JP5145127B2 - Complex plant - Google Patents

Description

  The present invention relates to a predetermined manufacturing plant (for example, an oil refinery plant, a chemical plant, a steel mill, a thermal power / nuclear power plant) that takes seawater and uses it as cooling water in carrying out a predetermined manufacturing process, and heats LNG to the heat of seawater. Regarding a complex plant adjacent to an LNG plant equipped with vaporization equipment to be vaporized by replacement, more specifically, from the LNG plant side, a cooling system in the manufacturing plant is used, and from the manufacturing plant side, the LNG plant generates The present invention relates to an interactive complex plant that uses the cold energy of LNG.

  In recent years, in response to the global warming problem caused by the increase in carbon dioxide, it has been demanded to strengthen efforts for environmental conservation on a global scale. In Japan, options for energy suppliers are diversifying as regulations on the energy industry progress alongside environmental initiatives. Against this background, the demand for LNG, a clean energy, has been increasing year by year, and it has been evaluated as a fuel for industrial use, including power generation and city gas.

  Therefore, simply adding an existing LNG plant does not keep up with demand, and securing a site for constructing a new LNG plant has become an urgent issue. As one trial, a plan has been made to replace a part of the site of an oil refinery plant that can be reduced in size with the site of an LNG plant and to add an LNG plant to an existing manufacturing plant.

  However, if a new LNG plant is installed separately from the existing manufacturing plant, the seawater intake equipment, defoaming equipment, and LNG vaporization equipment for supplying seawater as a heat medium to the LNG vaporization equipment Ancillary equipment such as wastewater treatment equipment to return the exchanged seawater to the sea is inevitable, and including the installation space for that, not only will it require a lot of land to construct the LNG plant, but also the construction cost Soaring.

  In addition, there are places where the amount of (waste water) is regulated by prefectural regulations and local regulations. However, if the above-mentioned incidental facilities are installed, the existing production plant (for manufacturing processes and cooling) Evaluation is based on the total amount of (taken) water taken from the LNG plant combined with the amount of water taken (waste) from the LNG plant (such as seawater used for the heat exchange) Therefore, the amount of water taken (waste) from the LNG plant is added, and there may be a situation in which construction of the LNG plant is not approved due to conflict with the water withdrawal (waste water) regulations.

  Furthermore, for example, according to the Setouchi Law, when changing the amount of drainage at an establishment where the maximum amount of drainage per day is 50 cubic meters or more, an environmental assessment must be carried out prior to construction. If ancillary facilities are installed, the total amount of drainage will increase and the need to conduct environmental assessments will arise. If this happens, the environmental assessment will take a long period of 2 to 3 years, and this will be a factor in prolonging the construction plan of the LNG plant within the scope of the Setouchi Law.

The present invention has been made in view of the above problems, and in carrying out a predetermined manufacturing process, seawater is taken in through a water intake line and used as cooling water, and then heat exchanged seawater is returned to the sea through a water discharge line. the production plant, a composite plant the LNG plant, newly features by replacing a portion of land for the production plant to the site of the LNG plant comprising a vaporization equipment to vaporize the LNG by heat exchange with sea water, the by also features the LNG plant production plant, so that no water intake and drainage of seawater increases, seawater heat exchange part of the sea water from the production plant water intake line in the vaporization equipment of the LNG plant supply line for supplying a is connected to the existing water intake line, the heat exchanger the water temperature is lower than water temperature at the time of intake Return line for returning the seawater intake line, characterized in that it is connected to the downstream side of the intake line than the supply line.

According to complex plant having the above structure, part of the intake seawater is supplied to the vaporization equipment LNG plant from intake line at seawater intake equipment manufacturing plant. LNG supplied to the vaporization facility is vaporized by heat exchange with seawater, and is supplied to a place where LNG is used as fuel, such as a thermal power plant, via a pipeline or the like. The water temperature becomes lower than that at the time of water intake due to cold heat, and it is returned to the intake line of the manufacturing plant.

  And when this cooled seawater is returned to an intake line, the water temperature of the whole seawater which flows through an intake line falls, and this seawater will be used as cooling water of a manufacturing plant. Furthermore, the seawater heat-exchanged through the cooling system in the manufacturing plant is in a state where the water temperature has risen higher than that at the time of supplying the cooling water due to heat input, and is returned to the sea as a warm drainage.

  Thus, according to the complex plant having the above-described configuration, the LNG plant and the manufacturing plant share the incidental facilities such as seawater intake facilities, defoaming facilities, and wastewater treatment facilities, and each plant is independent. Therefore, the amount of water intake (drainage) is smaller than the total amount of water intake (drainage) when each of the incidental facilities is provided. In other words, when the LNG plant uses ancillary facilities of the manufacturing plant, even if the LNG plant is added to the manufacturing plant, the amount of water taken (waste) is the same as that of the manufacturing plant alone.

  As described above, the present invention eliminates the need for a new incidental facility for the LNG plant by using the incidental facility of the manufacturing plant by the LNG plant. Construction costs can also be reduced. This is not the case where a part of the site of the existing manufacturing plant is replaced with the site of the LNG plant and the LNG plant is added to the existing manufacturing plant, but when both the manufacturing plant and the LNG plant are newly constructed. Even if there is, it is the same.

  And even if an LNG plant is added to the production plant, the amount of water taken (waste) will not increase, so there is no worry of conflicting water intake (waste water) regulations, and construction of the LNG plant will be possible regardless of location. There is an advantage that it is easy to be approved. Moreover, since the environmental assessment required by the Setouchi Law is not required, the construction plan for constructing an LNG plant within the scope of the Setouchi Law can be shortened.

  Furthermore, since the temperature of the cooling water supplied to the manufacturing plant is lowered by utilizing the cold heat of LNG, the present invention not only increases the cooling efficiency in the manufacturing plant, but also does not increase the temperature of the waste water. Also desirable for the environment.

  Hereinafter, as an embodiment of the present invention, a case where an LNG plant is installed in a refinery will be described with reference to FIG.

  First, the refinery A will be described. The refinery A includes a crude oil tank, an atmospheric distillation apparatus, a vacuum distillation apparatus, a naphtha hydrodesulfurization apparatus, a catalytic reformer, a debenzene apparatus, a kerosene hydrodesulfurization apparatus, a light oil. Various oil production facilities 1 such as a deep hydrodesulfurization apparatus, a heavy gas oil hydrocracking apparatus, a heavy oil direct desulfurization apparatus, and a heavy oil fluid catalytic cracking apparatus are installed. Since these facilities are well known, a detailed description is omitted, and it should be noted that the facilities vary slightly depending on the scale of the refinery.

  Since various oil refineries require cooling when the manufacturing process is performed, seawater is taken from them and used as cooling water. Seawater is taken from a water intake 2 by a seawater intake facility (not shown), supplied to various oil refineries 1 through an intake line 3, and the seawater that has been heat-exchanged through a cooling system is discharged (drainage). The water is returned to the sea from the water discharge (drainage) port 5 through the line 4.

  On the other hand, the LNG plant B will be described. The LNG plant B temporarily stores the LNG loaded on the LNG ship 6 in the LNG tank 8 via the receiving line 7 and supplies the LNG in the LNG tank 8 with the discharge pump 9. The LNG is sent to the vaporizer 11 via the line 10, where LNG is vaporized by heat exchange with seawater and sent to each supply destination by the pipeline 12. In some cases, LNG is shipped in a liquid state without vaporizing LNG.

  Seawater used as a heat medium for vaporizing LNG by the vaporizer 11 is supplied from the intake line 3 of the refinery A. That is, the supply line 13 is branched from the intake line 3 so that a part of the seawater flows to the vaporizer 11. Moreover, the seawater after heat exchange is returned to the intake line 3. That is, the seawater after heat exchange from the vaporizer 11 is returned to the intake line 3 through the return line 14.

  The return line 14 is connected to the downstream side of the intake line 3 with respect to the supply line 13, so that the seawater that reaches the vaporizer 11 through the supply line 13 is cooled by the cold heat of LNG, and this cooled seawater Flows into the intake line 3 through the return line 14, and as a result, the temperature of the entire seawater from the intake line 3 to the various oil refineries 1 decreases, and this seawater is used as cooling water for the various oil refineries 1.

  In addition, the seawater that has been heat-exchanged through the cooling systems in the various oil refineries 1 has a water temperature that is higher than that at the time of cooling water supply due to heat input, but since the seawater was originally cooled by the cold heat of LNG, The temperature can be kept lower than when not passing through the vaporizer 11. For example, when operating seawater refinery A alone without passing seawater through the vaporizer 11, a cooling system is used for seawater temperature (about 30 ° C in summer, about 8 ° C in winter, average 15 ° C). The temperature of seawater that is heat-exchanged through (ie, drainage temperature) is about + 8 ° C., but according to this embodiment, the temperature of seawater when cooling water is supplied is about 3 ° C. lower by passing through the vaporizer 11. As a result, the seawater temperature (that is, the drainage temperature) that is heat-exchanged through the cooling system is about + 5 ° C. Therefore, according to the present embodiment, the drainage temperature can be lowered by about 3 ° C., which is an effective environmental measure against warm drainage.

  In addition, if LNG plant B is constructed based on a plan in which part of the site of refinery A that can be reduced in scale is replaced with the site of LNG plant B and LNG plant B is installed in the existing refinery A. For example, LNG plant B uses the auxiliary facilities such as refinery A's seawater intake facilities, defoaming facilities, and wastewater treatment facilities. Can be used.

  Furthermore, because the LNG plant B uses the incidental facilities of the refinery A, the amount of water taken (drained) will not increase even if the LNG plant B is newly constructed. , Environmental assessment issues can be easily cleared.

  Further, if an intermediate medium type LNG vaporizer is used as the vaporizer 11, the intermediate medium type LNG vaporizer is compact and requires less installation space, so that not only can the land be effectively utilized, If it is a medium type LNG vaporizer, piping work will be easy and the refinement | purification on the refinery A side will be unnecessary.

  In addition, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the summary of this invention.

The conceptual diagram of the complex plant which concerns on this embodiment is shown.

Explanation of symbols

  A ... Refinery (predetermined production plant), B ... LNG plant, 1 ... Oil refinery equipment, 2 ... Water intake, 3 ... Water intake line, 4 ... Water discharge (drainage) line, 5 ... Water discharge (drainage) port, 6 ... LNG Ship, 7 ... Receiving line, 8 ... LNG tank, 9 ... Discharge pump, 10 ... Supply line, 11 ... Vaporizer, 12 ... Pipeline, 13 ... Supply line, 14 ... Return line

Claims (2)

LNG is vaporized by heat exchange with seawater in an existing production plant that takes in seawater through a water intake line and uses it as cooling water in carrying out a predetermined production process, and then returns the heat-exchanged seawater to the sea through the water discharge line. An LNG plant equipped with vaporization equipment is a complex plant newly installed by substituting a part of the site of the production plant with the site of the LNG plant ,
Wherein the production plant also by features a LNG plant, so that no water intake and drainage of seawater is increased, the a production plant water intake line for heat exchange part of the sea water in the vaporization equipment of the LNG plant The supply line for supplying seawater is connected to the existing intake line, and the return line for returning the seawater after heat exchange whose water temperature is lower than the water temperature at the time of intake to the intake line is located on the intake line rather than the supply line. A complex plant connected to the downstream side. The combined plant according to claim 1 , wherein an intermediate medium LNG vaporizer is used as the vaporization facility.

Images