CN114440510A - Refrigerant unit system and control device and control method thereof - Google Patents
Refrigerant unit system and control device and control method thereof Download PDFInfo
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- CN114440510A CN114440510A CN202011223786.5A CN202011223786A CN114440510A CN 114440510 A CN114440510 A CN 114440510A CN 202011223786 A CN202011223786 A CN 202011223786A CN 114440510 A CN114440510 A CN 114440510A
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B49/00—Arrangement or mounting of control or safety devices
- F25B49/02—Arrangement or mounting of control or safety devices for compression type machines, plants or systems
- F25B49/022—Compressor control arrangements
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2600/00—Control issues
- F25B2600/25—Control of valves
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Abstract
A refrigerant unit system and a control device and a control method thereof are provided. The refrigerant unit system comprises at least one group of refrigerant units, each group of refrigerant units comprises at least one refrigerant compressor with a machine head and a valve block, at least one group of refrigerant units comprises a variable-frequency refrigerant compressor with a variable-frequency machine head, and the variable-frequency machine head is in driving connection with a frequency converter. The control device includes: the temperature sensor is used for detecting temperature signals of ice water or hot water; the temperature controller is used for receiving the temperature signal and outputting a frequency conversion control signal to the frequency converter; and the valve block controller is connected with the valve block controller through a valve block control signal line respectively, and is used for generating a corresponding valve block control signal according to the frequency signal of the frequency conversion machine head output by the frequency converter and outputting the corresponding valve block control signal to the valve block of the corresponding refrigerant compressor so as to drive the valve block to act. According to the invention, by using the frequency signal of the frequency converter, the valve block and the frequency converter can be controlled to operate at proper positions so as to reduce the temperature difference and improve the energy-saving efficiency.
Description
Technical Field
The invention relates to a compressor technology, in particular to a refrigerant unit system and a control device and a control method thereof.
Background
In order to achieve the purpose of capacity adjustment, most of the existing refrigerant compressors adopt a valve block to control the refrigerant output or change the volume ratio, and the commonly used valve block capacity adjustment ratios are 100%, 75%, 50%, 25% and the like. The position of the valve block is controlled by the water temperature of the heat exchanger, and when the water temperature is lower than a set value, the valve block moves from a high position to a low position (for example, the water temperature is reduced from 100% to 75%); when the water temperature rises to a certain set value, the valve block moves from the low gear to the high gear (for example, from 75% to 100%).
Each set of cold water or heat pump unit can use one or more than one refrigerant compressor to run in parallel to improve the unit capacity. If the fixed frequency machine heads are used, because the valve block positions of all the capacity sections have different actuating temperatures, according to the prior art, different valve block actuating temperatures must be set during operation.
If the frequency converter is used for driving the refrigerant compressor, the temperature sensor is used for collecting ice water temperature signals, the ice water temperature signals are calculated by a temperature controller (such as a PID controller), then frequency conversion frequency instructions are output to the frequency converter, and the frequency converter is driven to operate at a certain frequency. Since the maximum and minimum rotation speed limits are set during the operation of the refrigerant compressor, the inverter must set the operation ranges of the maximum frequency and the minimum frequency (for example, the minimum frequency is 50% of the maximum frequency), so the temperature difference in the inverter range is small (conventionally called as constant temperature). Because of the proximity to constant temperature, variable frequency drives are more energy efficient than fixed frequency drives and are more temperature-constant, but different temperature differentials must still be set to generate the valve block actuation signals.
Disclosure of Invention
In view of the above, an object of the present invention is to provide a refrigerant unit system, a control device and a control method thereof, which can reduce temperature difference and improve energy saving efficiency.
In order to achieve the purpose, the invention provides a control device of a refrigerant unit system, which is characterized in that the refrigerant unit system comprises at least one group of refrigerant units, each group of refrigerant units comprises at least one refrigerant compressor with a machine head and a valve block, at least one group of refrigerant units comprises a variable-frequency refrigerant compressor with a variable-frequency machine head, and the variable-frequency machine head is in driving connection with a frequency converter; the control device includes: the temperature sensor is used for detecting temperature signals of ice water or hot water; the temperature controller is used for receiving the temperature signal and outputting a frequency conversion control signal to the frequency converter, and the temperature controller is electrically connected with the temperature sensor; and the valve block controller is used for generating corresponding valve block control signals according to the frequency signals of the frequency converter head output by the frequency converter and outputting the corresponding valve block control signals to the corresponding valve blocks of the refrigerant compressor through the corresponding valve block signal control lines so as to drive the valve blocks to act.
In order to achieve the above object, the present invention further provides a refrigerant unit system, which is characterized by comprising the above control device.
In order to achieve the above object, the present invention further provides a control method of a refrigerant unit system, which is characterized in that the refrigerant unit system comprises at least one group of refrigerant units, each group of refrigerant units comprises at least one refrigerant compressor with a machine head and a valve block, and at least one group of refrigerant units comprises a variable frequency refrigerant compressor with a variable frequency machine head, and the variable frequency machine head is in driving connection with a frequency converter; the control method comprises the following steps: detecting a temperature signal of ice water or hot water by using a temperature sensor; receiving the temperature signal by using a temperature controller and outputting a frequency conversion control signal to the frequency converter; and generating a corresponding valve block control signal by using a valve block controller according to the frequency signal of the frequency conversion machine head output by the frequency converter, and outputting the corresponding valve block control signal to a corresponding valve block of the refrigerant compressor through a corresponding valve block signal control line so as to drive the valve block to act.
On one hand, the invention can control the valve block and the frequency converter to operate at proper positions by using the frequency signal of the frequency converter so as to reduce the temperature difference and improve the energy-saving efficiency.
On the other hand, the valve block switching of the variable-frequency and fixed-frequency refrigerant compressor can be realized under the principle of constant temperature by reasonably matching the variable-frequency machine head and the fixed-frequency machine head, so that the output temperature is more stable, the consumed power is lower, and the energy is saved. As long as the power collocation is proper, the signals processed by the valve block controller can drive the variable-frequency or fixed-frequency refrigerant compressors of other units in the same unit or in the same ice-water pipe network so as to achieve the seamless joint control function. When a plurality of refrigerant compressors are in the same pipe network, accurate joint control pressure or temperature can be achieved as long as the frequency conversion power range of the frequency conversion refrigerant compressor is enough. The output signal of the valve block controller can be extended infinitely in theory and can be connected in parallel or in series with the control signal of the existing unit to achieve more reliable logic.
The above description will be described in detail by embodiments, and further explanation will be provided for the technical solution of the present invention.
Drawings
In order to make the aforementioned and other objects, features, and advantages of the invention, as well as others which will become apparent, reference is made to the following description taken in conjunction with the accompanying drawings in which:
fig. 1 is a schematic structural diagram of a preferred refrigerant unit system according to the present invention;
FIG. 2 is a schematic flow chart of a control method of the refrigerant unit system according to the present invention;
fig. 3 is a schematic flow chart of a control method when at least one refrigerant unit of the refrigerant unit system of the present invention only includes a variable frequency refrigerant compressor having a variable frequency head;
fig. 4A and 4B are schematic diagrams illustrating a flow of a control method when at least one refrigerant unit of the refrigerant unit system of the present invention includes a variable frequency refrigerant compressor having a variable frequency head and a fixed frequency refrigerant compressor having a fixed frequency head.
Detailed Description
For a better understanding and completeness of the description of the present invention, reference is made to the appended drawings and various embodiments described below in which like reference numerals represent the same or similar elements. In other instances, well-known elements and steps have not been described in detail in order to avoid unnecessarily obscuring the present invention. In addition, for the sake of simplifying the drawings, some conventional structures and elements are shown in the drawings in a simple schematic manner.
In the description of the embodiments and the claims, reference to "connected" may generally mean that an element is indirectly coupled to another element through another element or that an element is directly connected to another element without passing through the other element.
The refrigerant unit system comprises at least one refrigerant unit, wherein each refrigerant unit can comprise at least one refrigerant compressor with a machine head and a valve block. And at least one group of refrigerant units comprises a variable-frequency refrigerant compressor with a variable-frequency machine head, wherein the variable-frequency machine head is in driving connection with the frequency converter. The refrigerant unit system also comprises a control device which comprises a temperature sensor, a temperature controller and a valve block controller. The temperature sensor can be used for detecting the temperature signal of the ice water or the hot water of the heat exchanger. The temperature controller can be used for receiving the temperature signal and outputting a frequency conversion control signal to the frequency converter, and the temperature controller is electrically connected with the temperature sensor. The valve block of each refrigerant compressor is respectively connected with the valve block controller through a valve block control signal line, and the valve block controller can be used for generating a corresponding valve block control signal according to the frequency signal of the frequency conversion machine head output by the frequency converter and outputting the corresponding valve block control signal to the corresponding valve block of the refrigerant compressor through the corresponding valve block signal control line so as to drive the valve block to act.
As shown in fig. 1, a preferred refrigerant unit system of the present invention includes two refrigerant units, such as a first refrigerant unit 50 and a second refrigerant unit 60. The first refrigerant unit 50 includes two refrigerant compressors running in parallel, for example, a variable frequency refrigerant compressor having a variable frequency head 10 and a fixed frequency refrigerant compressor having a fixed frequency head 20; the second refrigerant unit 60 also includes two refrigerant compressors operating in parallel, for example, the refrigerant compressor includes a refrigerant compressor having a head 30 and a refrigerant compressor having a head 40, where the heads 30 and 40 may be both frequency conversion heads, or both frequency fixed heads, or one of the frequency conversion heads and the other frequency fixed head, which are not intended to limit the present invention. The frequency converter 70 is connected to the frequency converter head 10 of the first refrigerant unit 50 in a driving manner, for example, by outputting a driving signal (e.g., a power output signal) S1 to the frequency converter head 10 to drive the frequency converter head 10. The refrigerant unit system further includes a control device, which includes, for example, a temperature sensor 110, a temperature controller 100, and a valve block controller 80. The temperature sensor 110 detects a temperature signal (e.g., an analog signal) S8 of the ice water or the hot water in the heat exchanger, and transmits the temperature signal S8 to the temperature controller 100. The temperature controller 100 can be, for example, a PID controller, and then outputs a frequency conversion control signal (e.g., a frequency conversion command) S7 from the temperature controller 100 to the frequency converter 70, and the frequency converter 70 outputs a driving signal S1 to the frequency converter head 10 after receiving the frequency conversion control signal S7 to drive the frequency converter head 10, and simultaneously outputs a frequency signal (e.g., a frequency analog signal) S2 of the frequency converter head 10 to the valve block controller 80. The valve block controller 80 can generate a corresponding valve block control signal according to the frequency signal S2 output by the frequency converter 70 and output the corresponding valve block control signal to the valve block of each refrigerant compressor in each refrigerant unit through the corresponding valve block signal control line S3, S4, S5, S6 to drive the valve block to operate, that is, the valve block of each refrigerant compressor in each refrigerant unit is connected to the valve block controller 80 through the corresponding valve block control signal line, for example, the valve block control signal of the inverter head is output to the inverter head 10 of the first refrigerant unit 50 through the inverter head valve block signal control line S3, the valve block control signal of the fixed frequency head is output to the fixed frequency head 20 of the first refrigerant unit 50 through the fixed frequency head valve block signal control line S4, and the valve block control signals of the other units are output to the head 30 of the second refrigerant unit 60 through the other head valve block signal control lines S5, the valve block control signals of the other units are output to the head 40 of the second refrigerant unit 60 via the other unit head valve block signal control line S6, and are used to control the operation of the valve blocks of each head.
In the present invention, the phrase "the valve block is connected to the valve block controller through the valve block control signal line" does not mean that the valve block is directly connected to the valve block controller, but means that the valve block controller can control the position of the valve block by driving the piston and the connecting rod by the oil in or out of the hydraulic cylinder through the opening or closing of the control valve on the fluid delivery line through the valve block control signal line. In other words, the valve block may be controlled by the valve block controller and its position adjusted.
Of course, it is understood that in other embodiments, the refrigerant unit of the present invention may include only the first refrigerant unit 50. The first refrigerant unit 50 may only include an inverter refrigerant compressor having the inverter head 10. Alternatively, the refrigerant unit may include more refrigerant units. The second refrigerant unit 60 may include only one or two refrigerant compressors, or may include three or more refrigerant compressors, which are not intended to limit the present invention. In the present invention, the refrigerant compressor may be a screw-type refrigerant compressor, for example.
Preferably, in the present invention, the valve block controller 80 outputs the corresponding valve block control signal to drive the valve block to operate, for example, when the frequency signal S2 is greater than a first set value or less than a second set value. The first set value may be, for example, 85% of the highest frequency set by the frequency converter 70, and the second set value may be, for example, 65% of the highest frequency set by the frequency converter 70. Of course, it should be understood that the first set value and the second set value are not limited to the above values, and may be designed to be other values according to actual needs, and these are not intended to limit the present invention.
More preferably, in the present invention, when the frequency signal S2 is not greater than the first setting value or not less than the second setting value, or after the valve block control signal is output, the valve block controller 80 is further configured to count a delay time, and resume detecting and performing the next action after the delay time. The delay time is generally set to 1 minute or more, and preferably set to 1 to 3 minutes, for example. Of course, it should be understood that the delay time is not limited to the above values, and other values may be designed according to actual needs, which are not intended to limit the present invention.
In the present invention, the valve block controller 80 includes a start/stop terminal respectively connected to the machine heads of the refrigerant compressors, and a plurality of actuation signal terminals respectively connected to different gears of the valve blocks of the refrigerant compressors.
Accordingly, as shown in fig. 2, the method 200 for controlling a refrigerant unit system of the present invention mainly includes:
step S201, detecting a temperature signal of ice water or hot water by using a temperature sensor;
step S202, receiving a temperature signal by using a temperature controller and outputting a frequency conversion control signal to a frequency converter;
and step S203, generating a corresponding valve block control signal by using the valve block controller according to the frequency signal of the frequency conversion machine head output by the frequency converter, and outputting the corresponding valve block control signal to a corresponding valve block of the refrigerant compressor through a corresponding valve block signal control line so as to drive the valve block to act.
As shown in fig. 3, it shows a flow of a control method when at least one refrigerant unit of the refrigerant unit system of the present invention only includes an inverter refrigerant compressor having an inverter head. Referring to fig. 1 in combination, step S301: the temperature controller (100) outputs a variable frequency control signal (S7) to the frequency converter (70) according to the temperature signal (S8) transmitted by the temperature sensor (110). Step S302: the frequency converter (70) carries out frequency conversion control on the frequency conversion machine head (10) according to the frequency conversion control signal (S7), and transmits the frequency signal (S2) of the frequency conversion machine head (10) to the valve block controller (80). Step S303: when controlling a single inverter head (10), the valve block controller (80) receives a frequency signal (S2) from the inverter (70), and determines whether the frequency signal is greater than a first set value (e.g., 85% of the highest frequency) or less than a second set value (e.g., 65% of the highest frequency). If yes, go to step S304: when the frequency signal is larger than a first set value, the controller (80) starts integration or timing, and when the integration or timing reaches a first preset value, a valve block loading control signal is output to a valve block of the frequency conversion machine head (10) through a frequency conversion machine valve block signal control line (S3) so as to adjust the position of the valve block of the frequency conversion machine head (for example, move to a high gear). Step S306: after the signal is output, the valve block controller (80) clears the integration or timing data to prepare for integration or timing of the next action, counts a delay time (e.g., 1-3 minutes) to avoid the valve block from oscillating continuously between the load rising and the load falling, and then returns to step S301 to obtain the adjusted temperature signal of the ice water or the hot water. Further, step S305: if the frequency signal (S2) is less than the second set value, the valve block controller (80) also starts integration or timing, and when the integration or timing reaches a second preset value, a valve block load reduction control signal is output to the valve block of the inverter head (10) through the inverter head valve block signal control line (S3) to adjust the position of the valve block of the inverter head (for example, move to a lower gear). Step S306: after the signal is output, the valve block controller (80) clears the integration or timing data to prepare for integration or timing of the next action, counts a delay time (e.g., 1-3 minutes) to avoid the valve block from oscillating continuously between the load-up and load-down, and then returns to step S301 to obtain the adjusted temperature signal of the ice water or the hot water.
When the valve block controller (80) determines that the frequency signal is between two set values (e.g., between 85% and 65% of the highest frequency) according to the determination in step S303, the valve block controller (80) does not perform integration, and directly performs step S306: the valve block controller (80) counts a delay time (e.g., 1-3 minutes), and then returns to step S301 to obtain the temperature signal of the ice water or the hot water.
According to the invention, the output frequency signal of the frequency converter (70) is used, and a corresponding valve block control signal can be generated after integration or timing is carried out by the valve block controller (80), and the valve block can be driven to adjust the position by matching with reasonable delay time through corresponding valve block signal control lines (S3, S4, S5 and S6), so that the output capacity of the refrigerant compressor can be changed under the principle of keeping the constant temperature of ice water or hot water.
As shown in fig. 4A and 4B, a flow of a control method when at least one refrigerant unit of the refrigerant unit system of the present invention includes a variable-frequency refrigerant compressor having a variable-frequency head and a fixed-frequency refrigerant compressor having a fixed-frequency head is shown. Referring to fig. 1, in the present embodiment, there are two heads in the refrigerant machine set, one is a variable frequency head (10) of the variable frequency refrigerant compressor, and the other is a fixed frequency head (20) of the fixed frequency refrigerant compressor, and according to the existing control mode, the variable frequency head (10) will be operated first and stopped last. Therefore, if only the frequency conversion machine head (10) is in operation, the output signal of the valve block controller (80) can control the valve block of the frequency conversion machine head (10) to carry out load lifting or load reducing. If the valve block of the frequency conversion machine head (10) reaches 100% gear (namely full-load gear) and the valve block controller (80) outputs the load-increasing signal, the frequency conversion machine head (20) is started through a valve block signal control line (S4) of the frequency conversion machine head and the signal of the valve block controller (80) is used for controlling the valve block of the frequency conversion machine head (20).
Wherein, step S401: the temperature controller (100) outputs a variable frequency control signal (S7) to the frequency converter (70) according to the temperature signal (S8) transmitted by the temperature sensor (110). Step S402: the frequency converter (70) carries out frequency conversion control on the frequency conversion machine head (10) according to the frequency conversion control signal (S7), and transmits the frequency signal (S2) of the frequency conversion machine head (10) to the valve block controller (80). Step S403: the valve block controller (80) determines whether the frequency signal (S2) is greater than a first set value (e.g., 85% of the highest frequency) or less than a second set value (e.g., 65% of the highest frequency).
In detail, if the valve block controller (80) determines that the frequency signal (S2) is greater than the first set value, the method proceeds to step S404: when the frequency signal (S2) is larger than the first set value, the valve block controller (80) judges whether the valve block position of the frequency conversion machine head (10) is in a 100% gear position. If yes, proceed to step S4041: when the frequency signal (S2) is greater than the first set value and the valve block of the frequency conversion machine head (10) is in a 100% gear position, the valve block controller (80) starts the fixed-frequency refrigerant compressor, and the valve block controller (80) outputs a valve block load reduction control signal to the valve block of the frequency conversion machine head (10) to control the valve block to move towards a low gear position. In addition, when the valve block position of the fixed-frequency handpiece (20) is less than or equal to 50% of the gear, the valve block controller (80) can further simultaneously control the valve block of the fixed-frequency handpiece (20) to move to the gear of more than 50%. Step S406 is then performed: after the signal is output, the valve block controller (80) clears the integration or timing data to prepare for integration or timing of the next action, counts a delay time (e.g., 1-3 minutes) to avoid the valve block from oscillating continuously between the load rising and the load falling, and then returns to step S401 to obtain the adjusted temperature signal of the ice water or the hot water.
Further, step S4042: when the frequency signal (S2) is greater than the first set value and the valve block of the frequency conversion machine head (10) is not in the 100% gear, the valve block controller (80) starts integration or timing, and when the integration or timing reaches a third set value, a valve block load-lifting control signal is output to the valve block of the frequency conversion machine head (10) so as to adjust the position of the valve block of the frequency conversion machine head (10) (for example, the control valve block moves to a high gear). Step S406 is then performed: after the signal is output, the valve block controller (80) clears the integration or timing data to prepare for integration or timing of the next action, counts a delay time (e.g., 1-3 minutes) to avoid the valve block from oscillating continuously between the load rising and the load falling, and then returns to step S401 to obtain the adjusted temperature signal of the ice water or the hot water.
In detail, after step S403, step S405: when the frequency signal (S2) is less than the second set value, the valve block controller (80) determines whether the valve block position of the pilot head (20) is less than or equal to 50% of the gear. If yes, proceed to step S4051: and the valve block controller (80) judges whether the position of the valve block of the frequency conversion machine head (10) is less than or equal to 50% of the gear. If yes, go to step S4053: and the valve block controller (80) starts integration or timing, outputs a valve block loading control signal to the valve block of the frequency conversion machine head (10) when the integration or timing reaches a fourth preset value so as to control the valve block to move towards a high gear, for example, the position of the valve block of the frequency conversion machine head (10) can be adjusted to be 100% of a gear, and the frequency fixed machine head (20) is closed at the same time. In practical operation, when the fixed frequency handpiece (20) is closed, the valve block controller (80) controls the fixed frequency handpiece (20) to keep a minimum rotating speed, so that the fixed frequency handpiece (20) is in a low load state. In addition, according to the step S4051, if the valve block controller (80) judges that the valve block position of the frequency conversion machine head (10) is larger than 50% gear, the step S4055 is carried out: and the valve block controller (80) starts integration or timing, and outputs a valve block load reduction control signal to the valve block of the frequency conversion machine head (10) when the integration or timing reaches a fifth preset value so as to adjust the position of the valve block of the frequency conversion machine head (10) (for example, the valve block is controlled to move to a low gear). It is worth mentioning that when the valve block of the frequency conversion machine head (10) is in the 50% gear position, the valve block controller (80) performs step S4053 to control the valve block to move to the high gear position.
After step S4053 or step S4055 is executed, step S406 is performed: after the signal is output, the valve block controller (80) clears the integration or timing data to prepare for integration or timing of the next action, counts a delay time (e.g., 1-3 minutes) to avoid the valve block from oscillating continuously between the load-up and load-down, and then returns to step S401 to obtain the adjusted temperature signal of the ice water or the hot water.
When the valve block controller (80) determines in step S405 that the frequency signal (S2) is smaller than the second set value and the valve block position of the fixed frequency hand piece (20) is larger than the 50% shift position, the process proceeds to step S4052: the valve block controller (80) starts integration or timing, and outputs a valve block load reduction control signal to the valve block of the fixed frequency head (20) when the integration or timing reaches a sixth preset value so as to adjust the valve block position of the fixed frequency head (20) (for example, the control valve block moves to a low gear). Step S406 is then performed: after the signal is output, the valve block controller (80) clears the integration or timing data to prepare for integration or timing of the next action, counts a delay time (e.g., 1-3 minutes) to avoid the valve block from oscillating continuously between the load rising and the load falling, and then returns to step S401 to obtain the adjusted temperature signal of the ice water or the hot water.
When the frequency signal (S2) is between the first setting value and the second setting value, the valve block controller (80) does not perform integration or timing, and directly performs step S406: the valve block controller (80) counts a delay time (e.g., 1-3 minutes), and then returns to step S401 to obtain the temperature signal of the ice water or the hot water.
In the embodiment, in cooperation with the characteristics of the refrigerant compressor, after the fixed-frequency head (20) is started, the valve block of the variable-frequency head (10) can be controlled to reduce the load so as to prevent the fixed-frequency head (10) from operating in the range of 25% of gears. The frequency conversion machine head (10) can be prevented from operating in an interval below 25% of gears by controlling the on or off of the frequency conversion machine head (20). For example, after the fixed frequency handpiece (20) is started, the valve block of the variable frequency handpiece (10) is firstly loaded down from a 100% gear to a 75% gear, so that the valve block of the fixed frequency handpiece (20) is loaded up from a 25% gear to a 50% gear. If the load is continuously increased, under the condition that the valve block of the fixed frequency handpiece (20) is positioned at a 50% gear, the valve block of the variable frequency handpiece (10) is still at a 75% gear, and the controller (80) can firstly load the valve block of the variable frequency handpiece (10) to a 100% gear. Because the valve block of the variable frequency handpiece (10) has reached 100% gear, the valve block of the fixed frequency handpiece (20) will be driven thereafter via the fixed frequency handpiece valve block signal control line (S4) if the valve block controller (80) outputs an up-load signal. Similarly, when the valve block of the fixed-frequency machine head (20) is in a 50% gear position, if the valve block controller (80) sends a load reduction signal, in order to avoid the fixed-frequency machine head operating in a 25% gear position, the system firstly reduces the valve block of the variable-frequency machine head (10) to a 75% or 50% gear position so as to maintain the valve block of the fixed-frequency machine head (20) to operate in a gear position state of more than 50%; when the valve block of the frequency conversion machine head (10) is located at a 50% gear, if the valve block controller (80) sends out a load reduction signal again under the condition, the valve block of the frequency conversion machine head (10) is loaded to a 75% gear or a 100% gear, and the fixed frequency machine head (20) is closed. The above switching manner is to avoid the fault phenomena such as oil loss caused by the refrigerant compressor operating too long under the low load condition, so it is not necessary to use the switching logic, as long as the refrigerant compressor can be prevented from operating too long under the low load condition.
In the present invention, when performing integration or timing, the valve block controller 80 may set the integration full to 500, for example, start sampling frequency data at regular intervals when the frequency signal output by the frequency converter is higher than 85%, add 1 to 1 (frequency signal is 86%), add 10 to 10 (frequency signal is 95%), and so on, and add the sampled values, and when the sampled value is greater than 500, the valve block controller 80 outputs an up-loading signal. This is a conventional technique. Of course, in other embodiments, the timing may be started directly when the frequency signal exceeds 85%, and the valve block controller 80 may output the load up signal once the duration of the time exceeding 85% is greater than a certain time (e.g., 2 minutes). The load shedding manner is the same principle, and is not described herein again.
In the invention, when the frequency signal output by the frequency converter reaches the upper limit value (for example, 85%), the frequency signal of the frequency converter can be integrated by using a PID integration principle, and a valve block load-lifting signal or a starting signal is sent out when the integration reaches a full-range value. Or, the timing may be started when the frequency signal of the frequency converter reaches an upper limit value (for example, 85%), and if the time that the frequency signal continues to be above the upper limit value reaches a preset timing time, the valve block load-up signal or the start-stop signal is sent out. When the frequency signal of the frequency converter reaches a lower limit value (for example, 65%), the frequency signal of the frequency converter can be integrated by using a PID integration principle, and a valve block load reduction signal or a start-stop signal is sent out when the integration reaches a full range value. It is also possible to start timing when the frequency signal of the frequency converter reaches a lower limit value (for example, 65%), and if the frequency signal is below the lower limit value for a predetermined timing time, issue a valve block load-up signal or a start signal. The preset time is about 1 to 3 minutes.
By reasonably matching the frequency conversion machine head and the fixed frequency machine head, the valve block switching of the frequency conversion and fixed frequency refrigerant compressor can be realized under the principle of constant temperature, so that the output temperature is more stable, the consumed power is lower, and the energy is saved. As long as the power collocation is proper, the signals processed by the valve block controller can drive the variable-frequency or fixed-frequency refrigerant compressors of other units in the same unit or in the same ice-water pipe network so as to achieve the seamless joint control function. When a plurality of refrigerant compressors are in the same pipe network, accurate joint control pressure can be achieved as long as the frequency conversion power range of the frequency conversion refrigerant compressor is enough. The output signal of the valve block controller can be extended infinitely in theory and can be connected in parallel or in series with the control signal of the existing unit to achieve more reliable logic. For example, when the machine set is increased, the output contact of the valve block controller is increased and the program software is changed.
Although the present invention has been described with reference to the above embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention.
Claims (21)
1. The control device of the refrigerant unit system is characterized by comprising at least one refrigerant unit, wherein each refrigerant unit comprises at least one refrigerant compressor with a machine head and a valve block, at least one refrigerant unit comprises a variable-frequency refrigerant compressor with a variable-frequency machine head, and the variable-frequency machine head is in driving connection with a frequency converter; the control device includes:
the temperature sensor is used for detecting temperature signals of ice water or hot water;
the temperature controller is used for receiving the temperature signal and outputting a frequency conversion control signal to the frequency converter, and the temperature controller is electrically connected with the temperature sensor;
and the valve block controller is used for generating corresponding valve block control signals according to the frequency signals of the frequency converter head output by the frequency converter and outputting the corresponding valve block control signals to the corresponding valve blocks of the refrigerant compressor through the corresponding valve block signal control lines so as to drive the valve blocks to act.
2. The control device of claim 1, wherein the valve block controller outputs the corresponding valve block control signal to drive the valve block to act when the frequency signal is greater than a first set value or less than a second set value.
3. The control apparatus of claim 2, wherein the valve block controller is further configured to count a delay time when the frequency signal is not greater than the first set value or not less than the second set value or after outputting the valve block control signal, and resume sensing and performing a next action after the delay time.
4. The control device of claim 3, wherein the at least one refrigerant unit includes only an inverter refrigerant compressor having an inverter head, wherein,
when the frequency signal is greater than the first set value, the valve block controller starts integration or timing, and when the integration or timing reaches a first preset value, a valve block loading control signal is output to a valve block of the frequency conversion machine head to control the valve block to move to a high gear;
when the frequency signal is smaller than the second set value, the valve block controller starts integration or timing, and when the integration or timing reaches a second preset value, a valve block load reduction control signal is output to a valve block of the frequency conversion machine head to control the valve block to move to a low gear;
the valve block controller does not integrate or time when the frequency signal is between the first set point and the second set point.
5. The control apparatus of claim 4, wherein the valve block controller is further configured to clear the integration or timing data after outputting the valve block up control signal or the valve block down control signal in preparation for integration or timing of a next action.
6. The control device of claim 3, wherein the at least one refrigerant unit comprises an inverter refrigerant compressor having an inverter head and a fixed-frequency refrigerant compressor having a fixed-frequency head, wherein,
when the frequency signal is greater than the first set value and the valve block of the variable-frequency machine head is in a 100% gear position, the valve block controller starts the fixed-frequency refrigerant compressor and starts to control the valve block of the fixed-frequency machine head of the fixed-frequency refrigerant compressor by using the valve block controller;
when the frequency signal is greater than the first set value and the valve block of the frequency conversion machine head is not in a 100% gear position, the valve block controller starts integration or timing, and when the integration or timing reaches a third preset value, a valve block loading control signal is output to the valve block of the frequency conversion machine head to control the valve block to move to a high gear position;
when the frequency signal is smaller than the second set value and the position of the valve block of the fixed-frequency handpiece is smaller than or equal to 50% of the gear, if the position of the valve block of the variable-frequency handpiece is smaller than or equal to 50% of the gear, the valve block controller starts integration or timing, and when the integration or timing reaches a fourth preset value, a valve block loading control signal is output to the valve block of the variable-frequency handpiece to control the valve block to move to a high gear;
when the frequency signal is smaller than the second set value and the position of the valve block of the fixed-frequency handpiece is smaller than 50% gears, if the position of the valve block of the variable-frequency handpiece is larger than 50% gears, the valve block controller starts integration or timing, and when the integration or timing reaches a fifth preset value, a valve block load reduction control signal is output to the valve block of the variable-frequency handpiece to control the valve block to move to a low gear;
when the frequency signal is smaller than the second set value and the position of the valve block of the fixed-frequency machine head is larger than 50% of gears, the valve block controller starts integration or timing, and when the integration or timing reaches a sixth preset value, a valve block load reduction control signal is output to the valve block of the fixed-frequency machine head to control the valve block to move to a low gear;
when the frequency signal is between the first set point and the second set point, the valve block controller does not integrate or time.
7. The control device of claim 6, wherein when the frequency signal is greater than the first setting value and the valve block of the inverter head is in a 100% gear, after the constant frequency refrigerant compressor is started, the valve block controller outputs a valve block load reduction control signal to the valve block of the inverter head to control the valve block to move to a low gear, and/or the valve block controller simultaneously controls the valve block of the constant frequency head to move to a gear of more than 50%.
8. The control device according to claim 6 or 7, wherein after outputting the valve block load up control signal or the valve block load down control signal, the valve block controller is further configured to clear the integration or the timing data to prepare for integration or timing of a next action.
9. The control device of claim 2, wherein the first set point is 85% of the highest frequency and the second set point is 65% of the highest frequency.
10. The control device of claim 2, wherein the valve block controller comprises a start/stop terminal connected to the head of each refrigerant compressor, and a plurality of actuation signal terminals connected to different gears of the valve block of each refrigerant compressor; and/or the refrigerant compressor is a screw-type refrigerant compressor; and/or a plurality of refrigerant compressors in the refrigerant unit are in parallel operation.
11. A refrigerant machine set system, characterized in that, it comprises the control device as claimed in any one of claims 1 to 10.
12. The control method of the refrigerant unit system is characterized in that the refrigerant unit system comprises at least one group of refrigerant units, each group of refrigerant units comprises at least one refrigerant compressor with a machine head and a valve block, at least one group of refrigerant units comprises a variable-frequency refrigerant compressor with a variable-frequency machine head, and the variable-frequency machine head is in driving connection with a frequency converter; the control method comprises the following steps:
detecting a temperature signal of ice water or hot water by using a temperature sensor;
receiving the temperature signal by using a temperature controller and outputting a frequency conversion control signal to the frequency converter so as to carry out frequency conversion control on the frequency conversion machine head;
and generating a corresponding valve block control signal by using a valve block controller according to the frequency signal of the frequency conversion machine head output by the frequency converter, and outputting the corresponding valve block control signal to a corresponding valve block of the refrigerant compressor through a corresponding valve block signal control line so as to drive the valve block to act.
13. The control method according to claim 12, wherein,
when the frequency signal is larger than a first set value or smaller than a second set value, the valve block controller outputs a corresponding valve block control signal to drive the valve block to act.
14. The control method according to claim 13, wherein,
when the frequency signal is not greater than the first set value or not less than the second set value, or after the valve block control signal is output, the valve block controller counts a delay time, and resumes the detection and the next action after the delay time.
15. The control method as claimed in claim 14, wherein the at least one refrigerant unit includes only an inverter refrigerant compressor having an inverter head, wherein,
when the frequency signal is greater than the first set value, the valve block controller starts integration or timing, and when the integration or timing reaches a first preset value, a valve block loading control signal is output to a valve block of the frequency conversion machine head to control the valve block to move to a high gear;
when the frequency signal is smaller than the second set value, the valve block controller starts integration or timing, and when the integration or timing reaches a second preset value, a valve block load reduction control signal is output to a valve block of the frequency conversion machine head to control the valve block to move to a low gear;
the valve block controller does not integrate or time when the frequency signal is between the first set point and the second set point.
16. The control method according to claim 15, wherein,
after outputting the valve block load-up control signal or the valve block load-down control signal, the valve block controller clears the integration or the timing data to prepare integration or timing of the next action.
17. The control method as claimed in claim 14, wherein the at least one refrigerant unit includes an inverter refrigerant compressor having an inverter head and a fixed-frequency refrigerant compressor having a fixed-frequency head, wherein,
when the frequency signal is greater than the first set value and the valve block of the variable-frequency machine head is in a 100% gear position, the valve block controller starts the fixed-frequency refrigerant compressor and starts to control the valve block of the fixed-frequency machine head of the fixed-frequency refrigerant compressor by using the valve block controller;
when the frequency signal is greater than the first set value and the valve block of the frequency conversion machine head is not in a 100% gear position, the valve block controller starts integration or timing, and when the integration or timing reaches a third preset value, a valve block loading control signal is output to the valve block of the frequency conversion machine head to control the valve block to move to a high gear position;
when the frequency signal is smaller than the second set value and the position of the valve block of the fixed-frequency handpiece is smaller than or equal to 50% of the gear, if the position of the valve block of the variable-frequency handpiece is smaller than or equal to 50% of the gear, the valve block controller starts integration or timing, and when the integration or timing reaches a fourth preset value, a valve block loading control signal is output to the valve block of the variable-frequency handpiece to control the valve block to move to a high gear;
when the frequency signal is smaller than the second set value and the position of the valve block of the fixed-frequency handpiece is smaller than or equal to 50% of the gear, if the position of the valve block of the variable-frequency handpiece is larger than 50% of the gear, the valve block controller starts integration or timing, and when the integration or timing reaches a fifth preset value, a valve block load reduction control signal is output to the valve block of the variable-frequency handpiece to control the valve block to move to a lower gear;
when the frequency signal is smaller than the second set value and the position of the valve block of the fixed-frequency machine head is larger than 50% of the gear, the valve block controller starts integration or timing, and when the integration or timing reaches a sixth preset value, a valve block load reduction control signal is output to the valve block of the fixed-frequency machine head to control the valve block to move to a low gear;
the valve block controller does not integrate or time when the frequency signal is between the first set point and the second set point.
18. The control method according to claim 17, wherein,
when the frequency signal is greater than the first set value and the valve block of the frequency conversion machine head is in a 100% gear, after the frequency-fixed refrigerant compressor is started, the valve block controller outputs a valve block load reduction control signal to the valve block of the frequency conversion machine head to control the valve block to move to a low gear, and/or the valve block controller simultaneously controls the valve block of the frequency-fixed machine head to move to a gear of more than 50%.
19. The control method according to claim 17 or 18, wherein,
after the valve block load-up control signal or the valve block load-down control signal is output, the valve block controller clears the integration or the timing data to prepare integration or timing of the next action.
20. The control method according to claim 13, wherein the first set point is 85% of the highest frequency and the second set point is 65% of the highest frequency.
21. The control method according to claim 14, wherein the delay time is set to 1 minute or more.
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