Reciprocating compressor, control method of reciprocating compressor and refrigerator

Abstract

The invention relates to the field of compressors, and provides a reciprocating compressor, a control method thereof and a refrigerator. The reciprocating compressor comprises an air cylinder, a piston, a crankshaft and a gulp valve arranged at a gulp port, the piston reciprocates in a cavity, the motion cycle of the piston comprises an expansion stroke, an intake stroke, a compression stroke and an exhaust stroke, and the gulp valve is basically opened only in an effective gulp area of the compression stroke and closed in other time periods, so that the gulp pressure loss is reduced, and the service life of the gulp valve is prolonged. The compressor energy efficiency is improved. The gulp valve can be an electric control valve or a non-electric control mechanical valve linked with the crankshaft / piston. The compressor can be applied to a refrigerator refrigerating system, one compressor serves a refrigerating chamber and a freezing chamber at the same time, and the thermodynamic perfection degree and the energy-saving effect are improved.

Description

Technical Field

[0001] The present invention relates to the field of compressors, and in particular to a reciprocating compressor, a control method for a reciprocating compressor, and a refrigerator. Background Art

[0002] Injection reheat technology improves compressor performance by injecting an intermediate-pressure refrigerant gas during the compression process, particularly enhancing the compressor's heating capacity in low-temperature environments. It is primarily used in scroll compressors and is widely used in large-scale low-temperature heating equipment such as air conditioners and heat pumps.

[0003] Chinese patent CN108071590A discloses a cylinder compressor, which uses an independent reciprocating compression chamber of the compressor to actively inhale and compress intermediate temperature steam, applies the concept of jet enthalpy increase technology to the refrigeration system of the refrigerator, constructs an independent compression refrigeration cycle that matches the refrigerator refrigeration system, and improves the adaptability to all working conditions and energy saving effect. However, the air supply port of the cylinder compressor is set on the side wall of the cylinder. When replenishing air, in order to avoid the backflow of replenishing air, the position of the air supply hole needs to be set at the position of the side wall close to the bottom dead center of the piston, and the air supply pressure range and air supply volume are limited. In addition, the air supply hole located at this position will cause the pressure in the cylinder to be only slightly higher than the intake pressure during air replenishment, resulting in large air supply pressure loss, low thermodynamic perfection, and limited energy efficiency improvement. Summary of the Invention

[0004] In response to the above problems, one aspect of the present invention provides a reciprocating compressor that can ensure a suitable air supply pressure range and air supply volume and reduce air supply pressure loss.

[0005] A first aspect of the present invention provides a reciprocating compressor, comprising a cylinder, a piston, an air supply valve and a pressure control mechanism, wherein the cylinder has a chamber and an air inlet, an exhaust port and an air supply port connected to the chamber; the piston reciprocates in the chamber; the air supply valve is arranged at the air supply port; the pressure control mechanism is configured to control the air supply valve to open when the pressure in the chamber is within a specified range, the specified range having an upper limit value and a lower limit value, the upper limit value is less than or equal to the air supply pressure of the air supply port, and the lower limit value is greater than the air intake pressure of the air inlet port.

[0006] Optionally, the pressure control mechanism is further configured to control the air supply valve to open when the pressure in the chamber is within a specified range and the pressure in the chamber is rising.

[0007] Optionally, one movement cycle of the piston includes an expansion stroke, an intake stroke, a compression stroke and an exhaust stroke, and the air supply valve is closed during the time periods corresponding to the expansion stroke and the intake stroke.

[0008] Optionally, the pressure control mechanism includes a pressure sensor and a controller, the pressure sensor detects the air pressure in the chamber; the controller is communicated with the pressure sensor and the air supply valve, and controls the opening and closing of the air supply valve according to the detection result of the pressure sensor.

[0009] Optionally, the pressure control mechanism includes a push rod, a first spring, a first pressure membrane box, a second spring and a second pressure membrane box, the push rod has a through hole corresponding to the air supply port; the first spring is arranged on one side of the push rod; one end of the first spring is connected to the push rod, and the other end is connected to the first pressure membrane box, and the first pressure membrane box is connected to the side of the air supply port away from the chamber; the second spring is arranged on the side of the push rod opposite to the first spring; one end of the second spring is connected to the push rod, and the other end is connected to the second pressure membrane box, and the second pressure membrane box is connected to the chamber.

[0010] Optionally, the lower limit value is greater than the intake pressure of the intake port by a prescribed pressure value.

[0011] Optionally, one movement cycle of the piston includes an expansion stroke, an intake stroke, a compression stroke and an exhaust stroke, and the air supply valve is closed during a period corresponding to the intake stroke.

[0012] Optionally, the upper limit value is less than or equal to the gas supply pressure of the gas supply port.

[0013] Optionally, the air supply port is provided on the side wall of the cylinder, or the air supply port, the air inlet port and the air outlet port are provided on the same end cover of the cylinder, or the air supply port is provided on the piston.

[0014] The second aspect of the present invention provides a control method for a reciprocating compressor, which includes a cylinder, a piston and an air supply valve. The cylinder has a chamber and an air inlet, an exhaust port and an air supply port connected to the chamber; the piston reciprocates in the chamber; the air supply valve is arranged at the air supply port, and the air supply valve opens when the pressure in the chamber is within a specified range. The specified range has an upper limit value and a lower limit value, the upper limit value is less than or equal to the air supply pressure of the air supply port, and the lower limit value is greater than the air intake pressure of the air inlet port.

[0015] The third aspect of the present invention provides a refrigerator, comprising a first refrigeration circuit and a second refrigeration circuit, the first refrigeration circuit being composed of a reciprocating compressor, a condenser, a refrigerating chamber throttling element and a refrigerating chamber evaporator connected in sequence; the second refrigeration circuit being composed of a reciprocating compressor, a condenser, a freezing chamber throttling element and a freezing chamber evaporator connected in sequence; the reciprocating compressor comprising a cylinder, a piston, an air supply valve and a pressure control mechanism, the cylinder having a chamber and an air inlet, an exhaust port and an air supply port connected to the chamber, the air inlet being connected to the refrigerant outlet of the freezing chamber evaporator, the exhaust port being connected to the refrigerant inlet of the condenser, and the air supply port being connected to the refrigerant outlet of the refrigerating chamber evaporator; the piston reciprocating in the chamber; the air supply valve being arranged at the air supply port; the pressure control mechanism being configured to control the air supply valve to open when the pressure in the chamber is within a specified range, the specified range having an upper limit value and a lower limit value, the upper limit value being less than or equal to the air supply pressure of the air supply port, and the lower limit value being greater than the air intake pressure of the air inlet port.

[0016] Beneficial effects

[0017] By adding an air supply valve and opening it in the effective air supply area and closing it as much as possible in the ineffective air supply area, the air supply pressure range and air supply volume can be effectively guaranteed and the air supply pressure loss can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 1 is a schematic structural diagram of a reciprocating compressor according to one embodiment of the present invention.

[0019] Figure 2 This is a refrigerant flow system diagram of a refrigerator's refrigeration system.

[0020] Figure 3 This is a schematic diagram of the changing states of various parameters of a reciprocating compressor in one or more embodiments of the present invention during one cycle of the reciprocating motion of the piston.

[0021] Figure 4 Schematic diagram of the structure of a reciprocating compressor provided in some embodiments of the present invention.

[0022] Figure 5 This is a schematic diagram of using a ball valve as an air supply valve to achieve precise control of the opening and closing timing in some embodiments of the present invention.

[0023] Figure 6 It is an air supply valve provided in some embodiments of the present invention, which is similar to a ball valve and can be opened and closed within a specific angle range.

[0024] Figure 7 It is an air supply valve provided in other embodiments of the present invention that can be linked with the crankshaft and can be opened and closed at a specific angle or stroke range.

[0025] Figure 8 Schematic diagram of the structure of a reciprocating compressor provided in some embodiments of the present invention.

[0026] Figure 9 It is a schematic structural diagram of a reciprocating compressor provided in some other embodiments of the present invention.

[0027] Figure 10 This is a schematic diagram of the principle of a pressure control mechanism in some embodiments of the present invention, which utilizes the detection of the pressure in the cylinder in conjunction with feedback control to achieve air replenishment in the effective air replenishment area as much as possible and avoid air replenishment in the ineffective air replenishment area.

[0028] Figure 11 The structure of the air supply valve for implementing pressure feedback control in some embodiments of the present invention is shown.

[0029] Reference numerals:

[0030] Reciprocating compressor 100; cylinder 102; piston 104; crankshaft 106; connecting rod 108; air inlet 110; exhaust port 112; side wall 114; air supply port 116; air supply valve 118; end cover 120; chamber 122; refrigeration system 200; first refrigeration circuit 201; second refrigeration circuit 202; refrigerator compartment evaporator 204; freezer compartment evaporator 205; condenser 206; refrigerator compartment throttling element 207; freezer compartment throttling element 208; valve stem 301; ball 303; valve body 305; air flow channel 307; opening 309; channel structure 311; movable part 313; push rod 402; first spring 404; second spring 406; first pressure membrane box 408; second pressure membrane box 410; through hole 412. DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] One or more embodiments of the present invention provide a reciprocating compressor 100. Figure 1 FIG. 1 is a schematic structural diagram of a reciprocating compressor 100 according to an embodiment of the present invention.

[0033] refer to Figure 1 The reciprocating compressor 100, or cylinder compressor, includes a cylinder 102, a piston 104, a crankshaft 106, and a connecting rod 108. The piston 104 is disposed in the cylinder 102 and can be moved along a chamber 122 in the cylinder 102. Figure 1The piston 104 reciprocates in the vertical direction. The vertical movement of the piston 104 is driven by the crankshaft 106 via the connecting rod 108. The crankshaft 106 is driven to rotate by a motor (not shown). The connecting rod 108 converts the rotation of the crankshaft 106 into the vertical movement of the crankshaft 106.

[0034] The cylinder 102 is at the end away from the crankshaft 106, i.e. Figure 1 An air inlet 110 and an exhaust port 112 are provided at the top of the cylinder, and an air supply port 116 is provided on one sidewall 114. An air inlet valve is provided on the air inlet 110, and an air exhaust valve is provided on the exhaust port 112. The piston 104 can move upward within the cylinder 102 to a point where the top end abuts the air inlet 110 and the exhaust port 112, i.e., the top dead center, where the air in the cylinder 102 is exhausted through the exhaust port 112. It can then move downward to a point below the air supply port 116, where air is either introduced through the air inlet 110 or supplied through the air supply port 116.

[0035] One cycle of the up and down reciprocating motion of the piston 104 includes Figure 1 During the downward movement of the top of the cylinder 102, piston 104 moves downward, causing the gas inside cylinder 102 to expand and the pressure to decrease. When the piston 104 moves to the appropriate position, the air inlet 110 opens, and the refrigerant enters the chamber 122 inside cylinder 102 through the air inlet 110. After the intake process is completed, piston 104 returns and moves upward, closing both the air inlet 110 and the exhaust port 112. After piston 104 compresses the refrigerant inside, exhaust port 112 opens at the appropriate time, and piston 104 continues to move upward, discharging the compressed refrigerant through exhaust port 112, completing one cycle of reciprocating motion.

[0036] In one or more embodiments of the present invention, the reciprocating compressor 100 includes an air supply valve 118 disposed at the air supply port 116. The air supply valve 118 is configured to open and close the air supply port 116 in synchronization with the reciprocating motion of the piston 104. Specifically, the air supply port 116 is opened and closed at appropriate times, thereby reducing pressure loss during air supply and improving energy efficiency. The specific timing for opening and closing the air supply port 116 will be described in detail below.

[0037] The following combination Figure 2 , an applicable device of the reciprocating compressor 100 in one or more embodiments of the present invention is introduced. Figure 2 It is a refrigerant flow system diagram of a refrigeration system 200 of a refrigerator.

[0038] refer to Figure 2The refrigerator's refrigeration system 200 includes a first refrigeration circuit 201 and a second refrigeration circuit 202. The evaporator of the first refrigeration circuit 201 is located in a position corresponding to the refrigerator compartment and is used to cool the refrigerator compartment. It is called the refrigerator compartment evaporator 204. The evaporator of the second refrigeration circuit 202 is located in a position corresponding to the freezer compartment and is used to cool the freezer compartment. It is called the freezer compartment evaporator 205. The two refrigeration circuits share the compressor and condenser 206.

[0039] Specifically, the first refrigeration circuit 201 is composed of a reciprocating compressor 100, a condenser 206, a refrigeration chamber throttling element 207 (capillary tube), and a refrigeration chamber evaporator 204, which are connected in sequence. The second refrigeration circuit 202 is composed of a reciprocating compressor 100, a condenser 206, a freezer chamber throttling element 208 (capillary tube), and a freezer chamber evaporator 205, which are connected in sequence. In the first refrigeration circuit 201, the refrigerant outlet of the refrigeration chamber evaporator 204 is connected to the air supply port 116 of the reciprocating compressor 100; in the second refrigeration circuit 202, the refrigerant outlet of the freezer chamber evaporator 205 is connected to the air inlet 110 of the reciprocating compressor 100; and the refrigerant inlet of the condenser 206 is connected to the exhaust port 112 of the reciprocating compressor 100.

[0040] By applying one or more reciprocating compressors 100 of the present invention to the refrigeration system 200 of the above-mentioned refrigerator, a single reciprocating compressor 100 can provide two evaporation temperatures, the lower temperature of which is applied to the freezer evaporator 205, and the higher temperature is applied to the refrigerator evaporator 204. The corresponding degree of compression work can be performed as needed, thereby improving the thermodynamic perfection of the system.

[0041] Figure 3 1 is a schematic diagram illustrating the changing states of various parameters of the reciprocating compressor 100 during one cycle of the reciprocating motion of the piston 104 in one or more embodiments of the present invention.

[0042] refer to Figure 3 A cycle of the piston 104's up-and-down reciprocating motion includes an expansion stroke, an intake stroke, a compression stroke, and an exhaust stroke, performed sequentially. The expansion stroke corresponds to the range of travel from the piston 104's top dead center to the opening of the intake port 110; the intake stroke corresponds to the range of travel from the opening of the intake port 110 to the piston's bottom dead center; the compression stroke corresponds to the range of travel from the piston's bottom dead center to the opening of the exhaust port 112; and the exhaust stroke corresponds to the range of travel from the opening of the exhaust port 112 to the piston's top dead center.

[0043] In one or more embodiments of the present invention, during the reciprocating motion of piston 104, crankshaft 106 maintains a constant rotational speed, i.e., the crankshaft 106 rotational speed remains constant, while the crankshaft angle increases linearly from 0° to 360°. For ease of explanation, herein, crankshaft angles of 0° and 360° correspond to the top dead center of piston 104, and 180° corresponds to the bottom dead center of piston 104. In other embodiments, the corresponding manner and the numerical expression method can be flexibly adjusted as needed, and are not limited thereto.

[0044] During the uniform rotation of the crankshaft 106, the working volume of the cylinder 102 increases first and then decreases. The pressure Pin in the cylinder 102 is as follows: Figure 3 The pressure in cylinder 102 changes as shown in the bottom curve. During the expansion stroke, the pressure in cylinder 102 gradually decreases. When the intake stroke begins, the intake port 110 opens, and the pressure in the intake port 110 and the pressure in the cylinder 102 are balanced, with the pressure in cylinder 102 being substantially equal to the intake pressure. When the compression stroke begins, the intake port 110 and the exhaust port 112 close, and as piston 104 compresses and performs work, the pressure in cylinder 102 gradually increases. When the exhaust stroke begins, the exhaust port 112 opens, and the pressure in cylinder 102 and the exhaust passage are balanced, with the pressure in cylinder 102 being substantially equal to the exhaust pressure.

[0045] In some embodiments of the present invention, the air supply valve 118 can be controlled to supply air only in the effective air supply area, while ignoring the ineffective air supply area, to reduce air supply pressure loss and improve energy conservation. Specifically, the effective air supply area is the area during the compression stroke that is lower than the air supply pressure and higher than the intake pressure. Preferably, the area is higher than the intake pressure by a specified pressure value and lower than the air supply pressure. The specified pressure value can be, for example, half the difference between the air supply pressure and the intake pressure.

[0046] The invalid air supply area includes multiple areas in the expansion stroke, intake stroke and compression stroke. In the solution disclosed in patent CN108071590A, since the air supply timing of the air supply port 116 is not controlled, the opening and closing of the air supply port 116 is achieved only by blocking / unblocking the air supply port 116 during the reciprocating motion of the piston 104. Air supply is also performed during part of the expansion stroke and intake stroke (specifically, in the area where Pin is lower than the air supply pressure during the expansion stroke and intake stroke). However, the pressure loss of this part of the air supply is large, which is not conducive to improving energy efficiency. In some embodiments of the present invention, by prohibiting air supply in these invalid air supply areas, especially during the time period when the piston 104 does not separate the chamber 122 from the air supply port 116, by closing the air supply valve 118, the air supply pressure loss can be effectively reduced and the energy efficiency of the system can be improved.

[0047] Specifically, in some embodiments, during one opening and closing cycle of the supply valve 118, the supply valve 118 is closed for at least a portion of the time period corresponding to the intake stroke of the piston 104. Furthermore, during one opening and closing cycle of the supply valve 118, the supply valve 118 is closed for the entire time period corresponding to the intake stroke of the piston 104. In some embodiments, during one opening and closing cycle of the supply valve 118, the supply valve 118 is closed for the entire time period corresponding to the expansion stroke of the piston 104. By using the supply valve 118 to prohibit supplying air to the cylinder 102 during these inactive supply zones, supply pressure loss can be effectively reduced, thereby improving system energy efficiency.

[0048] The inactive air supply period may also include a portion of the compression stroke of piston 104, specifically the period when the pressure in cylinder 102 is only slightly higher than the intake pressure, in other words, the initial stage of the compression stroke. In some embodiments, the opening and closing timing of air supply valve 118 can be controlled to close air supply valve 118 during this period, thereby avoiding air supply pressure loss during this period and improving system energy efficiency.

[0049] In some embodiments, crank angles of 0° and 360° correspond to piston 104 being at top dead center, and crank angle of 180° corresponds to piston 104 being at bottom dead center. The inlet valve 118 opens within a crank angle range of (θ1, θ2). In some embodiments, 180° ≤ θ1 ≤ θ2 ≤ 320°.

[0050] In other embodiments, the opening and closing of the inlet valve 118 may be controlled based on the pressure Pin by a pressure control mechanism. For example, the inlet valve 118 may be opened to supply air only when the pressure Pin in the cylinder 102 exceeds the intake pressure by a predetermined pressure value. The predetermined pressure value may be, for example, half the difference between the inlet pressure and the inlet pressure.

[0051] The following introduces some mechanisms and control methods for controlling the on-off timing of the air supply valve 118, including a timing control mechanism and a pressure control mechanism. The timing control mechanism controls the on-off of the air supply valve 118 according to a pre-set or feedback-controlled timing; the pressure control mechanism controls the on-off of the air supply valve 118 according to the pressure of the internal chamber 122 of the cylinder 102; both can achieve the effect of replenishing air in the effective air supply area as much as possible, and avoid replenishing air in the invalid air supply area, thereby reducing the air supply pressure loss and improving energy efficiency. It should be noted that the following description is only exemplary and does not include all methods that can realize the control of the on-off timing of the air supply valve 118. Other suitable mechanisms and methods that can control the on-off timing of the air supply valve 118 that are not listed should be included in the scope of the embodiment of the present invention and will not be repeated here.

[0052] Figure 41 is a schematic structural diagram of a reciprocating compressor 100 provided in some embodiments of the present invention. Figure 4 The reciprocating compressor 100 uses a solenoid valve as the air supply valve 118 and uses a timing control signal to control the opening and closing of the air supply valve 118. The timing control signal can be pre-set or feedback controlled according to the detection of the sensor.

[0053] The sensor may be a pressure sensor for detecting the pressure within the cylinder 102, or a Hall effect sensor, magnetoelectric sensor, or the like for detecting the crank angle of the crankshaft 106. In some embodiments, the timing control signal may also be obtained by processing a signal reflecting the motor's rotation angle obtained from the motor. In other embodiments, the sensor may also be a sensor for detecting the on / off status of the intake port 110 and the exhaust port 112, a sensor for detecting the travel of the piston 104, or a combination of these types of sensors, which are not limited in the embodiments of the present invention.

[0054] By detecting the crankshaft angle, the pressure within cylinder 102, or other parameters, in some embodiments of the present invention, a control unit in communication with the sensor can calculate the current motion state of piston 104, specifically, the stroke and position of the piston within its reciprocating motion. By combining these stroke and position determinations, a timing control signal can be set to control the solenoid valve to ensure that air is supplied only in the effective air supply area and to avoid supplying air in the ineffective air supply area, thereby effectively reducing air supply pressure loss and improving energy efficiency.

[0055] In some other embodiments of the present invention, the reciprocating compressor 100 may also use any other form of electronically controlled valve such as an electronic expansion valve, which can use a timing control signal to perform precise switching timing control as the air supply valve 118. The embodiments of the present invention do not limit this.

[0056] In other embodiments of the present invention, a non-electrically controlled valve may be used as the air supply valve 118 to achieve periodic and precise control of the opening and closing timing of the air supply valve 118. Because the crankshaft 106 and the piston 104 rotate or reciprocate with the same period, the non-electrically controlled valve can be connected to the crankshaft 106 or the piston 104, and can be opened and closed synchronously with the reciprocating motion of the piston 104.

[0057] Figure 5 This is a schematic diagram of using a ball valve as the air supply valve 118 to achieve precise control of the opening and closing timing in some embodiments of the present invention.

[0058] refer to Figure 5The ball valve includes a valve stem 301, a ball 303, and a valve body 305. The valve body 305 is disposed in an air flow channel 307 for supplying air to the air supply port 116. The ball 303 is disposed in the air flow channel 307. The ball 303 has an opening 309 extending through its center and can be driven by the valve stem 301 to rotate within the valve body 305. Specifically, the valve stem 301 is coupled to the crankshaft 106. The rotation of the crankshaft 106 drives the valve stem 301, which in turn drives the ball 303 to rotate within the valve body 305.

[0059] When the opening 309 rotates to an angle opposite to the air flow channel 307, the air supply valve 118 opens, connecting the air flow channel 307, and allowing air to be supplied to the cylinder 102 through the air supply port 116. When the opening 309 rotates to an angle offset from the air flow channel 307, the air supply valve 118 closes, and the air flow channel 307 is closed. In one or more embodiments of the present invention, the duration or angle range of the opening of the air supply valve 118 in each cycle can be adjusted by adjusting the size of the opening 309 and the size of the air flow channel 307.

[0060] In order to ensure that the air supply valve 118 supplies air only in the effective air supply area as much as possible and avoids supplying air in the invalid air supply area as much as possible, in some embodiments of the present invention, the correspondence between the opening period of the air supply valve 118 and the effective air supply area can be achieved by accurately setting the structure and matching method of the connection mechanism (such as a coupling) between the valve stem 301 and the crankshaft 106.

[0061] Figure 6 It is an air supply valve 118 provided in some embodiments of the present invention, which is similar to a ball valve and can be opened and closed within a specific angle range. Figure 6 The top diagram is a schematic diagram of the structure of the air supply valve 118, while the middle and bottom diagrams illustrate the two critical switching states of the air supply valve 118. The air supply valve 118 includes a valve stem 301 and an air flow channel 307. The air flow channel 307 is arranged orthogonally to the valve stem 301 and communicates with the air supply port 116. Air can be supplied to the cylinder 102 through the air flow channel 307 and the air supply port 116.

[0062] A hollow channel structure 311 is formed at the end of the valve stem 301. As the valve stem 301 rotates, the channel structure 311 also rotates. During certain angles during the valve stem 301's rotation cycle, the channel structure 311 may be opposite the airflow channel 307. During these periods, the air supply port 116 is open. At other angles during the valve stem 301's rotation cycle, the channel structure 311 and the airflow channel 307 are offset from each other. During these periods, the air supply port 116 is closed.

[0063] In order to ensure that the air supply valve 118 supplies air only in the effective air supply area as much as possible and avoids supplying air in the invalid air supply area, in some embodiments of the present invention, the correspondence between the opening period of the air supply valve 118 and the effective air supply area can be achieved by accurately setting the structure and matching method of the connection mechanism of the valve stem 301 and the crankshaft 106.

[0064] Figure 7 In some other embodiments of the present invention, the air supply valve 118 can be linked with the crankshaft 106 to achieve opening and closing at a specific angle or stroke range. Figure 7 This type of air supply valve 118 includes a valve body 305 and a movable component 313. The valve body 305 has an air flow channel 307 connected to the air supply port 116 and a movable component 313 track intersecting with the air flow channel 307. Specifically, in some embodiments of the present invention, the air flow channel 307 and the movable component 313 track are arranged orthogonally.

[0065] The movable member 313 is connected to the crankshaft 106 or the piston 104 via a connecting rod 108 and can be driven by the crankshaft 106 or the piston 104 to reciprocate within the movable member 313 track. The movable member 313 has an opening 309 extending along the direction of the airflow channel 307. When the movable member 313 reciprocates within the movable member 313 track, the opening 309 is aligned with the airflow channel 307 during certain periods of time and offset from the airflow channel 307 during other periods of time. When the opening 309 is aligned with the airflow channel 307, the air supply valve 118 opens, the airflow channel 307 is open, and air supply to the cylinder 102 is allowed through the air supply port 116. When the opening 309 is offset from the airflow channel 307, the air supply valve 118 closes, closing the airflow channel 307.

[0066] In order to replenish air in the effective air replenishment area as much as possible and avoid replenishing air in the invalid air replenishment area, in some embodiments of the present invention, the correspondence between the opening period of the air replenishment valve 118 and the effective air replenishment area can be achieved by accurately setting the connection method between the movable component 313 and the crankshaft 106 and the piston 104.

[0067] In the above manner, the reciprocating compressor 100 provided in some embodiments of the present invention is provided with an air supply valve 118 at the air supply port 116, and the opening and closing of the air supply valve 118 is controlled synchronously with the stroke of the piston 104, and the air supply valve 118 is opened and closed as much as possible. Figure 3 The effective air replenishment area shown in the figure is used to replenish air, while avoiding replenishing air in the ineffective air replenishment area, thereby effectively reducing the air replenishment pressure loss and improving energy efficiency.

[0068] In addition, another advantage of the reciprocating compressor 100 is that the location of the air supply port 116 can be more flexible. Figure 81 is a schematic structural diagram of a reciprocating compressor 100 provided in some embodiments of the present invention. Figure 8 The cylinder 102 includes a sidewall 114 and an end cap 120. The end cap 120 is disposed at one end of the sidewall 114 that is closest to the top dead center. In some embodiments of the present invention, not only are the air inlet 110 and the exhaust port 112 disposed on the end cap 120, but the air supply port 116 is also disposed on the end cap 120. Due to the presence of the air supply valve 118, the air supply port 116 no longer relies on the piston 104 blocking / unblocking the air supply port 116 to open or close. This makes the location of the air supply port 116 more flexible, as long as air can be supplied to the cylinder 102 through the air supply port during the time period corresponding to the effective air supply zone.

[0069] Figure 9 1 is a schematic structural diagram of a reciprocating compressor 100 provided in some other embodiments of the present invention. Figure 9 In some embodiments of the present invention, the air supply port 116 may be provided through the piston 104. During the expansion stroke and the intake stroke, the air supply port 116 is closed by the air supply valve 118, and is opened only during the effective air supply region of the compression stroke.

[0070] In summary, the addition of the air supply valve 118 not only allows the reciprocating compressor 100 to be controlled to supply air substantially only in the effective air supply area, but also allows for greater flexibility in the placement of the air supply port 116, eliminating the need for placement on the sidewall 114. Furthermore, even if the air supply port 116 is located on the sidewall 114, it need not be positioned close to the bottom dead center of the piston 104, effectively increasing the air supply pressure range and air supply volume.

[0071] The above shows an implementation of a timing control mechanism that can replenish gas in the effective gas replenishment area as much as possible and avoid replenishing gas in the ineffective gas replenishment area. In other implementations of the present invention, a pressure control mechanism can also be used.

[0072] Figure 10 This is a schematic diagram of the principle of a pressure control mechanism in some embodiments of the present invention, which utilizes the detection of the pressure in the cylinder 102 in conjunction with feedback control to achieve gas replenishment in the effective gas replenishment area as much as possible and avoid gas replenishment in the ineffective gas replenishment area.

[0073] refer to Figure 10 The pressure control mechanism may include a pressure sensor to detect the air pressure in the chamber 122 of the cylinder 102 (i.e., the pressure Pin in the cylinder 102). The pressure sensor is communicated with the controller of the reciprocating compressor 100. The controller is also communicated with the air supply valve 118 to send a feedback control signal to the air supply valve 118 to control the opening and closing of the air supply valve 118.

[0074] The controller is configured to control the opening and closing of the air supply valve 118 based on the detection results of the pressure sensor. It should be noted that "based on the detection results of the pressure sensor" here does not limit the detection results to be the only factor for judgment. In some embodiments, the detection results of the pressure sensor can be combined with other judgment factors to jointly determine whether to open or close the air supply valve 118.

[0075] In some embodiments, the controller is configured to: when the detection result of the pressure sensor corresponds to the air pressure range of the effective air supply area, control the air supply valve 118 to open; and when the detection result of the pressure sensor does not correspond to the air pressure range of the effective air supply area, close the air supply valve 118.

[0076] The pressure range of the effective air supply zone (i.e., the specified range) has an upper limit and a lower limit. The upper limit is less than or equal to the air supply pressure at the air supply port 116, and the lower limit is greater than the intake pressure at the air inlet 110. In some embodiments, the lower limit can be increased to increase the air supply pressure and reduce air supply pressure loss. Specifically, the lower limit can be higher than the intake pressure at the air inlet 110 by a specified pressure value. For example, the specified pressure value can be half the difference between the air supply pressure and the intake pressure.

[0077] In some embodiments of the present invention, if the opening and closing of the inflator valve 118 is controlled solely based on feedback from the pressure sensor's detection results, the inflator valve 118 may open to replenish air during the expansion stroke of the piston 104. In some embodiments of the present invention, additional feedback control conditions can be added to prohibit the inflator port 116 from replenishing air during the expansion stroke. Specifically, inflator port 116 may only be activated during the rising edge of air pressure, and not during the falling edge. In other words, inflator port 116 may only be activated during the compression stroke, not during the expansion stroke. For example, the currently acquired air pressure value can be compared with the pressure value acquired a specified time ago to determine whether the current pressure is rising or falling. The opening and closing of the inflator valve 118 can then be controlled based on whether the pressure range is within the effective inflator zone. Specifically, inflator valve 118 is controlled to open when the pressure within chamber 122 is within the effective inflator zone and is rising.

[0078] In some embodiments of the present invention, the pressure control mechanism can control the opening and closing of the air supply valve 118, which is an electrically controlled valve, based on the feedback control signal. In other embodiments, the pressure control mechanism can also be implemented using a mechanical structure.

[0079] Figure 11 FIG2 shows the structure of the air supply valve 118 for realizing pressure feedback control in some embodiments of the present invention. Figure 11The pressure control mechanism includes a push rod 402, a first spring 404, a second spring 406, a first pressure capsule 408, and a second pressure capsule 410. The push rod 402 has a through hole 412 corresponding to the air supply port 116. The first spring 404 and the second spring 406 are disposed on opposite sides of the push rod 402. One end of the first spring 404 abuts the push rod 402, and the other end abuts the first pressure capsule 408. The first pressure capsule 408 communicates with the side of the air supply port 116 away from the chamber 122, thereby applying the air supply pressure Pm to the first pressure capsule 408. The second spring 406 abuts one end of the push rod 402, and the other end abuts the second pressure capsule 410. The second pressure capsule 410 communicates with the chamber 122, thereby applying the internal pressure Pin of the chamber 122 to the second pressure capsule 410.

[0080] Based on force analysis, the position of push rod 402 can be controlled by the difference Pm-Pin between the gas supply pressure and the internal pressure of chamber 122. Specifically, when Pm-Pin is within a specified range, through hole 412 of push rod 402 connects to gas supply port 116, and gas supply begins. When Pm-Pin is outside the specified range, through hole 412 of push rod 402 becomes disengaged from gas supply port 116, and gas supply ceases.

[0081] By properly selecting first spring 404 and second spring 406, and appropriately setting the size and position of through-hole 412, a pressure control mechanism can be mechanically implemented. This pressure control mechanism eliminates the need for electronic control components, utilizing a mechanical structure to perform pressure detection and feedback control, strictly preventing backflow of supplemental gas, and improving safety and stability. It should also be noted that the above mechanical implementation of the pressure control mechanism is merely illustrative, and the present invention does not limit the specific form of implementation of the aforementioned pressure control mechanism, and electronic control is also possible.

[0082] It should be noted that in the embodiments of the present invention, opening the air supply valve 118 can also be achieved by increasing its opening, and closing the air supply valve 118 can also be achieved by decreasing its opening, and these are equivalent in terms of effect. As long as the air supply volume is increased in the effective air supply area and decreased in the ineffective air supply area, the same or similar effects as those of the embodiments of the present invention can be achieved, reducing air supply pressure loss and improving energy efficiency.

[0083] The above are merely optional embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A reciprocating compressor, characterized in that: include: The cylinder comprises a chamber and an air inlet, an air outlet and an air supply port communicating with the chamber; a piston reciprocating within the chamber; An air supply valve is provided at the air supply port; A pressure control mechanism, wherein the pressure control mechanism is configured to control the air supply valve to open when the pressure in the chamber is within a specified range, wherein the specified range has an upper limit value and a lower limit value, wherein the upper limit value is less than or equal to the air supply pressure of the air supply port, and the lower limit value is greater than the air intake pressure of the air intake port.

2. The reciprocating compressor according to claim 1, wherein The pressure control mechanism is further configured as: When the pressure in the chamber is within the prescribed range and the pressure in the chamber is rising, the air supply valve is controlled to open.

3. The reciprocating compressor according to claim 2, wherein One movement cycle of the piston includes an expansion stroke, an intake stroke, a compression stroke, and an exhaust stroke, and the air supply valve is closed during time periods corresponding to the expansion stroke and the intake stroke.

4. The reciprocating compressor according to claim 1, wherein The pressure control mechanism includes A pressure sensor, detecting the air pressure in the chamber; The controller is in communication with the pressure sensor and the air supply valve, and controls the opening and closing of the air supply valve according to the detection result of the pressure sensor.

5. The reciprocating compressor according to claim 1, wherein The pressure control mechanism comprises: A push rod having a through hole corresponding to the air supply port; a first spring, disposed on one side of the push rod; a first pressure membrane box, wherein one end of the first spring is connected to the push rod, and the other end is connected to the first pressure membrane box, and the first pressure membrane box is connected to a side of the air supply port away from the chamber; a second spring, disposed on a side of the push rod opposite to the first spring; The second pressure membrane box, one end of the second spring is connected to the push rod, and the other end is connected to the second pressure membrane box, and the second pressure membrane box is communicated with the chamber.

6. The reciprocating compressor according to claim 1, wherein The lower limit value is higher than the intake pressure of the intake port by a predetermined pressure value.

7. The reciprocating compressor according to claim 1, wherein One movement cycle of the piston includes an expansion stroke, an intake stroke, a compression stroke, and an exhaust stroke, and the air supply valve is closed during a period corresponding to the intake stroke.

8. The reciprocating compressor according to claim 1, wherein The upper limit value is less than or equal to the gas supply pressure of the gas supply port.

9. The reciprocating compressor according to claim 1, wherein The air supply port is provided on the side wall of the cylinder, or, The air supply port, the air inlet port and the exhaust port are arranged on the same end cover of the cylinder, or The air supply port is arranged on the piston.

10. A method for controlling a reciprocating compressor, the reciprocating compressor comprising: The cylinder comprises a chamber and an air inlet, an air outlet and an air supply port communicating with the chamber; a piston reciprocating within the chamber; The air supply valve is provided at the air supply port, and the control method is characterized in that: The air supply valve opens when the pressure in the chamber is within a specified range, and the specified range has an upper limit and a lower limit, the upper limit is less than or equal to the air supply pressure of the air supply port, and the lower limit is greater than the air intake pressure of the air intake port.

11. A refrigerator, characterized in that: include: The first refrigeration circuit is composed of a reciprocating compressor, a condenser, a throttling element for the refrigeration chamber, and an evaporator for the refrigeration chamber connected in sequence; The second refrigeration circuit is composed of the reciprocating compressor, the condenser, the freezing chamber throttling element and the freezing chamber evaporator connected in sequence; The reciprocating compressor comprises: a cylinder having a chamber and an air inlet, an exhaust port, and an air supply port connected to the chamber, wherein the air inlet is connected to the refrigerant outlet of the freezer compartment evaporator, the exhaust port is connected to the refrigerant inlet of the condenser, and the air supply port is connected to the refrigerant outlet of the refrigerator compartment evaporator; a piston reciprocating within the chamber; An air supply valve is provided at the air supply port; A pressure control mechanism, wherein the pressure control mechanism is configured to control the air supply valve to open when the pressure in the chamber is within a specified range, wherein the specified range has an upper limit value and a lower limit value, wherein the upper limit value is less than or equal to the air supply pressure of the air supply port, and the lower limit value is greater than the air intake pressure of the air intake port.

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