JP2012041990A - Nitrogen supply facilities - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide nitrogen supply facilities enabling reduction of the cost of the facilities.SOLUTION: The nitrogen supply facilities supply a nitrogen gas for common use and a nitrogen gas for emergency at pressure higher than that of the nitrogen gas for common use to nitrogen-using facilities. The nitrogen supply facilities include: a supply line for the nitrogen gas for common use, used for supply of the nitrogen gas for common use; and a supply line for the nitrogen gas for emergency, used for supply of the nitrogen gas for emergency; wherein the supply line for the nitrogen gas for common use and the supply line for the nitrogen gas for emergency are installed as nitrogen gas supply lines, each of which has an independent and separate system.

Description

 The present invention relates to a nitrogen supply facility.

  Conventionally, as a nitrogen supply source in the LNG terminal, a PSA (Pressure Swing Adsorption) type nitrogen gas generator (hereinafter referred to as a PSA nitrogen gas generator) and liquid nitrogen stored in a tank are used. As is well known, a PSA nitrogen gas generator is an apparatus that generates high-purity nitrogen gas by separating oxygen and nitrogen in the air using an adsorbent.

  As shown in FIG. 2, in normal time, nitrogen gas generated by the PSA nitrogen gas generator (hereinafter referred to as “normal nitrogen gas”) is supplied to the nitrogen use facility 30 in the LNG base via the normal nitrogen supply line 10. To do. On the other hand, in an emergency, high-pressure nitrogen gas (hereinafter referred to as emergency nitrogen gas) generated by heating liquid nitrogen is joined to the regular nitrogen supply line 10 via the emergency nitrogen supply line 20 to use nitrogen. Supply to the facility 30. For example, when the nitrogen use facility 30 is a vent stack, the normal nitrogen gas is used for purging the vent stack, and the emergency nitrogen gas is used for extinguishing fire when a fire occurs (see Patent Document 1 below).

JP 10-337463 A

  As described above, in an emergency, the emergency nitrogen gas generated by heating the liquid nitrogen is joined to the regular nitrogen supply line 10 via the emergency nitrogen supply line 20 and supplied to the nitrogen utilization facility 30. Since the emergency nitrogen gas has a higher pressure than the normal nitrogen gas, the supply of the normal nitrogen gas by the PSA nitrogen gas generator is stopped. For this reason, all of the nitrogen gas supply required in an emergency must be covered by emergency nitrogen gas, leading to an increase in the size of liquid nitrogen equipment (tanks, piping, etc.), resulting in an increase in equipment costs. was there.

 This invention is made | formed in view of the situation mentioned above, and it aims at providing the nitrogen supply equipment which can aim at reduction of installation cost.

  In order to solve the above-mentioned problem, in the present invention, as a first solving means related to a nitrogen supply facility, nitrogen is supplied to the nitrogen-using facility with the common nitrogen gas and the emergency nitrogen gas having a pressure higher than that of the regular nitrogen gas. A supply facility comprising: a normal nitrogen gas supply line used for supplying the normal nitrogen gas; and an emergency nitrogen gas supply line used for supplying the emergency nitrogen gas. The line and the emergency nitrogen gas supply line are installed as separate independent nitrogen gas supply lines.

  Further, in the present invention, as a second solving means relating to the nitrogen supply facility, in the first solving means, an auxiliary nitrogen gas supply line connecting the normal nitrogen gas supply line and the emergency nitrogen gas supply line; And a flow rate adjusting valve inserted in the middle of the auxiliary nitrogen gas supply line, and a control device for controlling the valve opening of the flow rate adjusting valve according to the pressure of the normal nitrogen gas supply line. Features.

 According to the nitrogen supply facility according to the present invention, since the nitrogen gas supply amount necessary in an emergency can be covered by the normal nitrogen gas and the emergency nitrogen gas, the liquid nitrogen facility (tank, piping, etc.) can be downsized. As a result, the equipment cost can be reduced.

It is a composition schematic diagram of nitrogen supply equipment A in this embodiment. It is the structure schematic of the conventional nitrogen supply equipment.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a nitrogen supply facility A in the present embodiment. As shown in FIG. 1, the nitrogen supply facility A supplies a normal nitrogen gas and an emergency nitrogen gas having a pressure higher than that of the normal nitrogen gas to the nitrogen use facility 30. , An emergency nitrogen gas supply line 2, an auxiliary nitrogen gas supply line 3, a flow rate adjusting valve 4 and a control device 5.

The normal nitrogen gas supply line 1 is a nitrogen gas supply line that is used to supply, for example, nitrogen gas (normal nitrogen gas) generated by a PSA nitrogen gas generator (not shown) to the nitrogen-using facility 30 at a normal time. . The emergency nitrogen gas supply line 2 is used to supply nitrogen gas (emergency nitrogen gas) generated by heating liquid nitrogen stored in a tank, for example, to the nitrogen using facility 30 in an emergency. Supply line.
The normal nitrogen gas supply line 1 and the emergency nitrogen gas supply line 2 are installed as separate independent nitrogen gas supply lines.

  The auxiliary nitrogen gas supply line 3 is an auxiliary nitrogen gas supply line that connects the normal nitrogen gas supply line 1 and the emergency nitrogen gas supply line 2. The flow rate adjustment valve 4 is an electromagnetic valve inserted in the middle of the auxiliary nitrogen gas supply line 3, and the valve opening degree is controlled by an opening degree control signal input from the control device 5. The control device 5 is, for example, a PIC (Pressure Indicator Controller) and controls the valve opening degree of the flow rate adjusting valve 4 according to the pressure of the regular nitrogen gas supply line 1 (outputs an opening degree control signal to the flow rate adjusting valve 4). )

  In the nitrogen supply facility A having such a configuration, the normal nitrogen gas is supplied to the nitrogen using facility 30 through the normal nitrogen gas supply line 1 in a normal time. For example, when the nitrogen use facility 30 is a vent stack, the normal nitrogen gas is used for purging the vent stack. The flow rate adjustment valve 4 is in a closed state unless an opening degree control signal is input from the control device 5.

  Here, the control device 5 supplies the necessary amount of the normal nitrogen gas to the nitrogen use facility 30 when the pressure of the normal nitrogen gas supply line 1 falls below a predetermined threshold value when supplying the normal nitrogen gas. If not, the flow rate adjusting valve 4 is opened by outputting an opening degree control signal to the flow rate adjusting valve 4, and emergency nitrogen gas is generated by controlling equipment for heating liquid nitrogen. The emergency nitrogen gas is joined to the regular nitrogen gas supply line 1 via the auxiliary nitrogen gas supply line 3 and supplied to the nitrogen use facility 30.

 Thereby, the shortage of the common nitrogen gas can be supplemented with the emergency nitrogen gas. Since the emergency nitrogen gas has a higher pressure than the normal nitrogen gas, if the flow rate of the emergency nitrogen gas joining the normal nitrogen gas supply line 1 via the auxiliary nitrogen gas supply line 3 is large, the PSA nitrogen gas generator Since the supply of the normal nitrogen gas is stopped, it is necessary to appropriately control the opening degree of the flow rate adjusting valve 4 so that the flow rate of the emergency nitrogen gas flowing through the auxiliary nitrogen gas supply line 3 does not interfere with the supply of the normal nitrogen gas. is there.

  On the other hand, in the nitrogen supply facility A, in an emergency, emergency nitrogen gas is supplied to the nitrogen using facility 30 via the emergency nitrogen gas supply line 2. For example, when the nitrogen use facility 30 is a vent stack, the emergency nitrogen gas is used for extinguishing fire when a fire occurs. In an emergency, the flow rate adjusting valve 4 is always closed, and the normal nitrogen gas is supplied to the nitrogen using facility 30 through the normal nitrogen gas supply line 1 together with the emergency nitrogen gas.

  That is, in an emergency, the normal nitrogen gas and the emergency nitrogen gas do not merge but are supplied to the nitrogen-using facility 30 through separate nitrogen gas supply lines that are completely independent of each other, and are extinguished when a fire occurs. Used for emergency use. Here, since the normal nitrogen gas and the emergency nitrogen gas do not merge upstream of the nitrogen use facility 30, the supply of the normal nitrogen gas by the PSA nitrogen gas generator does not stop.

  As described above, according to the nitrogen supply facility A in the present embodiment, the nitrogen gas supply amount necessary in an emergency can be covered by the normal nitrogen gas and the emergency nitrogen gas, so the liquid nitrogen facility (tank, piping, etc.) ) Can be reduced in size, and as a result, the equipment cost can be reduced.

  In the above embodiment, the auxiliary nitrogen gas supply line 3, the flow rate adjustment valve 4 and the control device 5 are illustrated in the nitrogen supply facility A. However, when there is no possibility that the normal nitrogen gas is insufficient during normal times. It is not always necessary to provide these facilities. Moreover, the nitrogen use equipment 30 which should supply normal nitrogen gas and emergency nitrogen gas through the nitrogen gas supply line of another independent system is not limited to a vent stack, but includes a return gas blower, a breathing tank, a BOG compressor, etc. The equipment may be.

 A ... Nitrogen supply equipment, 1 ... Regular nitrogen gas supply line, 2 ... Emergency nitrogen gas supply line, 3 ... Auxiliary nitrogen gas supply line, 4 ... Flow control valve, 5 ... Control device

Claims (2)

Nitrogen supply equipment for supplying normal nitrogen gas and emergency nitrogen gas having a pressure higher than that of the normal nitrogen gas to the nitrogen use equipment,
A normal nitrogen gas supply line used for supplying the normal nitrogen gas;
An emergency nitrogen gas supply line used to supply the emergency nitrogen gas,
The nitrogen supply facility, wherein the normal nitrogen gas supply line and the emergency nitrogen gas supply line are installed as separate independent nitrogen gas supply lines. An auxiliary nitrogen gas supply line connecting the normal nitrogen gas supply line and the emergency nitrogen gas supply line;
A flow rate adjusting valve inserted in the middle of the auxiliary nitrogen gas supply line;
The nitrogen supply facility according to claim 1, further comprising: a control device that controls a valve opening degree of the flow rate adjusting valve according to a pressure of the common nitrogen gas supply line.

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