JP6812532B1 - Reciprocating compression expander - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate an increase in size of an apparatus, to resist a strong spring force for closing a valve, and to easily open a valve with a simple mechanism with a low pushing force in response to a load of a reciprocating compression / expander. To be able to let. SOLUTION: A first valve that opens and sucks a low-pressure compressible fluid from a low-pressure path into a main body cylinder and a valve that opens and sucks from the first valve and is compressed by the operation of a main body piston to become a high pressure. The second valve (8) that discharges the compressible fluid into the high-pressure path (9), or the second valve (8) that opens and allows the high-pressure compressible fluid to flow into the main body cylinder from the high-pressure path and opens. The first valve, which flows in from the second valve and is expanded by the operation of the main body piston to discharge the compressible fluid which has become low pressure, to the low pressure path, and the hydraulically driven or electric second valve which operates the first valve and the second valve. It includes a valve driving mechanism (1) and a second valve driving mechanism (17, 18, 27) for operating the second valve by the fluid pressure of a compressible fluid. [Selection diagram] Fig. 3

Description

The present invention relates to, for example, a reciprocating compression expander suitable for use in compressing or expanding a compressible fluid.

Conventionally, solar power generation devices, wind power generation devices, and the like have already been widely used as renewable energy. However, in a power generation device using these natural energies, since the amount of power generation fluctuates greatly, it is difficult to effectively use the power generation device according to the power demand.

This is because the amount of power generated by natural energy, which cannot be controlled by humans, sometimes greatly exceeds the required power to generate excessive surplus power, which in the worst case causes a blackout phenomenon of power. May also occur. For this reason, in the case of a power generation device using natural energy, a part of the power generation device is cut off so as not to generate such an excessive surplus power.

Then, as a countermeasure against this excessive surplus power, it is conceivable to temporarily store the surplus power in the storage battery and release it when the power demand is likely to increase to supply the power to the grid to level the power. This storage battery-based storage method directly stores electrical energy and is ideal in terms of utilization, but the storage battery requires a special metal or the like, and is an extremely expensive energy storage device.

Another solution for preserving surplus power based on natural energy is to convert electrical energy into compressed air energy and store it. Regarding this storage method, a pilot plant for an energy storage device that converts it into compressed air energy has been constructed, and demonstration experiments have been completed.

In this method, an electric motor is operated using surplus electric power, the compressor is rotationally driven by the electric motor to form compressed air, which is temporarily stored in a tank, and when the electric power is insufficient, the expander is driven by the compressed air to generate electric power. The machine is driven to rotate, which generates electricity and converts it back into electric power. As a result of the demonstration experiment, it has been confirmed that the total efficiency is 60 to 70%. In this energy storage device, a screw type compressor is used as a compression expander.

On the other hand, as a compressor, there is also a reciprocating type using a piston. In the conventional reciprocating compressor using this piston, the suction valve and the discharge valve are operated only by a simple spring force using a leaf spring or the like (see Patent Document 1).

However, in the above-mentioned conventional screw type compressor, the following problems are concerned. That is, in the screw compressor, a certain structural gap is inevitably generated between the male and female rotors and between the rotor and the casing, and the material to be compressed leaks through this gap during compression, resulting in compression efficiency and expansion efficiency. Decreases.

Further, when both the compression stroke and the expansion stroke are performed by one compression / expansion machine, the rotation directions of the compression / expansion machine are reversed in each stroke. Therefore, in order to simplify the electric power device by rotating the electric motor used for compression and the generator used for power generation in the same direction, some kind of switching device or the like is required.

In addition, the screw compressor has a relatively small capacity and is not suitable for a large-capacity energy storage device. Further, in the screw type compressor, the capacity cannot be adjusted by the compression expander alone, and a pressure regulator for compressed air or the like is required. Further, in order to solve such a problem, a converter such as a converter may be required in the power system, and in this case, there is a problem that the device itself becomes expensive.

On the other hand, in the conventional reciprocating compressor, the suction valve and the discharge valve are operated by a spring such as a leaf spring as described above. In this case, only the spring force preset by the differential pressure from the internal pressure is operated. Therefore, the intake valve and the discharge valve are operated, and there is a problem that it is not always easy to arbitrarily and optimally adjust the intake flow rate and the discharge flow rate. Further, there is a problem that it cannot be used as an expander.

For this reason, the inventor of the present application has developed a new reciprocating compression / expansion machine, which has extremely high efficiency regardless of whether it is used for compression or expansion, has the same rotation direction, has a large capacity, and has a large capacity. 2019-227516 is a reciprocating compression / expansion machine that is suitable for such purposes, has extremely easy capacity adjustment, and does not require a converter such as a converter in the power system and is inexpensive even when used in a power storage plant. Proposed by.

Japanese Unexamined Patent Publication No. 2-130278

However, the reciprocating compression expander proposed by the inventor of the present application has a structure in which the suction valve for sucking the compressible fluid and the discharge valve for discharging the compressible fluid are closed by, for example, an air spring. The spring force of this air spring is the inertial force generated from the weight of the operating part and its acceleration, the sealing property to prevent fluid leakage from the valve seal part, and the differential pressure acting on the valve umbrella part when the valve is opened. Etc. are taken into consideration when determining.

On the other hand, in an internal combustion engine, for example, the differential pressure applied to the valve umbrella portion of the umbrella valve is about 1 bar at most, but reciprocating compression for compressing the compressible fluid to a high pressure or expanding the high-pressure compressible fluid. In the expander, the differential pressure is about 10 times that of the internal combustion engine, although it is a moment when the valve is opened. Therefore, for example, it is necessary to increase the spring force of the above-mentioned air spring so that the valve can be closed reliably.

Especially during compression, the internal pressure of the cylinder becomes extremely high, and the valve umbrella portion of the discharge valve is pressed from the inside of the cylinder to the valve closing side with a strong force. Therefore, in order to open the discharge valve at the time of compression, the spring force of the above-mentioned strong air spring also synergizes, and an extremely large pushing force is required. However, as can be inferred from the solid line portion in FIG. 6, once the discharge valve is opened, the differential pressure applied to the valve umbrella portion of the discharge valve sharply decreases due to the flow of the compressible fluid.

As described above, in the reciprocating compression / expansion machine used for compressing and expanding the compressible fluid, it is necessary to further increase the spring force of the air spring in order to ensure the valve closing. Due to the strong spring force of the air spring, there is a problem that an extremely large driving force is required for the hydraulic drive or the electric valve drive mechanism for opening the valve. Further, as described above, the internal pressure of the cylinder becomes extremely high, especially during compression, and the valve umbrella portion is also pressed toward the valve closing side by this, and the valve is manually driven to open the valve, although it is a moment when the valve is opened. There is a problem that the electric valve drive mechanism requires a larger driving force.

In order to obtain this large driving force, there is a method in which the valve opening is a cam drive type, but in the case of the cam drive type, there is a problem that the device generally becomes large. Further, in the case of the hydraulic drive or electric valve drive mechanism proposed by the inventor of the present application described above, it is necessary to supply high hydraulic pressure to the hydraulic cylinder for a moment when the valve is opened. There is concern that the pressure of the hydraulic source will be increased and that a special hydraulic booster will be required. Further, since the differential pressure applied to the valve umbrella portion changes according to the load of the reciprocating compression / expander, there is a concern that the pressure of the hydraulic source needs to be controlled according to the load.

The present invention has been made to solve such a problem, eliminates the increase in size of the device, resists the strong spring force for closing the valve, and applies the load of the reciprocating compression / expander. Accordingly, it is an object of the present invention to provide a reciprocating compression / expansion machine capable of easily opening a valve with a simple mechanism with a low pushing force.

In order to solve the above-mentioned problems, the reciprocating compression / expander of the present invention has a main body piston that slides in the main body cylinder, a crank shaft that is connected to the main body piston and rotates, and a low-pressure compressibility that opens a valve. The first valve that sucks the fluid from the low pressure path into the main body cylinder and the second valve that opens and sucks in from the first valve and discharges the compressible fluid that is compressed by the operation of the main body piston and becomes high pressure to the high pressure path. Or, the valve is opened to allow high-pressure compressive fluid to flow into the main body cylinder from the high-pressure path, and the valve is opened to flow in from the second valve and expanded by the operation of the main body piston to reduce the pressure. A first valve that discharges the sexual fluid to the low pressure path, a hydraulically driven or electric first valve drive mechanism that operates the first and second valves, and a second valve that is operated by the fluid pressure of the compressive fluid. It is equipped with 2 valve drive mechanisms.

As described above, by further providing the second valve drive mechanism that operates the second valve by the fluid pressure of the compressible fluid, the driving force of the first valve drive mechanism that is hydraulically driven or electrically driven is not particularly increased. The second valve can be easily opened.

In the reciprocating compression / expansion machine, it is desirable that the second valve drive mechanism includes a fluid pressure piston that is connected to the second valve and operates the second valve by applying the fluid pressure of the compressible fluid to the piston surface. ..

In this way, the second valve drive mechanism is connected to the second valve and includes a fluid pressure piston that operates the second valve by applying the fluid pressure of the compressible fluid to the piston surface, whereby the compressible fluid is provided. A second valve drive mechanism that operates by fluid pressure can be easily formed. In addition, it has a great advantage that it does not require an external energy source such as electric pressure or electricity.

In the reciprocating compression / expansion machine, it is desirable that the fluid pressure piston applies the fluid pressure of the compressible fluid in the high pressure path to the first piston surface on the second valve side of the piston surface.

In this way, the fluid pressure of the compressible fluid in the high-pressure path of the reciprocating compression expander is applied to the first piston surface on the second valve side of the fluid pressure piston, so that the second valve of the fluid pressure piston is applied. The pressing force due to the fluid pressure of the compressive fluid applied to the first piston surface on the side and the pressing force due to the fluid pressure of the compressible fluid applied to the second valve from the high pressure path side are appropriately offset, and during compression or expansion. In either case, the valve opening operation of the second valve is less affected by the fluid pressure of the compressible fluid in the high-pressure path. That is, in all operating states of the reciprocating compression expander, the pushing force of the first valve drive mechanism, which is hydraulically or electrically driven, to the valve opening side of the second valve is specially applied only for opening the second valve. There is no need to increase it.

In the reciprocating compression / expansion machine, the fluid pressure cylinder that slides the fluid pressure piston inside preferably includes a high-pressure fluid communication passage that connects the first cylinder chamber on the second valve side and the high-pressure passage.

In this way, the fluid pressure cylinder that slides the fluid pressure piston inside is provided with a high-pressure fluid communication passage that connects the first cylinder chamber on the second valve side and the high-pressure passage of the reciprocating compression / expander. The pressing force due to the fluid pressure of the compressive fluid applied to the first piston surface on the second valve side of the fluid pressure piston and the pressing force due to the fluid pressure of the compressible fluid applied to the second valve from the high pressure path side are appropriately offset. In both compression and expansion, the valve opening operation of the second valve is less affected by the fluid pressure of the compressible fluid in the high-pressure path. That is, in all operating states of the reciprocating compression expander, the pushing force of the first valve drive mechanism, which is hydraulically or electrically driven, to the valve opening side of the second valve is specially applied only for opening the second valve. There is no need to increase it.

In the reciprocating compression / expansion machine, the outer diameter of the fluid pressure piston on the second valve side is formed to be substantially the same as the outer diameter of the exposed surface exposed on the high pressure path side of the second valve when the second valve is closed. Is desirable.

In this way, the outer diameter of the second valve side of the fluid pressure piston is formed to be substantially the same as the outer diameter of the exposed surface exposed on the high pressure path side of the second valve when the second valve is closed, so that the fluid pressure is formed. The pressing force due to the fluid pressure of the compressive fluid applied to the first piston surface on the second valve side of the piston and the pressing force due to the fluid pressure of the compressible fluid applied to the second valve from the high pressure path side are almost offset, and during compression. Or, at any time during expansion, the valve opening operation of the second valve is less affected by the fluid pressure of the compressible fluid in the high-pressure path. That is, in all operating states of the reciprocating compression expander, the pushing force of the first valve drive mechanism, which is hydraulically or electrically driven, to the valve opening side of the second valve is specially applied only for opening the second valve. There is no need to increase it.

In the reciprocating compression / expansion machine, it is desirable that the high-pressure fluid communication passage extends the fluid pressure cylinder toward the high-pressure road side without substantially changing the inner diameter.

In this way, the high-pressure fluid communication passage is such that the fluid pressure cylinder extends toward the high-pressure path side without substantially changing the inner diameter, so that the fluid pressure cylinder also serves as the high-pressure fluid communication passage, and the high-pressure fluid communication passage also serves. Is easy to form. Further, since the inner diameter does not change, the fluid pressure of the compressible fluid in the high-pressure path can be applied to the fluid pressure cylinder without reducing the pressure.

In the reciprocating compression / expansion machine, it is desirable that the fluid pressure piston applies the fluid pressure of the compressible fluid in the main body cylinder to the second piston surface on the anti-second valve side.

In this way, the fluid pressure of the compressible fluid in the main body cylinder of the reciprocating compression expander is applied to the second piston surface on the anti-second valve side of the fluid pressure piston, so that the fluid pressure is applied to the second piston surface. The pressing force on the valve opening side of the second valve generated by the fluid pressure of the compressible fluid and the pressing force on the valve closing side of the second valve due to the fluid pressure of the compressible fluid in the main body cylinder applied to the second valve. Is offset accordingly, and even if an extremely high fluid pressure of a compressible fluid is applied to the main body cylinder, for example, during compression, the action of this fluid pressure piston causes hydraulic drive only for opening the second valve. Alternatively, it is not necessary to particularly increase the pushing force of the electric first valve drive mechanism to the valve opening side of the second valve.

On the other hand, when the fluid pressure of the compressible fluid in the main body cylinder of the reciprocating compression inflator is low as in the case of expansion, the pressure applied to the first piston surface on the anti-second valve side of the fluid pressure piston also increases accordingly. Since it is reduced, the pressing force applied to the fluid pressure piston is automatically and optimally adjusted in all operating states of the reciprocating compression expander.

In the reciprocating compression / expansion machine, the fluid pressure cylinder that slides the fluid pressure piston inside preferably includes a cylinder communication passage that communicates the second cylinder chamber on the anti-second valve side and the inside of the main body cylinder.

In this way, the fluid pressure cylinder that slides the fluid pressure piston inside is provided with a cylinder communication passage that communicates the second cylinder chamber on the anti-second valve side and the inside of the main body cylinder, so that the anti-deflection of the fluid pressure piston is provided. The pressing force on the valve opening side of the second valve generated by the fluid pressure of the compressive fluid applied to the second piston surface on the two-valve side and the second due to the fluid pressure of the compressive fluid in the main body cylinder applied to the second valve. Even if the pressing force on the valve closing side of the valve is appropriately offset and an extremely high compressive fluid fluid pressure is applied to the main body cylinder, for example, during compression, the action of this fluid pressure piston causes the first It is not necessary to particularly increase the pushing force of the first valve drive mechanism, which is hydraulically or electrically driven, to the valve opening side of the second valve only for opening the two valves.

On the other hand, when the fluid pressure of the compressible fluid in the main body cylinder is low as in the case of expansion, the pressure applied to the second piston surface on the anti-second valve side of the fluid pressure piston also decreases accordingly, so that it is a reciprocating type. The pressing force applied to the fluid pressure piston is automatically and optimally adjusted in all operating conditions of the compression expander.

As described above, the reciprocating compression / expander of the present invention has a main body piston that slides in the main body cylinder, a crank shaft that is connected to the main body piston and rotates, and a low pressure path that opens a valve to pass a low pressure compressive fluid. The first valve that sucks into the main body cylinder from, and the second valve that opens and discharges the compressible fluid that is sucked from the first valve and compressed by the operation of the main body piston to a high pressure path, or opens. A second valve that valves and allows high-pressure compressive fluid to flow into the main body cylinder from the high-pressure path, and a low-pressure compressive fluid that opens and flows in from the second valve and is expanded by the operation of the main body piston to become low pressure. It includes a first valve that discharges to the road, a hydraulically driven or electric valve driving mechanism that operates the first and second valves, and a second valve driving mechanism that operates the second valve by the fluid pressure of a compressible fluid. ..

Therefore, it is possible to eliminate the increase in size of the device, resist the strong spring force for closing the valve, and easily open the valve with a simple mechanism with a low pushing force according to the load of the reciprocating compression / expander. It has the excellent effect of being able to speak.

It is the schematic which shows the reciprocating compression expansion machine. It is the schematic which shows the valve drive mechanism of the hydraulic drive of the reciprocating compression expansion machine of FIG. It is a partial vertical sectional view which shows the detail of the reciprocating compression expansion machine which concerns on this invention. It is a graph which shows the relationship between the crank angle and the air pressure in the main body cylinder at the time of compression of the reciprocating compression expansion machine of FIG. It is a graph which shows the relationship between the crank angle and the air pressure in the main body cylinder at the time of expansion of the reciprocating compression inflator of FIG. It is a graph which shows the relationship between the crank angle and the hydraulic pressure required for a hydraulic cylinder at the time of compression of the return type compression expansion machine of FIG. It is a partial vertical sectional view which shows the other form of the balance piston of FIG.

A mode for carrying out the reciprocating compression / expansion machine according to the present invention will be described in detail with reference to FIGS. 1 to 7.

As shown in FIG. 1, the reciprocating compression / expander 1 includes a main body piston 3 that airtightly slides in the main body cylinder 2, and a crankshaft 5 that is connected to the main body piston 3 via a connecting rod 4 and rotates. Has. Further, during the compression stroke (during compression), the suction valve (first valve) 7 that sucks low-pressure air (compressible fluid) from the outside into the main body cylinder and the suction valve 7 are sucked in and the main body piston 3 operates. It has a discharge valve (second valve) 8 that discharges compressed air that has become high pressure to the outside through a high pressure air passage (high pressure passage) 9 described later.

During the expansion stroke (during expansion) of the reciprocating compressor 1, the discharge valve 8 is opened, and high-pressure compressed air flows from the outside through the high-pressure air passage 9 into the main body cylinder 2. On the other hand, the above-mentioned suction valve 7 is opened, flows in from the discharge valve 8, is expanded by the operation of the main body piston 3, and discharges the low-pressure air to the outside.

As shown in FIG. 2, an air spring 11 that always urges the suction valve 7 toward the valve closing side is arranged on the valve shaft 7a of the suction valve 7. Further, the hydraulic cylinder 12 is directly connected to the valve shaft 7a of the suction valve 7 via the air spring 11. That is, when the hydraulic cylinder 12 is flooded, the hydraulic cylinder 12 opens the suction valve 7 against the urging force of the air spring 11.

A hydraulic actuator 13 is arranged on the upstream side of the hydraulic cylinder 12, and the operation of the hydraulic actuator 13 is controlled by an electronic control valve 25. Further, the controller 20 electrically controls the operation of the electronic control valve 25. The electronic control valve 25 is supplied with oil from the inlet hydraulic main pipe 14 and discharged from the outlet hydraulic main pipe 15.

Similar to the suction valve 7 described above, the discharge valve 8 also has an air spring 11, a hydraulic cylinder 12, and the like arranged in this order toward the upstream side of the valve drive mechanism, and the suction valve 7 and the discharge valve 8 are controllers. It is operated independently of each other by the control of 20. That is, the suction valve 7 and the discharge valve 8 open and close independently of each other on the valve drive mechanism. However, in the program in the controller 20, both may be operated in relation to each other in some way.

As described above, the hydraulic cylinder 12 is connected to the valve shaft 7a of the suction valve 7 and the valve shaft 8a of the discharge valve 8, respectively, to directly open the suction valve 7 and the discharge valve 8, respectively. Therefore, the on-off valve operation of the suction valve 7 and the discharge valve 8 is performed extremely quickly and reliably as instructed by the controller 20. A hydraulically driven valve drive mechanism (first valve drive mechanism) is formed by the air spring 11, the hydraulic cylinder 12, the hydraulic actuator 13, the electronic control valve 25, and the controller 20.

The controller 20 includes a crank angle detection sensor (not shown) that detects the rotation angle of the crank shaft 5, and a compressed air tank internal pressure detection sensor (not shown) that detects the air pressure of compressed air in a high-pressure air passage 9, an external compressed air tank, or the like. Alternatively, an electric power detection sensor (not shown) that detects the rotational power of an external generator that is connected to the crank shaft 5 and is rotationally driven is electrically connected, and the controller 20 is connected to each parameter detected by these sensors. Based on this, the operation of the electronic control valve 25 described above is controlled, and the suction valve 7 and the discharge valve 8 of the reciprocating compressor 1 are opened and closed independently of each other via the hydraulic actuator 13 and the hydraulic cylinder 12.

As shown in FIG. 2, when the suction valve 7 or the discharge valve 8 of the reciprocating compression / expansion machine 1 is closed, the hydraulic cylinder 12 is not supplied with the oil pressure from the hydraulic actuator 13, so that the suction valve 7 or the discharge valve 8 is used. The valve is closed by the urging force of the air spring 11. When the controller 20 electrically sends an instruction to open the valve to the electronic control valve 25, the electronic control valve 25 operates the hydraulic actuator 13 by the hydraulic pressure supplied from the inlet hydraulic main pipe 14 to supply the hydraulic pressure to the hydraulic cylinder 12. Let me. As a result, the suction valve 7 or the discharge valve 8 is opened against the urging force of the air spring 11.

When the controller 20 electrically sends a valve closing instruction to the electronic control valve 25, the electronic control valve 25 operates the hydraulic actuator 13 to shut off the supply of the oil pressure to the hydraulic cylinder 12 and release the oil pressure. As a result, the suction valve 7 or the discharge valve 8 is closed by the urging force of the air spring 11. The flood pressure is discharged from the outlet hydraulic main pipe 15.

During the compression stroke of the reciprocating compressor 1, the controller 20 opens the suction valve 7 to suck in low-pressure air, and the main body piston 3 reciprocates via the crank shaft 5 by an external electric motor or the like. After the sucked air is adiabatically compressed to raise the pressure and temperature of the air in the main body cylinder 2, the discharge valve 8 is opened and the compressed air is discharged through the high pressure air passage 9 to the outside. Supply to a compressed air tank, etc. (not shown).

By doing so, for example, the surplus electric power can be once converted into compressed air energy and stored in an external compressed air tank or the like, and the rotational power of the external electric motor can be adjusted by the controller 20 on the valve drive mechanism side. It can also be done, and the electric control on the motor side can be simplified.

Further, during the expansion stroke of the reciprocating compression / expansion machine 1, the controller 20 opens the discharge valve 8 to allow high-pressure air to flow in from the outside through the high-pressure air passage 9, and operates the main body piston 3 by the air pressure. The inflowing air is adiabatically expanded to reduce the pressure and temperature of the air in the main body cylinder 2, and then the suction valve 7 is opened to discharge the air having the reduced pressure and temperature to the outside. At the same time, power can be generated by an external generator or the like that is connected to the clang shaft 5 and rotationally driven via the clang shaft 5 that is rotationally driven by the main body piston 3.

By doing so, for example, surplus electric power can be converted into compressed air energy, temporarily stored in an external compressed air tank or the like, and the pressure energy of the stored air can be regenerated as electric power when necessary. Then, the rotational power of the external generator can be adjusted by the controller 20 on the first valve drive mechanism side, and the electric control on the generator side can be simplified.

As shown in FIGS. 2 and 3, the reciprocating compression / expansion machine 1 has a circular flat plate on the valve shaft 8a between the valve umbrella portion 8b and the above-mentioned air spring 11 of the discharge valve 8 which is an umbrella type valve. A balanced piston (second valve drive mechanism, fluid pressure piston) 17 is arranged.

As shown in FIG. 3, the valve umbrella portion 8b side (third) of the discharge valve 8 of the balance piston cylinder (second valve drive mechanism, fluid pressure cylinder, high-pressure fluid communication passage) 18 in which the balance piston 17 slides inside. The 2 valve side) is fully opened in the high pressure air passage 9 extending from the discharge valve 8 to the outside, and the pressure (fluid pressure) P1 of the compressed air in the high pressure air passage 9 is on the valve umbrella portion 8b side of the balance piston 17. It covers the first piston surface 17a of the above.

Further, the balance piston cylinder 18 extends to the valve umbrella portion 8b side as it is without changing its inner diameter and continues to the high pressure air passage 9, thereby forming the first cylinder chamber 18a on the valve umbrella portion 8b side. .. Further, the balance piston cylinder is formed so as to extend toward the high pressure air passage 9 side without substantially changing its inner diameter.

That is, in the reciprocating compression / expansion machine 1, the balance piston cylinder 18 that slides the balance piston 17 inside is the high-pressure air that extends outward from the first cylinder chamber 18a and the discharge valve 8 via the balance piston cylinder 18. The discharge valve 8 is communicated with the road 9 and the outer diameter of the balance piston 17 on the valve umbrella portion 8b side or the inner diameter of the balance piston cylinder 18 on the valve umbrella portion 8b side is in the closed state of the discharge valve 8. It is formed to be substantially the same as the outer diameter of the exposed surface 8c exposed into the high-pressure air passage 9.

The operating force of the balance piston 17 is the pressure effective area S2 on which the exposed surface 8c on the high pressure air passage 9 side applied to the discharge valve 8 effectively receives the air pressure in the closed state, and the valve umbrella portion 8b side of the balance piston 17. The first piston surface 17a is affected by the ratio with the atmospheric pressure effective area S3 that effectively receives air pressure.

However, in the reciprocating compression expander 1, although the compressed air in the high-pressure air passage 9 is a compressible fluid, the high-pressure air passage 9 covering the first piston surface 17a of the balance piston 17 as described above. Since the pressure of the compressed air inside is formed so as not to be depressurized as much as possible, the pressing force of the compressed air on the high-pressure air passage 9 side applied to the discharge valve 8 and the pressing force of the compressed air pressure P2 are applied to the first piston surface 17a of the balance piston 17. The pressing pressure due to the pressure P3 of the compressed air is almost canceled, and the pressure of the compressed air in the high-pressure air passage 9 is less affected by the valve opening operation of the discharge valve 8 during both compression and expansion. There is.

That is, in all the operating states of the reciprocating compression / expansion machine 1, it is not necessary to particularly increase the pushing force of the hydraulic cylinder 12 with respect to the discharge valve 8 toward the valve opening side. Further, it is necessary to reliably close the discharge valve 8 when the air pressure in the main body cylinder 2 is low due to the pressing force of the compressed air pressure P3 applied to the first piston surface 17a of the balance piston 17. It is also possible to weaken the high spring force of the air spring 11.

On the other hand, between the air spring 11 side (anti-second valve side) of the balance piston cylinder 18, that is, the second cylinder chamber 18b on the side opposite to the first piston chamber 18a described above, and the inside of the main body cylinder 2. A pressure supply path (cylinder communication path) 19 is provided, and the second cylinder chamber 18b of the balance piston cylinder 18 and the inside of the main body cylinder 2 are communicated with each other via the pressure supply path 19.

That is, the compressed air in the main body cylinder 2 is supplied to the second cylinder chamber 18b of the balance piston cylinder 18, which is on the air spring 11 side of the balance piston 17, that is, on the side opposite to the first piston surface 17a described above. A pressure P4 close to the pressure (fluid pressure) P1 of the compressed air in the main body cylinder 2 is applied to the second piston surface 17b.

Therefore, the pressing force due to the pressure of the compressed air applied to the second piston surface 17b of the balance piston 17 and the pressing force due to the pressure of the compressed air applied to the discharge valve 8 on the main body cylinder 2 side are appropriately offset, and during compression. Alternatively, it is less likely to be affected by the pressure of the compressed air in the main body cylinder 2 in the valve opening operation of the discharge valve 8 at any time of expansion.

The pressure P4 in the second cylinder chamber 18b of the balance piston cylinder 18 appropriately changes according to the fluctuation of the pressure P1 of the compressed air on the main body cylinder 2 side applied to the discharge valve 8. That is, in all the operating states of the reciprocating compression / expansion machine 1, it is not necessary to particularly increase the pushing force of the hydraulic cylinder 12 with respect to the discharge valve 8 toward the valve opening side.

Further, since the air as the compressed inflatable material of the reciprocating type compression / expansion machine 1 is a compressible fluid, it is affected by the cross-sectional area, length, shape, etc. of the pressure supply path 19 and is applied to the discharge valve 8. The pressure P1 of the compressed air on the main body cylinder 2 side of the reciprocating compression expander 1 and the pressure P4 in the second cylinder chamber 18b of the balance piston cylinder 18 are not necessarily the same in all operating states of the reciprocating compression expander 1. It is not always the case.

Further, an effective atmospheric pressure area S1 in which the end surface of the valve umbrella portion 8b of the discharge valve 8 on the main body cylinder 2 side effectively receives air pressure, and an effective atmospheric pressure area S4 in which the second piston surface 17b of the balance piston 17 effectively receives air pressure. The influence of the hydraulic cylinder 12 on the pushing force of the discharge valve 8 differs depending on the ratio and the like.

FIG. 4 is a graph showing the relationship between the crank angle during compression of the reciprocating compression / expander 1 and the air pressure in the main body cylinder 2, and FIG. 5 shows the crank at the time of expansion of the reciprocating compression / expansion machine 1. It is a graph which shows the relationship between the angle and the air pressure in a main body cylinder 2. As shown in FIGS. 4 and 5, the pressure P1 of the compressed air in the main body cylinder 2 of the reciprocating compression expander 1 varies greatly depending on the crank angle, but the discharge valve 8 is opened during both compression and expansion. It is sometimes shown that the pressure is almost maximum.

In FIG. 6, the solid line shows the relationship between the crank angle in the conventional reciprocating compression / expander and the operating pressure of the hydraulic cylinder required when the discharge valve is opened, and the broken line shows the relationship in the main reciprocating compression / expansion machine 1. The relationship between the crank angle and the operating pressure of the hydraulic cylinder 12 required when the discharge valve 8 is opened is shown, and the two-dot chain line shows the on-off valve state of the discharge valve 8 with respect to the crank angle.

As shown in FIG. 6, in the reciprocating compression / expansion machine 1, the operating pressure of the hydraulic cylinder 12 required when the discharge valve 8 is opened is significantly lower than that of the conventional reciprocating compression / expansion machine. It is close to the operating pressure of the hydraulic cylinder 12 after the valve is opened.

As shown in FIG. 7, for example, in order to change the ratio of the effective atmospheric pressure area of the first piston surface 27a on the valve umbrella portion side (second valve side) of the balance piston 27 and the second piston surface 27b on the air spring side. , The stepped balance piston 27 can also be used. Thereby, the above-mentioned effective atmospheric pressure areas S3 to S4 can be changed to adjust the operating pressure required for the hydraulic cylinder 12 by the reciprocating compression / expansion machine 1.

As described above, the reciprocating compressor 1 opens the suction valve 7 for sucking low-pressure compressed air from the outside into the main body cylinder 2, and opens the valve and sucks the compressed air from the main body piston 7. A discharge valve 8 that discharges compressed air compressed by the operation of 3 to a high pressure air passage 9, or a discharge valve that opens and allows high-pressure compressed air to flow into the main body cylinder 2 from the high pressure air passage 9. 8 and the suction valve 7 that opens and discharges the compressed air that flows in from the discharge valve 8 and is expanded by the operation of the main body piston 3 to the outside, and the hydraulic pressure that operates the suction valve 7 and the discharge valve 8. Since it is provided with drive or electric valve drive mechanisms 12, 13, 20, 25, and a balance piston 17 and a balance piston cylinder 18 that operate the discharge valve 8 by the pressure of compressed air, the size of the device is eliminated and the device is closed. The discharge valve 8 can be easily opened with a low pushing force by a simple mechanism against the strong spring force of the air spring 11 for valve and according to the load of the reciprocating compressor 1. ..

The reciprocating compression / expansion machine 1 described above is merely an example, and various modifications can be made based on the gist of the present invention, and these are not excluded from the scope of the present invention.

1 Reciprocating compression expander 2 Main body cylinder 3 Main body piston 4 Connecting rod 5 Crankshaft 7 Suction valve (1st valve)
7a Valve shaft 8 Discharge valve (second valve)
8a Valve shaft 8b Valve umbrella 8c Exposed surface 9 High pressure air passage (high pressure passage)
11 Air spring 12 Hydraulic cylinder (first valve drive mechanism)
13 Hydraulic actuator (first valve drive mechanism)
14 Inlet hydraulic main pipe 15 Outlet hydraulic main pipe 17 Balance piston (second valve drive mechanism, fluid pressure piston)
17a First piston surface 17b Second piston surface 18 Balanced piston cylinder (second valve drive mechanism, fluid pressure cylinder, high-pressure fluid communication passage)
18a 1st cylinder chamber 18b 2nd cylinder chamber 19 Pressure supply path (cylinder communication passage)
20 controller (first valve drive mechanism)
25 Electronically controlled valve (first valve drive mechanism)
27 Stepped balance piston (second valve drive mechanism, fluid pressure piston)
27a 1st piston surface 27b 2nd piston surface P1, P2, P3, P4 Pressure (fluid pressure)
S1, S2, S3, S4 Atmospheric pressure effective area

Claims (3)

A main body piston (3) that slides in the main body cylinder (2), a crank shaft (5) that is connected to the main body piston and rotates, and a valve is opened to allow low-pressure compressive fluid to flow from the low-pressure path into the main body cylinder. The first valve (7) that sucks into the valve and the second valve (8) that opens and discharges the compressible fluid that is sucked from the first valve and compressed by the operation of the main body piston to a high pressure. ) Or, the second valve (8), which is opened to allow high-pressure compressive fluid to flow into the main body cylinder from the high-pressure path, and the valve is opened to flow in from the second valve and expand by the operation of the main body piston. A first valve (7) that discharges the compressible fluid that has become low pressure to a low pressure path, and a hydraulically driven or electric first valve driving mechanism (12,) that operates the first valve and the second valve. 13, 20, 25) and the fluid that operates the second valve by applying the fluid pressure of the compressible fluid to the first and second piston surfaces (17a, 17b) on both sides connected to the second valve. A reciprocating compression / expander equipped with a pressure piston (17). A main body piston (3) that slides in the main body cylinder (2), a crank shaft (5) that is connected to the main body piston and rotates, and a valve is opened to allow a low-pressure compressive fluid to flow from the low-pressure path into the main body cylinder. The first valve (7) that sucks into the valve and the second valve (8) that opens and discharges the compressible fluid that is sucked from the first valve and compressed by the operation of the main body piston to a high pressure. ) Or, the second valve (8), which is opened to allow high-pressure compressive fluid to flow into the main body cylinder from the high-pressure path, and the valve is opened to flow in from the second valve and expand by the operation of the main body piston. A first valve (7) that discharges the compressible fluid that has become low pressure to a low pressure path, and a hydraulically driven or electric first valve driving mechanism (12,) that operates the first valve and the second valve. 13, 20, 25) and the fluid pressure piston (17) that is connected to the second valve and operates the second valve by applying the fluid pressure of the compressible fluid to the piston surfaces (17a, 17b). The fluid pressure piston is a reciprocating compression expander characterized in that the fluid pressure of the compressible fluid in the main body cylinder is applied to the second piston surface (17b) on the opposite side of the second valve (8). .. A main body piston (3) that slides in the main body cylinder (2), a crank shaft (5) that is connected to the main body piston and rotates, and a valve is opened to allow a low-pressure compressive fluid to flow from the low-pressure path into the main body cylinder. The first valve (7) that sucks into the valve and the second valve (8) that opens and discharges the compressible fluid that is sucked from the first valve and compressed by the operation of the main body piston to a high pressure. ) Or, a second valve that opens and allows high-pressure compressive fluid to flow into the main body cylinder from the high-pressure path, and a second valve that opens and flows in from the second valve and is expanded by the operation of the main body piston to reduce the pressure. The first valve (7) for discharging the compressible fluid to the low pressure path, and the first hydraulically driven or electric valve driving mechanism (12, 13, 20) for operating the first valve and the second valve. , 25) and a fluid pressure piston (17) that operates the second valve by applying the fluid pressure of the compressible fluid to the piston surfaces (17a, 17b) connected to the second valve. The fluid pressure cylinder (18) for sliding the fluid pressure piston inside further includes a cylinder communication passage (19) for communicating the second cylinder chamber (18b) on the second valve side and the inside of the main body cylinder. A reciprocating compression / expansion machine characterized by this.

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