A high and low temperature freezing and refrigeration system and control method thereof

Abstract

The present invention discloses a high-low temperature freezing and refrigeration system and a control method thereof, comprising a timing switch, a star converter, a delta converter, a conversion component, a high-temperature screw compressor, a low-temperature screw compressor, a protection component, a temperature measuring device 1, an information feedback transmitter, a sub-control switch, a temperature measuring device 2, a temperature comparison feedback device, an information transmitter and an adjustment switch. The present invention measures the temperature in the warehouse by using a temperature measuring device 1, and then controls the high-temperature screw compressor and the low-temperature screw compressor to work alternately by using a sub-control switch.

Description

Technical Field

[0001] The invention relates to a refrigeration system, in particular to a high-low temperature freezing refrigeration system and a control method thereof, belonging to the technical field of refrigeration systems. Background Art

[0002] The refrigeration principle of a general refrigerator is that the function of the compressor is to compress the steam with lower pressure into steam with higher pressure, so that the volume of the steam decreases and the pressure increases. The compressor inhales the working fluid steam with lower pressure from the evaporator, increases its pressure and then sends it to the condenser, where it condenses into a liquid with higher pressure. After being throttled by the throttle valve, it becomes a liquid with lower pressure and then is sent to the evaporator, where it absorbs heat and evaporates to become steam with lower pressure, which is then sent to the inlet of the compressor, thus completing the refrigeration cycle.

[0003] The current refrigeration system has certain defects. It is not convenient to control the high-temperature screw compressor and the low-temperature screw compressor according to the temperature in the warehouse, which makes the cold storage energy consumption high and fails to achieve the effect of high efficiency, low consumption and safe operation. Therefore, a high and low temperature freezing refrigeration system and its control method are proposed to solve the above problems. Summary of the invention

[0004] The object of the present invention is to provide a high and low temperature freezing and refrigeration system and a control method thereof in order to solve the above problems.

[0005] The present invention achieves the above-mentioned purpose through the following technical scheme: a high-low temperature refrigeration system, including a timing switching switch, a star converter, a triangle converter, a conversion working component, a high-temperature screw compressor, a low-temperature screw compressor and a protection component. One end of the timing switching switch is electrically connected to the star converter and the triangle converter through a wire, one end of the star converter and the triangle converter is electrically connected to the conversion working component through a wire, one end of the conversion working component is electrically connected to the high-temperature screw compressor and the low-temperature screw compressor through a connecting line, and the high-temperature screw compressor and the low-temperature screw compressor are both equipped with a protection component.

[0006] Preferably, the conversion working component includes a temperature measuring device, an information feedback transmitter and a sub-control switch, one end of the timing switching switch is connected to the temperature measuring device through a wire, one end of the temperature measuring device is electrically connected to the information feedback transmitter, one end of the information feedback transmitter is connected to the sub-control switch through a wire, and one end of the sub-control switch is respectively connected to the high-temperature screw compressor and the low-temperature screw compressor through a wire.

[0007] Preferably, one end of the timing switch is connected to an external power supply circuit via a wire, and one end of the high-temperature screw compressor and the low-temperature screw compressor are connected to an external power supply circuit via a connecting line.

[0008] Preferably, the protection components are provided in two groups, the two groups of protection components have the same structure, and the two groups of protection components are respectively installed on the high-temperature screw compressor and the low-temperature screw compressor.

[0009] Preferably, the protection component includes a second temperature measuring device, a temperature comparison feedback device, an information transmitter and an adjustment switch. The second temperature measuring device is fixedly mounted on the high-temperature screw compressor. One end of the second temperature measuring device is electrically connected to the temperature comparison feedback device through a wire. One end of the temperature comparison feedback device is connected to the information transmitter. One end of the information transmitter is connected to the adjustment switch through a wire. One end of the adjustment switch is connected to the high-temperature screw compressor through a wire.

[0010] Preferably, the high-temperature screw compressor and the low-temperature screw compressor are installed with an intake pressure protection component, and the intake pressure protection component includes a pressure measuring device, a pressure comparison feedback device and a control switch. The high-temperature screw compressor is fixedly installed with a pressure measuring device, one end of the pressure measuring device is connected to the pressure comparison feedback device through a wire, and one end of the pressure comparison feedback device is installed with a control switch, and one end of the control switch is electrically connected to the high-temperature screw compressor through a wire.

[0011] Preferably, the high-medium and high-pressure protection components are installed on the high-temperature screw compressor and the low-temperature screw compressor, and the high-medium and high-pressure protection components include a pressure measuring device 2, a pressure maintaining valve and a control switch 2. The high-temperature screw compressor is fixedly installed with the pressure measuring device 2, a pressure maintaining valve is installed at one end of the pressure measuring device 2, and a control switch 2 is installed at one end of the pressure maintaining valve through a wire, and one end of the control switch 2 is electrically connected to the high-temperature screw compressor.

[0012] Preferably, one end of the temperature measuring device is fixedly mounted on the inner wall of the cold storage by bolts.

[0013] Preferably, one end of the timing switch is fixedly mounted on the inner wall of the cold storage by a fixing bolt.

[0014] A high and low temperature freezing and refrigeration system and a control method thereof, the control method comprising the following steps:

[0015] (1) Connect the refrigeration system to the external power supply line by starting the timer switch. After the star contactor runs for 3 seconds, it switches to the delta contactor. The interval between the star contactor tripping and the delta contactor switching on is set to 0.3% / second.

[0016] (2) The high-temperature screw compressor is powered on and runs. Under the premise of ensuring all protection parameters, the high-temperature screw compressor runs in the high-temperature operation section, which reduces the temperature of the cold storage. The temperature measuring device measures the temperature of the cold storage. When the storage temperature reaches -13°C, the temperature measuring device sends a signal to the information feedback transmitter, and then stops the high-temperature screw compressor through the sub-control switch. At this time, the low-temperature screw compressor starts and runs according to the design parameters, and stops when it reaches -35°C.

[0017] (3) The operation of the high-temperature screw compressor and the low-temperature screw compressor will generate heat, causing the temperature of the high-temperature screw compressor and the low-temperature screw compressor to rise. The second temperature measuring device measures the temperature of the high-temperature screw compressor and the low-temperature screw compressor. When the motor temperature is less than 80°C, the compressor is loaded to 100% according to the use demand. When the motor temperature is between 80°C and 90°C, the compressor maintains the current load or unloads according to the use demand. When the motor temperature reaches 90°C, the temperature comparison feedback starts to work and sends a signal to the adjustment switch through the information transmitter. The compressor is forced to unload to 75% load or unload to 50% load according to the use demand. When the motor temperature reaches 95°C, the compressor is forced to unload to 50% load. When the motor temperature reaches 100°C, the compressor alarms and stops. After the compressor is unloaded, the motor temperature is less than 75°C, and the compressor is loaded and unloaded again according to the use demand.

[0018] (4) The pressure measuring device measures the suction pressure of the high-temperature screw compressor and the low-temperature screw compressor. When the suction pressure is greater than 1G, the pressure comparison feedback device sends a signal to the control switch 1, and the compressor is unloaded to 50% operation. When the suction pressure is less than or equal to 1G and the compressor temperature is less than 80°C, the compressor is loaded and operated according to the use demand;

[0019] (5) The pressure measuring device 2 measures the medium and high pressures of the high-temperature screw compressor and the low-temperature screw compressor. When the medium and high pressure is less than or equal to 0.5G, the pressure maintaining valve and the control switch 2 must be unloaded to 50% operation. When the high pressure - medium pressure is greater than 3.5G, the compressor is normally loaded.

[0020] The beneficial effects of the present invention are:

[0021] The present invention controls the star contactor to trip and the delta contactor to work alternately through a timed switching switch, measures the temperature in the warehouse through a temperature measuring device, and then controls the high-temperature screw compressor and the low-temperature screw compressor to work alternately through a sub-control switch, thereby solving the problem that it is inconvenient to control the high-temperature screw compressor and the low-temperature screw compressor to work according to the temperature in the warehouse, resulting in high energy consumption of the cold storage and failure to achieve high efficiency, low consumption and safe operation effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0023] Figure 1 This is a schematic diagram of the structure of the access control system of the present invention;

[0024] Figure 2 This is a flow chart of the positioning method of the present invention.

[0025] In the figure: 1. timing switching switch, 2. star converter, 3. triangle converter, 4. conversion working component, 5. high temperature screw compressor, 6. low temperature screw compressor, 7. protection component, 41. temperature measuring device 1, 42. information feedback transmitter, 43. sub-control switch, 71. temperature measuring device 2, 72. temperature comparison feedback device, 73. information transmitter, 74. adjustment switch. DETAILED DESCRIPTION

[0026] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below 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 creative work are within the scope of protection of the present invention.

[0027] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0028] In the description of the present invention, it is necessary to understand that the orientations or positional relationships indicated by the terms "upper", "lower", "top", "bottom", "inside", "outside", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0029] See also Figure 1-2As shown, a high and low temperature freezing and refrigeration system includes a timing switch 1, a star converter 2, a triangle converter 3, a conversion working component 4, a high temperature screw compressor 5, a low temperature screw compressor 6 and a protection component 7. One end of the timing switch 1 is electrically connected to the star converter 2 and the triangle converter 3 through a wire, one end of the star converter 2 and the triangle converter 3 is electrically connected to the conversion working component 4 through a wire, one end of the conversion working component 4 is electrically connected to the high temperature screw compressor 5 and the low temperature screw compressor 6 through a connecting line, and the high temperature screw compressor 5 and the low temperature screw compressor 6 are both equipped with a protection component 7.

[0030] The conversion working component 4 includes a temperature measuring device 41, an information feedback transmitter 42 and a sub-control switch 43. One end of the timing switching switch 1 is connected to the temperature measuring device 41 through a wire, one end of the temperature measuring device 41 is electrically connected to the information feedback transmitter 42, one end of the information feedback transmitter 42 is connected to the sub-control switch 43 through a wire, and one end of the sub-control switch 43 is respectively connected to the high-temperature screw compressor 5 and the low-temperature screw compressor 6 through a wire.

[0031] One end of the timing switch 1 is connected to an external power supply circuit via a wire, and one end of the high-temperature screw compressor 5 and the low-temperature screw compressor 6 are connected to an external power supply circuit via a connecting wire.

[0032] The protection components 7 are provided with two groups, and the two groups of the protection components 7 have the same structure. The two groups of the protection components 7 are respectively installed on the high-temperature screw compressor 5 and the low-temperature screw compressor 6.

[0033] The protection component 7 includes a temperature measuring device 71, a temperature comparison feedback device 72, an information transmitter 73 and an adjustment switch 74. The temperature measuring device 71 is fixedly mounted on the high-temperature screw compressor 5. One end of the temperature measuring device 71 is electrically connected to the temperature comparison feedback device 72 via a wire. One end of the temperature comparison feedback device 72 is connected to the information transmitter 73. One end of the information transmitter 73 is connected to the adjustment switch 74 via a wire. One end of the adjustment switch 74 is connected to the high-temperature screw compressor 5 via a wire.

[0034] The high-temperature screw compressor 5 and the low-temperature screw compressor 6 are installed with an intake pressure protection component, and the intake pressure protection component includes a pressure measuring device, a pressure comparison feedback device and a control switch. The high-temperature screw compressor 5 is fixedly installed with a pressure measuring device, and one end of the pressure measuring device is connected to the pressure comparison feedback device through a wire, and one end of the pressure comparison feedback device is installed with a control switch, and one end of the control switch is electrically connected to the high-temperature screw compressor 5 through a wire.

[0035] The high- and medium-pressure protection components 7 are installed on the high-temperature screw compressor 5 and the low-temperature screw compressor 6. The high- and medium-pressure protection components include two pressure measuring devices, a pressure maintaining valve and two control switches. The two pressure measuring devices are fixedly installed on the high-temperature screw compressor 5. The two pressure measuring devices are installed at one end of the two pressure measuring devices. The two control switches are installed at one end of the two pressure maintaining valves through a wire, and one end of the two control switches is electrically connected to the high-temperature screw compressor 5.

[0036] One end of the temperature measuring device 41 is fixedly mounted on the inner wall of the cold storage by bolts.

[0037] One end of the timing switch 1 is fixedly mounted on the inner wall of the cold storage by means of fixing bolts.

[0038] A high and low temperature freezing and refrigeration system and a control method thereof, the control method comprising the following steps:

[0039] Step 1: Connect the refrigeration system to the external power supply line by starting the timer switch 1. After the star contactor runs for 3 seconds, it switches to the delta contactor. The interval between the star contactor tripping and the delta contactor switching on is set to 0.3% / second.

[0040] Step 2: The high-temperature screw compressor 5 is powered on and runs. The high-temperature screw compressor 5 runs in the high-temperature operation section under the premise of ensuring all protection parameters, so that the temperature of the cold storage is reduced. The temperature measuring device measures the temperature of the cold storage. When the storage temperature reaches -13°C, the temperature measuring device sends a signal to the information feedback transmitter 42, and then stops the high-temperature screw compressor 5 through the sub-control switch 43. At this time, the low-temperature screw compressor 6 starts and runs according to the design parameters, reaching -35°C to unload and shut down.

[0041] Step 3: The high-temperature screw compressor 5 and the low-temperature screw compressor 6 generate heat during operation, which increases the temperature of the high-temperature screw compressor 5 and the low-temperature screw compressor 6. The temperature measuring device 2 71 measures the temperature of the high-temperature screw compressor 5 and the low-temperature screw compressor 6. When the motor temperature is less than 80°C, the compressor can be loaded to 100% according to the use demand. When the motor temperature is between 80°C and 90°C, the compressor can maintain the current load or unload according to the use demand. When the motor temperature reaches 90°C, the temperature comparison feedback starts to work, and a signal is sent to the adjustment switch 74 through the information transmitter 73. The compressor is forced to unload to 75% load or unload to 50% load according to the use demand. When the motor temperature reaches 95°C, the compressor is forced to unload to 50% load. When the motor temperature reaches 100°C, the compressor alarms and shuts down. After the compressor is unloaded, when the motor temperature is less than 75°C, the compressor can be loaded and unloaded again according to the use demand.

[0042] Step 4: The pressure measuring device measures the suction pressure of the high-temperature screw compressor 5 and the low-temperature screw compressor 6. When the suction pressure is greater than 1G, the pressure comparison feedback device sends a signal to the control switch 1, and the compressor is unloaded to 50% operation. When the suction pressure is less than / =1G and the compressor temperature is less than 80℃, the compressor can be loaded and operated according to the usage requirements.

[0043] Step 5: The pressure measuring device 2 measures the medium and high pressures of the high-temperature screw compressor 5 and the low-temperature screw compressor 6. When the medium and high pressure is < / =0.5G, the pressure maintaining valve and the control switch 2 must be unloaded to 50% operation. When the high pressure-medium pressure is >3.5G, the compressor can be loaded normally.

[0044] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations within the meaning and scope of the elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0045] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high and low temperature freezing and refrigeration system, characterized in that: The invention comprises a timing switch (1), a star converter (2), a delta converter (3), a conversion working component (4), a high-temperature screw compressor (5), a low-temperature screw compressor (6) and a protection component (7), wherein one end of the timing switch (1) is electrically connected to the star converter (2) and the delta converter (3) via a wire, one end of the star converter (2) and the delta converter (3) is electrically connected to the conversion working component (4) via a wire, one end of the conversion working component (4) is electrically connected to the high-temperature screw compressor (5) and the low-temperature screw compressor (6) via a connecting wire, and the high-temperature screw compressor (5) and the low-temperature screw compressor (6) are both equipped with a protection component (7); The high-temperature screw compressor (5) and the low-temperature screw compressor (6) are provided with an air suction pressure protection component, the air suction pressure protection component comprising a pressure measuring device, a pressure comparison feedback device and a control switch. The high-temperature screw compressor (5) is fixedly provided with the pressure measuring device, one end of the pressure measuring device is connected to the pressure comparison feedback device via a wire, and one end of the pressure comparison feedback device is provided with the control switch, and one end of the control switch is electrically connected to the high-temperature screw compressor (5) via a wire. The conversion working component (4) comprises a temperature measuring device (41), an information feedback transmitter (42) and a sub-control switch (43); one end of the timing switch (1) is connected to the temperature measuring device (41) via a wire; one end of the temperature measuring device (41) is electrically connected to the information feedback transmitter (42); one end of the information feedback transmitter (42) is connected to the sub-control switch (43) via a wire; and one end of the sub-control switch (43) is respectively connected to the high-temperature screw compressor (5) and the low-temperature screw compressor (6) via a wire; The protection component (7) comprises a second temperature measuring device (71), a temperature comparison feedback device (72), an information transmitter (73) and an adjustment switch (74); the second temperature measuring device (71) is fixedly mounted on the high-temperature screw compressor (5); one end of the second temperature measuring device (71) is electrically connected to the temperature comparison feedback device (72) via a wire; one end of the temperature comparison feedback device (72) is connected to the information transmitter (73); one end of the information transmitter (73) is connected to the adjustment switch (74) via a wire; and one end of the adjustment switch (74) is connected to the high-temperature screw compressor (5) via a wire; The high- and medium-pressure protection components are installed on the high-temperature screw compressor (5) and the low-temperature screw compressor (6), and the high- and medium-pressure protection components include a second pressure measuring device, a pressure maintaining valve, and a second control switch. The second pressure measuring device is fixedly installed on the high-temperature screw compressor (5), a pressure maintaining valve is installed at one end of the second pressure measuring device, and a second control switch is installed at one end of the pressure maintaining valve via a wire, and one end of the second control switch is electrically connected to the high-temperature screw compressor (5).

2. A high and low temperature freezing and refrigeration system according to claim 1, characterized in that: One end of the timing switch (1) is connected to an external power supply line via a wire, and one end of the high-temperature screw compressor (5) and the low-temperature screw compressor (6) are connected to an external power supply line via a connecting wire.

3. A high and low temperature freezing and refrigeration system according to claim 1, characterized in that: The protection components (7) are provided in two groups, the two groups of protection components (7) have the same structure, and the two groups of protection components (7) are respectively installed on the high-temperature screw compressor (5) and the low-temperature screw compressor (6).

4. A high and low temperature freezing and refrigeration system according to claim 1, characterized in that: One end of the temperature measuring device (41) is fixedly mounted on the inner wall of the cold storage by bolts.

5. A high and low temperature freezing and refrigeration system according to claim 1, characterized in that: One end of the timing switch (1) is fixedly mounted on the inner wall of the cold storage by means of fixing bolts.

6. A control method according to any one of claims 1 to 5, characterized in that: The control method comprises the following steps: Step 1: Connect the refrigeration system to the external power supply line by starting the timer switch (1). After the star contactor operates for 3 seconds, it switches to the delta contactor. The interval between the star contactor tripping and the delta contactor switching on is set to 0.3% / second. Step 2: The high-temperature screw compressor (5) is powered on and operated. The high-temperature screw compressor (5) operates in the high-temperature operation section under the premise of ensuring all protection parameters, so that the temperature of the cold storage is reduced. The temperature measuring device measures the temperature of the cold storage. When the storage temperature reaches -13°C, the temperature measuring device sends a signal to the information feedback transmitter (42), and then stops the high-temperature screw compressor (5) through the sub-control switch (43). At this time, the low-temperature screw compressor (6) is started and operates according to the design parameters, and stops when the temperature reaches -35°C. Step 3: The operation of the high-temperature screw compressor (5) and the low-temperature screw compressor (6) generates heat, causing the temperature of the high-temperature screw compressor (5) and the low-temperature screw compressor (6) to rise. The second temperature measuring device (71) measures the temperature of the high-temperature screw compressor (5) and the low-temperature screw compressor (6). When the motor temperature is less than 80°C, the compressor is loaded to 100% according to the use demand. When the motor temperature is between 80°C and 90°C, the compressor maintains the current load or unloads according to the use demand. When the motor temperature reaches 90°C, the temperature comparison feedback starts to work and sends a signal to the adjustment switch (74) through the information transmitter (73). The compressor is forced to unload to 75% load or unload to 50% load according to the use demand. When the motor temperature reaches 95°C, the compressor is forced to unload to 50% load. When the motor temperature reaches 100°C, the compressor alarms and stops. After the compressor is unloaded, if the motor temperature is less than 75°C, the compressor is loaded and unloaded again according to the use demand. Step 4: The pressure measuring device measures the suction pressure of the high-temperature screw compressor (5) and the low-temperature screw compressor (6). When the suction pressure is greater than 1G, the pressure comparison feedback device sends a signal to the control switch 1, and the compressor is unloaded to 50% operation. When the suction pressure is less than or equal to 1G and the compressor temperature is less than 80°C, the compressor is loaded and operated according to the use demand. Step 5: The pressure measuring device 2 measures the medium and high pressures of the high-temperature screw compressor (5) and the low-temperature screw compressor (6). When the medium and high pressure is less than or equal to 0.5G, the pressure maintaining valve and the control switch 2 must be unloaded to 50% operation. When the high pressure - medium pressure is greater than 3.5G, the compressor is normally loaded.

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