil tank. Therefore, the air side oil can not contain hydrogen. Therefore, there is a vacuum treatment system in the single flow seal oil system, which separates the air, hydrogen and water gas of the seal oil and discharges them into the atmosphere. The principle of vacuum treatment system is that at a certain temperature, the amount of gas in the seal oil is proportional to the partial pressure of the gas. When the pressure decreases under the action of vacuum pump, the gas overflows from the oil and is pumped out of the oil tank by vacuum pump, so as to reduce the air, hydrogen and water vapor in the sealing oil.

 

The schematic diagram of single flow seal oil system is shown in figure 20-4.

 

1.3. Description of sealing oil system

1.3.1. Double flow seal oil system. The double flow seal oil system is divided into two parts: the air side oil circuit and the hydrogen side oil circuit, as shown in Figure 20-2. In the double flow seal oil system, the air side seal oil plays the main sealing role, and the hydrogen side seal oil "follows" the air side seal oil pressure, which can maintain the hydrogen purity in the generator and reduce the amount of hydrogen supplement.

1.3.1.1. Air side sealing oil circuit. The air side seal oil pump driven by AC motor obtains the oil source from the air side oil return tank. It sends part of the oil into the air side of the seal pad through the oil cooler and filter, and the other part of the oil passes through the main differential pressure regulating valve through the bypass. Through the differential pressure regulating valve, the air side seal oil pressure at the seal pad is always kept at a high level of 84kpa. In addition, the air side sealing oil DC standby pump makes the oil circulate in the same way. The sealing oil from the air side of the sealing pad is mixed with the oil from the generator bearing and flows into the bearing oil return tank (air side oil return tank). A range hood is set on the bearing return oil tank to extract the hydrogen that may exist in the return oil, so as to prevent excessive hydrogen from entering the lubricating oil system.

1.3.1.2. Standby oil circuit of air side turbine. The high-pressure standby oil sent by the lubricating oil system of the steam turbine, after decompression, is controlled to 56 kPa by the standby differential pressure valve, and then injected into the air side of the sealing pad through the oil cooler and filter. The main differential pressure valve and the standby differential pressure valve are set with a certain gradient of control pressure to realize undisturbed automatic switching. The standby oil source of steam turbine is composed of high pressure standby oil source and low pressure standby oil source. The high-pressure standby oil source is provided by the high-pressure oil pump driven by the main shaft of steam turbine and the standby oil pump of AC sealing oil. When the steam turbine is in normal operation, the high-pressure oil pump driven by the main shaft of the steam turbine provides the standby oil source; when the steam turbine is idling or stopped, the AC seal oil standby oil pump provides the high-pressure standby oil source. The low pressure standby oil is provided by the lubricating oil pump.

1.3.1.3. Air side standby oil circuit. Since the air side is the main sealing oil circuit, a series of standby oil sources are set up on the air side to ensure the safe operation of the generator. ① The first standby oil source is turbine main oil pump and AC standby oil pump. ② The second standby oil source is DC standby oil pump. The above two oil sources can provide normal pressure of sealing oil. ③ The third standby is the low pressure lubricating oil of the steam turbine, which can only maintain the pressure in the generator at or below 14kPa.

1.3.1.4. Hydrogen side sealing oil circuit. The sealing oil from the hydrogen side of the sealing pad in the generator first flows into the defoamer box on the end cover of the generator, and most of the hydrogen in the sealing oil on the hydrogen side is separated out in the defoamer box. The seal oil overflowing from the defoaming tank flows into the hydrogen side oil return tank (hydrogen side oil return control tank). The hydrogen side oil return tank is used to isolate hydrogen and sealing oil. The oil pump of the seal oil on the hydrogen side obtains the oil source from the oil return tank on the hydrogen side. It discharges most of the oil to the hydrogen side of the sealing pad through the oil cooler, oil filter and balance valve pump. A bypass pipe is installed at the outlet of the oil pump to roughly adjust the oil pressure at the hydrogen side, and the oil pressure at the inlet of the sealing pad at the hydrogen side is automatically adjusted through the balance valve to automatically track the oil pressure at the air side, so as to achieve the level of basic balance with the oil pressure at the air side. In addition, the hydrogen side seal oil standby oil pump is paralleled at both ends of the main oil pump, so that the hydrogen side standby oil pump circulates in the same way.

1.3.2. Single flow seal oil system. The single flow seal oil system is shown in figure 20-4. In the single flow seal oil system, there is no similar double flow seal oil supply system on the hydrogen side. In order to maintain the hydrogen purity in the generator, a vacuum seal oil treatment system is set up.

The redundancy settings in the system are as follows:

① Two 100% AC seal main oil pumps are standby for each other and one 100% DC seal main oil pump is standby for each other.

② Two 100% seal oil coolers are standby for each other.

③ Two 100% seal oil filters are standby for each other.

④ Two 100% sealing differential pressure regulating valves are standby for each other.

During normal operation, the main seal oil pump draws seal oil from the seal oil vacuum tank, and then sends the seal oil to the seal pad through the cooler, oil filter and Oil hydrogen differential pressure regulating valve. The sealing oil supplied to the shaft seal flows to the hydrogen side and the air side of the shaft seal through the gap between the shaft and the sealing bush. The seal oil discharged from the air side of the shaft seal directly flows into the bearing oil return pipeline, and then returns to the seal oil vacuum tank.

The oil discharged from the hydrogen side of the seal ring enters the generator defoaming tank (front chamber). In the defoaming tank, the flow rate of the oil will be reduced, so that the residual gas bubbles will overflow and the foam in the oil will be eliminated. Then, the sealing oil flows into the hydrogen side oil tank from the generator defoaming tank, and the hydrogen side oil tank acts as a barrier to gas leakage. The float valve in the hydrogen side oil return tank controls the oil level in the vacuum oil tank at the preset oil level, so as to prevent gas from entering the sealing oil system. During normal operation, the ball valve of the hydrogen side oil tank is in the open state to return the seal oil from the hydrogen side to the air side of the seal oil. Since the sealing oil vacuum tank is in vacuum state, the sealing oil flowing out of the hydrogen side tank will be sucked into the sealing oil vacuum tank. If the flow to the vacuum tank is too large, the oil from the hydrogen side tank will flow to the air side tank. A small amount of oil with hydrogen flows to the air side oil return tank, which will not cause danger to the environment, because the air side oil tank of the sealing oil is connected with the oil fume exhaust fan, thus discharging the hydrogen in the oil into the atmosphere.

In the vacuum oil tank, the sealing oil first goes through the surface area expansion device, and the gas (hydrogen, air and water vapor) contained in the sealing oil is pumped out by the vacuum pump, so as to maintain the high purity of the sealing oil and prevent the hydrogen pollution in the generator. The vacuum pressure in the vacuum oil tank is automatically controlled by a vacuum pressure regulating valve, and the oil level in the vacuum oil tank is automatically adjusted by a ball valve.

Three seal oil pumps are provided in the system for oil circulation. If the main seal oil pump 1 cannot operate normally due to mechanical failure or electrical failure, the main seal oil pump 2 will work automatically. If both main pumps fail to work, the supply of sealing oil will be completed by DC standby sealing oil pump without interruption. In order to improve the reliability, the oil source of the sealing oil of AC oil pump and DC oil pump is designed as an independent system. The oil source of AC sealing oil pump is vacuum oil tank, and the oil source of DC sealing oil is air side return oil tank.

1.4 equipment description of sealing oil system

1.4.1. Double flow seal oil system. See figure 20-5 for the outline of double flow sealing oil system.

1.4.1.1. Defoaming box. The oil from the hydrogen side of the sealing pad first flows into the defoaming box on the end cover of the generator, where the gas can expand and overflow from the oil. The defoaming box is installed in the lower end cover of the generator, and the oil level in the box is not too high through the straight pipe overflow device. A U-shaped pipe is installed on the connecting pipe between them to prevent the oil fume circulating in the generator due to the inconsistent pressure difference between the fans on both sides. A float type high oil level alarm switch is installed on the side of the defoaming box at the steam end and excitation end of the generator. When the oil level in the box reaches a certain level, the high oil level alarm of the defoaming box will be sent out, so that the operators can deal with it in time, so as to prevent the sealing oil from flowing into the generator.

1.4.1.2. Sealing oil system. There are two air side oil pumps on the oil supply device of sealing oil system, which are air side AC main oil pump and air side DC standby oil pump. In addition, one or two seal oil pumps are set on the hydrogen side.

The seal oil pump is a three screw horizontal oil pump. A double thread drive rotor and two driven screws are closely engaged to run together, and narrow clearance is found in casing liner. The casing of the pump is equipped with casing liner, which is sealed by cover at the transmission end and non drive end. Screw pump is suitable for use in the worse conditions, and because there is no control parts susceptible to dust, there is relatively large room for the viscosity change of sealing oil. Since all moving parts only rotate, they can reach rated speed in a short time.

Since the air side sealing oil is the main sealing oil source, a series of standby oil sources are set on the air side. The hydrogen side oil pump can be out of operation in a short time (one or several days) without affecting the hydrogen seal of the generator. However, the hydrogen purity in the generator will decrease faster than that in normal operation, and the hydrogen supplement of the generator will increase. Therefore, it is not recommended that the hydrogen side oil pump be out of operation for a long time.

The power supply of the air side DC standby oil pump in the sealing oil unit is supplied by the battery. Due to the limited capacity of the battery, if the AC oil source and the high-pressure oil source of the turbine on the air side of the sealing oil cannot be recovered in a short time, it is required to immediately reduce the hydrogen pressure in the generator to 14kpa or lower, so as to avoid hydrogen leakage after the standby oil pump is stopped.

1.4.1.3. air side oil return tank and exhaust hood. The oil drain pipe of the bearing of the generator end cover is equipped with the bearing oil return oil seal box (or air side return oil tank). The generator bearing lubricating oil and air side sealing oil are collected into the box, most of the oil is returned to the main oil tank through the U-shaped oil seal pipe, and a part of the oil source is sent to the air side sealing oil circuit as the oil source of the air side sealing oil. The U-tube also prevents hydrogen from escaping from the generator from entering the main oil tank of the turbine lubricating oil system in case of failure of generator shaft seal (this may cause hydrogen to rush out suddenly through the oil discharge pipeline). A vacuum jade force meter is also installed on the fume exhauster connected to the air side return tank, which can observe the vacuum degree in the oil tank on site.

There is an interface at the top of the air side return tank, and it is connected with a set of lampblack exhauster device. This device keeps the gas pressure in the air side return tank at negative pressure, generally -500 ~ -150Pa, so as to ensure that hydrogen does not enter the main oil tank of lubricating oil system with the bearing return oil. There are two fume exhausters, each of which is standby.

1.4.1.4. differential pressure valve and balance valve. There are two differential pressure valves in the sealing oil system - the main differential pressure valve and the standby differential pressure valve. The main differential pressure valve is connected to the inlet and outlet of the air side sealing oil pump, which plays the role of bypass pressure regulation. The signals are respectively taken from the air pressure in the engine (transmitted by oil pressure) and the outlet oil pressure at the air side of the sealing oil. The valve can automatically adjust the bypass flow, so as to ensure that the sealing oil pressure is always higher than the air pressure in the machine 84kPa.

The standby differential pressure valve is connected in the high-pressure standby oil circuit of the air side steam turbine. The signal oil pressure is also taken from the air pressure (transmitted by oil pressure) and the outlet pressure of the air side of the sealing oil. The valve directly regulates the flow of the main oil circuit of the standby oil to ensure that the oil pressure of the standby seal oil is always higher than the gas pressure in the machine 56kPa.

Two balance valves are installed at the outlet of hydrogen side, respectively connected to the sealing oil circuit to the excitation end and the sealing oil circuit to the steam end. Their signals are respectively taken from the air and hydrogen side oil pressure at the respective sealing shells. The opening of balance valve is adjusted automatically by the change of oil pressure on air and hydrogen side, so that the oil pressure difference between air and hydrogen side at the sealing pad is kept within ± 490pa.

1.4.1.5. return oil control box (return tank on hydrogen side). The return oil control box on the hydrogen side is the separation tank and the hydrogen side oil storage tank of the hydrogen side oil circuit. A certain oil level must be maintained during operation. It is composed of box, makeup oil discharge float valve, liquid level indicator and low level alarm switch.

Because the oil pressure on the hollow and hydrogen side of the sealing pad can not be balanced, there are still a few oil flowing through each other on the air and hydrogen side. Thus, the oil quantity in the oil path of the hydrogen side will be increased or decreased due to long-term accumulation. Once this happens, the return oil control box on the hydrogen side can automatically control the oil level. When the oil level in the tank is high, the float ball will open the oil drain valve to drain the excess oil to the oil circuit on the air side; when the oil level of the tank is low, the float ball will open the oil filling valve to make the oil on the air side fill in. If the floating ball loses the automatic regulation function, the opening and closing of the makeup and oil discharge valve can be forced by the two top and bottom pins of the ball valve (this operation mode is not recommended). In order to make the oil level in the tank not too low, a low oil level alarm switch is installed on the box. If the oil level in the tank reaches the low oil level alarm limit, the alarm switch will send out an alarm signal. Generally, the liquid level in the tank can be monitored locally by the oil level indicator installed on the box.

1.4.1.6. oil filter. The oil filter adopts self-cleaning chip or fiber structure, which is characterized by high precision and less than 80 μ M. in operation, the dirt attached to the filter element can be removed by turning the handle. It is recommended to rotate the handle once every 8 hours until it can be flexibly turned (self-cleaning chip). Since two sets of oil filters are installed in the oil circuit on the air and hydrogen sides for each other, when the filter element is blocked seriously, the standby filter can be put into operation, the filter running can be isolated, the filter element removed, and the filter element can be cleaned or replaced thoroughly.

1.4.1.7. oil cooler. When the seal oil passes through the sealing pad, the relative rotation of the generator rotor and the seal Bush causes the oil temperature of the seal oil to rise, so a seal oil cooler is set in the sealing oil system. Because the sealing oil air and hydrogen side are relatively independent, the oil cooler is also divided into air side cooler and hydrogen side cooler. There are two kinds of coolers, plate plate and shell type. By adjusting the cooling water quantity, the oil temperature can be adjusted. The cooling water circuit in the oil circuit of sealing oil air and hydrogen side is provided with temperature regulating device to make the oil temperature within the specified range.

1.4.2. single flow sealing oil system. See figure 20-6 for the configuration of single flow sealing oil system.

1.4.2.1. bubble elimination box. The oil from the hydrogen side of the sealing pad first flows into the defoaming box on the end cover of the generator, where the gas can expand and overflow from the oil. The defoaming box is installed in the lower end cover of the generator, and the oil level in the box is not too high through the straight pipe overflow device. One bubble elimination box is installed at the excitation end, and a U-shaped pipe is installed on the connecting pipe between them to prevent the inconsistent pressure difference between fans on both sides, so as to prevent the oil smoke circulating in the generator. A float type high oil level alarm switch is installed at the steam end and the side of the bubble elimination box at the excitation end of the generator. When the oil level in the tank is too high to a certain extent, the alarm will be sent out to enable the operators to handle it in time, so as to prevent the sealing oil from flowing into the generator.

1.4.2.2. seal oil pump. The sealing oil pumps on the oil supply unit of the sealing oil system are 3, which are two AC main oil pumps and one DC standby oil pump respectively.

The seal oil pump is a three screw vertical oil pump. A double thread drive rotor and two driven screws are closely engaged to move together, and narrow clearance is found in the sleeve liner. The casing of the pump is equipped with casing liner, which is sealed by cover at the transmission end and non drive end. Screw pump is suitable for use in the worse conditions, and because there is no control parts susceptible to dust, the change of viscosity of seal oil is allowed to be relatively large. Since all moving parts only rotate, rated speed can be achieved in a short time

If main seal oil pump 1 fails to operate due to mechanical or electrical faults, main seal oil pump 2 will automatically operate. If both pumps fail to work, the supply of seal oil is done by the DC standby seal oil pump without interruption. The power supply of the air side DC standby oil pump in the sealing oil unit is supplied by the battery. Due to the limited capacity of the battery, if the AC oil source and the high-pressure oil source of the turbine on the air side of the sealing oil cannot be recovered in a short time, it is required to immediately reduce the hydrogen pressure in the generator to 14kpa or lower, so as to avoid hydrogen leakage after the standby oil pump is stopped,

1.4.2.3. air side oil return tank and exhaust hood. The oil drain pipe of the bearing of the generator end cover is equipped with the bearing oil return oil seal box (or air side return oil tank). The generator bearing lubricating oil and air side sealing oil are collected into the box, most of the oil is returned to the main oil tank through U-type oil seal pipe, and a part of the oil source is sent to the air side sealing oil circuit as the oil source of air side sealing oil. The U-tube also prevents hydrogen from escaping from the generator from entering the main oil tank of the turbine lubricating oil system in the event of a failure of the generator shaft seal (which may cause hydrogen to rush out suddenly through the oil discharge pipeline). A vacuum pressure gauge is also installed on the air side return tank to observe the vacuum degree in the tank locally.

In the single flow sealing oil system, the volume of the air side return tank is large, so that there is sufficient oil source for the sealing oil. Because of the large volume of oil tank, the sealing oil system can provide supplementary oil source without relying on the lubricating oil system for a long time, and can be independently debugged after the generator is installed.

The air side return tank item part has an interface, which is connected with a set of lampblack exhauster device. This device keeps the gas pressure in the air side return tank at negative pressure, generally -500 ~ -150Pa, so as to ensure that hydrogen does not enter the main oil tank of lubricating oil system with the bearing return oil. There are two fume exhausters, each of which is standby.

1.4.2.4. differential pressure valve. The differential pressure valve of the sealing oil system has two main differential pressure valves and standby differential pressure valves. The differential pressure valve is arranged downstream of the filter, which plays the role of throttling and pressure regulation. The signals are respectively taken from the air pressure in the machine (transmitted by oil pressure) and the outlet oil pressure at the air side of the sealing oil. The valve can automatically adjust the flow rate of sealing oil, so as to ensure that the sealing oil pressure is always higher than the air pressure in the machine. Two differential pressure valves are connected in parallel, and the setting pressure of one differential valve is slightly lower than the other, which is used as standby. When the main differential pressure valve exits for some reason, the standby differential pressure valve will operate without disturbance automatically, so as to ensure the system working reliability.

1.4.2.5. return oil control box (hydrogen side tank) at hydrogen side. The return oil control box on the hydrogen side is the separation tank and the hydrogen side oil storage tank of the hydrogen side oil circuit. A certain oil level must be maintained during operation. It is composed of box, oil discharge float valve, liquid level indicator and low level alarm switch.

In the single flow seal oil system, the hydrogen side oil tank only has the function of oil discharge, so only the oil discharge ball valve is set in the oil tank, and the hydrogen side oil return control box can automatically control the oil level. When the oil level in the oil tank is high, the floating ball will open the oil drain valve to discharge the excess oil to the air side oil circuit. If the oil will not be discharged automatically, the floating valve will lose its function. A low oil level alarm switch is installed on the box. If the oil level in the box reaches the low oil level alarm limit, the alarm switch will send out an alarm signal. Generally, the liquid level in the tank can be monitored locally through the oil level indicator installed on the tank.

1.4.2.6. Oil filter. The filter element of the oil filter adopts self-cleaning chip, which is characterized by high filter precision, less than 40 μ M. In addition, the dirt attached to the filter element can be removed by turning the handle during operation. It is recommended to turn the handle every 8h until it is flexible. Differential pressure transmitter is set at the inlet and outlet of the filter to remotely monitor the operation status of the filter.

1.4.2.7. Oil cooler. When the sealing oil passes through the sealing pad, the relative rotation of the generator rotor and the sealing pad causes the oil temperature of the sealing oil to rise, so the sealing oil cooler is set in the sealing oil system. By adjusting the amount of cooling water, the oil temperature can be adjusted. A temperature regulating device is set in the cooling water circuit of the air and hydrogen side oil circuit of the sealing oil to control the oil temperature within the specified range.

1.4.2.8. Vacuum tank. The oil in the vacuum oil tank is taken from the generator bearing and the return oil tank of the air side sealing oil (sealing oil storage tank). The float valve in the vacuum tank can keep the oil level in the tank at the preset level. When the oil level is low, the valve can draw oil from the seal oil storage tank and the hydrogen side tank for replenishment. The vacuum pump can keep the sealing oil in the vacuum tank in a vacuum state and extract most of the gas absorbed when the sealing oil contacts with hydrogen and air, so as to avoid the reduction of hydrogen purity in the generator to a great extent.

1.4.2.9. Vacuum oil pump. The vacuum pump establishes a negative pressure in the vacuum oil tank and removes the gas produced by the sealing oil. When the high oil level alarm signal is sent from the vacuum oil tank, in order to prevent the sealing oil from entering the vacuum system, the operation of the vacuum pump should be disconnected immediately.

The vacuum pump is an oil sealed rotary vane pump. The drive motor is directly flange mounted to the pump housing. The vacuum pump and the motor shaft are connected by an elastic coupling structure. All bearings are sliding bearings, using forced oil lubrication. The vacuum pump is composed of several parts. All parts are pin positioning installation type to ensure easy disassembly.

 

2. Main technical parameters (see table 20-1 ~ table 20-3)

Table 20-1 technical parameters of QFSN-2 300MW sealing oil system (double flow)

No. Parameter Index
1 Oil quantity of hydrogen side sealing pad  (design value,L/min)  50 (total of both sides) 
2 Oil quantity of air side sealing pad  (design value, L / min)  150 (total of both sides) 
3 Oil inlet temperature of sealing pad at air and hydrogen sides  (℃)  3849
4 Oil outlet temperature of sealing pad  (air side / hydrogen side, ℃)  55.6/65.5
5 Balance pressure difference between air side and hydrogen side  (Pa)  490
6 Seal oil cooler  (tubular)   
6.1 Heat exchange rate  (air side / hydrogen side,KW)  97/30
6.2 Secondary water volume  (air side / hydrogen side, m3/h)  34/8
6.3 Secondary inlet water temperature  (℃)  38
6.4 Secondary water pressure drop  (air side / hydrogen side, kPa)  35/14
7 Vacuum degree of air side oil return tank  (Pa)  -250-500
8 Filtration accuracy of oil filter (μm)  80
9 Low pressure oil pressure of steam turbine  (seal pad inlet)  (MPa)  0.882.1
9.1 Maximum supply flow required by the unit (m3/h)  24
10 Low pressure oil pressure of steam turbine  (seal pad inlet)  (MPa)  0.2
10.1 Maximum supply flow required by the unit (m3/h)  18
11 Power supply  
11.1 Air side AC pump 15KW380VAC50Hz
11.2 Air side DC pump 10KW220VDC
11.3 Hydrogen side AC pump 4KW380VAC50Hz
11.4 Hydrogen side DC pump 4KW220VDC
11.5 Smoke exhaust fan 2×3KW380VAC50Hz
12 Dimension of sealing oil unit (L×W×H,mm×mm×mm)  3580×3060×2500
13 Mass of sealing oil unit (kg)  6800

 

Table 20-2 technical parameters of QFSN-2 600MW sealing oil system (double flow)

No. Parameter Index
1 Oil quantity of hydrogen side sealing pad  (design value,L/min)  51total of both sides
2 Oil quantity of air side sealing pad  (design value, L / min)  220total of both sides
3 Oil inlet temperature of sealing pad at air and hydrogen sides  (℃)  3849
4 Oil outlet temperature of sealing pad  (air side / hydrogen side, ℃)  55.6/65.5
5 Balance pressure difference between air side and hydrogen side  (Pa)  490
6 Seal oil cooler  (tubular)   
6.1 Heat exchange rate  (air side / hydrogen side,KW)  183/37
6.2 Secondary water volume  (air side / hydrogen side, m3/h)  46/15
6.3 Secondary inlet water temperature  (℃)  38
6.4 Secondary water pressure drop  (air side / hydrogen side, kPa)  35/21
7 Vacuum degree of air side oil return tank  (Pa)  -250-500
8 Filtration accuracy of oil filter (μm)  80
9 Low pressure oil pressure of steam turbine  (seal pad inlet)  (MPa)  0.882.1
9.1 Maximum supply flow required by the unit (m3/h)  28
10 Low pressure oil pressure of steam turbine  (seal pad inlet)  (MPa)  0.2
10.1 Maximum supply flow required by the unit (m3/h)  21
11 Power supply  
11.1 Air side AC pump 15KW380VAC
11.2 Air side DC pump 15KW220VDC
11.3 Hydrogen side AC pump 4KW380VAC
11.4 Smoke exhaust fan 2×3KW380VAC
12 Dimension of sealing oil unit (L×W×H,mm×mm×mm)  5000×2700×2010
13 Mass of sealing oil unit (kg)  8500

 

Table 20-3 technical data of THDF 1000MW seal oil system (single flow)

No. Parameter Index
1 Oil quantity of sealing pad (design value, L / min) 200total of both sides
2 Oil inlet temperature of sealing pad () 3849
3 Oil outlet temperature of sealing pad () 65
4 Seal oil cooler (plate type)  
4.1 Heat exchange power (kW) 183
4.2 Secondary water volume  (air side / hydrogen side, m3/h)  53
4.3 Secondary inlet water temperature  ( 38
4.4 Secondary water pressure drop  (air side / hydrogen side, kPa)  35
5 Vacuum degree of air side oil return tank  (Pa)  -5000-150
6 Vacuum degree of vacuum tank (PA) -40
7 Filtration accuracy of oil filter (μm)  40
8 Power supply  
8.1 Air side AC pump 2×15KW380VAC
8.2 Air side DC pump 15KW220VDC
8.3 Vaccum pump 370W380VAC
8.4 Smoke exhaust fan 2×1.5KW380VAC
9 Dimension of sealing oil unit (L×W×H,mm×mm×mm)  5700×2200×3150
10 Mass of sealing oil unit (kg)  7650