JPS58222986A - Power recovery device - Google Patents

Abstract

PURPOSE:To heighten the power recovery efficiency by recovering the energy of high pressure liquid made avaitable through its pressure reduction by means of a hydraulic motor and by returning the pressure energy as it is to the process through a pressure medium as the energy for coal slurry transportation. CONSTITUTION:Since a pressure medium is discharged from the cylinder chamber of a pressure medium cylinder 9a via a flow rate regulating mechanism 19a, dissolved gas in a solution produced during coal liquefaction in a pressure reducing cylinder 7a (Operation of cylinders 7b and 7c is similar to that of cylinder 7a though their phases are different.) expands. At this time of pressure reduction, a pressure medium discharged from the cylinder 9a is supplied to a hydraulic motor 26 via a switching valve 22a so that the pressure energy is recovered as power to drive a coal slurry feeding pump 25 connected to the hydraulic motor 26 via an electric motor M2. Thus, the energy recovered during reducing the pressure of high pressure liquid can be returned directly as a high pressure liquid supplying source in the process.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power recovery device, specifically, to a chemical plant that includes a step of reducing the pressure of a high-pressure liquid containing dissolved gas and solid particles. This invention relates to a device that recovers the energy possessed by an object as power.

As a chemical plant that includes the process of reducing the pressure of high-pressure liquid,
Although there are various conventional methods, in this specification, we will use lime liquefaction plants as an example, which has been re-recognized in recent years due to the deterioration of the petroleum situation. A case will be described in which power is recovered from a high-temperature, high-pressure coal liquefaction product solution containing 1 m of mineral particles.

In this lime liquefaction plant, lime is crushed and dehydrated, then a solvent is added to form a slurry, this is subjected to external pressure and preheating, and then liquefied by a hydrogenation reaction, and the resulting coal liquefaction product solution is made into a gas-liquid mixture. After that, the pressure is reduced, and then the heavy and light oil products are fractionally distilled. Conventionally, this pressure reduction of the coal liquefaction product solution was carried out using the throttling effect of a flow rate control valve, but the life of the valve was short due to wear due to ash and other mineral particles, and the coal liquefaction product solution had In view of the fact that pressure energy is wasted as heat energy, a device for recovering the pressure energy has recently been proposed, for example, in Japanese Patent Application No. 108365/1982. In this 'iIJ force recovery device, the pressure energy of the coal liquefaction product solution is converted into the pressure energy of the pressure medium in the cylinder, and the hydraulic motor etc. is driven by the pressure medium with external pressure accumulated. When the pressure of the coal liquefaction product solution is reduced in the cylinder, when the pressure is reduced,
The decompression fluid discharged from the cylinder corresponding to that cylinder is added to the amount discharged from other cylinders connected in parallel, causing a problem in which the flow rate of the decompression fluid fluctuates, and energy cannot be recovered during depressurization. , there was a problem of poor energy recovery efficiency.

The present invention has been made in view of these problems, and allows the energy of high-pressure liquid containing dissolved gas to be directly fed back to the process as energy for transporting lime slurry without causing flow rate fluctuations in the reduced-pressure liquid. The purpose is to provide a power recovery device. Another object of the present invention is to provide a power recovery device that minimizes energy conversion loss and has high recovery efficiency.

The power recovery device according to the present invention includes a high-pressure liquid supply valve that supplies a high-pressure liquid containing dissolved gas and solid particles, and a reduced-pressure liquid discharge valve that discharges a reduced-pressure liquid obtained by reducing the pressure of the high-pressure liquid. A plunger type cylinder for pressure reduction is arranged in parallel with the high pressure liquid supply source and the reduced pressure liquid receiving part, respectively, and supplies low pressure liquid. A plurality of pressurizing plunger-type cylinders equipped with a check valve for supplying low-pressure liquid and a check valve for discharging external pressure liquid that has increased the pressure of the low-pressure liquid are used as a low-pressure liquid supply source and an external-pressure liquid receiving part. The pressure medium inflow/outflow mechanism has the same number of plunger type cylinders for pressure reduction and plunger type cylinders for external pressure, respectively arranged in parallel, and further has a plunger connected to the plunger of the pressure reduction cylinder and a pressure medium inflow/outflow chamber. A pressure medium inflow and outflow chamber is connected to a pressure medium supply source, and the pressure medium inflow and outflow chamber is connected to a pressure medium inflow and outflow chamber of a pressure medium inflow and outflow mechanism having a plunger connected to a plunger of a pressurizing cylinder and a pressure medium inflow and outflow chamber. It is characterized in that it is connected to a motor via a switching valve, and the energy recovered when reducing the pressure of high-pressure liquid is directly fed back as a high-pressure liquid supply source in the process.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings.

In FIG. 1 showing an example in which the power recovery device of the present invention is applied to a coal liquefaction plant, 1 is a tank that accommodates lime slurry as a low-pressure liquid, 2 is a variable discharge pump that pumps the coal slurry in the tank, and 3 is a preheater, 4 is a coal hydrogenation liquefaction reaction tower, 5 is a high-pressure side gas-liquid separation tower, 6 is a low-pressure side gas-liquid separation tower, 7 is a plunger type cylinder for pressure reduction, 9.11 is a plunger type cylinder for pressure medium , 13 is a plunger type cylinder for suction, 15a, 15b, '15C are high pressure liquid supply valves, 16a116b, 16C are pressure reducing liquid discharge valves, 23a to 2
3C124a-24C are check valves, 19a-19C are flow rate adjustment mechanisms, 21 are accumulators, 17a-17C,
18, 22a to 22C are switching valves, 25 is a low pressure liquid supply pump, 26 is a hydraulic motor, 28 is a pressure medium tank, 29
is a pressure medium supply pump, 30 is an IJ valve, 31
32 is an oil cooler, 32 is a check valve, 34a to 34b are pressure detectors, and M1 to M3 are electric motors.

In the coal liquefaction plant, the coal slurry from the tank 1 is pressurized to about 200 to 300 Kg/tyA by the pump 2 and the power recovery device described below, and is then pressure-fed to the preheater 3 via the supply fins 33. . The coal slurry preheated to approximately 300 to 400°C in the preheater 3 is sent to the reaction tower 4, where it is liquefied by the action of added hydrogen and a catalyst, becoming a high-temperature, high-pressure lime liquefaction product solution and flowing to the high-pressure side. It is sent to the gas-liquid separation tower 5. The separated gas is led out of the system from the top of the gas-liquid separation tower 5, and the lime liquefaction product solution led out from the bottom of the tower is collected by the power recovery device according to the present invention.
The pressure is reduced to about 7/d to 0 to 100 and transported to the low pressure side gas-liquid separation tower 6.

When the power recovery device of the present invention reduces the pressure of a high-temperature, high-pressure coal liquefaction product solution to the fractional distillation operating pressure for the next step, the power recovery device uses the pressure energy of the coal liquefaction product solution to pressurize the coal slurry and transport it. It is applied to recover the liquid as a power source for the pump, and as shown in Figure 2, high-pressure liquid is supplied (state A→state 13), depressurized (B→C), and drained (C-+
D), pressure increase (1)→A), and this operation cycle is performed by the following operations.

High-pressure liquid supply valves 15a, 15b, 15C and reduced-pressure liquid discharge valves 16a, 16b, 16 (respectively), high-pressure side gas-liquid separation tower 5 as a high-pressure liquid supply source and low-pressure side gas-liquid separation tower as a reduced-pressure liquid receiving part Since the depressurizing cylinders 7a, 7b, and 7C connected in parallel to each other in the cylinder 6 are the same in operation except for the phase difference, for convenience, the depressurizing cylinder 7a system in the state A after the external pressure stroke is To explain the operation, first, among the high pressure liquid supply valve 15a and the pressure reducing liquid discharge valve 16a which are in the closed state, the high pressure liquid supply valve 15a is opened and the switching valve 17a is switched from the neutral position to the first position. A high-pressure coal liquefaction product solution is supplied from the liquid separation tower 5 to the cylinder 7a, and the plunger 8a is reciprocated to the left in the figure by the pressure energy. The plunger 10a of the decompression side pressure medium cylinder 9a connected to this reservoir plunger 8a is pushed to the left in the figure, and the pressure medium in the cylinder chamber, such as hydraulic oil or a solvent for producing coal slurry, is
It is supplied to the external pressure side pressure medium cylinder la through the flow rate adjustment mechanism 19a and the switching valve 22a which is switched from the open position to the first position during the liquid supply stroke. Plunger 14 of boosting cylinder 3a,
,.

The plunger 12a connected to 3 is pushed to the left in the figure, and as a result, the pressure of the lime slurry in the external pressure cylinder 13a is increased, and the lime slurry supply line 3 passes through the check valve 2=3a.
3. After the high pressure liquid is supplied to the pressure reducing cylinder 7a in this way and the switching valve 22a is returned to the neutral position, the high pressure liquid supply valve 15a is closed, and the liquid supply process ends.

Then, when the switch -jT22a is switched to the second position, a depressurization stroke is carried out, that is, the pressure medium cylinder 9
As the pressure medium is discharged from the cylinder chamber a through the flow rate adjustment mechanism 19a, the dissolved gas in the coal liquefaction product solution in the pressure reducing cylinder 7a expands. In the power recovery device of the present invention, during this pressure reduction, the pressure medium discharged from the cylinder 9a is transferred to the hydraulic motor 2 via the switching valve 22a.
6, and the energy at the time of pressure reduction is recovered. That is, by driving the hydraulic motor 26 with a pressure medium,
The power is recovered to drive the coal slurry supply pump 25 connected to the hydraulic motor 26 via the electric motor M2. The coal slurry discharged by this supply pump 25 is
Supplied to external pressure cylinders in other systems. When the coal liquefied product solution in the pressure reducing cylinder 7a is reduced to a predetermined pressure, the switching valve 22a is closed and the pressure reducing process ends.

Next, the pressure reducing liquid discharge valve 16a is opened, and the switching valve 22a is opened.
When the pump is switched to the first position, the lime slurry supplied from the pump 25 to the pressurizing cylinder 13a causes the plunger 14a to move back to the right in the figure, causing the pressure medium in the pressurizing side pressure medium cylinder lla to flow out. , flow rate adjustment mechanism 1
It is supplied to the decompression side pressure medium cylinder 9a via 9a. Therefore, the plunger 10a moves back and the plunger 8a
is pushed to the right in the figure, and the depressurized coal liquefaction product solution in the decompression cylinder 7a is transferred to the low pressure side gas-liquid separation tower 6 via the decompression liquid discharge valve 163. After that, the switching valve 22a
is switched to the neutral position, the switching valve 17a is switched to the second position, the remaining transfer is completed, and after returning to the neutral position, the depressurized liquid discharge valve 163 is closed, thereby completing the liquid draining process. Next, by switching the switching valve 17a to the second position again, the high-pressure pressure medium stored in the accumulator by the action of the pressure-medium supply pump 290 (or alternatively, the high-pressure pressure medium supplied from the pump 29) is removed. ) is the second
The lime liquefaction product solution in the pressure reduction cylinder 7a flows into the pressure medium cylinder 9a on the pressure reduction side through the switching valve 17a, which has been switched to the position, and presses the plunger 10a to the right. The pressure is increased to the same pressure as the coal liquefaction product solution from 5. Next, the switching valve 17a is returned to the neutral position to end the external pressure stroke and proceed to the next liquid supply stroke, thereby repeating the operation cycle.

The above operation is repeated for each system of the pressure reducing cylinders 7a, 7b, 7c.
3a to 23C are boost side pressure J medium cylinders lla;
1lb111C (7) Plunger 12a, 12b, 12
The external pressure cylinder 13 automatically opens and closes following the movement of C, and as shown in the time chart of FIG.
The supply of coal slurry to a, 13b, and 13C and the discharge from the external pressure cylinder are performed sequentially and continuously, and when the coal liquefaction product solution is depressurized, the pressure medium cylinder 9 on the decompression side
The pressure medium discharged from the pressurizing cylinder 130 must not affect the lime slurry, so the amount of slurry discharged from the external pressure cylinder 13 to the coal slurry supply line is almost constant, and fluctuations in flow rate can be prevented. can. The discharge amount of the variable displacement pump 2 is controlled by a signal from a sensor 34 that detects the liquid level of the high-pressure side gas-liquid separation tower 5, thereby ensuring the amount of coal slurry necessary for the lime liquefaction plant.

In addition, the energy at the time of depressurizing the high-pressure liquid is recovered by the hydraulic motor 26, and the pressure energy is directly returned to the process as pressure energy via the crushed pressure medium, so there is little energy conversion loss and power Recovery efficiency can be significantly increased.

[Brief explanation of the drawing]

Fig. 1 is a system diagram of a coal liquefaction plant to which the present invention is applied, Fig. 2 is a finger pressure diagram showing the operating cycle of the power recovery device according to the present invention, and Fig. 3 is a power recovery diagram in Fig. 1. It is a time chart of opening and closing of the valve of the device. 5-High pressure side gas-liquid separation tower, 6-Low pressure side gas-liquid separation tower, 7-Cylinder for pressure reduction, 9-Cylinder for pressure medium on pressure reduction side, 11-
Column pressure side pressure medium cylinder, 13 - Pressure increase cylinder, 1
5a, 15b, 15C ~ High pressure liquid supply valve, 16a, 16b
, 16C~Reducing liquid discharge valve, 17a, 17b, 17C, 2
2a, 22b. 22C-t7J exchange valve, 23a, 23b, 23C ~ check valve for pressurized liquid discharge, 24a, 24b, 24C ~ check valve for low pressure liquid supply, 25 ~ low pressure liquid flood pump, 26 ~ hydraulic motor,
35 ~ Emergency pressure reducing valve. Patent Applicant Kobe Steel Co., Ltd. Immediately Patent Attorney Aobai Bo and 1 other person Figure 2 Client information - Figure 3 Procedural amendment (voluntary) 1. Indication of the case Patent Application No. 107341 of 1988 2. Name of the invention Power recovery device 3 Relationship with the case of the person making the amendment Patent applicant representative Takayoshi Takahashi 4, agent 7 Contents of the amendment ■,) The following parts in the specification are corrected, (1) Page 3 1
Correct ``hydraulic morph'' in line 5 to ``pressure motor''. (2) Page 7, lines 11-13 [Liquid supply...(D-,
A) Correct J as follows. "Axillary culm supply (state A - state B), decompression stroke (B-.C), drainage stroke (C-, D), pressure increase stroke (D - A)
J(3) Insert "above the figure" before "first position" on page 8, line 6. (4) Page 8, line 15, before “1st position”, “below the figure”
Insert. (5) On page 9, line 5, before ``2nd position'', add ``above the figure'' by 1 alien. (6) On page 10, line 1, ``Closed'' should be corrected to ``Return to the intermediary device.'' (7) On page 10, line 3, before “1st position”, “below the figure”
(8) Insert ``below the figure'' in front of ``2nd position'' on page 10, line 14. (9) Insert "lower in the figure" before "second position" on page 10, line 17. 00 Page 12, line 4, "variable displacement type" is corrected to "variable discharge type". 2.) Correct Figure 1 of the drawing as shown in the attached sheet. Above 1・-□

Claims (1)

[Claims] (1) A plurality of plunger-type cylinders for pressure reduction, each equipped with a high-pressure liquid supply valve that supplies high-pressure liquid containing dissolved gas and solid particles, and a reduced-pressure liquid discharge valve that discharges the reduced-pressure liquid obtained by reducing the pressure of the high-pressure liquid. are arranged in parallel with the high-pressure liquid supply source and the reduced-pressure liquid receiving part, respectively, and a low-pressure liquid supply check valve that supplies low-pressure liquid and an external-pressure liquid discharge check valve that discharges the pressurized liquid that has increased the pressure of the resistive liquid. A plurality of plunger-type cylinders for external pressure are arranged in parallel in each of the low-pressure liquid supply source and the external pressure liquid receiving part, and the number of plunger-type cylinders for pressure reduction and the plunger-type cylinders for pressure increase are the same, and A pressure medium inflow and outflow chamber of a pressure medium inflow and outflow mechanism having a plunger connected to a plunger of a cylinder and a pressure medium inflow and outflow chamber is connected to a pressure medium supply source, and the pressure medium inflow and outflow chamber is connected to a plunger of an external pressure cylinder. The pressure medium inflow and outflow chamber of a pressure medium inflow and outflow mechanism having a plunger and a pressure medium inflow and outflow chamber is connected via a switching valve to a hydraulic motor, and the recovered energy when depressurizing high pressure liquid is directly used to supply high pressure liquid in the process. A power recovery device characterized by returning power as a power source.