JP2002155869A - Refrigerating cycle device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid collision of a piston with a cylinder without largely reducing output refrigerating capacity in a refrigerating cycle device 110 using a linear compressor 1. SOLUTION: This refrigerating cycle device is provided with a position detecting sensor 23 to detect a position of the piston. When the detected position of the piston gets closer to a cylinder head over a predetermined limit position, it is determined that the piston has possibility of colliding with the cylinder, and at least one of heat exchange quantities at heat exchangers 21 and 22 and a valve opening of an expansion valve 4 is controlled in such a way that top clearance is enlarged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigeration cycle apparatus, and more particularly, to a refrigeration cycle apparatus for compressing gaseous refrigerant.
The present invention relates to a refrigeration cycle apparatus using a linear compressor that reciprocates a piston in a cylinder by a linear motor.

[0002]

2. Description of the Related Art Conventionally, as means for compressing a gaseous refrigerant (hereinafter also referred to as refrigerant gas), there has been a refrigeration cycle apparatus using a linear compressor which compresses refrigerant gas by reciprocating a piston in a cylinder by a linear motor. Are known. As a specific application example of the refrigeration cycle device,
An air conditioner that keeps the temperature within room temperature comfortably, and a refrigerator that keeps the inside of the refrigerator at a proper low temperature state can be considered.

FIG. 5 is a view for explaining an air conditioner using a conventional refrigeration cycle apparatus. This air conditioner (refrigeration cycle device) 100 is used indoors, for example, in a room 10.
And an outdoor unit 100b disposed outside to dispose of heat to the outside air or absorb heat from the outside air.

[0004] The indoor unit 100a is an indoor heat exchanger (load-side heat exchanger) 8 for exchanging heat between indoor air and a refrigerant.
And a room temperature detector 9 for detecting a room temperature as a temperature around the indoor heat exchanger 8.

The outdoor unit 100b includes a heat source side heat exchanger (outdoor heat exchanger) 3 for exchanging heat between the outside air and the refrigerant, and a heat exchanger 3 between the outdoor heat exchanger 3 and the indoor heat exchanger 8. A linear compressor 1 is provided in a part of the gas side flow passage 11 through which the refrigerant gas flows, and compresses the low-pressure refrigerant gas to generate a high-pressure refrigerant gas. Further, the outdoor unit 100b is disposed in a part of the liquid side flow passage 14 between the outdoor heat exchanger 3 and the indoor heat exchanger 8 through which the liquid refrigerant (hereinafter, also referred to as refrigerant liquid) flows. An expansion valve (throttle valve) 4 for adjusting the cross-sectional area of the passage, and a direction in which the refrigerant gas flows in the gas side flow passage 11 and a direction in which the refrigerant liquid flows in the liquid side flow passage 12, for heating the room. It has a four-way valve 2 for switching between a cycle and a cooling cycle for cooling the room.

Here, in the above-mentioned heating cycle, the indoor heat exchanger 8 condenses the refrigerant gas supplied from the gas side flow passage 11 to release the condensed heat into the room and obtains the refrigerant gas by condensing the refrigerant gas. The refrigerant liquid is discharged into the liquid side flow passage 12, while in the cooling cycle, the refrigerant liquid from the liquid side flow passage 12 is vaporized to remove heat of vaporization from indoor air and to be obtained by vaporization of the refrigerant liquid. The refrigerant gas is discharged to the gas side flow passage 11.

In the above-mentioned heating cycle, the outdoor heat exchanger 3 vaporizes the refrigerant liquid from the liquid side flow passage 12 to remove the vaporization heat from the outside air, and converts the refrigerant gas obtained by the vaporization of the refrigerant liquid into gas. Discharged into the side flow passage 11,
In the cooling cycle, the refrigerant gas supplied from the gas side flow passage 11 is condensed to release heat of condensation to the atmosphere, and the refrigerant liquid obtained by condensing the refrigerant gas is discharged to the liquid side flow passage 12.

In the heating cycle, the four-way valve 2 sends high-pressure refrigerant gas from the linear compressor 1 to the indoor heat exchanger 8 through the gas-side flow passage 11, and sends the high-pressure refrigerant gas from the outdoor heat exchanger 3 to the gas-side flow. The low-pressure refrigerant gas is sent to the linear compressor 1 via the passage 11, while in the cooling cycle, the high-pressure refrigerant gas is sent from the linear compressor 1 to the outdoor heat exchanger 3 via the gas side flow passage 11, and The connection state between the gas discharge pipe 1a and the gas suction pipe 1b of the linear compressor 1 and the gas side flow path 11 is switched so that the low-pressure refrigerant gas is sent from the heat exchanger 8 to the linear compressor 1 via the gas side flow path.

Furthermore, the gas side flow passage 1 of the outdoor unit 100b
1, a pressure detector 13 for detecting the pressure of the refrigerant gas flowing through the gas side flow passage 11 is attached, and a superheat degree detector 14 for detecting the degree of superheat of the refrigerant gas is provided to the suction pipe 1b of the linear compressor 1. Is attached. An accumulator 5 is provided in the suction pipe 1b of the linear compressor 1.
The refrigerant liquid in the gas side flow passage 11 is removed by the accumulator 5.

In the air conditioner 100, the outdoor heat exchanger 3, the indoor heat exchanger 8, the gas side flow passage 11 and the liquid side flow passage 12 therebetween, and the gas side flow passage 11 are arranged. The linear compressor 1, its discharge pipe 1a, the suction pipe 1b, and the four-way valve 2 form a circulation closed circuit of the refrigerant, and the refrigerant sealed in the circulation closed circuit is circulated by the linear compressor 1, so that the refrigerant is closed in the circulation closed circuit. A well-known heat pump cycle is formed.

Here, the amount of heat exchange in the outdoor heat exchanger 3 and the indoor heat exchanger 8 is adjusted by changing the air volume of a fan (not shown) provided in the outdoor unit 100b and the indoor unit 100a, respectively. It is common to do this. The expansion valve 4 adjusts the refrigerant circulation amount. Specifically, as the expansion valve 4, a throttle device such as an electromagnetic valve for restricting the flow rate of fluid is used. Further, the pressure detector 13 is installed in a portion of the gas side pipe 11 between the linear compressor 1 and the indoor heat exchanger 8, so that the low pressure side pressure during the cooling operation and the high pressure side pressure during the heating operation. Will be detected. The installation position of the pressure detector 13 is not limited to this part.
In, the high pressure side pressure during the cooling operation, the position to detect the low pressure side pressure during the heating operation, and in both the cooling operation and the cooling operation, the position to detect either the high pressure side or the low pressure side pressure, for example, linear Discharge pipe 1a of compressor 1
Or a part of the suction pipe 1b.

Also, the suction pipe 1b of the linear compressor 1
A superheat degree detector 14 is attached to a part of the linear compressor 1. The superheat degree detector 14 detects the superheat degree of the refrigerant gas as a temperature difference between the suction temperature of the linear compressor 1 and the suction saturation temperature. is there. The suction saturation temperature is a temperature at which both the refrigerant gas and the refrigerant liquid exist under the suction pressure. The suction saturation temperature may be the refrigerant saturation temperature of the heat source-side heat exchanger or the load-side heat exchanger that functions as an evaporator. In place of the superheat detector 14, a supercool detector (not shown) for detecting the supercool degree of the refrigerant gas is used.
May be used. In this case, the temperature difference between the discharge temperature of the linear compressor 1 and the temperature near the inlet of the expansion valve 4 is used as the degree of supercooling of the refrigerant gas.

The amount of heat exchange between the outdoor heat exchanger 3 and the indoor heat exchanger 8 or the degree of opening of the expansion valve 4 is usually such that the temperature of the room 10 is kept comfortable and the pressure and superheat of the refrigerant gas are maintained. Alternatively, control is performed so that the degree of supercooling is appropriately maintained.

The refrigerant may be any kind of refrigerant. For example, the refrigerant may be a single refrigerant, a mixed refrigerant (azeotropic mixed refrigerant, non-azeotropic mixed refrigerant), hydrogen, Freon, or the like.
An HFC refrigerant using carbon and a natural refrigerant can be used. Here, examples of the natural refrigerant include an HC (hydrocarbon) refrigerant and a CO ₂ refrigerant. The single refrigerant is a refrigerant composed of a single substance, for example, a refrigerant made of propane, carbon dioxide, or the like. This single refrigerant does not change temperature when evaporated under constant pressure conditions. An azeotropic mixed refrigerant is a refrigerant obtained by mixing a plurality of substances, and, like a single refrigerant, does not change its temperature when evaporated under a constant pressure condition. Further, the non-azeotropic mixed refrigerant is a refrigerant obtained by mixing a plurality of substances, but unlike a single refrigerant, changes in temperature when evaporating under a constant pressure condition.

In FIG. 1, reference numeral 20a denotes a joint member of a pipe constituting the gas side flow path 11, and reference numeral 20b denotes a joint member of a pipe constituting the liquid side flow path 12.

Next, the operation will be described. During the heating operation, a heating cycle in which the refrigerant flows in the direction indicated by the solid arrow A in FIG. 5 is formed.

That is, the low-pressure refrigerant gas sucked into the linear compressor 1 is compressed by the linear compressor 1 to become high-temperature and high-pressure vapor and discharged from the discharge pipe 1a. The high-temperature and high-pressure refrigerant gas discharged from the linear compressor 1 flows into the indoor heat exchanger 8 from the gas side flow passage 11 through the four-way valve 2.

During the heating operation, the indoor heat exchanger 8 functions as a condenser. In the indoor heat exchanger 8, the high-temperature and high-pressure refrigerant gas is condensed to generate heat of condensation. From the room 10. This makes room 1
Zero heating is performed. The refrigerant liquid generated by the condensation of the refrigerant gas is discharged to the liquid side flow passage 12 of the indoor heat exchanger 8. Further, the indoor heat exchanger 8 is connected to the liquid side flow passage 12.
The refrigerant liquid discharged to the outside flows into the outdoor heat exchanger 3 through the expansion valve 4 of the outdoor unit 100b.

During the heating operation, the outdoor heat exchanger 3 functions as an evaporator, so that the refrigerant liquid flowing into the outdoor heat exchanger 3 receives heat from outside air and evaporates. As a result, the refrigerant liquid becomes low-pressure refrigerant gas and is discharged to the gas side flow passage 11 of the outdoor heat exchanger 3. The low-pressure refrigerant gas discharged to the gas side flow passage 11 of the outdoor heat exchanger 3 passes through the four-way valve 2 and is further drawn into the linear compressor 1 through the suction pipe 1b to which the accumulator 5 is attached. In the accumulator 5, the refrigerant liquid flowing through the gas side flow passage 11 together with the low-pressure refrigerant gas is removed.

On the other hand, during the cooling operation, a cooling cycle in which the refrigerant flows in the direction indicated by the dotted arrow B in FIG. 5 is formed. That is, first, similarly to the time of the heating operation, the low-pressure refrigerant gas sucked into the linear compressor 1 is compressed by the linear compressor 1 to become high-pressure steam, and the discharge pipe 1 a
Is discharged from The high-pressure refrigerant gas discharged from the linear compressor 1 flows into the outdoor heat exchanger 3 from the gas-side flow path 11 through the four-way valve 2.

During the cooling operation, the outdoor heat exchanger 3 functions as a condenser, so that the high-pressure refrigerant gas is condensed into a refrigerant liquid in the outdoor heat exchanger 3. At this time, the heat of condensation is released to the outside air. The refrigerant liquid generated by the condensation of the refrigerant gas is discharged from the outdoor heat exchanger 3 to the liquid side flow passage 12. Further, the refrigerant liquid discharged from the outdoor heat exchanger 3 to the liquid side flow passage 12 flows into the indoor heat exchanger 8 through the expansion valve 4 of the outdoor unit 100b.

During the cooling operation, the indoor heat exchanger 8 functions as an evaporator, so that the refrigerant liquid flowing into the indoor heat exchanger 8 receives heat from indoor air and evaporates. Thereby, the room is cooled. Then, the low-pressure refrigerant gas generated by the evaporation of the refrigerant liquid is discharged from the indoor heat exchanger 8 to the gas side flow passage 11. The low-pressure refrigerant gas discharged from the indoor heat exchanger 8 to the gas side flow passage 11 passes through the four-way valve 2, and is further sucked into the linear compressor 1 through the suction pipe 1 b to which the accumulator 5 is attached. In the accumulator 5, the refrigerant liquid flowing through the gas side flow passage 11 together with the low-pressure refrigerant gas is removed.

Next, the linear compressor 1 constituting the outdoor unit 100b will be described in detail. FIG. 6 is a sectional view showing the structure of the linear compressor 1. The linear compressor 1 includes a cylinder portion 41a and a motor portion 41b arranged along a predetermined axis, a piston 42 disposed inside the cylinder portion 41a and slidably supported along the axis direction, and one end thereof. A piston rod 42a fixed to the back side of the piston 42, and a support spring (resonant spring) provided at the other end of the piston rod 42a
51.

A magnet 43 is attached to the piston rod 42a.
An electromagnet 44 composed of an outer yoke 44a and a stator coil 44b embedded in the outer yoke 44a
Is attached. This electromagnet 44 and magnet 4
The piston 42 reciprocates along its axial direction due to the electromagnetic force generated between the piston 42 and the spring 51 and the resonance force of the spring 51. In the linear compressor 1, the electromagnet 44 and the magnet 43 form a linear motor 52.

Further, the cylinder part 4 on the cylinder head side
1a, a cylinder upper inner surface 45, a piston compression surface,
A compression chamber 46, which is a closed space surrounded by the cylinder peripheral wall surface, is formed. On the cylinder inner surface 45,
One end of a gas-side suction pipe 1b for sucking low-pressure refrigerant gas from the gas-side flow passage 11 into the compression chamber 46 is open. One end of a discharge pipe 1a for discharging high-pressure refrigerant gas to the outside is open. A suction valve 49 and a discharge valve 50 for preventing the backflow of the refrigerant gas are attached to the suction pipe 1b and the discharge pipe 1a.

In the linear compressor 1, the piston 42 reciprocates in the axial direction by the intermittent supply of the drive current from the motor driver (not shown) to the linear motor 52, and the low-pressure refrigerant flows into the compression chamber 46. The suction of the gas, the compression of the refrigerant gas in the compression chamber 46, and the discharge of the compressed high-pressure refrigerant gas from the compression chamber 46 are repeatedly performed.

In the linear compressor 1 used in such a refrigeration cycle apparatus 100, there is a danger that the tip of the piston collides with the upper surface of the cylinder due to the structure, and the stroke of the piston (that is, from piston top dead center to piston bottom dead center). The degree of collision danger (collision danger) changes depending on the distance) and the load condition.

Therefore, as a control device for the linear compressor, the position of the piston is detected by a displacement sensor, the risk of collision is determined from the position information, and the linear motor supplied to the linear compressor 1 is supplied in accordance with the risk. A device that controls a drive current to avoid collision between a piston and a cylinder has been proposed (see Japanese Patent Application Laid-Open No. H11-324911).

FIG. 7 is a diagram for explaining the control device of the linear compressor described in the above publication. The linear compressor control device 70 outputs the output of the position sensor 23 provided in the linear compressor 1 (the position sensor 23).
Collision danger determining means 25 that determines the danger of collision, which is a possibility that the piston collides with the cylinder, based on the information indicating the relative distance between the piston and the cylinder measured in, and outputs collision danger information. A motor driver 72 for supplying a sine wave current, which is a drive current for the linear motor, to the linear compressor 1 based on the collision risk information.

The linear compressor control device 7
0 has a linear compressor control means 71 for controlling the motor driver 72 so that the amplitude and frequency of the sine wave current, which is the drive current supplied to the linear compressor 1, changes according to the collision risk information. . For example,
The linear compressor control means 71 controls the motor driver 72 such that if the collision risk increases, the stroke of the piston of the linear compressor 1 decreases due to the decrease in the amplitude of the sine wave current as the drive current.

Next, the operation will be described. A sine wave current is supplied to the linear compressor 1 from the motor driver 72 as a drive current for the linear motor, and the sine wave current drives the linear compressor 1.

At this time, the position sensor 23 measures the relative distance between the piston compression surface of the linear compressor 1 and the inner wall surface of the upper part of the cylinder.
, Information indicating the relative distance (relative distance information) is output to the collision risk determining means 25.

The collision risk determining means 25 determines the possibility of the piston colliding with the cylinder as a collision risk based on the relative distance information, and outputs information indicating the collision risk to the linear compressor control means 71. . Specifically, the collision risk determining means 25 determines whether the relative distance has become smaller than a preset limit distance,
Furthermore, the collision risk is derived according to how much the relative distance is smaller than the limit distance.

When the information indicating the risk of collision is input to the linear compressor control means 71, the motor driver 72 is controlled so that the stroke of the piston is changed by adjusting the amplitude of the drive current according to the risk of collision. Done. For example, by increasing the current amplitude value to be reduced as the collision risk increases,
The collision avoidance of the piston is more reliably performed.

[0035]

However, in such a conventional method for controlling a linear compressor, the driving power of the linear motor supplied to the linear compressor is reduced, so that the piston does not collide with the cylinder. Therefore, the stroke of the piston is reduced due to the reduction in the drive current. As a result, there is a problem that the linear compressor cannot exhibit the refrigeration capacity desired by the user.

Further, when the stroke of the piston is reduced, the center position of the reciprocating movement of the piston approaches the cylinder head side due to a change in the refrigerating cycle, so that the piston tends to collide with the cylinder.

The present invention has been made to solve such a problem, and when the risk of the piston colliding with the cylinder increases, the piston and the cylinder can be connected without reducing the driving capacity of the linear compressor. It is an object of the present invention to provide a refrigeration cycle device capable of reliably avoiding collision of the refrigeration cycle.

[0038]

A refrigeration cycle apparatus according to the present invention (claim 1) comprises a first heat exchanger, a second heat exchanger, and a refrigerant from the second heat exchanger to the first heat exchanger. One circulation pipe for sending the refrigerant to the heat exchanger, a second circulation pipe for sending the refrigerant from the first heat exchanger to the second heat exchanger, and a part of the first circulation pipe. , A cylinder and a piston forming a gas compression chamber, and a linear motor for reciprocating the piston. The gaseous refrigerant from the second heat exchanger side is sucked and compressed, and the compressed gaseous refrigerant is Refrigeration cycle comprising: a linear compressor that discharges water to a first heat exchanger side; and a throttle valve that is disposed in a part of the second flow pipe and that adjusts a cross-sectional area of the passage by its valve opening. In the device,
Position detecting means for detecting the position of the piston and outputting piston position information indicating the position; determining a risk of the piston colliding with the cylinder based on the piston position information; Collision risk determining means for outputting degree information, the amount of heat exchange in the first heat exchanger,
At least one of the heat exchange amount in the second heat exchanger and the valve opening of the throttle valve is set as a control target, and the gaseous refrigerant in the linear compressor is controlled according to the collision risk indicated by the collision risk information. And a system control means for controlling the control object so that the top clearance is widened by an increase in the pressure difference between the suction pressure and the discharge pressure.

According to a second aspect of the present invention, in the refrigeration cycle apparatus according to the first aspect, the collision risk determining means includes a piston position corresponding to a predetermined phase of the piston reciprocation based on the piston position information. However, when approaching the cylinder head side from a preset limit position, it is determined that there is a risk of the piston colliding with the cylinder.

According to a third aspect of the present invention, in the refrigeration cycle apparatus according to the first aspect, the collision risk determining means determines a piston position corresponding to a predetermined phase of the piston reciprocation based on the piston position information. It is determined in advance which of a plurality of danger determination areas is arranged from the cylinder head side to the opposite side along the reciprocating direction of the piston, and the piston position is determined. It is determined that the closer the included risk determination area is to the cylinder head, the higher the collision risk is.

According to a fourth aspect of the present invention, in the refrigeration cycle apparatus according to the first aspect, the position detecting means detects the position of the piston at predetermined time intervals and outputs the plurality of piston position information. The collision risk determining means determines a piston speed when the piston passes a predetermined determination position based on the plurality of piston position information, and determines the collision risk based on the piston speed. It is to be done.

According to a fifth aspect of the present invention, in the refrigeration cycle apparatus according to the first aspect, a top dead center of the piston is calculated based on the piston position information, and top dead center information indicating the top dead center is calculated. Output top dead center calculation means, the collision risk determination means receives the top dead center information, and when the top dead center of the piston approaches the cylinder head side from a preset limit position, It is determined that there is a risk of the piston colliding with the cylinder.

According to a sixth aspect of the present invention, in the refrigeration cycle apparatus according to the fifth aspect, the collision risk determining means sets the top dead center of the piston in advance based on the top dead center information. Further, it is determined which of the plurality of risk determination areas is arranged from the cylinder head side to the opposite side along the reciprocating direction of the piston, and the piston includes the top dead center. The collision risk is determined to be higher as the risk determination area is closer to the cylinder head.

According to a seventh aspect of the present invention, in the refrigeration cycle apparatus according to the first aspect, the system control means includes:
The control target is controlled based on the piston position information such that the top dead center of the piston is maintained at a predetermined position.

According to the present invention (claim 8), in the refrigeration cycle apparatus according to claim 1, the suction pressure of the linear compressor, the discharge pressure thereof, the pressure of the gaseous refrigerant sent to the first heat exchanger, and A pressure detector that detects a pressure value of at least one of the pressures of the gaseous refrigerant generated in the second heat exchanger as a setting target pressure and outputs detection pressure information indicating a detection value of the setting target pressure; , The pressure to be set
A pressure setter that sets a predetermined value based on the command signal and outputs set pressure information indicating a set value of the set target pressure; and a set value of the set target pressure based on the set pressure information and the detected pressure information. And a pressure controller that outputs information indicating the control amount to the control target so that the difference between the detected value and the detected value is small, and the system control unit includes:
The pressure setter is instructed by the command signal so that the set value of the setting target pressure becomes a value corresponding to the collision risk indicated by the collision risk information.

According to the present invention (claim 9), in the refrigeration cycle apparatus according to claim 1, the temperature of the refrigerant sucked into the linear compressor, the temperature of the refrigerant discharged from the linear compressor, the first heat exchanger. At least one of the temperature of the refrigerant in the second heat exchanger.
A temperature detector that detects the temperature value as one of the setting target temperatures and outputs detection temperature information indicating the detection value of the setting target temperature, and sets the setting target temperature to a predetermined value based on a command signal; A temperature setting device that outputs set temperature information indicating a set value of the set target temperature, and a difference value between the set value of the set target temperature and the detected value is reduced based on the set temperature information and the detected temperature information. A temperature controller that outputs information indicating the control amount of the control target, wherein the system control means controls the temperature setter to set the set target temperature to the collision danger degree information. Is instructed by the command signal so as to have a value corresponding to the degree of collision danger indicated by.

According to a tenth aspect of the present invention, in the refrigeration cycle apparatus according to the first aspect, the system control means avoids collision of the piston with the cylinder with respect to the controlled object based on the collision risk information. A first anti-collision operation system controller for outputting first control information indicating a first control amount for performing the operation, and a second anti-collision operation system controller for operating the linear compressor in an optimal state set in advance for the control target. A system controller for normal operation that outputs second control information indicating a second control amount, and a weighting process for receiving the first and second control information and weighting the first control amount and the second control amount Is performed such that the larger the collision risk indicated by the collision risk information is, the larger the weighting ratio for the first control amount is compared to the second control amount. And control amount determining means for outputting the total sum of the second control amounts as information indicating a third control amount for the control target, wherein the control target is controlled by the third control amount. It is.

According to the present invention (claim 11), in the refrigeration cycle apparatus according to claim 1, the system control means indicates a drive current of a linear motor supplied to the linear compressor, and the drive current indicates the collision risk information. Current control means for controlling to decrease in accordance with an increase in the collision risk; a heat exchange amount in the first heat exchanger and a second heat in accordance with the collision risk indicated by the collision risk information The first control that controls at least one of the heat exchange amount in the exchanger and the valve opening of the throttle valve, and the second control that controls the drive current of the linear motor. It was done.

[0049]

Embodiments of the present invention will be described below. (Embodiment 1) FIG. 1 is a block diagram for explaining a refrigeration cycle apparatus according to Embodiment 1 of the present invention. In the first embodiment, the refrigeration cycle device constitutes an air conditioner.

This refrigeration cycle apparatus 110 includes a linear compressor 1 having a position detector 23 for detecting the position of a piston and outputting piston position information Pi, a heat source side heat exchanger 21 for discharging and absorbing heat, and And a load-side heat exchanger 22 for cooling and heating the load.

Here, between the linear compressor 1 and the heat source side heat exchanger 21, a refrigerant gas passage 30 for flowing a refrigerant gas therebetween is formed, and a part of the refrigerant gas passage 30 is formed. The linear compressor 1 is arranged. Here, the heat source side heat exchanger 21 and the linear compressor 1 are connected by a first refrigerant gas pipe 30a, and the load side heat exchanger 22 and the linear compressor 1 are connected by a second refrigerant gas pipe 30b. ing. The refrigerant gas passage 30 corresponds to a gas passage formed by the gas side flow passage 11, the four-way valve 2, the gas discharge pipe 1a, and the gas suction pipe 1b shown in FIG.

The heat source side heat exchanger 21 and the load side heat exchanger 22
A refrigerant liquid passage 31 through which refrigerant liquid flows is formed between the heat source side heat exchanger 21 and the load side heat exchanger 22. An expansion valve 4 for restricting the flow of the refrigerant liquid between the expansion valve 4 is provided.
Here, the heat source side heat exchanger 21 and the expansion valve 4 are connected by a first refrigerant liquid pipe 31a, and the load side heat exchanger 2
2 and the expansion valve 4 are connected by a second refrigerant liquid pipe 31b.

Then, the linear compressor 1, the first
The refrigerant gas pipe 30a, the heat source side heat exchanger 21, the first refrigerant liquid pipe 31a, the expansion valve 4, the second refrigerant liquid pipe 31b, the load side heat exchanger 22, and the second refrigerant gas pipe 30b Is formed.

The refrigeration cycle apparatus 110 calculates a top dead center position of the piston based on the piston position information Pi, and outputs information Ud indicating the top dead center position. A collision risk determining unit 25 that determines the risk of collision between the piston and the cylinder based on the dead center position information Ud and outputs information (risk information) Cd indicating the risk.

The refrigeration cycle apparatus 110 is configured to control the pressure of the refrigerant gas discharged from the linear compressor 1 or the pressure of the refrigerant gas sucked into the linear compressor 1, the pressure of the heat source side refrigerant gas inside the heat source side heat exchanger 21, A pressure detector that detects at least one pressure value of the pressure of the load-side refrigerant gas inside the load-side heat exchanger 22 as a setting target and outputs detected pressure value information Pd; A system control unit 26 that outputs a control signal Sc based on the control signal Sc, a pressure setter 27 that sets the value of the pressure to be set based on the control signal Sc, and outputs set pressure value information Ps. On the basis of the set pressure value information Ps and the detected pressure value information Pd, the heat source side heat exchanger 2 is set so that the detected pressure value approaches the set pressure value.
1 and a pressure controller 29 that controls at least one of the heat exchange amount in the load side heat exchanger 22 and the valve opening of the expansion valve 4 as control objects.

Here, the pressure controller 29 outputs information indicating the manipulated variable of the controlled object to at least one of the heat source side heat exchanger 21, the load side heat exchanger 22, and the expansion valve 4. The top dead center calculation means 24, the collision risk determination means 25, the pressure detector 28, the system control means 2
6. The linear compressor control unit 110a includes the pressure setting unit 27 and the pressure controller 29.

Hereinafter, the linear compressor control unit 110a
The specific configuration of each section will be described. The system control unit 26 specifically includes the collision risk determination unit 25
The top clearance is increased by increasing the pressure difference between the discharge pressure (high pressure side) and the suction pressure (low pressure side) of the linear compressor 1 so that the collision between the piston and the cylinder is avoided based on the collision risk information from. The control signal Sc is output to the pressure setting device 27.

As the position detecting means 23, a position sensor such as an operation transformer, a gap sensor or a laser displacement meter is generally used. This position sensor includes:
A device that monitors the piston position over the entire stroke of the piston or a device that measures the distance between a piston position corresponding to a predetermined specific phase in the reciprocating motion of the piston and a predetermined portion of the cylinder may be used. When measuring the distance between the piston position at a specific phase and a predetermined portion of the cylinder, the piston position information having a high resolution can be obtained. Further, as the position detecting means 23,
A method of calculating a piston position using a current or a voltage input to the linear compressor 1 may be used.

As a specific method of calculating the top dead center position by the top dead center calculation means 24, the piston position information is acquired from the position detection means 23 at every predetermined sampling time, and the acquired piston position information is obtained. There is a method of obtaining the top dead center position from the piston position at which the differential value becomes zero.

There is also a method of detecting the above top dead center position from the drive current by utilizing the fact that the frequency of the piston reciprocation is equal to the frequency of the drive current input to the linear compressor 1. Specifically, a zero-cross timing of the drive current is obtained based on the drive current, a timing at which the amplitude of the drive current is maximized is calculated from the zero-cross timing, and a piston position corresponding to the timing is determined as a top dead center position. To be adopted. When the frequency of the piston reciprocating motion matches the resonance frequency of the support spring 51 (see FIG. 6), the phase of the reciprocating piston and the phase of the driving current are shifted by 1/4 cycle. The timing at which the piston is located at the top dead center is obtained as a timing shifted by ４ cycle from the timing at which the amplitude of the drive current is maximized.

Further, when an algorithm for driving the linear motor at the resonance frequency of the support spring 51 (see FIG. 6) is used as an operation algorithm of the driver of the linear motor 52 (see FIG. 6) constituting the linear compressor 1. Since the phase of the drive current input to the linear motor is shifted by 90 degrees with respect to the phase of the piston, there is also a method of directly obtaining information indicating the top dead center position of the piston from the zero cross timing of the input drive current. .

However, in the above-described method, since the top dead center position information and the bottom dead center position information are obtained alternately, a method of selecting only the top dead center information is required. As a method for selecting only the top dead center information, since the top dead center is a position closer to the cylinder head than the bottom dead center, position information closer to the cylinder head is adopted from two consecutive position information. There is a method. As other methods of selecting the top dead center position, the top dead center is a point where the piston moves away from the cylinder head after approaching the cylinder head, and a support spring 51 inside the linear compressor 1 (see FIG. 6).
Due to the rigidity of the piston, the point where the piston displacement per unit time (piston speed) differs at the same position when the piston approaches the top dead center position and when the piston moves away from the top dead center position There is. in this way,
The top dead center and the bottom dead center are distinguished by the difference in the piston speed, and the top dead center position of the piston is selected.

Specifically, the collision risk determining means 25 determines that there is a collision risk if the piston top dead center exceeds a predetermined limit top dead center position.

Next, the operation will be described. First, the heat exchange operation of the refrigeration cycle device will be described. In the refrigeration cycle apparatus 110 of the first embodiment, a sine wave current having a constant frequency and a constant amplitude is supplied as a drive current from a motor driver (not shown) to the linear compressor 1, and the linear compressor 1 is driven by the sine wave current. One linear motor (see FIG. 6) is driven. During operation of the linear compressor 1, the piston reciprocates in the cylinder by the linear motor, and compressed refrigerant gas is generated.

During the cooling operation, the generated compressed refrigerant gas flows into the heat source side heat exchanger 21 through the pipe 30a,
It condenses in the heat source side heat exchanger 21. The heat of condensation generated at this time is released into the atmosphere by the heat source side heat exchanger 21. The refrigerant liquid generated by the condensation of the refrigerant gas is supplied to the pipe 31
a and flows into the load side heat exchanger 22 through the expansion valve 4 installed in a part thereof, and evaporates in the load side heat exchanger 22. At the time of this evaporation, heat exchange between the surrounding air and the refrigerant in the load side heat exchanger 22 removes evaporation heat from the surrounding air and lowers the temperature of the surrounding air. The refrigerant gas generated by the evaporation of the refrigerant liquid returns to the linear compressor 1 through the pipe 30b. Thus, during cooling operation,
The compressed refrigerant gas generated by the linear compressor 1 is
It returns to the linear compressor 1 via the heat source side heat exchanger 21, the expansion valve 4, and the load side heat exchanger 22 in this order.

On the other hand, during the heating operation, the compressed refrigerant gas generated by the linear compressor 1 is supplied to the load side heat exchanger 22, the expansion valve 4, the heat source side heat exchanger 2
1 to the linear compressor 1 via this sequence.

That is, the generated compressed refrigerant gas is supplied to the pipe 3
Ob flows into the load side heat exchanger 22 and condenses in the load side heat exchanger 22. During this condensation, heat of condensation is released by heat exchange between the surrounding air and the refrigerant in the load side heat exchanger 22, and the temperature of the surrounding air rises. Then, the refrigerant liquid generated by the condensation of the refrigerant gas flows into the heat source side heat exchanger 21 through the pipe 31 and the expansion valve 4 provided in a part thereof, and evaporates in the heat source side heat exchanger 21.
At this time, the refrigerant receives evaporation heat from the atmosphere. The refrigerant gas generated by the evaporation of the refrigerant liquid returns to the linear compressor 1 through the pipe 30a.

Next, the control operation of the linear compressor 1 constituting the refrigeration cycle apparatus 110 will be described. During operation of the refrigeration cycle apparatus 110, the position sensor 23 measures the relative distance between the piston compression surface of the linear compressor 1 and the inner wall surface of the upper portion of the cylinder (that is, the size of the top clearance). Thus, the pressure of the refrigerant gas in at least one of the heat exchangers 21 and 22 and the linear compressor 1 is measured.

The top dead center calculation means 24 outputs information indicating the relative distance from the position sensor 23 (relative distance information).
The top dead center of the piston is calculated based on the piston position information Pi output as (1), and information (top dead center information) Ud indicating the top dead center is output to the collision risk determination unit 25. In the collision risk determining means 25, the possibility of the piston colliding with the cylinder is determined as a collision risk based on the top dead center information Ud, and information (collision risk information) Cd indicating the collision risk is determined by the system control. Output to the means 26. In the system control means 26, a control signal Sc corresponding to the collision risk information Cd is output to the pressure setter 27. In the pressure setting device 27, based on the control signal Sc, each heat exchanger 21,
A target pressure value of the refrigerant gas in at least one of the compressor 22 and the linear compressor 1 is set.

Further, the pressure controller 29 determines the measured pressure value and the target pressure value based on the target pressure value of the refrigerant gas set by the pressure setting device 27 and the measured pressure value detected by the pressure detector 28. The control signal Fc is output to at least one of the heat exchangers 21 and 22 and the expansion valve 4 so that the difference value between the control signal Fc and the heat exchanger 21 and 22 becomes smaller.

The operation of the pressure controller 29 will be specifically described below. First, a cooling operation in which the heat source side heat exchanger 21 functions as a condenser and the load side heat exchanger 22 functions as an evaporator will be described. In this case, when increasing the pressure of the refrigerant gas on the high pressure side to the target pressure value, the heat exchange amount reduction control for reducing the heat exchange amount of the heat source side heat exchanger 21 functioning as a condenser, and the opening degree of the expansion valve 3 are reduced. The valve opening reduction control to be performed or both the heat exchange amount reduction control and the valve opening reduction control are performed. Conversely, when the pressure of the high-pressure side refrigerant gas is reduced to the target pressure value, the heat exchange amount increase control for increasing the heat exchange amount of the heat source side heat exchanger 21 acting as a condenser, and the opening degree of the expansion valve 3 are increased. The valve opening increase control to be performed, or both the heat exchange amount increase control and the valve opening increase control are performed.

On the other hand, when increasing the low pressure side pressure of the refrigerant gas to the target pressure value, the heat exchange amount increase control for increasing the heat exchange amount of the load side heat exchanger 22 acting as an evaporator, and the opening degree of the expansion valve 3 are set. The control to increase the valve opening degree, or both the heat exchange amount increase control and the valve opening degree increase control, are performed.
Conversely, when reducing the low pressure side pressure of the refrigerant gas to the target pressure value, the heat exchange amount reduction control for reducing the heat exchange amount of the load side heat exchanger 22 functioning as an evaporator, and the opening degree of the expansion valve 3 are reduced. The valve opening reduction control or both the heat exchange amount reduction control and the valve opening reduction control are performed.

Next, the operation of the pressure controller 29 in the heating operation in which the heat source side heat exchanger 21 functions as an evaporator and the load side heat exchanger 22 functions as a condenser, contrary to the cooling operation, will be described. .

In this case, when raising the high pressure side pressure of the refrigerant gas to the target pressure value, the heat exchange amount reduction control for reducing the heat exchange amount of the load side heat exchanger 22 or the opening degree of the expansion valve 3 is reduced. The valve opening reduction control or both the heat exchange amount reduction control and the valve opening reduction control are performed. When reducing the high pressure side pressure of the refrigerant gas to the target pressure value, a heat exchange amount increase control for increasing the heat exchange amount of the load side heat exchanger 22, a valve opening increase control for increasing the opening of the expansion valve 3, or Both the heat exchange amount increase control and the valve opening degree increase control are performed.

On the other hand, when increasing the low pressure side pressure of the refrigerant gas to the target pressure value, a heat exchange amount increasing control for increasing the heat exchange amount of the heat source side heat exchanger 21 or a valve for increasing the opening degree of the expansion valve 3. The opening degree increase control or both the heat exchange amount increase control and the valve opening degree increase control are performed. When reducing the low pressure side pressure of the refrigerant gas to the target pressure value, a heat exchange amount reduction control for reducing the heat exchange amount of the heat source side heat exchanger 21 or a valve opening degree reduction control for decreasing the opening degree of the expansion valve 3, Alternatively, both the heat exchange amount reduction control and the valve opening degree reduction control are performed.

Here, when the drive current input to the linear compressor 1 changes due to the operation of the air conditioner, or when the load applied to each heat exchanger changes due to a change in air temperature, it is sucked into the linear compressor 1. When the pressure difference between the pressure of the refrigerant gas (hereinafter, referred to as the suction pressure) and the pressure of the refrigerant gas discharged from the linear compressor 1 (hereinafter, referred to as the discharge pressure) becomes small, the fluctuation of the piston stroke and the center of the reciprocating motion of the piston occur. Due to the change of the position, the collision risk increases.

In this case, control for increasing the pressure difference is performed so that the piston top dead center moves away from the inner surface of the upper part of the cylinder. That is, in this case, regardless of the heating operation and the cooling operation, the control for decreasing the heat exchange amount in the heat source side heat exchanger 21, the control for decreasing the opening degree of the expansion valve 4, and the load side heat exchanger 22 At least one of the controls for reducing the amount of heat exchange is performed. As a result, the top clearance of the linear compressor 1 is increased, and collision between the piston and the cylinder is avoided.

As described above, in the refrigeration cycle apparatus 110 of the first embodiment, based on the piston top dead center information Ud,
The probability that the piston collides with the cylinder is detected as a collision risk, and based on the collision risk, the heat source side heat exchanger 2 is detected.
1. By adjusting at least one of the amount of heat exchange in the load-side heat exchanger 22 and the valve opening of the expansion valve, the pressure difference between the suction pressure and the discharge pressure in the linear compressor 1 is determined by the top clearance of the linear compressor 1. Is increased so that the piston top dead center approaches the collision position where the piston collides with the cylinder, and when the danger of the piston collision increases, without reducing the drive current of the linear compressor 1, Piston collision can be avoided. That is, the piston collision avoidance can be performed without reducing the cooling capacity or the heating capacity.

Further, in the first embodiment, the top clearance of the linear compressor 1 is controlled so as to avoid the piston collision by using the piston top dead center information. You can do it.

Further, in the first embodiment, the target pressure value of the refrigerant gas in each of the heat exchangers 21 and 22 is set based on the collision risk information, and the refrigerant gas set by the pressure setter 27 is set. Based on the target pressure value and the actually measured pressure value detected by the pressure detector 28, the amount of heat exchange of the heat exchanger and the opening degree of the expansion valve are adjusted so that the difference between the actually measured pressure value and the target pressure value becomes small. Since the control is performed, the set target pressure value can be limited to an appropriate pressure range in consideration of the optimal pressure condition during the operation of the air conditioner. That is, control for avoiding piston collision can be performed while maintaining an efficient operation state as the air conditioner.

In the first embodiment, when the collision risk determining means 25 determines that the piston top dead center calculated on the basis of the piston position information exceeds a predetermined limit top dead center position, the collision danger determining means 25 determines whether or not the collision danger has occurred. Although it is determined that there is a risk, the collision risk determination means 25 determines that the piston top dead center and the piston top dead center are exceeded when the piston top dead center exceeds a predetermined limit top dead center position. The magnitude of the collision risk may be determined according to the distance from the point position.

The collision risk determining means 25 having such a configuration is described.
When the calculated top dead center position greatly exceeds the set critical top dead center position, it is determined that the collision risk in this case is extremely large. If the calculated top dead center position slightly exceeds the set limit top dead center position, it is determined that the collision risk is slightly higher. further,
If the calculated top dead center position does not reach the set limit top dead center position, it is determined that there is no collision risk.

Specifically, at least two or more top dead center positions are set along the axial direction of the cylinder,
A plurality of risk evaluation areas divided by the plurality of critical top dead center positions are set along the cylinder axis direction.
Then, the probability of the collision risk is determined based on which risk evaluation area each piston top dead center is located in.

FIG. 2 is a diagram for explaining an example of a judgment function for associating the piston top dead center position with the collision risk. In FIG. 2, the horizontal axis indicates the piston top dead center, the vertical axis indicates the magnitude of the collision risk (collision probability), and the collision risk determination position indicates the origin at the collision position where the piston collides with the cylinder head. Along the stroke direction of the piston, four determination positions x1, x2, x3, x4 (x1> x
2>x3> x4).

The magnitude of the collision risk is obtained as follows by the function shown in FIG. If the top dead center position calculated by the top dead center calculation means 24 exceeds the determination position x1 but does not exceed the determination position x2, it is determined that the probability of collision risk is 25%. Similarly, when the top dead center position is less than or equal to the determination position x1, when it is between the determination positions x2 and x3, when it is between the determination positions x3 and x4, and when it is greater than or equal to the determination position x4, the collision occurs. The probabilities as the risk are determined to be 0%, 50%, 75%, and 100%.

In the example of the collision risk determination shown in FIG. 2, four determination positions are set, but the number of determination positions is not limited to four. The more the preset determination positions are, the more precise the control for avoiding the piston collision can be.

In the collision risk determination example shown in FIG. 2, the collision risk is a function that changes stepwise as the piston top dead center position approaches the piston collision position (that is, a function that is continuous but cannot be differentiated). Function), the function indicating the correspondence between the piston top dead center position and the collision risk is a function that changes smoothly rather than stepwise as the piston top dead center position approaches the piston collision position (that is, the differential function). Possible function).

As described above, the control amount such as the amount of heat exchange is determined according to the size of the interval (top clearance) between the piston top dead center and the cylinder head, and the control for avoiding the piston collision is performed. It can be done finely.

In the first embodiment, the collision risk determining means 25 determines the collision risk based on the top dead center position information. Irrespective of the point position information, the position detecting means 23
The collision risk may be determined based on the piston position signal from the controller. Specifically, the collision risk determining means 25 determines that the predetermined reference portion of the piston has approached the cylinder head side from the predetermined limit position based on the piston position information from the position detecting means 23. When detected, a method of determining that the risk of collision is high is conceivable. In this case, the process of deriving the top dead center position is omitted, and it is possible to easily detect a state where there is a risk that the piston collides with the cylinder.

The collision risk determining means 25 is not limited to the one which determines the collision risk based on the piston top dead center position and the position of the piston reference region. May be used to determine the degree of collision danger. In this case, the speed of the piston is calculated based on discrete data obtained by sampling the position information. As a specific method, the distance between the piston position obtained by the latest sampling and the piston position obtained by the previous sampling is divided by the sampling period, and the distance that the piston moves per unit time ( That is, there is a method of calculating the current piston speed).

As described above, when the collision risk is determined based on the piston speed, not only the collision risk is determined, but also the piston is actually moved from the time when the collision risk is determined to be high. It is possible to estimate the time until the collision. For this reason, when the piston speed is high, it is considered that the time from the collision risk determination point to the actual collision of the piston is short. The collision of the piston can be avoided more reliably.

For example, when the refrigeration cycle is abnormal, the piston speed may increase rapidly. In such a case, the collision risk is determined based on the piston speed.
Control for avoiding piston collision with good responsiveness can be performed.

Further, in the first embodiment, as the refrigeration cycle device, the target pressure value of the refrigerant gas in each heat exchanger and the linear compressor 1 is set by the pressure setter 27 based on the control signal from the system control means 26. Set,
Based on the target pressure value from the pressure setter 27 and the actually measured pressure value from the pressure detector 28, the pressure controller 29 controls at least one of the amount of heat exchange in each heat exchanger and the valve opening of the expansion valve. The system control means 26
And at least one of the amount of heat exchange in the heat source side heat exchanger 21 and the load side heat exchanger 22 and the degree of opening of the expansion valve 3 may be directly controlled. In this case, the pressure setting device 27, the pressure detector 28, and the pressure controller 29 become unnecessary.

Specifically, when the collision risk determination unit 25 determines that the collision risk is high, the system control unit 26 determines whether the heat source side heat exchanger and the load side heat exchanger , And at least one of the expansion valves is controlled so that the pressure difference between the high-pressure side pressure of the refrigerant gas and the low-pressure side pressure of the refrigerant gas becomes large. That is, control for reducing the heat exchange amount of the heat source side heat exchanger 21 regardless of the heating operation or the cooling operation,
At least one of the control for decreasing the opening degree of the expansion valve 3 and the control for decreasing the heat exchange amount of the load-side heat exchanger 22 is performed.

In the first embodiment, when the collision risk determining means 25 determines that the piston collision risk is high, the system control means 2 operates as a refrigeration cycle apparatus.
6, the amount of heat exchange of each heat exchanger or the valve opening of the expansion valve is controlled so as to widen the gap (top clearance) between the piston and the cylinder. In addition to performing control when the collision risk is high, if the piston top dead center has not reached the critical top dead center position, the collision risk determination means 25 determines that the piston top dead center at that time is The determination information that the top dead center position has not been reached is output to the system control means 26, and the system control means 26 checks the heat exchange amount of each heat exchanger or the valve opening of the expansion valve so that the top clearance becomes a constant value. The degree may be controlled.

In this case, in the linear compressor 1, a higher volume efficiency is obtained as the top clearance is smaller. Therefore, as described above, the piston top dead center is set so that the top clearance is smaller than the critical top dead center position. By controlling, it is possible to always drive the linear compressor with the highest efficiency.

Further, in the first embodiment, the system control means controls the amount of heat exchange of each heat exchanger or the opening degree of the expansion valve so as to widen the gap (top clearance) between the piston and the cylinder. As described above, the system control means calculates not only the heat exchange amount of each heat exchanger or the valve opening degree of the expansion valve, but also the drive current of the linear motor supplied to the linear compressor 1 by the collision risk information indicated by the collision risk information. The control may be performed so as to decrease as the risk increases.

In this case, control for avoiding piston collision by the system control means can be made more responsive. That is, when the amount of heat exchange of each heat exchanger or the valve opening degree of the expansion valve is to be controlled, as in the control for avoiding the piston collision in the first embodiment, the responsiveness of the load-side heat Depending on the configuration of the system equipped as an exchanger, sufficient responsiveness may not be obtained in some cases.

In such a case, the control (second control) for avoiding piston collision with the drive current of the linear motor supplied to the linear compressor 1 as a control object is performed by the heat exchange amount of each heat exchanger. Alternatively, by performing the control with the valve opening of the expansion valve as the control target (first control),
The response speed can be increased. Moreover, in this case, the adverse effect in the second control using the drive current as a control object, that is, the decrease in the drive current of the linear motor causes the amplitude of the piston to decrease and the pressure difference in the linear compressor to decrease, thereby reducing the vibration of the piston. The phenomenon that the possibility of the piston collision increasing again due to the shift of the center position to the cylinder side is suppressed by the first control in which the heat exchange amount of each heat exchanger or the opening degree of the expansion valve is controlled. It becomes.

(Embodiment 2) FIG. 3 is a view for explaining a refrigeration cycle apparatus according to Embodiment 2 of the present invention. The refrigeration cycle apparatus 120 according to the second embodiment is different from the refrigeration cycle apparatus 110 according to the first embodiment in that the refrigerant is replaced with a linear compressor control unit 110a that performs control for avoiding piston collision based on the pressure of the refrigerant gas. It has a linear compressor control unit 120a that performs control for avoiding piston collision based on the gas temperature.

The linear compressor control section 120a
Is the linear compressor control unit 110a according to the first embodiment.
Similarly, the position detector 23 in the linear compressor 1
Top dead center calculating means 24 which calculates the top dead center position of the piston based on the piston position information Pi from the microcomputer and outputs information Ud indicating the top dead center position, and the piston and the cylinder based on the top dead center position information Ud. And a control signal S corresponding to the collision risk information Cd. The collision risk determination means 25 determines the risk of collision of the vehicle and outputs information (risk information) Cd indicating the risk.
and a system control means 26 for outputting c.

The linear compressor control unit 1
Reference numeral 20a denotes the temperature of the refrigerant gas discharged from the linear compressor 1, the temperature of the refrigerant gas sucked into the linear compressor 1, the heat source side heat exchanger 2 instead of the pressure detector 28 in the linear compressor control unit 110a.
The pressure at which at least one of the temperature of the heat source-side refrigerant gas inside the first heat exchanger 1 and the temperature of the load-side refrigerant gas inside the load-side heat exchanger 22 is detected as a setting target, and the detected temperature information Td is output. It has a detector 32.

The linear compressor controller 12
0a sets the temperature value to be set based on the control signal Sc from the system control means 26 in place of the pressure setter 27 and the pressure controller 29 in the linear compressor controller 110a, and sets Temperature value information P
s, and the amount of heat exchange in the heat source side heat exchanger 21 and the load side based on the set temperature value information Ts and the detected temperature value information Td so that the detected temperature value approaches the set temperature value. The temperature controller 33 controls at least one of the heat exchange amount in the heat exchanger 22 and the opening degree of the expansion valve 4 as a control target. Other configurations in the second embodiment are the same as those in the first embodiment.

Next, the operation will be described. The operation of the refrigeration cycle apparatus 120 other than the linear compressor control unit 120a is exactly the same as that of the first embodiment. During operation of the refrigeration cycle apparatus 120, the position of the piston is measured as the size of the top clearance by the position sensor 23, and at least the heat exchangers 21 and 22 and the linear compressor 1 are measured by the temperature detector 32. The pressure of the refrigerant gas in one is measured.

Then, the top dead center calculating means 24 calculates the piston position information Pi from the position sensor 23 based on the piston position information Pi.
The top dead center of the piston is calculated, and the top dead center information Ud is output to the collision risk determining means 25. In the collision risk determining means 25, the possibility of the piston colliding with the cylinder is determined as the collision risk based on the top dead center information Ud,
The collision risk information Cd is output to the system control means 26. Then, the system control means 26 outputs a control signal Sc corresponding to the collision risk information Cd to the temperature setting device 34. In the temperature setting device 34, based on the control signal Sc,
A target temperature value of the refrigerant gas in at least one of the heat exchangers 21 and 22 and the linear compressor 1 is set.

In the temperature controller 33, the temperature setting device 3
4 based on the target pressure value of the refrigerant gas set in step 4 and the measured temperature value detected by the temperature detector 32, so that the difference between the measured temperature value and the target temperature value is reduced. , 22 and at least one of the expansion valves 4 is output with a control signal Fc.

Hereinafter, the operation of the temperature controller 33 will be specifically described. First, a cooling operation in which the heat source side heat exchanger 21 functions as a condenser and the load side heat exchanger 22 functions as an evaporator will be described. In this case, when the temperature of the high-pressure side refrigerant gas is raised to the target temperature value, the heat exchange amount reduction control for reducing the heat exchange amount of the heat source side heat exchanger 21 acting as a condenser, and the opening degree of the expansion valve 3 are reduced. The valve opening reduction control to be performed or both the heat exchange amount reduction control and the valve opening reduction control are performed. Conversely, when the temperature of the high-pressure side refrigerant gas is reduced to the target temperature value, the heat exchange amount increase control for increasing the heat exchange amount of the heat source side heat exchanger 21 acting as a condenser, and the opening degree of the expansion valve 3 are increased. The valve opening increase control to be performed, or both the heat exchange amount increase control and the valve opening increase control are performed.

On the other hand, when the low pressure side temperature of the refrigerant gas is increased to the target temperature value, the heat exchange amount increase control for increasing the heat exchange amount of the load side heat exchanger 22 functioning as an evaporator, and the opening of the expansion valve 3 are controlled. The control to increase the valve opening degree, or both the heat exchange amount increase control and the valve opening degree increase control, are performed.
Conversely, when the low pressure side temperature of the refrigerant gas is reduced to the target temperature value, the heat exchange amount reduction control for reducing the heat exchange amount of the load side heat exchanger 22 functioning as an evaporator, and the opening degree of the expansion valve 3 are reduced. The valve opening reduction control or both the heat exchange amount reduction control and the valve opening reduction control are performed.

Next, the operation of the temperature controller 33 will be described for the case of the heating operation in which the heat source side heat exchanger 21 functions as an evaporator and the load side heat exchanger 22 functions as a condenser, contrary to the cooling operation. .

In this case, when the high pressure side temperature of the refrigerant gas is raised to the target temperature value, a heat exchange amount reduction control for reducing the heat exchange amount of the load side heat exchanger 22 and a valve for decreasing the opening degree of the expansion valve 3. The opening degree reduction control or both the heat exchange amount reduction control and the valve opening degree reduction control are performed. Conversely, when decreasing the high pressure side temperature of the refrigerant gas to the target temperature value,
Heat exchange amount increase control for increasing the heat exchange amount of the load side heat exchanger 22, valve opening increase control for increasing the opening of the expansion valve 3,
Alternatively, both the heat exchange amount increase control and the valve opening degree increase control are performed.

On the other hand, when increasing the low pressure side temperature of the refrigerant gas to the target temperature value, a heat exchange amount increase control for increasing the heat exchange amount of the heat source side heat exchanger 21 or a valve for increasing the opening degree of the expansion valve 3 The opening degree increase control or both the heat exchange amount increase control and the valve opening degree increase control are performed. Conversely, when decreasing the low pressure side temperature of the refrigerant gas to the target temperature value, a heat exchange amount reduction control for reducing the heat exchange amount of the heat source side heat exchanger 21 and a valve opening reduction for decreasing the opening of the expansion valve 3. The control or both the heat exchange amount reduction control and the valve opening degree reduction control are performed.

Here, when the drive current input to the linear compressor 1 changes due to the operation of the air conditioner, or when the load applied to each heat exchanger changes due to a change in air temperature, the refrigerant drawn by the linear compressor 1 changes. When the temperature difference between the gas temperature (hereinafter, referred to as the suction refrigerant temperature) and the temperature of the refrigerant gas discharged from the linear compressor 1 (hereinafter, referred to as the discharge refrigerant temperature) becomes small, the fluctuation of the piston stroke and the reciprocation of the piston reciprocate. Due to the change of the center position, the collision risk increases.

In this case, control is performed to increase the temperature difference so that the piston top dead center moves away from the inner surface of the upper part of the cylinder. That is, in this case, regardless of the heating operation and the cooling operation, the control for reducing the heat exchange amount in the heat source side heat exchanger, the control for reducing the opening degree of the expansion valve, and the heat exchange in the load side heat exchanger At least one of the controls for reducing the amount is performed. As a result, the top clearance of the linear compressor 1 is increased, and collision between the piston and the cylinder is avoided.

As described above, in the refrigeration cycle apparatus 120 according to the second embodiment, the probability that the piston collides with the cylinder is detected as the collision risk based on the piston top dead center information, and based on the collision risk, By adjusting at least one of the amount of heat exchange in the heat source side heat exchanger 21 and the load side heat exchanger 22 and the opening degree of the expansion valve 4, a difference value between the intake refrigerant temperature and the discharge refrigerant temperature in the linear compressor 1 is obtained. Since the temperature difference is changed, the top dead center of the piston approaches the collision position where the piston collides with the cylinder, and when the risk of the piston collision increases, the drive current of the linear compressor 1 is not reduced. , Piston collision can be avoided. That is, the piston collision avoidance can be performed without reducing the cooling capacity or the heating capacity.

Since the top clearance of the linear compressor 1 for avoiding piston collision is controlled using the piston top dead center information, control for avoiding piston collision can be performed at high speed and stably.

Further, in the second embodiment, since the top clearance of the linear compressor 1 is adjusted based on the temperature of the refrigerant, the air conditioner in which the degree of superheat or the degree of supercooling of the refrigerant is maintained in an appropriate range. The control of the refrigeration cycle for avoiding the piston collision under the comfortable driving can be simplified. In other words, it is possible to control the refrigeration cycle for avoiding the piston collision without impairing the comfortable temperature control desired by the user of the air conditioner as much as possible.

In the second embodiment, the refrigeration cycle for avoiding piston collision is controlled based on the temperature of the refrigerant gas. However, the refrigeration cycle for avoiding piston collision is controlled based on the temperature of the refrigerant liquid. May be controlled.

(Embodiment 3) FIG. 4 is a block diagram for explaining a refrigeration cycle apparatus according to Embodiment 3 of the present invention, and shows the configuration of system control means constituting the refrigeration cycle apparatus.

The refrigerating cycle device of the third embodiment is
Instead of the system control means 26 in the refrigeration cycle apparatus 110 of the first embodiment, an abnormality prevention control for controlling at least one of the heat exchange amount and the opening degree of the expansion valve so that the piston collision is reliably avoided, and a cooling and heating operation, A system control means 60 is provided which performs normal operation control for controlling the pressure of the refrigerant gas within an appropriate range and preventing overheating and overcooling from occurring, with a balance according to the collision risk.

The configuration of the system control means 60 for controlling the opening of the expansion valve 4 will be described in detail below. The system control means 60 provides the collision risk information C
a control unit 61 for anti-collision operation for controlling the opening degree of the expansion valve 4 in accordance with d, and for controlling the opening degree of the expansion valve so that the pressure of the refrigerant gas is kept within an appropriate range and overheating and overcooling do not occur. Operation control unit 62 and control amount V by abnormality prevention control
e, an expansion valve operation amount determiner 63 that determines a control amount Vb for the expansion valve 4 based on the control amount Vn by the normal operation control and the collision risk information Cd.

Here, the collision preventing operation control unit 61
Is different from the system control means 26 of the first embodiment in that only the opening of the expansion valve 4 is controlled, and a control amount Sc indicating the opening of the expansion valve 4 for reliably avoiding a piston collision.
e. In addition, the normal operation control unit 62 controls the temperature of the room to be air-conditioned and the air-conditioning target temperature set by the user based on the temperature of the refrigerant gas. In addition, a control amount Scn indicating an optimal opening degree of the expansion valve 4 is output so that a comfortable air-conditioning operation in which supercooling does not occur is performed.

Further, the expansion valve operation amount determiner 63 sets the value of the risk information Cd given from the risk determining means 25 as a coefficient α (0 ≦ α ≦ 1) to obtain a fuzzy signal represented by the following equation (1). The function determines the valve opening control amount Vb for adjusting the opening of the expansion valve 4. Vb = Ve × α + Vn × (1−α) (1)

The opening of the expansion valve 4 is set to an opening corresponding to the control amount Vb. Other configurations of the third embodiment are the same as those of the first embodiment.

Next, the operation will be described. The operation of the third embodiment is the same as that of the first embodiment except that the operation amount of the expansion valve 4 is determined based on the above relational expression (1). The operation to be determined will be described.

In the collision risk determining means 25, based on the piston top dead center information Ud calculated in the same manner as in the first embodiment, the information Cd indicating the collision risk is set such that the value of the collision risk increases as the possibility of collision increases. Is determined to be larger. Here, the value of the information Vcd is the coefficient value α (0 ≦ α ≦ 1).
It has become.

The collision prevention operation controller 61 operates the expansion valve 4 based on the collision risk information Cd from the collision risk determination means 25 so as to reliably avoid the piston collision (first operation amount). Ve is determined, and information Sce indicating the first operation amount Ve is output.

The controller 62 for normal operation determines an operation amount (second operation amount) Vn of the expansion valve 4 so that the refrigerant gas pressure, the degree of superheat, and the degree of supercooling are properly maintained. Is output as information Scn indicating the operation amount Vn.

In the expansion valve operation amount determiner 63, the third operation amount Vb of the expansion valve 4 is determined by the above equation (1). That is, the third operation amount Vb of the expansion valve 4 is obtained by multiplying the operation amount Ve from the collision prevention operation controller 61 by the value of the collision risk degree Cd as the coefficient α, and the normal operation controller 62. And the value obtained by multiplying the manipulated variable Vn from by the value obtained by subtracting the coefficient α from 1 is obtained as an addition value. The opening of the expansion valve 4 is adjusted in accordance with the third operation amount Vb.

As described above, in the third embodiment, the collision-prevention operation control unit 61 for determining the first control amount Vb for the expansion valve opening degree to reliably avoid the piston collision.
And a second control amount Vn for the opening degree of the expansion valve for maintaining the pressure, superheat degree and supercool degree of the refrigerant gas in appropriate ranges.
And an expansion valve operation amount determiner 63 that determines a third operation amount Vb obtained by weighting and averaging the first and second control amounts according to the collision risk. When the risk of collision of the piston is small,
The operation of the refrigeration cycle apparatus can be performed in a state where the pressure of the refrigerant gas, the degree of superheat and the degree of supercooling are set in relatively appropriate ranges, and when the risk of collision of the piston is large, priority is given to avoiding collision of the piston. The operation of the refrigeration cycle apparatus can be performed.

In the third embodiment, the control amount obtained by weighting the control amount (first control amount) for avoiding abnormality and the control amount (second control amount) for normal operation is obtained. As the (third control amount), a control amount for adjusting the opening degree of the expansion valve is shown, but as a third control amount, the heat exchange amount of the heat source side heat exchanger 21 and the load side heat exchanger 22 is determined. May be determined.

Further, in each of the above embodiments, the open loop control for uniquely determining the control amount corresponding to the detected position or speed of the piston is described as the control of the heat exchanger and the expansion valve. Control of exchangers and expansion valves
Feedback control for sequentially determining the control amount for the heat exchanger and the expansion valve based on the detected position or speed of the piston may be used.

[0132]

As described above, according to the refrigeration cycle apparatus according to the present invention (claim 1), the position detecting means for detecting the position of the piston reciprocating in the cylinder of the linear compressor, and the detected piston position Collision risk determining means for determining the risk of the piston colliding with the cylinder based on the heat exchange amount in the heat source side heat exchanger (first heat exchanger) and the load side heat exchanger (second heat exchanger). Heat exchanger), and at least one of the opening degree of a throttle valve that restricts the flow of the circulating refrigerant is controlled, and the top of the linear compressor is controlled according to the determined collision risk. System control means for controlling the control object so as to increase the clearance, so that when the steady-state operating state of the refrigeration cycle apparatus fluctuates, that is, when the heat source side heat exchanger or the load side heat exchanger Ambient temperature changes and the target temperature (e.g., room temperature setting of the air conditioner) when the change in occurs, the output of the refrigeration cycle apparatus, for example, without significantly reducing the cooling capacity or heating capacity required,
The collision between the piston and the cylinder in the linear compressor can be reliably avoided.

According to the present invention (claim 2), claim 1
In the refrigeration cycle apparatus described above, the collision risk determination means includes a step of, when the piston position corresponding to the predetermined phase of the piston reciprocating movement approaches a cylinder head side from a preset limit position, the piston collides with the cylinder. Since it is determined that there is a danger of collision, it is possible to easily detect a case where there is a risk of the piston colliding with the cylinder.

According to the present invention (Claim 3), Claim 1
In the refrigeration cycle apparatus described in the above, in the collision risk determining means, the piston position corresponding to the predetermined phase of the piston reciprocating motion is included in any of a plurality of risk determining regions set in advance. It is determined that as the risk determination area including the piston position is closer to the cylinder head, the collision risk is determined to be higher, so that the collision risk of the piston can be determined in a stepwise manner. The control can be performed finely.

According to the present invention (claim 4), claim 1
In the refrigeration cycle apparatus described above, the position detecting means detects a plurality of piston position information, and the collision risk determining means determines when the piston passes a predetermined determination position based on the plurality of piston position information. Is obtained, and the collision risk is determined based on the piston speed. Therefore, the collision risk can be easily obtained.

According to the present invention (claim 5), claim 1
The refrigeration cycle apparatus according to claim 1, further comprising a top dead center calculating unit that outputs top dead center information indicating a top dead center of the piston based on the piston position information, wherein the collision risk determining unit includes the top dead center information. When the top dead center of the piston is closer to the cylinder head side than the preset limit position, it is determined that there is a risk of the piston colliding with the cylinder. Not only can it be easily detected, but also control for avoiding piston collision can be performed quickly and stably.

According to the present invention (claim 6), claim 5
In the refrigeration cycle apparatus described in the above, in the collision risk determining means, the top dead center of the piston is included in any one of a plurality of predetermined risk determination areas based on the top dead center information. It is determined that the risk of collision is higher as the risk determination area including the top dead center of the piston is closer to the cylinder head, so that control for avoiding piston collision is performed quickly and stably. In addition to the above, control for avoiding the collision of the piston can be performed in detail by the stepwise determination of the risk of collision of the piston.

According to the present invention (claim 7), claim 1
In the refrigeration cycle apparatus described above, the system control means controls the control target based on the piston position information so that the top dead center of the piston is maintained at a predetermined position. It becomes possible to drive the compressor.

According to the present invention (claim 8), claim 1
In the refrigeration cycle apparatus described above, the suction pressure of the linear compressor, the discharge pressure thereof, the pressure of the gaseous refrigerant sent to the first heat exchanger, and the pressure of the gaseous refrigerant generated in the second heat exchanger A pressure detector that detects a pressure value of at least one of the set target pressures, a pressure setter that sets the set target pressure to a predetermined value, and a difference between a set value of the set target pressure and the detected value. A pressure controller that outputs information indicating the control amount to the controlled object so that the set value of the set target pressure is controlled by the pressure setter. The target pressure value is set within the appropriate pressure range in consideration of the optimal pressure conditions during the operation of the air conditioner, since the control is performed so that the value corresponds to the collision risk indicated by the degree information. Restrict Can. That is, control for avoiding piston collision can be performed while maintaining an efficient operation state as the air conditioner.

According to the present invention (Claim 9), Claim 1
In the refrigeration cycle apparatus described above, the temperature of the gaseous refrigerant sucked into the linear compressor, the temperature of the gaseous refrigerant discharged from the linear compressor, the temperature of the gaseous refrigerant in the first heat exchanger, and the second heat Temperature detection for detecting at least one of the temperature of the gaseous refrigerant in the exchanger, the temperature of the liquid refrigerant in the first heat exchanger, and the temperature of the liquid refrigerant in the second heat exchanger as target temperatures. And a temperature setter for setting the set target temperature to a predetermined value, and outputting information indicating the control amount of the control target so that the difference between the set value of the set target temperature and the detected value becomes smaller. A temperature controller for setting the temperature of the temperature setting device to a value corresponding to the collision risk indicated by the collision risk information. Since the controls, under comfortable operation of the air conditioner is maintained a degree of superheat and subcooling of the refrigerant in the proper range, the control of the refrigeration cycle for the piston collision can as simple. In other words, it is possible to control the refrigeration cycle for avoiding the piston collision without impairing the comfortable temperature control desired by the user of the air conditioner as much as possible.

According to the present invention (claim 10), in the refrigeration cycle apparatus according to claim 1, the system control means controls the control amount for avoiding the collision of the piston based on the collision risk information. And a system controller for anti-collision operation for outputting the first control information, and a normal operation for outputting second control information indicating a control amount for operating the linear compressor in a preset optimal state. The system controller and the weighting process for the first control amount and the second control amount are performed by comparing the first control amount with the second control amount as the collision risk indicated by the collision risk information increases. Control amount determining means for increasing the weighting ratio for the control target and outputting the sum of the weighted first and second control amounts as information indicating the third control amount for the control target. Since the control object is controlled by the third control amount, when the risk of collision of the piston is small, the pressure, superheat and supercool of the refrigerant gas are set in a relatively appropriate range. The operation of the refrigeration cycle apparatus can be performed, and when the risk of collision of the piston is high, the refrigeration cycle apparatus can be operated with priority given to avoiding the collision of the piston.

According to the present invention (claim 11), in the refrigeration cycle apparatus according to claim 1, the system control means is provided with current control means for controlling a drive current of a linear motor supplied to the linear compressor. The amount of heat exchange in the first heat exchanger, the amount of heat exchange in the second heat exchanger, and the degree of opening of the throttle valve according to the degree of collision risk indicated by the degree of collision risk information. Since the second control with the drive current of the linear motor as the control target is performed together with the first control with at least one control target,
By performing control using the drive current of the linear motor as a control object, the response speed of control for avoiding piston collision can be increased. As a result, unexpected collision of the piston can be avoided. In addition, it is possible to suppress the adverse effects in the control for avoiding the piston collision using the drive current as the control target. In other words, the phenomenon that the pressure difference of the linear compressor decreases due to the decrease in the drive current of the linear motor and the possibility of piston collision increases again depends on the amount of heat exchange of each heat exchanger or the valve opening of the expansion valve. The control for increasing the pressure difference of the linear compressor can be suppressed.

[Brief description of the drawings]

FIG. 1 is a block diagram for explaining a refrigeration cycle apparatus according to Embodiment 1 of the present invention.

FIG. 2 is a diagram illustrating an example of a collision risk determination function used in the first embodiment.

FIG. 3 is a block diagram for explaining a refrigeration cycle device according to Embodiment 2 of the present invention.

FIG. 4 is a block diagram for explaining a refrigeration cycle apparatus according to Embodiment 3 of the present invention.

FIG. 5 is a block diagram showing a system of a conventional refrigeration cycle device.

FIG. 6 is a cross-sectional view illustrating a linear compressor included in a conventional refrigeration cycle device.

FIG. 7 is a block diagram showing a conventional collision avoidance control device for a linear compressor.

[Explanation of symbols]

 Reference Signs List 1 linear compressor 1a discharge pipe 1b suction pipe 2 four-way valve 3 outdoor heat exchanger (heat source side heat exchanger) 4 expansion valve 5 accumulator 8 indoor heat exchanger (load side heat exchanger) 9 room temperature detector 10 room 11 gas side Pipe (first flow pipe) 12 Liquid side pipe (second flow pipe) 13 Pressure detector 14 Superheat degree detector 21 Heat source side heat exchanger 22 Load side heat exchanger 23 Position detection sensor 24 Above Dead point calculation means 25 Collision risk determination means 26, 60 System control means 27 Pressure setter 28 Pressure detector 29 Pressure controller 30 Gas side pipe 31 Liquid side pipe 32 Temperature detector 33 Temperature controller 34 Temperature setter 41a Cylinder Part 41b Motor part 42 Piston 42a Piston rod 43 Magnet 44a Outer yoke 44b Stator coil 46 Gas compression chamber 49 Suction bar Lube 50 Discharge valve 51 Resonant spring (support spring) 52 Linear motor 61 Anti-collision operation controller 62 Normal operation controller 63 Expansion valve operation amount determiner 100, 110, 120 Refrigeration cycle device 100a Indoor unit 100b Outdoor unit 110a, 120a Linear compressor control unit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hideki Nakata 1006 Kazuma Kadoma, Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. 72) Inventor Yuji Yoshida 1006 Kazuma, Kazuma, Osaka Prefecture F-term in Matsushita Electric Industrial Co., Ltd. CC98 5H540 AA10 BA03 BB04 BB06 BB09 EE04 FA12 FA14 FA16 FC07 FC10 GG01

Claims (11)

[Claims] 1. A first method for performing heat exchange by changing the state of a refrigerant.
And a second heat exchanger; a first flow conduit for sending refrigerant from the second heat exchanger to the first heat exchanger; and a refrigerant from the first heat exchanger to the second heat exchanger. A second flow pipe for feeding, a cylinder and a piston which are arranged in a part of the first flow pipe and form a gas compression chamber, and a linear motor for reciprocating the piston; A linear compressor that sucks and compresses the gaseous refrigerant from the heat exchanger side and discharges the compressed gaseous refrigerant to the first heat exchanger side; and a linear compressor that is disposed in a part of the second circulation pipe. A refrigeration cycle apparatus comprising: a throttle valve that adjusts a cross-sectional area of the passage according to a valve opening thereof; a position detection unit that detects a position of the piston and outputs piston position information indicating the position; Danger of the piston colliding with the cylinder based on position information Collision risk determining means for determining the degree of risk and outputting collision risk information indicating the degree of risk; a heat exchange amount in the first heat exchanger, a heat exchange amount in the second heat exchanger, and a throttle. At least one of the valve opening degrees of the valve is set as a control target, and the pressure difference between the suction pressure of the gaseous refrigerant in the linear compressor and the discharge pressure thereof is increased according to the collision risk indicated by the collision risk information. A refrigeration cycle apparatus comprising: a system control means for controlling the control object so that the top clearance is widened. 2. The refrigeration cycle apparatus according to claim 1, wherein the collision risk determining means determines, based on the piston position information, a piston position corresponding to a predetermined phase of the piston reciprocation in a predetermined limit. A refrigeration cycle apparatus for determining that there is a risk of the piston colliding with the cylinder when the cylinder approaches the cylinder head side from the position. 3. The refrigeration cycle apparatus according to claim 1, wherein the collision risk determining means sets a piston position corresponding to a predetermined phase of the piston reciprocation based on the piston position information. It is determined which of the plurality of danger determination areas is arranged from the cylinder head side to the opposite side along the reciprocating direction of the piston, and the danger determination area including the piston position is determined. A refrigeration cycle apparatus wherein the closer to the cylinder head, the higher the risk of collision is determined. 4. The refrigeration cycle apparatus according to claim 1, wherein the position detecting means detects the position of the piston at regular time intervals and outputs the plurality of pieces of piston position information. The degree determination means determines a piston speed when the piston passes a predetermined determination position based on the plurality of piston position information, and determines the collision risk based on the piston speed. Characteristic refrigeration cycle device. 5. The refrigeration cycle apparatus according to claim 1, wherein a top dead center of the piston is calculated based on the piston position information, and top dead center information indicating the top dead center is output. The collision risk determining means receives the top dead center information, and when the top dead center of the piston approaches a cylinder head side from a preset limit position, there is a risk that the piston collides with the cylinder. A refrigeration cycle apparatus characterized in that the refrigeration cycle apparatus is determined to have a property. 6. The refrigeration cycle apparatus according to claim 5, wherein the collision risk determining means sets the top dead center of the piston in a reciprocating direction of the piston based on the top dead center information. It is determined which of the plurality of risk determination areas are arranged from the cylinder head side to the opposite side along the cylinder, and the risk determination area including the top dead center of the piston is determined as the cylinder head. Closer to
A refrigeration cycle apparatus characterized in that the collision risk is determined to be high. 7. The refrigeration cycle apparatus according to claim 1, wherein the system control means controls the control target based on the piston position information such that a top dead center of the piston is maintained at a predetermined position. A refrigeration cycle apparatus characterized in that: 8. The refrigeration cycle apparatus according to claim 1, wherein the suction pressure of the linear compressor, the discharge pressure thereof, the pressure of the gaseous refrigerant sent to the first heat exchanger, and the pressure of the second heat exchanger. A pressure detector that detects a pressure value of at least one of the pressures of the gaseous refrigerant generated as a setting target pressure and outputs detection pressure information indicating a detection value of the setting target pressure; and A pressure setter that sets a predetermined value based on the command signal and outputs set pressure information indicating the set value of the set target pressure; and a set value of the set target pressure based on the set pressure information and the detected pressure information. And a pressure controller that outputs information indicating the control amount to the controlled object so that the difference between the detected value and the detected value is reduced. Setting target Set value of the force, to be a value corresponding to collision risk indicated by the collision risk information, the refrigeration cycle apparatus characterized in that the command by the command signal. 9. The refrigeration cycle apparatus according to claim 1, wherein the temperature of the refrigerant drawn into the linear compressor, the temperature of the refrigerant discharged from the linear compressor, the temperature of the refrigerant in the first heat exchanger, A temperature detector that detects a temperature value of at least one of the temperatures of the refrigerant in the heat exchanger as a setting target temperature and outputs detection temperature information indicating a detection value of the setting target temperature; A temperature setter that sets a predetermined value based on the command signal and outputs set temperature information indicating a set value of the set target temperature; and a set value of the set target temperature based on the set temperature information and the detected temperature information. And a temperature controller that outputs information indicating the control amount of the control target so that a difference value between the temperature control value and the detected value becomes small. Respect, the set value of the set target temperature, so that a value corresponding to collision risk indicated by the collision risk information, the refrigeration cycle apparatus characterized in that the command by the command signal. 10. The refrigeration cycle apparatus according to claim 1, wherein the system control means performs first control for avoiding a collision of the piston with a cylinder with respect to the control target based on the collision risk information. A system controller for anti-collision operation that outputs first control information indicating an amount, and a second control amount indicating a second control amount for operating the linear compressor in an optimal state set in advance for the control target. A normal operation system controller that outputs the second control information; and a weighting process for receiving the first and second control information and weighting the first control amount and the second control amount. Is performed so that the weighting ratio of the first control amount to the second control amount becomes larger as the collision risk indicated by the first control amount increases, and the weighted first and second control amounts Control amount determining means for outputting the sum as information indicating a third control amount for the control target, wherein the control target is controlled by the third control amount. . 11. The refrigeration cycle apparatus according to claim 1, wherein the system control means changes a drive current of a linear motor supplied to the linear compressor in accordance with an increase in the collision risk indicated by the collision risk information. Current control means for controlling the amount of heat exchange in the first heat exchanger and the amount of heat exchange in the second heat exchanger in accordance with the collision risk indicated by the collision risk information. And a second control for controlling the drive current of the linear motor as well as a first control for controlling at least one of the valve opening degrees of the throttle valve. Cycle equipment.