CN104423405B - Nitrogen air conditioning control system and method - Google Patents
Nitrogen air conditioning control system and method Download PDFInfo
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- CN104423405B CN104423405B CN201310414708.7A CN201310414708A CN104423405B CN 104423405 B CN104423405 B CN 104423405B CN 201310414708 A CN201310414708 A CN 201310414708A CN 104423405 B CN104423405 B CN 104423405B
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- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 title claims abstract description 459
- 229910052757 nitrogen Inorganic materials 0.000 title claims abstract description 222
- 238000004378 air conditioning Methods 0.000 title claims abstract description 19
- 238000000034 method Methods 0.000 title claims abstract description 19
- 239000001301 oxygen Substances 0.000 claims abstract description 86
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 86
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 83
- 239000007789 gas Substances 0.000 claims description 143
- 238000004320 controlled atmosphere Methods 0.000 claims description 99
- 238000004891 communication Methods 0.000 claims description 36
- 238000001514 detection method Methods 0.000 claims description 34
- 238000003860 storage Methods 0.000 claims description 28
- 239000013589 supplement Substances 0.000 claims description 8
- 230000003750 conditioning effect Effects 0.000 claims description 6
- 230000033228 biological regulation Effects 0.000 claims description 5
- 235000013305 food Nutrition 0.000 abstract description 7
- 230000002035 prolonged effect Effects 0.000 abstract 1
- 239000002808 molecular sieve Substances 0.000 description 83
- URGAHOPLAPQHLN-UHFFFAOYSA-N sodium aluminosilicate Chemical compound [Na+].[Al+3].[O-][Si]([O-])=O.[O-][Si]([O-])=O URGAHOPLAPQHLN-UHFFFAOYSA-N 0.000 description 83
- 229910001873 dinitrogen Inorganic materials 0.000 description 15
- 108010066114 cabin-2 Proteins 0.000 description 5
- 238000010586 diagram Methods 0.000 description 3
- 238000012544 monitoring process Methods 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 2
- 238000004887 air purification Methods 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 238000009833 condensation Methods 0.000 description 2
- 230000005494 condensation Effects 0.000 description 2
- 229910001882 dioxygen Inorganic materials 0.000 description 2
- 239000000428 dust Substances 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000003595 mist Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 241000894006 Bacteria Species 0.000 description 1
- 241000238631 Hexapoda Species 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 235000012055 fruits and vegetables Nutrition 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
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- Air Conditioning Control Device (AREA)
Abstract
The invention provides a nitrogen air conditioning control system and method. The nitrogen air conditioning control system comprises an air compressor and a nitrogen making machine, wherein the air compressor is connected with the nitrogen making machine, the nitrogen making machine is connected with the air inlet of an air conditioning bin, the air compressor is connected with the air outlet of the air conditioning bin through a circulating pipeline, a circulating valve group is arranged on the circulating pipeline for controlling air in the air outlet of the air conditioning bin to enter the air compressor through the circulating pipeline, the nitrogen making machine continuously adsorb oxygen in the air to effectively improve the working efficiency of the nitrogen making machine, and the nitrogen air conditioning duration is correspondingly shortened, thus not only is the power saved, are the dissipation of the nitrogen making machine and assorted equipment reduced and the service life is prolonged, but also the quality and the freshness of stored food are improved.
Description
Technical Field
The invention relates to the technical field of gas concentration monitoring and control, in particular to a nitrogen gas regulation control system and method.
Background
The nitrogen-filled controlled atmosphere technology is mainly used for storing food such as grains, fruits and vegetables, and the like, and can kill insects and inhibit bacteria, delay the shelf life and keep the freshness of the food. When the nitrogen is filled for adjustment, the filling mode, the filling amount, the exhaust amount, the air supplement amount, the circulation amount and the like directly influence the quality of the air adjustment effect, so how to realize the control of the system during the nitrogen filling and adjustment is very important.
At present, the traditional nitrogen gas-regulating control system adopts an external circulation type, after the nitrogen gas-regulating control system is started, external air is used as an air source, enters the nitrogen gas-regulating control system through an air compressor, is compressed by the air compressor and then is conveyed to an air purification device, so that dust, moisture and oil mist in the air purification device are removed. The purified air is then delivered to a nitrogen making machine to adsorb oxygen therein, finally high-concentration nitrogen is obtained and delivered to a modified atmosphere bin for storing food, the high-oxygen air (with the concentration of 21%) in the gas space (the gas space is the space in the bin-the space occupied by the stored materials) of the modified atmosphere bin is replaced by the nitrogen, and the high-oxygen air in the bin is discharged to the air outside the bin, so that a suitable low-oxygen storage environment is achieved. During the storage process of the food, the oxygen concentration at the outlet of the nitrogen making machine is read manually, and the gas output at the outlet of the nitrogen making machine is controlled to adjust the oxygen concentration in the gas adjusting bin.
However, in practical use, the applicant has found that the conventional nitrogen gas-conditioning control scheme has a long gas-conditioning process, which usually requires long-term gas conditioning, and not only increases the power consumption and shortens the service life of the nitrogen generator and the supporting equipment, but also affects the quality and freshness of the stored food.
Therefore, a nitrogen controlled atmosphere control scheme is needed to solve the above technical problems.
Disclosure of Invention
The invention provides a nitrogen controlled atmosphere control system and a nitrogen controlled atmosphere control method aiming at the defects in the prior art, and aims to solve the problem of long time consumption of nitrogen controlled atmosphere in the prior scheme.
In order to solve the technical problems, the invention adopts the following technical scheme:
a nitrogen modified atmosphere control system comprising: an air compressor and a nitrogen making machine, wherein the air compressor is connected with the nitrogen making machine, the nitrogen making machine is connected with an air inlet of the air conditioning bin, the nitrogen making machine is characterized in that,
the air compressor is connected with the air outlet of the air conditioning bin through a circulating pipeline, and a circulating valve group is arranged on the circulating pipeline and used for controlling the air at the air outlet of the air conditioning bin to enter the air compressor through the circulating pipeline.
Preferably, the circulating pipeline comprises a first circulating pipeline and a second circulating pipeline, one end of the first circulating pipeline is connected with an air inlet of the air compressor, and one end of the second circulating pipeline is connected with an air outlet of the modified atmosphere bin;
the circulating valve train includes: the first valve, the second valve and the fifth valve with adjustable opening and closing degrees; two ends of the first valve are respectively connected with the first circulating pipeline and the second circulating pipeline and used for controlling the connection and disconnection between the first circulating pipeline and the second circulating pipeline; the second valve is arranged on the second circulating pipeline, one end of the second valve is communicated with the outside air, and the second valve is used for controlling the on-off between the air outlet of the controlled atmosphere bin and the outside air; the fifth valve is arranged on the first circulating pipeline, one end of the fifth valve is communicated with the outside air, and the fifth valve is used for controlling the air inlet of the air compressor to be communicated with the outside air; alternatively, the recirculation valve train comprises: the first valve, the second valve, the third valve and the fourth valve with adjustable opening and closing degrees; two ends of the first valve are respectively connected with the first circulating pipeline and the second circulating pipeline and used for controlling the connection and disconnection between the first circulating pipeline and the second circulating pipeline; the second valve is arranged on the second circulating pipeline, one end of the second valve is communicated with the outside air, and the second valve is used for controlling the on-off between the air outlet of the controlled atmosphere bin and the outside air; the third valve and the fourth valve are arranged on the first circulating pipeline, and one end of the third valve is communicated with the outside air and used for controlling the air inlet of the air compressor to be communicated with the outside air; one end of the fourth valve is communicated with the outside air, and is used for controlling the degree of communication between the air inlet of the air compressor and the outside air.
Further, the system also comprises a controller, wherein the controller is internally preset with air inlet time length;
the initial state of the circulating valve group is that the circulating valve group is communicated with external air and is not communicated with an air compressor;
the controller is connected with the circulating valve set and used for controlling the circulating valve set to be communicated with the air compressor so as to enable external air to enter the air compressor through the circulating pipeline and start timing; and when the air inlet time length is up, controlling the circulating valve group to be isolated from the outside air so as to enable the air in the air conditioning bin to enter the air compressor through the circulating pipeline.
Further, the system also comprises a first oxygen meter arranged in the modified atmosphere bin; an oxygen concentration threshold is also preset in the controller;
the first oxygen meter is connected with the controller and used for detecting the oxygen concentration in the controlled atmosphere bin and sending the detected oxygen concentration detection value in the controlled atmosphere bin to the controller;
the controller is connected with the nitrogen generator, and the controller is also used for comparing the oxygen concentration detection value in the controlled atmosphere bin with a preset oxygen concentration threshold value and controlling the start and stop of the nitrogen generator according to the comparison result.
Furthermore, the system also comprises a flow meter arranged at the air outlet of the nitrogen making machine;
the flow meter is connected with the controller and used for detecting the gas output of the gas outlet of the nitrogen making machine and sending a detected gas output value to the controller;
the controller is also used for comparing the gas output detection value with the current rated flow value of the nitrogen making machine when judging that the oxygen concentration detection value in the gas conditioning bin is larger than the preset oxygen concentration threshold value, and controlling the communication degree of the circulating valve group and the outside air according to the comparison result; if the former is smaller than the latter, the circulation valve set is controlled to be communicated with the outside air, or the circulation valve set is controlled to increase the degree of communication with the outside air so as to supplement the outside air to enter the circulation pipeline; if the former is larger than the latter, the control circulation valve set reduces the degree of communication with the outside air.
Preferably, the controller is specifically configured to calculate a difference between the gas amount detection value and a rated flow value of the nitrogen generator in a current operating state, and calculate a ratio between the difference and the rated flow value of the nitrogen generator in the current operating state; and when the detected value of the air output is judged to be smaller than the rated flow value of the nitrogen making machine in the current working state, increasing the degree of the communication between the circulating valve group and the outside air according to the ratio; and when the detected gas output value is judged to be larger than the rated flow value of the nitrogen making machine in the current working state, reducing the degree of the communication between the circulating valve group and the outside air according to the ratio.
Preferably, the controller is specifically configured to control the nitrogen generator to stop operating when the detected value of the oxygen concentration in the controlled atmosphere bin is determined to be less than or equal to a preset oxygen concentration threshold value.
Further, the system also comprises a temperature control machine, a first temperature measuring instrument and a second temperature measuring instrument; a temperature difference threshold value delta t is also arranged in the controller;
the temperature control machine is connected with the gas outlet of the nitrogen making machine and is used for adjusting the temperature of gas discharged from the gas outlet of the nitrogen making machine;
the first temperature measuring instrument is arranged in the controlled atmosphere bin, is connected with the controller and is used for detecting the temperature in the controlled atmosphere bin and sending a detected temperature detection value t1 in the controlled atmosphere bin to the controller;
the second temperature measuring instrument is arranged at the outlet of the temperature control machine, is connected with the controller and is used for detecting the temperature of the gas after temperature adjustment by the temperature control machine and sending a detected temperature detection value t2 to the controller;
the controller is further used for calculating a difference value between t1 and t2, judging whether the difference value is within a range of a preset temperature difference threshold value delta t, and if not, sending a temperature adjusting signal to the temperature control machine to instruct the temperature control machine to adjust the temperature of the gas discharged from the gas outlet of the nitrogen making machine to (t1 +/-delta t); if t1 > t2, the temperature of the gas discharged from the gas outlet of the nitrogen generator is adjusted to (t1- Δ t), and if t1 < t2, the temperature of the gas discharged from the gas outlet of the nitrogen generator is adjusted to (t1+ Δ t).
A nitrogen controlled atmosphere control method is used in a nitrogen controlled atmosphere control system and comprises an initial controlled atmosphere control step and an operating controlled atmosphere control step, wherein the operating controlled atmosphere control step comprises the following steps:
and conveying the gas discharged from the gas outlet of the gas-adjusting bin to the gas inlet of an air compressor in the nitrogen gas-adjusting control system.
Specifically, the initial modified atmosphere control step comprises: controlling external air to enter an air compressor, starting timing, and controlling to start a nitrogen making machine; and when the preset air inlet time length is reached, controlling the air compressor to be isolated from the external air.
Further, the step of controlled atmosphere control in operation further comprises: detecting the oxygen concentration in the controlled atmosphere bin, comparing the detected oxygen concentration detection value in the controlled atmosphere bin with a preset oxygen concentration threshold value, and controlling the start and stop of the nitrogen making machine according to the comparison result; wherein, if the former is less than or equal to the latter, the nitrogen generator is controlled to stop working; if the former is larger than the latter, the nitrogen generator is controlled to continue working.
Further, the step of controlled atmosphere control in operation further comprises: detecting the air output of an air outlet of the nitrogen making machine when the nitrogen making machine operates, comparing the detected air output detection value with the current rated flow value of the nitrogen making machine when the oxygen concentration detection value in the controlled atmosphere bin is judged to be larger than the preset oxygen concentration threshold value, and controlling the air input of external air entering the nitrogen controlled atmosphere control system according to the comparison result; if the former is smaller than the latter, the air input of the external air into the nitrogen gas-regulating control system is increased; if the former is larger than the latter, the air input of the external air entering the nitrogen gas-regulating control system is reduced;
and the number of the first and second groups,
the operating controlled atmosphere control step further comprises a temperature adjusting step, and the temperature adjusting step comprises the following steps:
detecting the temperature in the air-conditioned cabin to obtain a temperature detection value t1, and detecting the temperature of the gas subjected to temperature regulation to obtain a temperature detection value t 2;
calculating the difference between t1 and t2, judging whether the difference is within the range of a preset temperature difference threshold value delta t, and if not, performing temperature adjustment to adjust the gas temperature to (t1 +/-delta t); if t1 > t2, the gas temperature is adjusted to (t1- Δ t), and if t1 < t2, the gas temperature is adjusted to (t1+ Δ t).
The invention has the following beneficial effects:
the invention utilizes the circulating pipeline to connect the controlled atmosphere bin and the air compressor, sets the circulating valve group on the circulating pipeline, and controls the circulating pipeline by controlling the circulating valve group, so as to convey the gas in the controlled atmosphere bin to the nitrogen controlled atmosphere control system through the circulating pipeline, and the nitrogen making machine continues to adsorb the oxygen therein, thus, the oxygen concentration of the gas after one controlled atmosphere treatment is lower than the oxygen concentration in the outside air, and the gas is conveyed to the system again for controlled atmosphere, thus effectively improving the working efficiency of the nitrogen making machine, correspondingly shortening the time of nitrogen controlled atmosphere, not only saving the electric power, reducing the loss of the nitrogen making machine and the corollary equipment, prolonging the service life of the equipment, but also improving the quality and the freshness of the stored food.
Drawings
Fig. 1 is a schematic structural diagram of a nitrogen controlled atmosphere control system according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a circulation control valve assembly;
FIG. 3 is a second schematic diagram of the structure of the circulation control valve set;
fig. 4 is a schematic flow chart of a nitrogen controlled atmosphere control method according to an embodiment of the present invention:
fig. 5 is a second schematic flow chart of the nitrogen controlled atmosphere control method according to the embodiment of the invention.
Detailed Description
The technical solution of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.
As shown in fig. 1, an embodiment of the present invention provides a nitrogen controlled atmosphere control system 1, which at least includes: the air conditioning system comprises an air compressor 10 and a molecular sieve nitrogen making machine 11, wherein the air compressor 10 is connected with the molecular sieve nitrogen making machine 11, the molecular sieve nitrogen making machine 11 is connected with an air inlet of the air conditioning bin 2, the air compressor 10 is connected with an air outlet of the air conditioning bin 2 through a circulating pipeline, and a circulating valve group 12 is arranged on the circulating pipeline and used for controlling air at the air outlet of the air conditioning bin 2 to enter the air compressor 11 through the circulating pipeline. The initial state of the circulating valve set 12 is air communication and non-air communication with the air compressor 10.
It should be noted that the nitrogen gas atmosphere control system 1 may also be used in other types of nitrogen generators, such as a cryogenic air-separation nitrogen generator and a membrane air-separation nitrogen generator, and the present invention is described by taking a molecular sieve nitrogen generator as an example.
An air treatment device (not shown) is further disposed between the air compressor 10 and the molecular sieve nitrogen generator 11, and the air treatment device may include: air storage tank, cold dryer, oil-water separator, precision filter and carbon bed filter. The air storage tank is used for storing air and balancing pressure; the oil-water separator, the fine filter and the carbon bed filter are used for removing moisture, oil mist, dust and the like in the air to purify and dry the air. The air treatment device belongs to the prior art, and the structure and connection relationship thereof are not described in detail herein.
The circulating pipeline comprises a first circulating pipeline and a second circulating pipeline, one end of the first circulating pipeline is connected with an air inlet of the air compressor 10, and one end of the second circulating pipeline is connected with an air outlet of the air-conditioned bin 2.
Two specific implementations of the circulation valve set 12 are shown in fig. 2 and 3, and the internal structure of the two circulation valve sets 13 will be described in detail below with reference to fig. 2 and 3, wherein the air compressor 10 is connected to the air inlet of the modified atmosphere bin 2 through a molecular sieve nitrogen making machine, which is not shown in fig. 2 and 3 for the purpose of clearly illustrating the structure of the circulation valve set 12.
As shown in fig. 2, the circulation valve group 12 includes: a first valve 121, a second valve 122, a third valve 123 and a fourth valve 124 with adjustable opening and closing degree. Two ends of the first valve 121 are respectively connected with the first circulation pipeline and the second circulation pipeline, and are used for controlling the connection and disconnection between the first circulation pipeline and the second circulation pipeline; the second valve 122 is arranged on the second circulating pipeline, one end of the second valve is communicated with the outside air, and the second valve is used for controlling the on-off between the air outlet of the controlled atmosphere bin 2 and the outside air; the third valve 123 and the fourth valve 124 are both disposed on the first circulation pipeline, and one end of the third valve 123 is communicated with the outside air for controlling the air inlet of the air compressor 10 to be communicated with the outside air; one end of the fourth valve 124 communicates with the outside air for controlling the degree to which the air intake of the air compressor 10 communicates with the outside air, i.e., the third valve 123 is connected in parallel with the fourth valve 124.
When the second valve 122, the third valve 123 and the fourth valve 124 are closed and the first valve 121 is opened, the gas in the modified atmosphere storage 2 can enter the air compressor 10 through the circulation pipeline (i.e. the second circulation pipeline and the first circulation pipeline in sequence), and the external air cannot enter the nitrogen modified atmosphere control system 1, so as to realize the internal circulation of the gas. When the second valve 122 and the third valve 123 are closed and the first valve 121 and the fourth valve 124 are opened, the external air may enter the first circulation line through the fourth valve 124 and be delivered to the air compressor 10 through the first circulation line. When the first valve 121 is closed and the second valve 122, the third valve 123 and the fourth valve 124 are opened, the circulating valve group 12 is in the initial state, and the outside air enters the modified atmosphere storage 2 through the second valve 122 but does not enter the air compressor 10, i.e. the modified atmosphere storage 2 is communicated with the outside air through the second circulating pipeline and the second valve 122.
Preferably, the first valve 121, the second valve 122 and the third valve 123 may be electrically controlled valves, and the fourth valve 124 may be a ball valve with an adjustable opening and closing degree, so as to control the degree of communication between the circulation valve group 12 and the outside air.
In order to simplify the internal structure of the circulation valve set 12, the third valve 123 and the fourth valve 124 may be combined into a fifth valve 125 with adjustable opening and closing degree, as shown in fig. 3, the circulation valve set 12 includes: a first valve 121, a second valve 122 and a fifth valve 125 with adjustable opening and closing degrees; two ends of the first valve 121 are respectively connected with the first circulation pipeline and the second circulation pipeline, and are used for controlling the connection and disconnection between the first circulation pipeline and the second circulation pipeline; the second valve 122 is arranged on the second circulating pipeline, one end of the second valve is communicated with the outside air, and the second valve is used for controlling the on-off between the air outlet of the controlled atmosphere bin 2 and the outside air; the fifth valve 125 is provided on the first circulation line, and has one end communicating with the outside air, for controlling the air inlet of the air compressor 10 to communicate with the outside air.
When the second valve 122 and the fifth valve 125 are closed and the first valve 121 is opened, the gas in the modified atmosphere storage 2 can enter the air compressor 10 through the circulation pipeline (i.e. the second circulation pipeline and the first circulation pipeline in sequence), and the external air cannot enter the nitrogen modified atmosphere control system 1, so as to realize the internal circulation of the gas. When the second valve 122 is closed, the first valve 121 is opened, and the fifth valve 125 is opened, under the action of the air compressor 10, the external air can enter the first circulation pipeline through the opened fifth valve 125, and is delivered to the air compressor 10 through the first circulation pipeline. When the first valve 121 is closed and the second valve 122 and the fifth valve 125 are opened, the circulating valve set 12 is in the initial state, the gas in the modified atmosphere storage 2 can be discharged to the outside of the storage through the second valve 122, and the outside air can enter the modified atmosphere storage 2 through the second valve 122, i.e. the modified atmosphere storage 2 is communicated with the outside air through the second circulating pipeline and the second valve 122, so that the nitrogen concentration in the modified atmosphere storage 2 in the initial state is the same as the nitrogen concentration in the air. In addition, when the circulation valve set 12 is in the initial state, the fifth valve 125 is also in the conducting state to deliver the external air to the air compressor 10.
Preferably, the first valve 121, the second valve 122 and the fifth valve 125 may be implemented by electrically controlled valves, wherein the opening and closing degree of the fifth valve 125 is adjustable.
Preferably, the nitrogen controlled atmosphere control system 1 provided by the embodiment of the present invention may further include a controller 13, configured to control the closing and conducting of the circulating valve set 12 and the start and stop of the molecular sieve nitrogen making machine 11, where an air intake duration is preset in the controller 13. Preferably, the Controller 13 may be a PLC (Programmable Logic Controller).
The controller 13 is connected to the circulation valve group 12, and is configured to control the circulation valve group 12 to be in communication with the air compressor 10, so that the external air enters the air compressor 10 through the circulation pipeline, and start timing, and control the circulation valve group 12 to be isolated from the external air when the intake duration arrives, so that the gas in the modified atmosphere bin 2 enters the air compressor 10 through the circulation pipeline, thereby implementing gas internal circulation of the nitrogen modified atmosphere control system.
In order to more clearly explain the technical means of the present invention, the structure of the circulation valve group 12 (structure of 3 valves) shown in fig. 3 is explained as an example.
Specifically, when the nitrogen gas atmosphere control system 1 is started, the controller 13 may send a control signal to the molecular sieve nitrogen making machine 11 according to a user instruction to turn on the molecular sieve nitrogen making machine 11, and control to open the first valve 121, close the second valve 122, and keep the fifth valve 125 open, so that the outside air enters the air compressor 10 through the open fifth valve 125 via the circulation line to provide the gas source for the molecular sieve nitrogen making machine 11. It should be noted that, when the first valve 121 is controlled to be opened, the controller 13 starts timing to monitor the intake time of the outside air. An air inlet time period is preset in the controller 13, when the air inlet time period is up, the controller 13 controls the fifth valve 125 in the circulation valve group 12 to close and keeps the second valve 122 closed so as to isolate the circulation valve group 12 from the outside air, and controls the first valve 121 to keep conducting, so that the gas in the modified atmosphere bin 2 passes through the first valve 121 and enters the air compressor 10 through the circulation pipeline, and the internal circulation of the gas in the nitrogen modified atmosphere control system is realized.
Furthermore, the nitrogen gas-adjusting control system 1 can also control the start and stop of the molecular sieve nitrogen making machine 11 according to the oxygen concentration in the gas-adjusting bin 2, so as to save energy and improve the automation degree of the system. The nitrogen modified atmosphere control system 1 also includes a first oxygen meter 14. The controller 13 is also preset with an oxygen concentration threshold, and the preset oxygen concentration threshold is set to be consistent with the target oxygen concentration in the modified atmosphere bin 2.
The first oxygen meter 14 is arranged in the modified atmosphere storage 2, is connected with the controller 13, and is used for detecting the oxygen concentration in the modified atmosphere storage 2 and sending the detected value of the oxygen concentration in the modified atmosphere storage 2 to the controller 13.
The controller 13 is connected with the molecular sieve nitrogen making machine 11, and the controller 13 is further used for comparing the oxygen concentration detection value in the air-conditioned cabin 2 with a preset oxygen concentration threshold value in the air-conditioned cabin and controlling the start and stop of the molecular sieve nitrogen making machine 11 according to the comparison result. When the former is less than or equal to the latter, it indicates that the oxygen concentration in the controlled atmosphere storage 2 has reached or is lower than the preset target oxygen concentration (i.e. the nitrogen concentration of the gas in the controlled atmosphere storage 2 is greater than or equal to the preset target nitrogen concentration), and the molecular sieve nitrogen making machine 11 is controlled to stop working. When the former is larger than the latter, the oxygen concentration in the air-conditioned cabin 2 is not yet reached to the preset target oxygen concentration, and the controller does not send a control instruction to the molecular sieve nitrogen making machine, so that the molecular sieve nitrogen making machine 11 continues to keep running.
Further, in order to realize the automatic control of the molecular sieve nitrogen generator 11, the nitrogen gas atmosphere control system 1 further includes a flow meter 15 for adjusting the operating state of the molecular sieve nitrogen generator 11 to an optimal state. The flow meter 15 is arranged at the gas outlet of the molecular sieve nitrogen making machine 11, is connected with the controller 13, and is used for detecting the gas output of the gas outlet of the molecular sieve nitrogen making machine 11 and sending the detected gas output value to the controller 13.
The controller 13 is further configured to compare the detected gas output value with a rated flow value of the molecular sieve nitrogen making machine 11 in the current working state when the detected oxygen concentration value in the controlled atmosphere bin 2 is judged to be greater than the preset oxygen concentration threshold value, and control the degree of communication between the circulation valve set and the outside air according to the comparison result. Wherein, the rated flow value of the molecular sieve nitrogen making machine 11 under the current working state is set in the controller 13 when the nitrogen gas atmosphere control system 1 is initialized.
If the detected gas output value is smaller than the current rated flow value of the molecular sieve nitrogen making machine 11, it indicates that the oxygen concentration in the gas to be controlled in the nitrogen gas controlled atmosphere control system 1 cannot meet the requirement of the molecular sieve nitrogen making machine 11 for saturation operation currently, and in order to improve the operation efficiency of the molecular sieve nitrogen making machine 11, the controller 13 may control the circulation valve group 12 to communicate with the outside air so as to supplement the outside air to enter the circulation pipeline, that is, the controller 13 controls the fifth valve 125 in the circulation valve group 12 to be communicated. Preferably, the controller 13 may control the fifth valve 125 to be partially opened, and control the second valve 122 to be kept closed, and control the first valve 121 to be kept opened. Alternatively, the controller 13 controls the circulation valve group 12 to increase the degree of communication with the outside air, that is, the controller 13 may control the fifth valve group 125 to increase the opening degree, and control the second valve 122 to remain closed, and control the first valve 121 to remain open.
If the detected gas output value is larger than the rated flow value of the molecular sieve nitrogen making machine 11 in the current working state, which indicates that the opening degree of the fifth valve 125 is too large, and the air entering the nitrogen gas atmosphere control system 1 is too much, the circulating valve group 12 is controlled to reduce the degree of communication with the outside air, that is, the controller 13 controls the fifth valve 125 to reduce the opening degree, controls the first valve 121 to be kept on, and controls the second valve 122 to be kept off.
Specifically, the controller 13 is configured to calculate a difference between the air volume detection value and a current rated flow value of the molecular sieve nitrogen making machine 11, calculate a ratio between the difference and the current rated flow value of the molecular sieve nitrogen making machine 11, and adjust a degree of communication between the circulation valve group 12 and the outside air according to the ratio, so as to accurately control an intake amount of the outside air entering the nitrogen gas atmosphere control system.
When the detected air output value is smaller than the current rated flow value of the molecular sieve nitrogen making machine 11, the controller 13 controls the circulation valve group 12 to increase the degree of communication between the circulation valve group 12 and the outside air according to the ratio, that is, the controller 13 correspondingly increases the opening and closing degree of the fifth valve 125 according to the ratio so as to supplement the corresponding outside air to enter the circulation pipeline.
When the detected value of the air output is equal to the current rated flow value of the molecular sieve nitrogen making machine 11, the controller 13 does not adjust the degree of the communication between the circulating valve set 12 and the outside air, so that the molecular sieve nitrogen making machine 11 keeps the current air output.
When the detected gas output value is larger than the current rated flow value of the molecular sieve nitrogen making machine 11, the controller 13 controls the circulating valve group 12 to reduce the degree of communication between the circulating valve group 12 and the outside air according to the ratio, that is, the controller 13 correspondingly reduces the opening degree of the fifth valve 125 according to the ratio.
The embodiment of the invention utilizes the circulating pipeline to connect the controlled atmosphere bin and the air compressor, the circulating valve group is arranged on the circulating pipeline, and the circulating pipeline is controlled by controlling the circulating valve group, so that the gas in the controlled atmosphere bin is conveyed to the nitrogen controlled atmosphere control system through the circulating pipeline, the working efficiency of the nitrogen making machine can be effectively improved, and the nitrogen controlled atmosphere time is shortened. To replace 200m3Taking the air in the space as an example, the gas production is 50m according to the working capacity of the molecular sieve nitrogen generator3And h, calculating the nitrogen with the gas production concentration of 99.0%, and if the oxygen concentration of the gas space of the modified atmosphere storage is reduced from 21% to below 2%, at least more than 15 hours are required to meet the requirement. Compared with the prior art that the air source is required to be obtained from the external air and the oxygen concentration is reduced from 21% to below 2%, the nitrogen controlled atmosphere control system of the invention fully utilizes the air in the controlled atmosphere binThe gas is used as the gas source of the nitrogen making equipment (the oxygen concentration is 21 percent lower than that of the air), the oxygen concentration is reduced to below 2 percent, the whole gas adjusting process only needs about 10 hours, and the time is greatly shortened compared with the corresponding gas adjusting process carried out by the prior art.
Further, in order to control the temperature of the gas entering the controlled atmosphere storage 2 and avoid the phenomenon that the temperature difference between the temperature of the gas (nitrogen) discharged from the gas outlet of the molecular sieve nitrogen making machine 11 and the temperature of the gas in the controlled atmosphere storage is too large, so that condensation is generated, and the mildew of the goods in the controlled atmosphere storage is caused, the nitrogen controlled atmosphere control system 1 can further comprise a temperature control machine 17.
The temperature control machine 17 is connected to the gas outlet of the molecular sieve nitrogen making machine 11, and is used for adjusting the temperature of the gas discharged from the gas outlet of the molecular sieve nitrogen making machine 11, for example, heating or cooling the gas.
Preferably, the nitrogen controlled atmosphere control system 1 may further include: a first thermometer 18 and a second thermometer 19. The temperature difference threshold Δ t is also preset in the controller 13.
The first temperature measuring instrument 18 is arranged in the modified atmosphere bin 2, is connected with the controller 13, and is used for detecting the temperature in the modified atmosphere bin 2 and sending the detected temperature value t1 in the modified atmosphere bin 2 to the controller 13.
The second temperature measuring instrument 19 may be disposed at the outlet of the temperature controller 17, and connected to the controller 13, and configured to detect the temperature of the gas after temperature adjustment by the temperature controller 17, and send a detected temperature value t2 to the controller 13.
The controller 13 is connected with the temperature control machine 17, and the controller 13 is further configured to calculate a difference between t1 and t2, determine whether the difference is within a range of a preset temperature difference threshold Δ t, and if not, send a temperature adjustment signal to the temperature control machine 17 to instruct the temperature control machine 17 to adjust the temperature of the gas discharged from the gas outlet of the molecular sieve nitrogen making machine 11 to (t1 ± Δ t) according to the temperature adjustment signal, that is, make t2 ═ t (t1 ± Δ t). If t1 is greater than t2, the temperature of the gas discharged from the gas outlet of the molecular sieve nitrogen generator 11 is adjusted to (t1- Δ t), and if t1 is less than t2, the temperature of the gas discharged from the gas outlet of the molecular sieve nitrogen generator 11 is adjusted to (t1+ Δ t).
The embodiment of the invention also provides a nitrogen controlled atmosphere control method, which is used in a nitrogen controlled atmosphere control system and comprises an initial controlled atmosphere control step and an operating controlled atmosphere control step, wherein the operating controlled atmosphere control step comprises the following steps: and conveying the gas discharged from the gas outlet of the gas conditioning bin to the gas inlet of the air compressor.
The following takes the structure of the circulation control valve block shown in fig. 3 as an example, and with reference to fig. 1 and 4, the initial modified atmosphere control step and the modified atmosphere control step in operation in the nitrogen modified atmosphere control flow will be described in detail.
First, an initial modified atmosphere control step is executed, namely step 401:
and step 401, controlling external air to enter an air compressor, starting timing, and controlling to start the molecular sieve nitrogen making machine 11.
Specifically, the controller 13 may send a control signal to the circulation valve set 12 according to a user instruction, so as to control the circulation valve set 12 to be communicated with the air compressor 10. That is, the controller 13 controls to open the first valve 121, close the second valve 122 and keep the fifth valve 125 open, so that the outside air is introduced into the air compressor 10 through the open fifth valve 125 via the circulation line (first circulation line) to provide the gas source for the molecular sieve nitrogen generator 11.
A timing module may be disposed in the controller 13, and when the controller 13 controls the first valve 121 to be turned on, the timing module starts timing to monitor the intake time of the external air.
The controller 13 controls the molecular sieve nitrogen making machine 11 to be started, and preferably, the controller 13 controls the molecular sieve nitrogen making machine 11 to operate at an operation gear corresponding to the maximum gas output.
After the initial modified atmosphere control step is completed, the modified atmosphere control step in operation, namely step 402-409, is executed.
When the intake time period is reached, the air compressor 10 is controlled to be isolated from the outside air, step 402.
Specifically, when the air intake duration is reached, the controller 13 controls the circulation valve set 12 to be isolated from the outside air, so that the air in the modified atmosphere bin 2 enters the air compressor 10 through the circulation pipeline. That is, the timing module stops timing, and the controller 13 controls the fifth valve 125 in the circulation valve set 12 to close and keeps the second valve 122 closed, so as to isolate the circulation valve set 12 from air, thereby preventing external air from entering the nitrogen gas atmosphere control system 1.
And step 403, conveying the gas discharged from the gas outlet of the controlled atmosphere bin 2 to the gas inlet of the air compressor 10.
Specifically, the controller 13 controls the first valve 121 to be kept open, so that the gas in the modified atmosphere storage 2 enters the air compressor 10 through the first valve 121 via the circulation pipelines (i.e., the second circulation pipeline and the first circulation pipeline), and the gas internal circulation of the nitrogen modified atmosphere control system is realized.
Step 404-; otherwise, controlling the molecular sieve nitrogen making machine 11 to continue working.
As the molecular sieve nitrogen generator 11 delivers nitrogen gas into the controlled atmosphere bin 2, the nitrogen gas concentration in the controlled atmosphere bin 2 gradually increases, and correspondingly, the oxygen gas concentration gradually decreases, and the controller 13 can obtain the oxygen gas concentration detection value a in the controlled atmosphere bin 2 in real time through the first oxygen content meter 14.
When the controller 13 compares the detected oxygen concentration value a with a preset oxygen concentration threshold value and determines that the detected oxygen concentration value a in the controlled atmosphere storage 2 is less than or equal to the preset oxygen concentration threshold value, which indicates that the nitrogen concentration in the controlled atmosphere storage 2 has reached or is higher than the target nitrogen concentration, the molecular sieve nitrogen making machine 11 is controlled to stop working, that is, step 406 is executed.
When the controller 13 determines that the detected value a of the oxygen concentration in the controlled atmosphere bin 2 is greater than the preset oxygen concentration threshold value, which indicates that the nitrogen concentration in the controlled atmosphere bin 2 has not reached the target nitrogen concentration, the controller 13 does not send a control instruction to the molecular sieve nitrogen making machine, so that the molecular sieve nitrogen making machine continues to keep operating, i.e., the molecular sieve nitrogen making machine 11 continues to operate.
And step 406, controlling the molecular sieve nitrogen making machine 11 to stop working.
Specifically, when the controller 13 determines that the detected value of the oxygen concentration in the air outlet blending bin 2 is less than or equal to the preset oxygen concentration threshold value, a control signal is sent to the molecular sieve nitrogen making machine 11 to control the molecular sieve nitrogen making machine 11 to stop working.
It should be noted that when the controller 13 determines that the detected oxygen concentration value a in the modified atmosphere storage 2 is greater than the preset oxygen concentration threshold value, the controller 13 may continue to execute step 404.
It can be seen from the above flow that after the nitrogen gas-adjusting control system is started (i.e. the molecular sieve nitrogen making machine 11 is started), the controller 13 can automatically control the circulating valve set 12 to adjust the degree of communication with the outside air, and after the oxygen concentration in the gas-adjusting cabin 2 reaches the preset target concentration, the molecular sieve nitrogen making machine 11 is automatically controlled to stop working, the whole process does not need manual monitoring and adjustment, the labor cost is saved, the automation degree of the nitrogen gas-adjusting control system is improved, and the operation process is simple, and the control is timely and accurate.
Further, during the operation of the molecular sieve nitrogen generator 11, the oxygen concentration of the gas delivered from the controlled atmosphere cabin 2 to the molecular sieve nitrogen generator 11 is changed (gradually decreased) in real time, and in order to adjust the molecular sieve nitrogen generator 11 to the optimal operation state, the controller 13 may further control the circulating valve set 12 to communicate with the air so as to supplement the air to the nitrogen controlled atmosphere control system 1. Namely, after the oxygen concentration detection value in the controlled atmosphere bin 2 is judged to be larger than the preset oxygen concentration threshold value, the following steps can be executed:
step 407-; if the former is larger than the latter, go to step 410; if the former is equal to the latter, the current gas output of the molecular sieve nitrogen making machine 11 is maintained.
Specifically, the controller 13 obtains the detected gas amount value of the molecular sieve nitrogen making machine 11 sent by the flow meter 15, and compares the detected gas amount value with the rated flow value of the molecular sieve nitrogen making machine 11 in the current working state.
If the controller 13 determines that the detected gas amount value is smaller than the rated flow value of the molecular sieve nitrogen making machine 11 in the current working state, which indicates that the air in the nitrogen gas atmosphere control system 1 is insufficient and the molecular sieve nitrogen making machine 11 cannot work at the rated flow, the controller 13 controls the circulation valve set 12 to communicate with the air, or controls the circulation valve set 12 to increase the degree of communication with the outside air to supplement the air, namely step 409 is executed.
If the controller 13 determines that the detected value of the outlet air amount is greater than the rated flow value of the molecular sieve nitrogen making machine 11 in the current operating state, which indicates that the degree of communication between the circulation valve set 12 and the outside air is too large, and the air entering the nitrogen gas atmosphere control system 1 is too much, the controller 13 controls the circulation valve set 12 to reduce the degree of communication between the circulation valve set 12 and the outside air, so as to reduce the amount of air entering the nitrogen gas atmosphere control system 1, i.e. step 410 is executed (at this time, the circulation valve set 12 and the air compressor 10 are still kept in conduction).
If the detected value of the air output is equal to the rated flow value of the molecular sieve nitrogen making machine 11 in the current working state, the controller 13 does not adjust the degree of the communication between the circulating valve group 12 and the outside air, so that the molecular sieve nitrogen making machine 11 maintains the current air output.
And step 409, increasing the air inflow of the external air into the nitrogen controlled atmosphere control system.
Specifically, the controller 13 controls the circulation valve group 12 to communicate with the outside air, or controls the circulation valve group 12 to increase the degree of communication with the outside air, so as to supplement the air into the circulation line.
The controller 13 may control the circulation valve group 12 to communicate with the air by controlling the second valve 122 to remain closed, the first valve 121 to remain open, and the fifth valve 125 to remain open, or controlling the second valve 122 to remain closed, the first valve 121 to remain open, and the fifth valve to increase the degree of communication with the outside air.
Specifically, the controller 13 calculates a difference between the detected gas output value of the molecular sieve nitrogen generator 11 and the rated flow rate value of the molecular sieve nitrogen generator 11 in the current operating state, calculates a ratio between the difference and the rated flow rate value of the molecular sieve nitrogen generator 11 in the current operating state, and increases the degree of communication between the circulating valve group 12 and the air according to the ratio, that is, increases the opening degree of the fifth valve 125 according to the ratio.
The controller 13 controls the circulation valve set 12 to communicate with the air so as to make up air enter the circulation pipeline, or controls the circulation valve set to increase the degree of communication with the outside air, and then continues to execute the step 404 until the oxygen concentration detection value A in the controlled atmosphere bin 2 is less than or equal to the preset oxygen concentration threshold value, and the controller 13 controls the molecular sieve nitrogen making machine 11 to stop working.
And step 410, reducing the air inflow of the external air into the nitrogen controlled atmosphere control system.
Specifically, the controller 13 reduces the degree of communication between the circulation valve group 12 and the outside air, that is, the controller 13 reduces the degree of communication between the circulation valve group 12 and the outside air by reducing the opening/closing degree of the fifth valve 125.
The controller 13 calculates a difference between the detected gas output value of the molecular sieve nitrogen generator 11 and the rated flow rate value of the molecular sieve nitrogen generator 11 in the current working state, calculates a ratio between the difference and the rated flow rate value of the molecular sieve nitrogen generator 11 in the current working state, and reduces the degree of communication between the circulation valve set 12 and the air according to the ratio, that is, reduces the opening degree of the fifth valve 125 according to the ratio.
After the controller 13 reduces the degree to which the circulation valve group 12 communicates with the outside air,
and continuing to execute the step 404 until the oxygen concentration detection value A in the controlled atmosphere bin 2 is less than or equal to the preset oxygen concentration threshold value, and controlling the molecular sieve nitrogen making machine 11 to stop working by the controller 13.
It can be seen from steps 406 and 410 that the controller 13 can automatically control the molecular sieve nitrogen making machine 11 to stop working when the oxygen concentration reaches the preset target oxygen concentration by comparing the oxygen concentration detection value in the controlled atmosphere bin with the oxygen concentration threshold value, thereby reducing the labor cost of manual monitoring. And the communication degree of the circulating valve group 12 and the outside air is automatically controlled by comparing the current air output of the molecular sieve nitrogen making machine 11 with the rated flow under the current working state, so that the automation degree of the system is improved.
Further, in order to control the temperature of the gas entering the controlled atmosphere cabin 2 and avoid the phenomenon that the temperature difference between the temperature of the gas discharged from the molecular sieve nitrogen making machine 11 and the temperature in the controlled atmosphere cabin is too large, so as to generate condensation and cause the storage object to mildew, as shown in fig. 5, the nitrogen controlled atmosphere control method according to the embodiment of the present invention may further include the following steps:
and step 501, detecting the temperature in the air-conditioned cabin to obtain a temperature detection value t1, and detecting the temperature of the gas subjected to temperature regulation to obtain a temperature detection value t 2.
Specifically, the controller 13 obtains a temperature detection value t1 in the controlled atmosphere bin 2 sent by the first temperature measuring instrument 18, and obtains a temperature detection value t2 of the gas after temperature adjustment by the temperature control machine 17 sent by the second temperature measuring instrument 19.
More specifically, a temperature control machine 17 may be provided at the gas outlet of the molecular sieve nitrogen making machine 11, and the temperature control machine 17 may be used to adjust the temperature of the gas discharged from the gas outlet of the molecular sieve nitrogen making machine 11.
A first temperature measuring instrument 18 can be arranged in the modified atmosphere bin 2, the first temperature measuring instrument 18 is connected with the controller 13 and is used for detecting the temperature in the modified atmosphere bin 2 and sending a detected temperature value t1 in the modified atmosphere bin 2 to the controller 13; a second temperature measuring instrument 19 may be disposed at an outlet of the temperature controller 17, and the second temperature measuring instrument 19 is connected to the controller 13, and is configured to detect the temperature of the gas after temperature adjustment by the temperature controller 17, and send a detected temperature value t2 to the controller 13.
Step 502, calculate the difference between t1 and t 2.
Specifically, the controller 13 calculates the difference between t1 and t 2.
Step 503, determining whether the difference is within the range of the preset temperature difference threshold Δ t, if not, executing step 504, otherwise, maintaining the current temperature of the gas.
Specifically, the controller 13 determines whether the difference is within the range of the preset temperature difference threshold Δ t, and if the difference between t1 and t2 is not within the range of Δ t, it indicates that the temperature difference between the gas temperature at the gas outlet of the molecular sieve nitrogen making machine 11 and the gas temperature in the controlled atmosphere bin 2 is too large, and temperature adjustment is required, i.e., step 504 is executed. If the controller 13 determines that the difference between t1 and t2 is within the range of Δ t, it indicates that the temperature difference between the gas temperature at the gas outlet of the molecular sieve nitrogen making machine 11 and the gas temperature in the gas conditioning bin 2 is moderate, and the current temperature of the gas at the gas outlet of the molecular sieve nitrogen making machine 11 is maintained without temperature conditioning.
In step 504, temperature adjustment is performed to adjust the gas temperature to (t1 ± Δ t).
Specifically, the controller 13 sends a temperature adjustment signal to the temperature controller 17 to instruct the temperature controller 17 to adjust t2 to (t1 ± Δ t). If t1 is greater than t2, the gas temperature is adjusted to (t1- Δ t), that is, the temperature controller 17 performs heating operation on the gas at the gas outlet of the molecular sieve nitrogen making machine 11. If t1 < t2, the gas temperature is adjusted to (t1+ Δ t), and the temperature controller 17 performs a refrigerating operation on the gas at the gas outlet of the molecular sieve nitrogen making machine 11.
It will be understood that the above embodiments are merely exemplary embodiments taken to illustrate the principles of the present invention, which is not limited thereto. It will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the spirit and substance of the invention, and these modifications and improvements are also considered to be within the scope of the invention.
Claims (10)
1. A nitrogen modified atmosphere control system comprising: an air compressor and a nitrogen making machine, wherein the air compressor is connected with the nitrogen making machine, the nitrogen making machine is connected with an air inlet of the air conditioning bin, the nitrogen making machine is characterized in that,
the air compressor is connected with an air outlet of the air conditioning bin through a circulating pipeline, and a circulating valve group is arranged on the circulating pipeline and used for controlling air at the air outlet of the air conditioning bin to enter the air compressor through the circulating pipeline; the system also comprises a controller, wherein the controller is internally preset with air inlet time length;
the initial state of the circulating valve group is that the circulating valve group is communicated with external air and is not communicated with an air compressor;
the controller is connected with the circulating valve set and used for controlling the circulating valve set to be communicated with the air compressor so as to enable external air to enter the air compressor through the circulating pipeline and start timing; and when the air inlet time length is up, controlling the circulating valve group to be isolated from the outside air so as to enable the air in the air conditioning bin to enter the air compressor through the circulating pipeline.
2. The control system of claim 1, wherein the circulation line comprises a first circulation line and a second circulation line, wherein one end of the first circulation line is connected with an air inlet of the air compressor, and one end of the second circulation line is connected with an air outlet of the modified atmosphere bin;
the circulating valve train includes: the first valve, the second valve and the fifth valve with adjustable opening and closing degrees; two ends of the first valve are respectively connected with the first circulating pipeline and the second circulating pipeline and used for controlling the connection and disconnection between the first circulating pipeline and the second circulating pipeline; the second valve is arranged on the second circulating pipeline, one end of the second valve is communicated with the outside air, and the second valve is used for controlling the on-off between the air outlet of the controlled atmosphere bin and the outside air; the fifth valve is arranged on the first circulating pipeline, one end of the fifth valve is communicated with the outside air, and the fifth valve is used for controlling the air inlet of the air compressor to be communicated with the outside air; or,
the circulating valve train includes: the first valve, the second valve, the third valve and the fourth valve with adjustable opening and closing degrees; two ends of the first valve are respectively connected with the first circulating pipeline and the second circulating pipeline and used for controlling the connection and disconnection between the first circulating pipeline and the second circulating pipeline; the second valve is arranged on the second circulating pipeline, one end of the second valve is communicated with the outside air, and the second valve is used for controlling the on-off between the air outlet of the controlled atmosphere bin and the outside air; the third valve and the fourth valve are arranged on the first circulating pipeline, and one end of the third valve is communicated with the outside air and used for controlling the air inlet of the air compressor to be communicated with the outside air; one end of the fourth valve is communicated with the outside air, and is used for controlling the degree of communication between the air inlet of the air compressor and the outside air.
3. The control system of claim 1, further comprising a first oxygen meter disposed in the modified atmosphere cabin; an oxygen concentration threshold is also preset in the controller;
the first oxygen meter is connected with the controller and used for detecting the oxygen concentration in the controlled atmosphere bin and sending the detected oxygen concentration detection value in the controlled atmosphere bin to the controller;
the controller is connected with the nitrogen generator, and the controller is also used for comparing the oxygen concentration detection value in the controlled atmosphere bin with a preset oxygen concentration threshold value and controlling the start and stop of the nitrogen generator according to the comparison result.
4. The control system of claim 3, further comprising a flow meter disposed at the outlet of the nitrogen generator;
the flow meter is connected with the controller and used for detecting the gas output of the gas outlet of the nitrogen making machine and sending a detected gas output value to the controller;
the controller is also used for comparing the gas output detection value with the current rated flow value of the nitrogen making machine when judging that the oxygen concentration detection value in the gas conditioning bin is larger than the preset oxygen concentration threshold value, and controlling the communication degree of the circulating valve group and the outside air according to the comparison result; if the former is smaller than the latter, the circulation valve set is controlled to be communicated with the outside air, or the circulation valve set is controlled to increase the degree of communication with the outside air so as to supplement the outside air to enter the circulation pipeline; if the former is larger than the latter, the control circulation valve set reduces the degree of communication with the outside air.
5. The control system of claim 4, wherein the controller is specifically configured to calculate a difference between the sensed gas quantity and a rated flow value of the nitrogen generator under the current operating condition, and to calculate a ratio between the difference and the rated flow value of the nitrogen generator under the current operating condition; and when the detected value of the air output is judged to be smaller than the rated flow value of the nitrogen making machine in the current working state, increasing the degree of the communication between the circulating valve group and the outside air according to the ratio; and when the detected gas output value is judged to be larger than the rated flow value of the nitrogen making machine in the current working state, reducing the degree of the communication between the circulating valve group and the outside air according to the ratio.
6. The control system of claim 3, wherein the controller is specifically configured to control the nitrogen generator to stop operating when the detected oxygen concentration value in the controlled atmosphere storage is determined to be less than or equal to a preset oxygen concentration threshold value.
7. A control system according to any one of claims 1 to 6, wherein the system further comprises a temperature controller, a first temperature gauge and a second temperature gauge; a temperature difference threshold value delta t is also arranged in the controller;
the temperature control machine is connected with the gas outlet of the nitrogen making machine and is used for adjusting the temperature of gas discharged from the gas outlet of the nitrogen making machine;
the first temperature measuring instrument is arranged in the controlled atmosphere bin, is connected with the controller and is used for detecting the temperature in the controlled atmosphere bin and sending a detected temperature detection value t1 in the controlled atmosphere bin to the controller;
the second temperature measuring instrument is arranged at the outlet of the temperature control machine, is connected with the controller and is used for detecting the temperature of the gas after temperature adjustment by the temperature control machine and sending a detected temperature detection value t2 to the controller;
the controller is further used for calculating a difference value between t1 and t2, judging whether the difference value is within a range of a preset temperature difference threshold value delta t, and if not, sending a temperature adjusting signal to the temperature control machine to instruct the temperature control machine to adjust the temperature of the gas discharged from the gas outlet of the nitrogen making machine to (t1 +/-delta t); if t1 > t2, the temperature of the gas discharged from the gas outlet of the nitrogen generator is adjusted to (t1- Δ t), and if t1 < t2, the temperature of the gas discharged from the gas outlet of the nitrogen generator is adjusted to (t1+ Δ t).
8. A nitrogen controlled atmosphere control method is used in a nitrogen controlled atmosphere control system and comprises an initial controlled atmosphere control step and an operating controlled atmosphere control step, and is characterized in that the operating controlled atmosphere control step comprises the following steps:
conveying gas discharged from a gas outlet of the gas-adjusting bin to a gas inlet of an air compressor in the nitrogen gas-adjusting control system;
the initial modified atmosphere control step comprises: controlling external air to enter an air compressor, starting timing, and controlling to start a nitrogen making machine; and when the preset air inlet time length is reached, controlling the air compressor to be isolated from the external air.
9. The method of claim 8, wherein the in-service modified atmosphere control step further comprises:
detecting the oxygen concentration in the controlled atmosphere bin, comparing the detected oxygen concentration detection value in the controlled atmosphere bin with a preset oxygen concentration threshold value, and controlling the start and stop of the nitrogen making machine according to the comparison result; wherein, if the former is less than or equal to the latter, the nitrogen generator is controlled to stop working; if the former is larger than the latter, the nitrogen generator is controlled to continue working.
10. The method of claim 9, wherein the in-service modified atmosphere control step further comprises:
detecting the air output of an air outlet of the nitrogen making machine when the nitrogen making machine operates, comparing the detected air output detection value with the current rated flow value of the nitrogen making machine when the oxygen concentration detection value in the controlled atmosphere bin is judged to be larger than the preset oxygen concentration threshold value, and controlling the air input of external air entering the nitrogen controlled atmosphere control system according to the comparison result; if the former is smaller than the latter, the air input of the external air into the nitrogen gas-regulating control system is increased; if the former is larger than the latter, the air input of the external air entering the nitrogen gas-regulating control system is reduced;
and the number of the first and second groups,
the operating controlled atmosphere control step further comprises a temperature adjusting step, and the temperature adjusting step comprises the following steps:
detecting the temperature in the air-conditioned cabin to obtain a temperature detection value t1, and detecting the temperature of the gas subjected to temperature regulation to obtain a temperature detection value t 2;
calculating the difference between t1 and t2, judging whether the difference is within the range of a preset temperature difference threshold value delta t, and if not, performing temperature adjustment to adjust the gas temperature to (t1 +/-delta t); if t1 > t2, the gas temperature is adjusted to (t1- Δ t), and if t1 < t2, the gas temperature is adjusted to (t1+ Δ t).
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| CN106594519A (en) * | 2016-12-26 | 2017-04-26 | 山东宏润空压机科技有限公司 | Nitrogen continuous supply device and control method thereof |
| CN107608262B (en) * | 2017-09-05 | 2020-10-09 | 无锡吉兴汽车声学部件科技有限公司 | Intelligent control system for concentration of automobile exhaust in laboratory |
| CN108181942A (en) * | 2017-12-13 | 2018-06-19 | 中国航空工业集团公司上海航空测控技术研究所 | A kind of airborne equipment of making nitrogen control device and method |
| CN110874106B (en) * | 2018-08-31 | 2022-09-02 | 伊利诺斯工具制品有限公司 | Gas control system and method for reflow oven |
| CN110694872A (en) * | 2019-11-14 | 2020-01-17 | 中山易必固新材料科技有限公司 | Gas protection device and inflation system for ultraviolet curing of plate |
| CN111990676A (en) * | 2020-08-14 | 2020-11-27 | 武汉东昌仓贮技术有限公司 | Gas conditioning and maintaining system and method for tobacco leaves |
| CN115067387A (en) * | 2022-07-21 | 2022-09-20 | 杭州辰睿空分设备制造有限公司 | Remote intelligent control system of nitrogen production system |
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