JPH0356796A - Oil heating device - Google Patents

Abstract

PURPOSE:To heat oil with good thermal efficiency and without causing any overheating by heating cooling water with steam supplied to the steam injector of a circulating pipe line, circulating the heated water through the circulating pipe line and heating low temperature oil running through an oil cooler. CONSTITUTION:A circulating pipe line 19 having a stop valve 20 and a steam injector 21 is provided between an inlet pipe 10a and an outlet pipe 10b for a heating media to an oil cooler 6. Furthermore, water while being circulated from the inlet pipe 10a to the circulating pipe line 19 via the heat exchange pipe 6a of the oil cooler 6, is heated with steam fed to the steam injector 21. the heated water is used to heat low temperature oil flowing through the oilcooler 6. According to the aforesaid construction, oil can be economically heated and oil deterioration can be prevented because the oil is not overheated.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is an oil heating device that heats oil for bearing lubrication and equipment operation in order to smooth the operation thereof, particularly in thermal power and nuclear power generation equipment. Regarding oil heating device I. (Prior Art) Oil is used in various types of mechanical equipment to smooth the operation of rotating and sliding parts of equipment, or to operate control equipment.For example, oil is used in thermal power plants, nuclear power plants, etc.
Large amounts of oil are used to lubricate turbine axles that rotate at high temperatures and high speeds. At the same time, pressure oil is used for control equipment that adjusts the output of the plant according to the load, and for operating valves that adjust the amount of steam flowing into the turbine based on the commands of the control equipment. The system shown in Figure 3 is known as a system that uses such oil. In the figure, oil in an oil tank 1 is turned into oil under pressure by an oil bomb 2 and sent out through an oil pipe 3. A portion of this oil is used as it is for the control equipment 4, valve operating device 5, etc., and a portion is cooled to a predetermined temperature through an oil cooler 6 and supplied to the bearing 7. The bearing 7 is heated by wear and tear on the bearing during turbine operation and by heat propagated from the high temperature turbine axle, and the temperature rises and returns to the oil tank 1. On the other hand, cooling water comes from sources such as rivers, the sea, and cooling water tanks.
The coolant is sent out by a cooling water bomb 9, distributed to various cooled devices 11 and the oil cooler 6 by a cooling water pipe 10 connected to a heat transfer tube 6a in the oil cooler 6, and after performing a cooling action in each cooler, It is discharged to the drainage canal 12. The cooling water pipe 10 is equipped with an inlet valve 17 and an outlet valve 18 for an oil cooler.
In the oil cooler 6, the oil flowing through it exchanges the heat received by the ring bridge 7 with the cooling water to maintain the oil temperature at an appropriate value. By the way, the temperature of the oil that is circulated in the oil system must be maintained within a certain appropriate range. That is, if the oil temperature is too high, the cooling effect in the wheel bearing 7 will be reduced, and the oil itself will deteriorate more quickly, making it necessary to replace the oil sooner. Additionally, if the oil temperature is too low, due to the characteristics of the oil, its viscosity will increase significantly and its fluidity will deteriorate, resulting in poor response, especially in the Illm equipment 4, valve operator 5, etc., and the I1 performance will not be satisfied. ．． For this reason, the temperature inside the oil tank 1 is usually between 55°C and 6°C.
The amount of cooling water in the oil cooler 6 and the amount of oil circulation are adjusted so that the temperature of the bearing 7 is around 5°C, or around 45°C to 50°C. Now, during normal operation, as mentioned above, if the plant is stopped for a long period of time for periodic inspections, the temperature of the oil in the oil system will drop to the same level as the atmospheric temperature, and especially in winter or in cold regions, the oil temperature will drop to near 0°C. As the temperature decreases, the viscosity of the oil increases,
For this reason, the control equipment 4 and the valve operating device 5 in particular cannot perform their full functions. To prevent this, a heater is generally installed in the oil tank 1 as shown in Figure 4. The heater is immersed in the oil in the tank (internal heater 13
), or one that heats the tank from outside (external heater 14
) etc. are used. Electricity or steam is generally used as the heating source for these heaters, and these heaters heat the tank interior to about 30°C to 40°C before starting the plant, so that the oil system equipment can fully function. I have to.

[Problem to be solved by the invention]

When heating the oil in the oil tank 1 before starting the plant, heating by the internal heater 13 or the external heater 14 has the following problems. +11 Since the oil is directly heated, there is a large risk that the oil near the heater will be locally heated, which will accelerate the deterioration of the oil. {2) Oxides due to local overheating of the oil accumulate on the heater surface in the case of the internal heater 13 and on the inner surface of the bottom of the tank in the case of the external heater 14, impeding heat transfer to the heater. (3) Since the oil is directly heated, if there is any operational inconvenience, such as overheating or exposure of the heating element due to a drop in the oil level, in the worst case, the oil may ignite and cause a fire. This is a cause for concern, and this requires various alarms and safety devices, which increases equipment costs. As a solution to the above problem, instead of heating the oil in the oil tank with a heater, it is possible to heat the cooling water and use the heated cooling water to raise the temperature of the oil flowing back through the oil cooler 6. In this method, as shown in FIG.
It is conceivable to install a steam blowing device l5 at 0a. In this case, by supplying steam from a steam supply source (not shown) to the steam blowing device yl 15 via the steam piping 16 to heat the cooling water, and passing the heated cooling water through the heat transfer tube 6a of the oil cooler 6. The oil flowing in the container 6b of the oil cooler 6 is heated.
However, this method becomes extremely uneconomical thermally when raising the oil cooler outlet temperature to a predetermined temperature, as shown in the temperature diagram during heat exchange in the oil cooler in Figure 6. In other words, when heating the oil flowing back into the oil cooler 6, cooling water whose inlet temperature is 5°C is heated to 50°C by steam supply from a steam blowing device, and this heated cooling water is sent to the oil cooler. i
The oil is heated by exchanging heat with the cooling water that has been heated by flowing lI, and the oil with an inlet temperature of 35°C is heated to an outlet temperature of 4=5.
Heat the oil to ℃. In this case, there is a problem in that in order to impart energy equivalent to ΔTl - 5°C to the oil, wasteful energy equivalent to ΔTt"40°C is released to the cooling water into the water discharge channel 12 (see Fig. 5). In order to avoid this problem, it would be convenient if the 45°C wastewater could be returned to the oil cooler 6 instead of being dumped into the drain, but this would require a new pump and the equipment cost would be high. There is a problem that.
In addition, when using the cooling water pump 9, various cooled equipment l
This is extremely inconvenient as hot water will also be distributed to 1. The purpose of the present invention is to prevent oil deterioration when heating oil, to achieve good thermal economy with low equipment costs, and to safely heat oil in an oil system to a predetermined temperature before starting a plant. The purpose is to provide a reheating system that can be used for heating oil. [Means for Solving the Problem] In order to solve the above problem, according to the present invention, an oil flow path and a cooling water flow path are provided in a container, and the oil flow path is connected to i! In an oil cooler in which heat is exchanged between flowing oil and cooling water supplied and discharged from an inlet pipe equipped with an inlet valve connected to the container and an outlet pipe equipped with an outlet valve and flowing through the cooling waterway. , a reflux line is provided which bypasses the oil cooler and connects to the inlet pipe and outlet pipe between each of the large mouth valve and the outlet valve and the oil cooler, and the reflux line is supplied with steam from a steam supply source. The oil heating device is constructed by providing a steam injector and a valve that circulate the cooling water into the cooling water flow path via the return pipe line with cooling water as the driving fluid and the driven fluid as the cooling water. [Function] The return pipe line connected to the inlet pipe and the outlet pipe between the inlet valve and the outlet valve and the oil cooling pipe, and the cooling water flow path in the container of the oil cooler, are connected to the inlet pipe and the outlet pipe. A cooling water circulation pipe is formed through the pipe. Therefore, if steam is supplied from a steam supply source to the steam injector provided in the reflux pipe, the cooling water will circulate and flow through the circulation pipe 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 mass path.
Therefore, the low temperature oil flowing through the oil flow path of the oil cooler is heated by exchanging heat with the heated cooling water. In addition,
Since the condensed water caused by the steam can flow out of the circulation pipe by slightly opening the outlet valve, it is possible to circulate a predetermined amount of heated cooling water in the circulation pipe. [Examples] Examples of the present invention will be described below based on the drawings.
Figure 1 is a system diagram of an oil heating system according to an embodiment of the present invention. In addition, in FIG. 1 and FIG. 2, which will be described later, FIG.
Parts that are the same as those in Fig. 5 are given the same reference numerals, and their explanations will be omitted. In FIG. 1, the inlet valve 1 of the cooling water pipe 10 is connected to the oil cooler 6 by communicating with the heat transfer tube 6a of the oil cooler 6.
A recirculation pipe 19 is provided connected to the inlet pipe 10a and the outlet pipe tab between the oil cooler 6 and the oil cooler 6 and the outlet valve 18, respectively. A steam injector 2 is supplied with steam from a steam supply source (not shown) through a steam pipe 22 to the reflux pipe l9.
1 and a stop valve 20 are provided. z1 In addition, FIG. 2 is a system diagram illustrating the arrangement of the oil heating system equipped with the reflux pipe 19 equipped with the steam synthesizer (d) and the stop valve 20 shown in FIG. 1. Next, we will explain the operation method for warming low-temperature oil before plant startup using the oil heating device with the above structure. When heating the oil in the oil system, use the inlet valve 1 of the cooling water pipe lO.
7 is fully closed, the outlet valve 18 is slightly opened, and the stop valve 20 of the reflux pipe 19 is fully opened. Next, when steam is supplied to the steam injector 2l from a steam supply source (not shown), the cooling water flows through the reflux pipe 19, the inlet pipe 10a, the heat transfer pipe 6a, the outlet pipe 10b, and the reflux pipe 19 in this order by the pumping action of the steam injector. As it circulates, the cooling water is heated by the supplied steam and its temperature rises. On the other hand, oil in the oil system flows into the container 6b of the oil cooler 6 by starting 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. Note that the steam supplied to the steam injector 2l is condensed by cooling water, but the amount of condensed water is reduced by the slightly opened Yamaguchi valve 1.
8 is discharged to the spillway l2. Since only a small amount of hot water is discharged into the drainage canal at this time, the energy loss can be virtually ignored. If the temperature on the cooling water side rises too much, the temperature of the hot water can be easily adjusted by slightly opening the inlet valve 17 and injecting cold cooling water. In addition, during normal operation, the stop valve 20 of the return pipe line 19 is completely idle and cooling water is allowed 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 obstructed. ．． [Effects of the Invention] As is clear from the above description, according to the present invention, a reflux line equipped with a steam injector and a valve is provided, and a circulation line is formed by this reflux line and the cooling water flow path of the oil cooler. The cooling water is heated by the steam supplied to the steam injector to make it hot water, and this warm water is circulated through the circulation pipe to warm the low-temperature oil flowing through the oil wave path of the oil cooler. This has good thermal economy and does not overheat the oil.
It does not cause oil deterioration, the temperature of the cooling water is extremely easy to adjust, and since the oil is heated with hot water, there is no risk of fire or the like, and the cost of equipment such as safety equipment can be reduced. Furthermore, the use of this device has the advantage that it can be used not only for heating the plant when it is started up, but also for heating oil for the purpose of flushing the oil system when constructing a new plant or remodeling the plant.

[Brief explanation 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. 3 is a system diagram of a conventional oil heating device. Figure 4 is a system diagram showing the oil system and cooling water system. Figure 4 is a system diagram showing the means for heating the oil in the oil tank in Figure 3. Figure 5 is a steam blowing device that warms the oil system and cooling water. System diagram showing a cooling water system equipped with
The figure is a temperature diagram showing the state of heat exchange in the oil cooler between the hot water flowing through the cooling water system and the oil flowing through the oil system in Figure 5. 6: Oil cooler, 6a: Heat exchanger tube, 6b: Container, 10a
: inlet pipe, tob : outlet pipe, l7: inlet valve, 18: outlet valve, 19: reflux pipe, 20: stop valve, 21: steam injector. Scene Figure 1 Figure 2 1z , 411 Figure 3 1z Figure 4-r 111 Figure 5 1z Figure 6

Claims (1)

[Claims] 1) Having an oil flow path and a cooling water flow path in a container, and oil flowing through the oil flow path and supplied from an inlet pipe equipped with an inlet valve and an outlet pipe equipped with an outlet valve connected to the container. In an oil cooler in which the cooling water that is discharged and flows through the cooling water exchanges heat, the oil cooler is bypassed and an inlet pipe and an outlet are connected between the inlet valve and the outlet valve, respectively, and the oil cooler. A steam injector that is provided with a reflux pipe connected to the reflux pipe, uses steam from a steam supply source as a driving fluid in the reflux pipe, and circulates the cooling water into the cooling water flow path via the reflux pipe with cooling water as a driven fluid. An oil heating device characterized by comprising: and a valve.