JPH11237129A - Refrigerating system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To utilize the expansion energy of an expansion machine effectively by a method wherein a heat exchanger is provided on the way of a pipeline communicating the exhaust port of a compressor with the inflow port of the expansion machine. SOLUTION: When a compression piston 3 has passed an upper dead point and is shifted to a lower dead point, the inside of a compression cylinder 2 is evacuated whereby a suction valve 4 is opened by an outside pressure and the outside air is sucked into the compression cylinder 2. Next, when the compression piston 3 has passed the lower dead point and is shifted to the upper dead point, the pressure in the compression cylinder 2 is increased and the suction valve 4 is closed whereby the outside air, sucked into the compression cylinder 2, is compressed by the compression piston 3 through adiabatic compression. When the outside air is compressed through adiabatic compression, the outside air becomes high-temperature compressed air. Subsequently, when the compression piston 3 has arrived at the vicinity of the upper dead point, an exhaust valve 7 is opened by the pressure of the compressed air whereby the high-temperature compressed air is sent into a heat exchanger 5 through a pipeline 6. Heat exchange between the high-temperature compressed air, sent from the compressor 1 through the pipeline 6, and cooling water is effected in the heat exchanger 5 whereby the high-temperature compressed air is cooled to a temperature near a normal temperature through primary cooling.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigeration system using air as a refrigerant.

[0002]

2. Description of the Related Art In recent years, the deterioration of the environment surrounding the earth, such as ozone depletion and global warming, which are affected by CFCs, has become a serious problem, and an environment-friendly refrigeration system that does not use CFCs has been required. As one of the flows, the development of a clean and safe refrigeration system using air in the natural world as a refrigerant is progressing.

[0003] Generally, in a refrigeration system using air as a refrigerant, outside air is sucked and compressed by a compressor, and the compressed and high-temperature air is guided to a heat exchanger and cooled to near normal temperature, and this is used as an expander. The temperature of the air is reduced to a low temperature of minus several tens of degrees, and the cold air is led to a freezing room to absorb the heat of the object and freeze.

[0004]

By the way, in the conventional refrigeration system, the compressor and the expander are driven by separate drive systems, respectively. Therefore, a power source for driving the compressor and a power for driving the expander are provided. Each required a source. Therefore, there has been a problem that power consumption is high, running costs are high, and uneconomical.

Accordingly, an object of the present invention is to provide an economical refrigeration system by effectively utilizing the expansion energy of an expander.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention operates a compressor in which a compression piston is reciprocally mounted in a compression cylinder, and a drive motor which constantly operates. And a crank device in which the piston rod of the compression piston of the compressor is connected to a crank pin that is taken out by reciprocating motion, and an expansion cylinder is arranged coaxially with the compression cylinder of the compressor, and the expansion piston is reciprocated in the expansion cylinder. An expander movably mounted, the expansion piston having a piston rod of the expansion piston connected to a piston lot of the compression piston such that the expansion piston reciprocates at a predetermined phase difference from the compression piston of the compressor; and A cooling system including an exhaust port and a heat exchanger provided in a pipe connecting the inflow port of the expander. The system.

Further, the present invention provides a compressor having a compression cylinder reciprocally mounted in a compression cylinder, and a crank having a piston rod of the compression piston of the compressor connected to a crank pin which is reciprocated by a cell motor only at the time of starting. A device and an expansion cylinder are arranged coaxially with a compression cylinder of the compressor, and an expansion piston is mounted in the expansion cylinder so as to be able to reciprocate. The expansion piston reciprocates with a compression piston of the compressor at a predetermined phase difference. An expander having a piston rod of the expansion piston connected to a piston lot of the compression piston so as to move;
A refrigerating system includes a heat exchanger provided in a pipe connecting the compressor and the expander, and an inlet pipe for introducing external compressed air connected in the pipe heat exchanger.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

1 and 2, reference numeral 1 denotes a compressor, in which a compression piston 3 is reciprocably mounted in a compression cylinder 2, and an intake valve 4 and a suction valve 4 for controlling the intake of outside air to the head of the compression cylinder 2. An exhaust valve 7 for controlling the transmission of compressed air adiabatically compressed in the compression cylinder 2 to the heat exchanger 5 through the pipe 6 is provided. The intake valve 4 and the exhaust valve 7 are automatic valves that are pushed open by the outside air pressure and the compressed air pressure.

[0010] A piston rod 8 projects from the compression piston 3 of the compressor 1 to the left in the figure, and the piston rod 8 is connected to a drive motor 10 via a crank device 9. Accordingly, the compression piston 3 reciprocates between the top dead center and the bottom dead center via the crank device 9 and the piston rod 8.

The compressor 1 sucks and compresses outside air and sends it to the heat exchanger 5 by reciprocating the compression piston 3 between the top dead center and the bottom dead center as described above. I have. That is, when the compression piston 3 moves to the bottom dead center after passing the top dead center, the pressure in the compression cylinder 2 is reduced, so that the intake valve 4 is opened at the outside pressure and the outside air is sucked into the compression cylinder 2. Next, when the compression piston 3 moves to the top dead center after passing the bottom dead center, the pressure in the compression cylinder 2 is increased, so that the intake valve 4 is closed and the compression cylinder 2 is closed.
The outside air sucked inside is adiabatically compressed by the compression piston 3.
When the outside air is adiabatically compressed, the outside air becomes hot compressed air.
Next, when the compression piston 3 reaches the vicinity of the top dead center, the exhaust valve 7 is opened by the compressed air pressure, and the high-temperature compressed air is sent to the heat exchanger 5 through the pipe 6.

In the heat exchanger 5, cooling water is circulated between, for example, a cooling tower (not shown), and exchanges heat between the high-temperature compressed air sent from the compressor 1 through the pipe 6 with the cooling water. The primary cooling to near normal temperature.

The crank device 9 converts the rotational motion of the drive motor 10 into a linear reciprocating motion of the compression piston 3 of the compressor 1. As shown in FIG. A crank main shaft 13 rotatably supported via a drive motor 10, a crank pin 14 connected to the piston rod 8 of the compressor 1, and an interposition between the main shaft 13 and the crank pin 14. The planetary mechanism 15 is fixedly provided on the crankcase 11 and is arranged concentrically with the center of rotation of the main shaft 13. A planetary member 17, for example, composed of a planetary gear that rolls along the inner periphery of the sun member 16, and the outer diameter of the Is set to 1/2 of the inner diameter, the rotational center of the planetary member 17, the crank pin 14 bearing 18
A counterbalancer 19 is formed integrally with the shaft end of the crank pin 14 so as to rotate as a rotational inertia force.
One end of a piston rod 8 of the compressor 1 is rotatably supported via a bearing 20 at a contact point between the outer peripheral pitch of the planetary member 17 and the axis of the compression cylinder 2 on the side surface of the piston.

As described above, the crank device 9 sets the outer diameter of the planet member 17 of the planetary mechanism 15 to half of the inner diameter of the sun member 16 and sets the outer peripheral pitch of the planet member 17 to a point corresponding to the outer peripheral pitch. By connecting the one piston rod 8, the distance from the rotation center of the main shaft 13 to the rotation center of the crankpin 14 is equal to the distance from the rotation center of the crankpin 14 to the connection point of the piston rod 8. The connection point moves along with the rotation of the planet member 17,
Move on a straight line passing through the center of rotation of the compressor 1 so that the piston rod 8 of the compression piston 3 of the compressor 1 can be reciprocated linearly with almost no swing. When the piston lot 8 reciprocates linearly without swinging, the compression piston 3 hardly receives a lateral force in the radial direction, so that so-called piston slap hardly occurs and vibration, noise, cavitation, wear loss, etc. Is greatly reduced.

The compressed air cooled to near normal temperature by the heat exchanger 5 is sent to an expander 22 through a pipe 21.

The expander 22 has an expansion piston 24 reciprocally mounted in an expansion cylinder 23 disposed coaxially with the compression cylinder 2 of the compressor 1 and a heat exchanger mounted on the head of the expansion cylinder 23. An inflow valve 25 for controlling the inflow of compressed air from the cylinder 5 and an outflow valve 27 for controlling the sending of low-temperature air adiabatically expanded in the expansion cylinder 23 to the chamber 26 are provided. The inflow valve 25 and the outflow valve 27 are opened and closed in a timely manner via a valve mechanism 28 as the drive motor 10 operates. The valve mechanism 28 is provided with rocker arms 29 and 30 so as to be swingable. One end of each of the rocker arms 29 and 30 is connected to the main shaft 13 of the crank device 9 with the operation of the drive motor 10.
A cam 37 and 38 provided on cam shafts 35 and 36 rotated via a timing pulley 31, a timing belt 32, and timing pulleys 33 and 34 are brought into contact with each other. The camshafts 35 and 36 are rotated by the operation of the drive motor 10, and the rockers 29 and 30 are rocked by the cams 37 and 38 so that the rocker arms 29 and 30 flow inward. The valve 25 and the outflow valve 27 are opened and closed in a timely manner.

The expansion piston 24 of the expander 22 has
A piston rod 39 protrudes to the right side in the figure, and the piston rod 39 and the piston rod 8 of the compression piston 3 move so that the compression piston 3 of the compressor 1 and the expansion piston 24 of the expander 22 reciprocate at a predetermined phase difference. Pin 4
When the compression piston 3 of the compressor 1 is reciprocated between the top dead center and the bottom dead center with the operation of the drive motor 10, the expansion piston 24 is synchronized with the compression piston 3. It reciprocates between a top dead center and a bottom dead center with a predetermined phase difference. Note that the piston rod 8 and the piston rod 39 can be composed of an integral continuous rod in principle. The reciprocating motion of the piston 3 and the expansion piston 24 can be made smooth.

The expander 22 adiabatically expands the compressed air introduced from the heat exchanger 5 by causing the expansion piston 24 to reciprocate between the top dead center and the bottom dead center as described above, thereby expanding the chamber 27. To be sent to That is, the inflow valve 25 is opened only for a short time when the expansion piston 24 starts to shift from the top dead center to the bottom dead center, and the compressed air primary cooled by the heat exchanger 5 flows into the expansion cylinder 23 through the pipe 26. Let it. Next, the compressed air that has flowed into the expansion cylinder 23 is adiabatically expanded to near atmospheric pressure while the expansion piston 24 reaches the bottom dead center. When the compressed air is adiabatically expanded to near the atmospheric pressure, the temperature of the compressed air decreases and becomes minus several tens of degrees of cool air. Next, the outflow valve 27 is opened while the expansion piston 24 moves from the bottom dead center to the top dead center, and the cool air in the expansion cylinder 23 is sent to the chamber 26.

The expander 22 includes an expansion cylinder 2.
When the compressed air is adiabatically expanded within the expansion piston 3, the expansion piston 24
Compression piston 3 of compressor 1
To assist the compression process movement. The compression process of the compression piston 3 of the compressor 1 and the expansion stroke of the expansion piston 24 of the expander 22 completely match, so that the main drive energy of the compression piston 3 is supplied from the drive motor 10, but the expansion piston A part of the expansion energy of the compressed air received by 24 is recovered and reused as the compression energy of the compression piston 3.

The cool air that has been secondarily cooled by the expander 22 and sent to the chamber 26 is temporarily retained in the chamber 26, and then sent to the freezing chamber to absorb the heat of the target object. It is intended to be frozen.

In this embodiment, the compression cylinder 2 of the compressor 1 and the expansion cylinder 23 of the expander 22 are coaxially arranged, and the piston rod 8 of the compression piston 3 of the compressor 1 is connected to the drive motor 10 via the crank device 9. By connecting the piston rod 39 of the expansion piston 24 of the expander 22 to the piston rod 8 of the compression piston 3 of the compressor 1, the compression piston 3 of the compressor 1 and the expansion piston 24 of the expander 22 are coaxial. Can be reciprocated synchronously with a predetermined phase difference.
And the expander 22 can be driven in conjunction with each other, and the adiabatic expansion energy of the expander 22 assists the reciprocating motion of the compression piston 3 of the compressor 1 to effectively use the adiabatic expansion energy as the adiabatic compression energy. it can.

FIG. 3 shows another embodiment of the present invention, which is driven by using external compressed air.

In this embodiment, an inlet pipe 41 for introducing external compressed air from a compressed air supply means (not shown) is connected in the middle of the pipe 21 and the main shaft 1 of the crank device 9 is connected.
3 is connected to a starter motor 42, and other configurations are the same as those of the embodiment shown in FIGS.

In this embodiment, the starter 42
And the external compressed air is introduced from the introduction pipe 41 to the pipe 21, whereby the compression piston 3 of the compressor 1 is moved between the top dead center and the bottom dead center via the crank device 9 with the operation of the starter motor 41. In addition to the reciprocating motion, the reciprocating motion of the compression piston 3 of the compressor 1 and the expansion cylinder 23 of the expander 22 through the pipe 21
Expansion piston 2 using external compressed air introduced into
4 is reciprocated between a top dead center and a bottom dead center, thereby freezing the cold air that has cooled the outside air to minus several tens degrees as in the embodiment shown in FIGS. They are sent to the room. In such an operation, even if the starter 42 is stopped after the system starts operating, the expansion piston 24 of the expander 22 is already reciprocated at high speed by the external compressed air to adiabatically expand the compressed air. Therefore, the compression piston 3 of the compressor 1 is continuously reciprocated by utilizing the energy of the reciprocating movement of the expansion piston 24 of the expander 22 and the energy of the adiabatic expansion. It becomes possible to drive only by using.

According to this embodiment, the compressor 1 and the expander 22 can be driven in conjunction with one power source of external compressed air, and the adiabatic expansion energy of the expander 22 is reduced by the adiabatic compression energy of the compressor 1. Can be used effectively.

In FIG. 3, the pipe 2 downstream of the heat exchanger 5
Although the introduction pipe 40 is connected to 1, even when the introduction pipe 40 is connected to the pipe 6 on the upstream side of the heat exchanger 5, the same operation and effect as in the case of FIG. 3 can be obtained.

Both of the above-described embodiments merely show preferred specific examples of the present invention, and the present invention is not limited to these embodiments, and various designs are possible within the technical idea thereof. Changes are possible.

[0028]

As described above, the present invention does not require two power sources such as a conventional drive source for driving a compressor and a drive source for driving an expander.
Since the compressor and the expander can be driven in conjunction with one power source, and the adiabatic expansion energy of the compressed air received by the expansion piston of the expander can be recovered and reused as the adiabatic compression energy of the compression piston of the compressor, thereby improving the efficiency. Compared with the conventional case, the power consumption can be significantly reduced, the running cost can be reduced, and an economic refrigeration system can be provided.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of a refrigeration system of the present invention.

FIG. 2 is a cross-sectional view of a main part of FIG.

FIG. 3 is a longitudinal sectional view of a main part of another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 Compression cylinder 3 Compression piston 4 Intake valve 5 Heat exchanger 6 Piping 7 Exhaust valve 8 Piston rod 9 Crank device 10 Drive motor 13 Main shaft 14 Crank pin 15 Planetary mechanism 22 Expander 23 Expansion cylinder 24 Expansion piston 25 Inflow valve 26 Chamber 27 Outflow valve 28 Valve train 39 Piston rod 41 Introducing pipe 42 Cell motor

Claims (2)

[Claims] 1. A compressor in which a compression piston is reciprocally mounted in a compression cylinder and a crank pin which is always operated by a drive motor and converts the rotational motion of the drive motor into reciprocal motion to take out the compressor. A crank device connected to a piston rod of a piston; an expansion cylinder arranged coaxially with a compression cylinder of the compressor; an expansion piston is reciprocally mounted in the expansion cylinder; An expander in which a piston rod of the expansion piston is connected to a piston lot of the compression piston so as to reciprocate with a piston at a predetermined phase difference; and in the middle of a pipe connecting an exhaust port of the compressor and an inflow port of the expander. A refrigeration system comprising: a heat exchanger provided in the refrigeration system. 2. A compressor in which a compression piston is reciprocally mounted in a compression cylinder, a crank device in which a piston rod of the compression piston of the compressor is connected to a crank pin reciprocated by a cell motor only at the time of starting, An expansion cylinder is arranged coaxially with the compression cylinder of the compressor, and an expansion piston is mounted in the expansion cylinder so as to be able to reciprocate.The expansion piston reciprocates with the compression piston of the compressor with a predetermined phase difference. An expander that connects a piston rod of the expansion piston to a piston lot of the compression piston; a heat exchanger provided in a pipe connecting the compressor and the expander; and a heat exchanger connected in the pipe in a heat exchanger. A refrigeration system comprising: an inlet pipe for introducing external compressed air.