JPH0769038B2 - Oil heating device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an oil heating device for heating oil for bearing lubrication and equipment operation in order to smooth its action, particularly in thermal power and nuclear power generation equipment. The present invention relates to an oil heating device.

[Conventional technology]

In various types of mechanical equipment, oil is used in the rotating and sliding parts of equipment in order to facilitate its operation or to operate control equipment. For example, in thermal power and nuclear power plants,
A large amount of oil is used for lubrication of turbine axles that rotate at high temperature and high speed. At the same time, pressure oil is used to operate a control device that adjusts the output of the plant according to the load and a valve that adjusts the amount of steam flowing into the turbine based on the command.

As a system using such oil, a system configured in the system shown in FIG. 3 is known. In the figure, the oil in the oil tank 1 becomes oil with a pressure by the oil pump 2 and is sent out through the oil pipe 3. A part of this oil is used as it is for the control device 4, the valve operating device 5, etc., and a part of it is cooled to a predetermined temperature through the oil cooler 6 and supplied to the bearing 7. The bearing 7 is heated by friction loss of the bearing during operation of the turbine and heat transmitted from the high temperature turbine axle, and the temperature rises and returns to the oil tank 1.

On the other hand, the cooling water is a cooling water source 8 such as a river, the sea, or a cooling water tank.
From the cooling water pump 9 and distributed by the cooling water pipe 10 connected to the heat transfer pipe 6a in the oil cooler 6 to the various coolers 11 and the oil cooler 6, and after cooling in each cooler,
It is discharged to the drainage channel 12. The cooling water pipe 10 is provided with an inlet valve 17 and an outlet valve 18 for the oil cooler. In the oil cooler 6, the oil flowing therethrough exchanges heat with the cooling water with the heat received by the bearing 7 to keep the oil temperature at an appropriate value.

By the way, the temperature of the oil circulated and used in the oil system needs to be maintained within an appropriate range. That is, when the oil temperature is too high, the cooling effect on the bearing 7 is reduced, and the oil itself is deteriorated quickly, so that it is necessary to replace the oil early. Further, if the oil temperature is too low, the viscosity of the oil will remarkably increase and the fluidity will deteriorate due to the characteristics of the oil.
The responsiveness of the valve actuator 5 and the like becomes poor and the function is not satisfied. Therefore, usually, the cooling water amount and the oil circulation amount of the oil cooler 6 are adjusted so that the temperature inside the oil tank 1 is about 55 ° C to 65 ° C and the temperature at the inlet of the bearing 7 is about 45 ° C to 50 ° C. There is.

As described above during normal operation, when the plant is stopped for a long period of time due to periodic inspections, the temperature of the oil in the oil system drops to the same temperature as the atmospheric temperature, and especially in winter and cold regions, the oil temperature is close to 0 ° C. The temperature drops, and the viscosity of the oil increases as it is,
Therefore, especially the control device 4 and the valve operating device 5 cannot exhibit sufficient functions. In order to prevent this, in general, a heater is often installed in the oil tank 1 as shown in FIG. The heater is immersed in the oil in the tank (internal heater 13)
Alternatively, a heater that heats from the outside of the tank (external heater 14) or the like is used. Electricity and steam are generally used as the heating source for these heaters, and these heaters heat the oil temperature in the tank to about 30 to 40 ° C prior to plant startup, so that oil system equipment can fully function. It is in a state.

[Problems to be Solved by the Invention]

When heating the oil in the oil tank 1 before starting the plant, the heating by the internal heater 13 and the external heater 14 has the following problems.

(1) Since the oil is directly heated, the oil near the heater is likely to be locally heated, which accelerates the deterioration of the oil.

(2) In the case of the internal heater 13, on the heater surface, the external heater
In the case of 14, oxides due to local overheating of oil are deposited on the inner surface of the tank bottom, which hinders the heat transfer of the heater.

(3) Since the oil is directly overheated, in the case of inconvenience in operation, for example, excessive heating, or exposure of the heating element due to deterioration of the oil level, in the worst case there is a risk of fire due to oil ignition. Therefore, various alarms and safety devices are required, which increases the equipment cost.

As a solution to the above problem, instead of heating the oil in the oil tank with a heater, the cooling water can be heated and the temperature of the oil flowing through the oil cooler 6 can be raised by the heated cooling water. As a possible method, it is conceivable to provide a steam blowing device 15 on the inlet pipe 10a between the inlet valve 17 of the cooling water pipe 10 and the oil cooler 6 as shown in FIG. In this case, by supplying steam to the steam blowing device 15 from a steam supply source (not shown) through the steam pipe 16 to heat the cooling water, and to pass the heated cooling water to the heat transfer pipe 6a of the oil cooler 6. Oil cooler 6
The oil flowing in the container 6b is heated.

However, in this method, when raising the oil cooler outlet temperature to a predetermined temperature, it becomes extremely uneconomical thermally as shown in the temperature diagram at the time of heat exchange in the oil cooler of FIG. That is, when heating the oil flowing through the oil cooler 6, the cooling water having an inlet temperature of 5 ° C. is heated to 50 ° C. by the steam supply by the steam blowing device, and the heated cooling water is heated by the oil cooler. The cooling water and the oil, which have been raised in temperature, are heat-exchanged with each other to heat the oil, and the oil having an inlet temperature of 35 ° C. is heated to an oil having an outlet temperature of 40 ° C. In this case, there is a problem that wasteful energy corresponding to ΔT ₂ = 40 ° C. is released to the water discharge channel 12 (see FIG. 5) to the cooling water in order to give energy for ΔT ₁ = 5 ° C. to the oil.

Also, in order to avoid the above problem, it is convenient if the waste water at 45 ° C. can be returned to the inlet of the oil cooler 6 instead of being discharged to the drainage channel, but it requires a new pump, There is a problem that the equipment cost becomes high. Further, when the cooling water pump 9 is used, hot water is distributed to the various cooled devices 11, which is extremely inconvenient.

An object of the present invention is to prevent deterioration of the oil when heating the oil, have a low thermal budget with a low equipment cost, and safely heat the oil temperature of the oil system to a predetermined temperature before starting the plant. The object of the present invention is to provide an oil warming device that can be used.

[Means for Solving the Problems]

In order to solve the above-mentioned problems, according to the present invention, an oil passage and a cooling water passage are provided in a container, and an oil flowing through the oil passage and an inlet valve connected to the container are provided. In an oil cooler in which heat is exchanged with cooling water which is supplied and discharged from an outlet pipe provided with an inlet pipe and an outlet valve and which flows through the cooling water passage,
A reflux pipe is provided which bypasses the oil cooler and is connected to the inlet pipe and the outlet pipe between each of the inlet valve and the outlet valve and the oil cooler, and the steam from the steam supply source is driven to the reflux pipe. It is assumed that the oil warming device is configured by providing a steam injector and a valve that are used as a fluid, the cooling water is a driven fluid, and the cooling water is circulated in the cooling water flow path through the reflux pipe.

[Action]

The reflux pipe connected to the inlet pipe and the outlet pipe between each of the inlet valve and the outlet valve and the oil cooling pipe and the cooling water flow passage in the container of the oil cooler are cooled through the inlet pipe and the outlet pipe. Form a water circulation line. Therefore, if steam is supplied from the steam supply source to the steam injector provided in the return conduit, the cooling water circulates in the circulation conduit due to the pumping action of the steam injector. At this time, the circulating cooling water is heated by the steam supplied to the steam injector and flows through the cooling water flow path.
Therefore, the low temperature oil flowing through the oil passage of the oil cooler is heated by exchanging heat with the heated cooling water. In addition,
Condensed water due to the condensation of the vapor can be made to flow out of the circulation pipe by opening the outlet valve slightly, so that it is possible to circulate a predetermined amount of heated cooling water in the circulation pipe.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a system diagram of an oil heating device according to an embodiment of the present invention. In addition, in FIG. 1 and FIG. 2 described later, FIG.
The same parts as those in FIG. 5 are designated by the same reference numerals, and the description thereof will be omitted. In FIG. 1, an inlet pipe 10a connected to the oil cooler 6 in communication with the heat transfer pipe 6a of the oil cooler 6 and between the oil cooler 6 and the inlet valve 17 and the outlet valve 18 of the cooling water pipe 10, respectively. A reflux line 19 is provided so as to be connected to the outlet pipe 10b. Steam is supplied to the reflux pipe 19 from a steam supply source (not shown).
A steam injector 21 and a stop valve 20 which are supplied via the above are provided.

Note that FIG. 2 is a system diagram in which an oil warming device having a reflux pipe line 19 having the steam synthesizer 21 and the stop valve 20 of FIG. 1 is arranged.

Next, an operating method for warming low-temperature oil before the plant is started by the oil warming device having the above-described configuration will be described. When heating the oil in the oil system, the inlet valve 17 of the cooling water pipe 10 is fully closed, the outlet valve 18 is slightly opened, and the stop valve 20 of the return line 19 is closed.
Fully open. Next, when steam is supplied to the steam injector 21 from a steam supply source (not shown), the cooling water is returned to the reflux pipe 19 → the inlet pipe 10a → the heat transfer pipe 6 by the pump action of the steam injector.
The cooling water circulates in the order of a-> the outlet pipe 10b-> the return pipe line 19, and the cooling water is heated by the supplied steam and rises in temperature.

On the other hand, the oil of the oil system flows into the container 6b of the oil cooler 6 by activating the oil pump 2, and is heated by exchanging heat with the heated cooling water (hot water) flowing through the heat transfer tube 6a. The cold oil in the system can be heated.

The steam supplied to the steam injector 21 is condensed by the cooling water, and the amount of the condensed water is discharged from the slightly opened outlet valve 18 to the water discharge passage 12. Since the amount of warm water discharged to the drainage channel at this time is small, the energy that is lost can be practically ignored.

If the temperature on the cooling water side rises too much, the inlet valve 17
The temperature of the hot water can be easily adjusted by opening a little and injecting cold cooling water.

Incidentally, during normal operation, the stop valve 20 of the return conduit 19 is fully closed to allow the cooling water to flow through the cooling pipe 10, so that the function of the cooling system is not hindered and the flow of the cooling water is not hindered. .

〔The invention's effect〕

As is apparent from the above description, according to the present invention, a steam injector and a reflux conduit provided with a valve are provided, and a circulation conduit is formed by this reflux conduit and the cooling water flow path of the oil cooler. By circulating this hot water in the circulation pipe while warming the cooling water by the steam supplied to the warm water to warm the low temperature oil flowing through the oil passage of the oil cooler, It has a good thermal economy and does not overheat oil,
Since the oil does not deteriorate and the temperature of the cooling water is extremely easy to adjust, and the oil is heated by hot water, there is no fear of fire and the like, and therefore the equipment cost of the safety device and the like can be saved.

The use of this device has the effect that it can be used not only for warming the plant when it is started, but also for warming the oil for flushing the oil system when the plant is newly installed or remodeled.

[Brief description of drawings]

FIG. 1 is a system diagram of an oil heating device according to an embodiment of the present invention, FIG. 2 is a system diagram showing an oil system and a cooling water system equipped with the oil heating device of FIG. 1, and FIG. 4 is a system diagram showing an oil system and a cooling water system, FIG. 4 is a system diagram showing means for heating oil in the oil tank shown in FIG. 3, and FIG. 5 is a steam blowing device for heating the oil system and cooling water. 6 is a system diagram showing a cooling water system including
The figure is a temperature diagram showing the heat exchange state in the oil cooler between the hot water flowing through the cooling water system and the oil flowing through the oil system in FIG. 6: Oil cooler, 6a: Heat transfer tube, 6b: Container, 10a: Inlet tube, 10b: Outlet tube, 17: Inlet valve, 18: Outlet valve, 19: Reflux line, 20: Stop valve, 21: Steam injector .

Claims (1)

[Claims] 1. An inlet pipe having an oil flow passage and a cooling water flow passage in a container, having an inlet valve connected to the oil flowing through the oil flow passage and the container, and an outlet having an outlet valve. In an oil cooler that exchanges heat with cooling water supplied and discharged from a pipe and flowing through the cooling water passage, bypassing this oil cooler, an inlet between each of the inlet valve and the outlet valve and the oil cooler. A reflux pipe connecting the pipe and the outlet pipe is provided, and the steam from the steam supply source is used as a driving fluid in the reflux pipe, and the cooling water is circulated in the cooling water flow passage through the reflux pipe as the driven fluid. An oil warming device, characterized in that a steam injector and a valve are provided.