Compressor control method and device for multi-module unit and multi-module unit

Abstract

The present invention discloses a compressor control method, device and multi-module unit of a multi-module unit. The multi-module unit includes at least one refrigerant system, each refrigerant system includes at least one compressor, and the method includes: monitoring the actual outlet water temperature and the water temperature change rate of the multi-module unit; according to the actual outlet water temperature and the water temperature change rate, controlling the number of compressors turned on and the operating frequency, so that the actual outlet water temperature is within the required temperature range and the compressors turned on are operated at the preset optimal frequency to the greatest extent, and the optimal frequency makes the compressor operate at the highest efficiency. When the load demand is large, the present invention can directly start a corresponding number of compressors instead of starting them one by one, so as to quickly respond to the load demand, achieve rapid temperature rise or temperature drop, and reduce loading and unloading time; set the optimal frequency, so that the compressor runs as close to the optimal frequency as possible, give full play to the efficiency of the compressor, improve the operating efficiency of the unit to a certain extent, and improve the energy efficiency of the whole machine.

Description

Technical Field

[0001] The present invention relates to the technical field of units, and in particular to a compressor control method and device for a multi-module unit and the multi-module unit. Background Art

[0002] Existing air-cooled hot and cold water units can achieve a larger output capacity through modular combination to meet the cooling or heating needs of office buildings, hospitals, etc. They are very popular with customers due to their flexible combination and high cost performance.

[0003] However, when modular units (which can be called multi-module units or modular machines) are currently in operation, a control method is adopted in which each independent module is opened at intervals. That is, in the control of multi-module units, each module is controlled independently, and when each module reaches its own opening condition, it is started and stopped at the normal starting sequence interval, and started one by one in sequence. When the number of modules is large, especially for variable frequency units, the compressor needs to be initialized for more than 3 minutes to start, and the frequency loading also takes time. Therefore, it takes a long time to meet the user's higher load requirements, and it is difficult to quickly achieve temperature rise or temperature drop, which affects the user's experience. In addition, due to the low efficiency of air-cooled heat exchange, the overall energy efficiency of the unit is also low.

[0004] Currently, no effective solution has been proposed to address the problem that multi-module units in the prior art cannot respond quickly to user needs and have low energy efficiency. Summary of the invention

[0005] The embodiments of the present invention provide a compressor control method and device for a multi-module unit and a multi-module unit, so as to at least solve the problem in the prior art that the multi-module unit cannot respond quickly to user needs and has low energy efficiency.

[0006] To solve the above technical problems, an embodiment of the present invention provides a compressor control method for a multi-module unit, wherein the multi-module unit includes at least one refrigerant system, each refrigerant system includes at least one compressor, and the method includes:

[0007] Monitoring the actual outlet water temperature and water temperature change rate of the multi-module unit;

[0008] According to the actual water outlet temperature and the water temperature change rate, the number of compressors turned on and the operating frequency are controlled so that the actual water outlet temperature is within the required temperature range and the turned-on compressors are operated at a preset optimal frequency to the greatest extent, wherein the optimal frequency makes the compressor operate at the highest efficiency.

[0009] Optionally, according to the actual outlet water temperature and the water temperature change rate, controlling the number of compressors to be turned on and the operating frequency includes:

[0010] Determining an operating mode of the multi-module unit, and determining a threshold set under the operating mode according to a current set temperature;

[0011] Determining the interval of the actual outlet water temperature according to the actual outlet water temperature and the threshold set;

[0012] The number of compressors turned on and the operating frequency are controlled according to the interval of the actual outlet water temperature and the water temperature change rate.

[0013] Optionally, determining the interval in which the actual outlet water temperature is located according to the actual outlet water temperature and the threshold set includes:

[0014] In the cooling mode, if the current actual outlet water temperature is greater than or equal to the first threshold, it is determined that the current actual outlet water temperature is in the first interval;

[0015] If the current actual outlet water temperature is greater than or equal to the second threshold and less than the first threshold, it is determined that the current actual outlet water temperature is in the second interval;

[0016] If the current actual outlet water temperature is greater than or equal to the third threshold value and less than the second threshold value, it is determined that the current actual outlet water temperature is in the third interval;

[0017] If the current actual outlet water temperature is greater than or equal to the fourth threshold value and less than the third threshold value, it is determined that the current actual outlet water temperature is in the fourth interval;

[0018] If the current actual outlet water temperature is less than the fourth threshold, it is determined that the current actual outlet water temperature is in the fifth interval.

[0019] Optionally, determining the interval in which the actual outlet water temperature is located according to the actual outlet water temperature and the threshold set includes:

[0020] In the heating mode, if the current actual outlet water temperature is less than or equal to the fifth threshold, it is determined that the current actual outlet water temperature is in the first interval;

[0021] If the current actual outlet water temperature is greater than the fifth threshold value and less than or equal to the sixth threshold value, it is determined that the current actual outlet water temperature is in the second interval;

[0022] If the current actual outlet water temperature is greater than the sixth threshold value and less than or equal to the seventh threshold value, it is determined that the current actual outlet water temperature is in the third interval;

[0023] If the current actual outlet water temperature is greater than the seventh threshold value and less than or equal to the eighth threshold value, it is determined that the current actual outlet water temperature is in the fourth interval;

[0024] If the current actual outlet water temperature is greater than the eighth threshold, it is determined that the current actual outlet water temperature is in the fifth interval.

[0025] Optionally, according to the interval of the actual outlet water temperature and the water temperature change rate, controlling the number of compressors to be turned on and the operating frequency includes:

[0026] If the current actual outlet water temperature is in the first interval, all compressors are turned on and the water temperature change rate is monitored;

[0027] When the water temperature change rate is less than or equal to the preset rate, the compressor to be adjusted is determined according to the first preset rule from the compressors that are turned on and whose frequencies are less than the optimal frequency, and the frequency of the compressor to be adjusted is increased by the first frequency. After the first preset time, if the water temperature change rate is still less than or equal to the preset rate, the step of determining the compressor to be adjusted according to the first preset rule from the compressors that are turned on and whose frequencies are less than the optimal frequency is returned to the execution, and the cycle is repeated until the water temperature change rate is greater than the preset rate or until the current actual water outlet temperature is not in the first interval;

[0028] When the water temperature change rate is greater than the preset rate, the compressor is controlled to maintain the current state.

[0029] Optionally, when the frequencies of all turned-on compressors are greater than or equal to the optimal frequency and the water temperature change rate is still less than or equal to the preset rate, the compressor currently to be adjusted is determined among the turned-on compressors according to a first preset rule, and the frequency of the compressor currently to be adjusted is increased by a first frequency. After a first preset time, if the water temperature change rate is still less than or equal to the preset rate, the process returns to executing the step of determining the compressor currently to be adjusted among the turned-on compressors according to the first preset rule, and the process repeats this cycle until the water temperature change rate is greater than the preset rate or until the current actual water outlet temperature is not in the first interval.

[0030] Optionally, when each refrigerant system includes at least two compressors, the at least two compressors are connected in parallel;

[0031] According to the interval of the actual outlet water temperature and the water temperature change rate, the number of compressors to be turned on and the operating frequency are controlled, including:

[0032] If the current actual outlet water temperature is in the second interval, a preset number of compressors are turned on in each refrigerant system, and the water temperature change rate is monitored;

[0033] When the water temperature change rate is less than or equal to the preset rate, the compressor to be adjusted is determined according to the first preset rule from the compressors that are turned on and whose frequencies are less than the optimal frequency, and the frequency of the compressor to be adjusted is increased by the first frequency. After the first preset time, if the water temperature change rate is still less than or equal to the preset rate, the step of determining the compressor to be adjusted according to the first preset rule from the compressors that are turned on and whose frequencies are less than the optimal frequency is returned to the execution, and the cycle is repeated until the water temperature change rate is greater than the preset rate or until the current actual water outlet temperature is not in the second interval;

[0034] When the water temperature change rate is greater than the preset rate, the compressor is controlled to maintain the current state.

[0035] Optionally, when the frequencies of all the compressors that have been turned on are greater than or equal to the optimal frequency, and the water temperature change rate is still less than or equal to the preset rate, a compressor that has not been turned on is started according to a second preset rule;

[0036] If there is no unturned compressor, the current compressor to be adjusted is determined among the turned-on compressors according to the first preset rule, and the frequency of the current compressor to be adjusted is increased by a first frequency. After the first preset time, if the water temperature change rate is still less than or equal to the preset rate, the process returns to the step of determining the current compressor to be adjusted among the turned-on compressors according to the first preset rule, and the process repeats this cycle until the water temperature change rate is greater than the preset rate or until the current actual water outlet temperature is not in the second interval.

[0037] Optionally, according to the interval of the actual outlet water temperature and the water temperature change rate, controlling the number of compressors to be turned on and the operating frequency includes:

[0038] If the current actual outlet water temperature is in the third interval, the compressor is started according to the second preset rule, and the water temperature change rate is monitored;

[0039] When the water temperature change rate is greater than the preset rate, the compressor to be adjusted is determined from the compressors that are turned on and have a frequency greater than the optimal frequency according to the first preset rule, and the frequency of the compressor to be adjusted is reduced by a second frequency. After the second preset time, if the water temperature change rate is still greater than the preset rate, the step of determining the compressor to be adjusted from the compressors that are turned on and have a frequency greater than the optimal frequency according to the first preset rule is returned to the execution, and the cycle is repeated until the water temperature change rate is less than or equal to the preset rate or until the current actual water outlet temperature is not in the third interval;

[0040] When the water temperature change rate is greater than or equal to n times the preset rate and less than or equal to the preset rate, the compressor is controlled to maintain the current state, 0<n<1;

[0041] When the water temperature change rate is less than n times the preset rate, the frequency of the turned-on compressor is increased with the third frequency as the frequency increase amplitude. When the frequencies of all turned-on compressors are greater than or equal to the optimal frequency and the water temperature change rate is still less than n times the preset rate, an unturned compressor is started according to the second preset rule. After the compressor is initialized, the frequency of the compressor is increased by the third frequency. After the third preset time, if the water temperature change rate is still less than n times the preset rate, the step of increasing the frequency of the compressor by the third frequency is returned to execute, and the cycle is repeated until the compressor is increased to the optimal frequency or until the water temperature change rate is greater than or equal to n times the preset rate or until the current actual water outlet temperature is not in the third interval.

[0042] Optionally, when the frequencies of all turned-on compressors are less than or equal to the optimal frequency, and the water temperature change rate is still greater than the preset rate, the compressor to be adjusted currently is determined among the turned-on compressors according to the first preset rule, and the frequency of the compressor to be adjusted currently is reduced by a second frequency. After a second preset time, if the water temperature change rate is still greater than the preset rate, the step of determining the compressor to be adjusted currently among the turned-on compressors according to the first preset rule is returned to and executed, and this cycle is repeated until the water temperature change rate is less than or equal to the preset rate or until the current actual water outlet temperature is not in the third interval;

[0043] If the frequency of any compressor drops to the minimum frequency, the compressor is controlled to maintain the operation at the minimum frequency.

[0044] Optionally, according to the interval of the actual outlet water temperature and the water temperature change rate, controlling the number of compressors to be turned on and the operating frequency includes:

[0045] If the current actual outlet water temperature is in the fourth interval, the number of compressors turned on and the operating frequency are controlled to maintain the current state.

[0046] Optionally, according to the interval of the actual outlet water temperature and the water temperature change rate, controlling the number of compressors to be turned on and the operating frequency includes:

[0047] If the current actual outlet water temperature is in the fifth interval, the compressor to be adjusted is determined from the compressors that are turned on and have a frequency greater than the optimal frequency according to the first preset rule, and the frequency of the compressor to be adjusted is reduced by a fourth frequency. After the fourth preset time, if the current actual outlet water temperature is still in the fifth interval, the step of determining the compressor to be adjusted from the compressors that are turned on and have a frequency greater than the optimal frequency according to the first preset rule is returned to be executed, and this cycle is repeated until the current actual outlet water temperature is not in the fifth interval;

[0048] If the frequencies of all the compressors that have been turned on are reduced to the lowest frequency, and the current actual outlet water temperature is still in the fifth interval, then one compressor is turned off every fifth preset time.

[0049] An embodiment of the present invention further provides a compressor control device for a multi-module unit, wherein the multi-module unit includes at least one refrigerant system, each refrigerant system includes at least one compressor, and the device includes:

[0050] A monitoring module, used to monitor the actual outlet water temperature and water temperature change rate of the multi-module unit;

[0051] The control module is used to control the number of compressors to be turned on and the operating frequency according to the actual water outlet temperature and the water temperature change rate, so that the actual water outlet temperature is within the required temperature range and the turned-on compressors are operated at a preset optimal frequency to the greatest extent, wherein the optimal frequency makes the compressor operate with the highest efficiency.

[0052] The embodiment of the present invention further provides a multi-module unit, comprising: a compressor control device of the multi-module unit described in the embodiment of the present invention.

[0053] An embodiment of the present invention further provides a computer device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method described in the embodiment of the present invention when executing the computer program.

[0054] The embodiment of the present invention further provides a non-volatile computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the method described in the embodiment of the present invention are implemented.

[0055] By applying the technical solution of the present invention, the number of compressors turned on and the operating frequency are controlled according to the actual outlet water temperature and the water temperature change rate, so that the actual outlet water temperature is within the required temperature range and the compressors turned on can be operated at the preset optimal frequency to the maximum extent. When the load demand is large, the corresponding number of compressors can be directly started instead of one by one, so as to quickly respond to the terminal load demand, achieve rapid temperature rise or temperature drop, improve user experience, and reduce loading and unloading time; and, set the optimal frequency so that the compressor can run as close to the optimal frequency as possible, give full play to the efficiency of the compressor, improve the operating efficiency of the unit to a certain extent, improve the energy efficiency of the whole unit, and solve the problem that the multi-module unit cannot respond quickly to user needs and has low energy efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 is a flow chart of a compressor control method for a multi-module unit provided in Embodiment 1 of the present invention;

[0057] Figure 2 is a compressor control flow chart provided by Embodiment 2 of the present invention;

[0058] Figure 3 It is a structural block diagram of a compressor control device for a multi-module unit provided in Embodiment 3 of the present invention. DETAILED DESCRIPTION

[0059] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0060] It should be noted that the terms "first", "second", etc. in the specification, claims and drawings of the present invention are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0061] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0062] The optional embodiments of the present invention are described in detail below with reference to the accompanying drawings. Example 1

[0063] This embodiment provides a compressor control method for a multi-module unit. The multi-module unit performs heat exchange through refrigerant circulation and water circulation, provides cold water or hot water to the terminal, and cools or heats the room. The multi-module unit includes at least one refrigerant system (also referred to as a module). These refrigerant systems are independent of each other, that is, the operation of any refrigerant system will not affect the normal operation of other refrigerant systems. Each refrigerant system includes at least one compressor. When the refrigerant system includes at least two compressors, the at least two compressors are connected in parallel.

[0064] Figure 1 is a flow chart of a compressor control method for a multi-module unit provided in Embodiment 1 of the present invention. Figure 1 As shown, the method comprises the following steps:

[0065] S101, monitoring the actual outlet water temperature and water temperature change rate of the multi-module unit.

[0066] S102, according to the actual outlet water temperature and the water temperature change rate, control the number of compressors turned on and the operating frequency, so that the actual outlet water temperature is within the required temperature range and the compressors turned on can operate at the preset optimal frequency to the greatest extent, wherein the optimal frequency makes the compressor operate at the highest efficiency.

[0067] The water temperature change rate refers to the rate of change of the water temperature. In practical applications, the actual outlet water temperature is periodically obtained at a certain interval of time t, and the difference between the current actual outlet water temperature and the actual outlet water temperature of the previous cycle is calculated, and the ratio of the difference to t is calculated to obtain the water temperature change rate. It should be noted that the water temperature change rate does not have a negative sign and takes a positive value.

[0068] The actual outlet water temperature can reflect the size of the terminal load demand, and the water temperature change rate can reflect the degree of match between the unit's current output capacity and the terminal load demand. For example, a large water temperature change rate indicates that the unit's current output capacity can meet the terminal load demand, and a small water temperature change rate indicates that the unit's current output capacity cannot meet the terminal load demand. For the cooling mode, the water temperature change rate is expressed as the water temperature drop rate, and for the heating mode, the water temperature change rate is expressed as the water temperature rise rate. The required temperature range can be determined based on the user's set temperature. The optimal frequency can be determined in advance through experiments, and the optimal frequency is less than the maximum frequency allowed for the compressor to operate.

[0069] This embodiment controls the number of compressors turned on and the operating frequency according to the actual outlet water temperature and the water temperature change rate, so that the actual outlet water temperature is within the required temperature range and the compressors turned on can be operated at the preset optimal frequency to the greatest extent. When the load demand is large, the corresponding number of compressors can be directly started instead of one by one, so as to quickly respond to the terminal load demand, achieve rapid temperature rise or temperature drop, improve user experience, and reduce loading and unloading time; and set the optimal frequency so that the compressor can run as close to the optimal frequency as possible, give full play to the efficiency of the compressor, improve the operating efficiency of the unit to a certain extent, improve the energy efficiency of the whole unit, and solve the problem that the multi-module unit cannot respond to user needs quickly and has low energy efficiency.

[0070] In one embodiment, the number of compressors turned on and the operating frequency are controlled according to the actual water outlet temperature and the water temperature change rate, including: determining the operating mode of the multi-module unit, and determining the threshold set under the operating mode according to the current set temperature; determining the interval of the actual water outlet temperature according to the actual water outlet temperature and the threshold set; controlling the number of compressors turned on and the operating frequency according to the interval of the actual water outlet temperature and the water temperature change rate.

[0071] Among them, the working mode of the multi-module unit is cooling mode or heating mode. Based on the current set temperature, according to different deviation values, at least two thresholds can be obtained to form a threshold set. For example, a, b, c, d are preset deviation values, a>b>c>d, a>0, b>0, c>0, d≤0, in cooling mode, the set temperature is T0, and the threshold sets A, B, C and D are calculated, A>B>C>D, where A=T0+a, B=T0+b, C=T0+c, D=T0+d, D≤T0; in heating mode, the set temperature is T0, and the threshold sets A', B', C' and D' are calculated, A'<B'<C'<D', where A'=T0-a, B'=T0-b, C'=T0-c, D'=T0-d, D'≥T0. Through the threshold set, the range of the actual outlet water temperature can be determined, thereby characterizing the magnitude of the terminal load demand. The number of thresholds can be set according to actual conditions.

[0072] Based on the actual water outlet temperature range and the water temperature change rate, this implementation can reasonably control the number of compressors turned on and the operating frequency, quickly respond to terminal load demands, and improve energy efficiency.

[0073] The specific situations of determining the range of the actual water outlet temperature are described below for the cooling mode and the heating mode respectively.

[0074] (1) In cooling mode

[0075] If the current actual outlet water temperature is greater than or equal to the first threshold, determining that the current actual outlet water temperature is in the first interval;

[0076] If the current actual outlet water temperature is greater than or equal to the second threshold and less than the first threshold, it is determined that the current actual outlet water temperature is in the second interval;

[0077] If the current actual outlet water temperature is greater than or equal to the third threshold value and less than the second threshold value, it is determined that the current actual outlet water temperature is in the third interval;

[0078] If the current actual outlet water temperature is greater than or equal to the fourth threshold value and less than the third threshold value, it is determined that the current actual outlet water temperature is in the fourth interval;

[0079] If the current actual outlet water temperature is less than the fourth threshold, it is determined that the current actual outlet water temperature is in the fifth interval.

[0080] (2) In heating mode

[0081] If the current actual outlet water temperature is less than or equal to the fifth threshold, it is determined that the current actual outlet water temperature is in the first interval;

[0082] If the current actual outlet water temperature is greater than the fifth threshold value and less than or equal to the sixth threshold value, it is determined that the current actual outlet water temperature is in the second interval;

[0083] If the current actual outlet water temperature is greater than the sixth threshold value and less than or equal to the seventh threshold value, it is determined that the current actual outlet water temperature is in the third interval;

[0084] If the current actual outlet water temperature is greater than the seventh threshold value and less than or equal to the eighth threshold value, it is determined that the current actual outlet water temperature is in the fourth interval;

[0085] If the current actual outlet water temperature is greater than the eighth threshold, it is determined that the current actual outlet water temperature is in the fifth interval.

[0086] The first threshold A, the second threshold B, the third threshold C and the fourth threshold D are a threshold set in the cooling mode, and the fifth threshold A', the sixth threshold B', the seventh threshold C' and the eighth threshold D' are a threshold set in the heating mode.

[0087] The actual water outlet temperature is in the first interval, indicating that the actual water outlet temperature deviates too much from the set temperature. The actual water outlet temperature is in the second interval, indicating that the actual water outlet temperature deviates a lot from the set temperature. The actual water outlet temperature is in the third interval, indicating that the actual water outlet temperature deviates little from the set temperature. The actual water outlet temperature is in the fourth interval, indicating that the actual water outlet temperature is within the required temperature range (i.e., it fluctuates slightly above and below the set temperature). The actual water outlet temperature is in the fifth interval, indicating that the cooling or heating capacity currently output by the unit is too large and has exceeded the load demand. For example, in cooling mode, the actual water outlet temperature is lower than the required temperature range, and in heating mode, the actual water outlet temperature is higher than the required temperature range.

[0088] According to the actual outlet water temperature range and the water temperature change rate, the number of compressors turned on and the operating frequency are controlled, including the following situations:

[0089] (1) If the current actual outlet water temperature is in the first interval, all compressors are turned on and the water temperature change rate is monitored;

[0090] When the water temperature change rate is less than or equal to the preset rate, the compressor to be adjusted is determined in accordance with the first preset rule from the compressors that are turned on and whose frequencies are less than the optimal frequency, and the frequency of the compressor to be adjusted is increased by the first frequency. After the first preset time, if the water temperature change rate is still less than or equal to the preset rate, the step of determining the compressor to be adjusted in accordance with the first preset rule from the compressors that are turned on and whose frequencies are less than the optimal frequency is returned to the execution, and the cycle is repeated until the water temperature change rate is greater than the preset rate or until the current actual water outlet temperature is not in the first interval;

[0091] When the water temperature change rate is greater than the preset rate, the compressor is controlled to maintain the current state.

[0092] Among them, the preset rate is a pre-set rate reference value. If the water temperature change rate is less than or equal to the preset rate, it means that the current output capacity of the unit cannot meet the terminal load demand; if the water temperature change rate is greater than the preset rate, it means that the current output capacity of the unit can meet the terminal load demand.

[0093] The first preset rule is a rule for determining the current compressor to be adjusted among the compressors that meet the adjustment conditions, including the adjustment order, for example, adjusting the frequency of each compressor in a certain order, specifically, adjusting the frequency of compressor 1 this time, if it needs to be adjusted again, then adjust the frequency of compressor 2 next time, and so on. When the frequencies of all compressors that meet the adjustment conditions are adjusted once, it means that one round of adjustment is completed, and the next round of adjustment starts from compressor 1); for another example, first adjust the frequency of the current compressor in a certain order, and after adjusting to a certain degree (for example, reaching the lowest frequency, or reaching the best frequency, or reaching the highest frequency, etc.), if it needs to be adjusted again, then adjust the frequency of the next compressor. Exemplarily, the above order can be in order from small to large numbers. The above adjustment conditions can be turned on, or turned on and the frequency is less than the best frequency, or turned on and the frequency is greater than the best frequency.

[0094] The first frequency a1 and the first preset time t1 are both preset. The value of the first frequency can be larger to meet the load demand as soon as possible. Controlling the compressor to maintain the current state includes: the number of compressors turned on remains unchanged, the compressors turned on maintain the current frequency unchanged, and the compressors not turned on remain turned off.

[0095] In this embodiment, when the actual outlet water temperature is in the first interval, it means that the actual outlet water temperature deviates too much from the set temperature. At this time, all compressors are directly turned on, so as to quickly respond to the terminal load demand. When the water temperature change rate is less than or equal to the preset rate, the frequency of each compressor that has been turned on is increased in sequence to improve the unit output capacity and reach the required temperature range as soon as possible. In addition, the frequency of the compressor that has been turned on and whose frequency is less than the optimal frequency is increased first, and the compressor is operated at the optimal frequency as much as possible, and the time for the compressor to operate at the optimal frequency is increased, thereby improving the unit operation efficiency.

[0096] Furthermore, when the frequencies of all turned-on compressors are greater than or equal to the optimal frequency and the water temperature change rate is still less than or equal to the preset rate, the compressor currently to be adjusted is determined among the turned-on compressors according to the first preset rule, and the frequency of the compressor currently to be adjusted is increased by the first frequency. After the first preset time, if the water temperature change rate is still less than or equal to the preset rate, the process returns to the step of determining the compressor currently to be adjusted among the turned-on compressors according to the first preset rule, and the cycle is repeated until the water temperature change rate is greater than the preset rate or until the current actual water outlet temperature is not in the first interval.

[0097] In this embodiment, when the frequencies of all the compressors that have been turned on are greater than or equal to the optimal frequency and there is still a need for frequency increase, the frequencies of the compressors that have been turned on continue to be increased in sequence to reach the required temperature range as quickly as possible.

[0098] (2) When each refrigerant system includes at least two compressors, the at least two compressors are connected in parallel, and the at least two compressors correspond to the same heat exchanger.

[0099] If the current actual outlet water temperature is in the second interval, a preset number of compressors are turned on in each refrigerant system, and the water temperature change rate is monitored;

[0100] When the water temperature change rate is less than or equal to the preset rate, the compressor to be adjusted is determined in accordance with the first preset rule from the compressors that are turned on and whose frequencies are less than the optimal frequency, and the frequency of the compressor to be adjusted is increased by the first frequency. After the first preset time, if the water temperature change rate is still less than or equal to the preset rate, the step of determining the compressor to be adjusted in accordance with the first preset rule from the compressors that are turned on and whose frequencies are less than the optimal frequency is returned to the execution, and the cycle is repeated until the water temperature change rate is greater than the preset rate or until the current actual water outlet temperature is not in the second interval;

[0101] When the water temperature change rate is greater than the preset rate, the compressor is controlled to maintain the current state.

[0102] The preset number is less than N, where N represents the total number of compressors connected in parallel in a single refrigerant system. The preset number can be set according to actual conditions, for example, to 1, 2, etc.

[0103] In this embodiment, when the actual outlet water temperature is in the second interval, it means that the actual outlet water temperature deviates greatly from the set temperature. At this time, some compressors are turned on in each refrigerant system to ensure a rapid response to the terminal load demand while avoiding energy waste caused by turning on all compressors. In addition, all heat exchangers in the unit can be fully utilized to make the evaporation temperature higher and the condensation temperature lower when some compressors in the refrigerant system are running, thereby improving energy efficiency. When the water temperature change rate is less than or equal to the preset rate, the frequency of each compressor that has been turned on is increased in sequence to increase the output capacity of the unit and reach the required temperature range as soon as possible. In addition, the frequency of the compressor that has been turned on and whose frequency is less than the optimal frequency is increased first, and the compressor is operated at the optimal frequency as much as possible, and the time for the compressor to operate at the optimal frequency is increased, thereby improving the operating efficiency of the unit.

[0104] It should be noted that if each refrigerant system includes only one compressor, the second interval and its related controls are cancelled.

[0105] It should be noted that if the actual outlet water temperature is in the second interval when the unit is started, some compressors will be turned on in each refrigerant system. If the actual outlet water temperature changes from other intervals to the second interval during the operation of the unit, the number of currently turned on compressors can be maintained, or it can be changed to turn on some compressors in each refrigerant system.

[0106] Furthermore, when the frequencies of all turned-on compressors are greater than or equal to the optimal frequency and the water temperature change rate is still less than or equal to the preset rate, a non-turned-on compressor is started according to the second preset rule; if there is no non-turned-on compressor, the current compressor to be adjusted is determined among the turned-on compressors according to the first preset rule, and the frequency of the current compressor to be adjusted is increased by the first frequency. After the first preset time, if the water temperature change rate is still less than or equal to the preset rate, the step of determining the current compressor to be adjusted among the turned-on compressors according to the first preset rule is returned to execute, and this cycle is repeated until the water temperature change rate is greater than the preset rate or until the current actual water outlet temperature is not in the second interval.

[0107] The second preset rule is a rule for determining the compressor to be started from the compressors that are not turned on. For example, the second preset rule may be a compressor rotation start-stop rule, that is, when the compressor needs to be turned off, the compressor with a long start time is turned off first, and when the compressor needs to be turned on, the compressor with a long stop time is turned on first. After the compressor is turned on, if there is a frequency increase demand, the frequency increase control can be performed according to the above steps.

[0108] In this embodiment, only some of the compressors are initially turned on. If the frequencies of all the turned-on compressors are greater than or equal to the optimal frequency and there is still a need for frequency increase, new compressors are turned on first for frequency increase, so that the turned-on compressors can operate at the optimal frequency, thereby improving the operating efficiency of the unit.

[0109] (3) If the current actual outlet water temperature is in the third interval, the compressor is started according to the second preset rule, and the water temperature change rate is monitored;

[0110] When the water temperature change rate is greater than the preset rate, the compressor to be adjusted is determined from the compressors that are turned on and have a frequency greater than the optimal frequency according to the first preset rule, and the frequency of the compressor to be adjusted is reduced by a second frequency. After the second preset time, if the water temperature change rate is still greater than the preset rate, the step of determining the compressor to be adjusted from the compressors that are turned on and have a frequency greater than the optimal frequency according to the first preset rule is returned to the execution, and the cycle is repeated until the water temperature change rate is less than or equal to the preset rate or until the current actual water outlet temperature is not in the third interval;

[0111] When the water temperature change rate is greater than or equal to n times the preset rate and less than or equal to the preset rate, the compressor is controlled to maintain the current state, 0<n<1;

[0112] When the water temperature change rate is less than n times the preset rate, the frequency of the turned-on compressor is increased with the third frequency as the frequency increase amplitude. When the frequencies of all turned-on compressors are greater than or equal to the optimal frequency and the water temperature change rate is still less than n times the preset rate, an unturned compressor is started according to the second preset rule. After the compressor is initialized, the frequency of the compressor is increased by the third frequency. After the third preset time, if the water temperature change rate is still less than n times the preset rate, the step of increasing the frequency of the compressor by the third frequency is returned to execute, and the cycle is repeated until the compressor is increased to the optimal frequency or until the water temperature change rate is greater than or equal to n times the preset rate or until the current actual water outlet temperature is not in the third interval.

[0113] The second frequency a2 and the second preset time t2 are both preset. The third frequency a3 and the third preset time t3 are both preset. Preferably, the third frequency is less than the first frequency.

[0114] In this embodiment, when the actual outlet water temperature is in the third interval, it means that the actual outlet water temperature is not much different from the set temperature. The compressor is increased or decreased in frequency according to the water temperature change rate and the preset rate, so that the unit output capacity can be changed in time to reach the required temperature range as soon as possible. In addition, the compressor is operated at the optimal frequency as much as possible, and the time for the compressor to operate at the optimal frequency is increased, thereby improving the unit operation efficiency.

[0115] Furthermore, when the frequencies of all turned-on compressors are less than or equal to the optimal frequency and the water temperature change rate is still greater than the preset rate, the compressor to be adjusted currently is determined among the turned-on compressors according to the first preset rule, and the frequency of the compressor to be adjusted currently is reduced by the second frequency. After the second preset time, if the water temperature change rate is still greater than the preset rate, the step of determining the compressor to be adjusted currently among the turned-on compressors according to the first preset rule is returned to and executed, and the cycle is repeated until the water temperature change rate is less than or equal to the preset rate or until the current actual water outlet temperature is not in the third interval; if the frequency of any compressor drops to the lowest frequency, the compressor is controlled to maintain operation at the lowest frequency.

[0116] In this embodiment, when the frequencies of all turned-on compressors are less than or equal to the optimal frequency and there is still a need for frequency reduction, the frequency of each compressor is reduced in sequence to reach the required temperature range as quickly as possible.

[0117] (4) If the current actual outlet water temperature is in the fourth interval, the number of compressors turned on and the operating frequency are controlled to maintain the current state.

[0118] In this embodiment, when the actual outlet water temperature is in the fourth interval, it means that the actual outlet water temperature is in the required temperature range, and there is no need to increase or decrease the frequency of the compressor.

[0119] (5) If the current actual outlet water temperature is in the fifth interval, the compressor to be adjusted is determined from the compressors that are turned on and have a frequency greater than the optimal frequency according to the first preset rule, and the frequency of the compressor to be adjusted is reduced by a fourth frequency. After the fourth preset time, if the current actual outlet water temperature is still in the fifth interval, the step of determining the compressor to be adjusted from the compressors that are turned on and have a frequency greater than the optimal frequency according to the first preset rule is returned to the execution, and the cycle is repeated until the current actual outlet water temperature is no longer in the fifth interval;

[0120] If the frequencies of all the compressors that have been turned on are reduced to the lowest frequency and the current actual outlet water temperature is still in the fifth interval, one compressor is turned off every fifth preset time.

[0121] Wherein, the fourth frequency a4 and the fourth preset time t4 are both preset. Preferably, the fourth frequency is greater than the second frequency. The values ​​of the first preset time t1, the second preset time t2, the third preset time t3 and the fourth preset time t4 can be equal or different. The fifth preset time can be set according to actual conditions, for example, set to 30 seconds.

[0122] In this embodiment, when the actual outlet water temperature is in the fifth interval, it means that the cooling or heating capacity currently output by the unit is too large and has exceeded the load demand. It is necessary to reduce the compressor frequency and the unit capacity output to maintain balance so that the actual outlet water temperature is within the required temperature range. Example 2

[0123] The compressor control method of the multi-module unit is described below in conjunction with a specific embodiment. However, it is worth noting that this specific embodiment is only for better illustrating the present application and does not constitute an improper limitation on the present application. The explanation of terms that are the same or corresponding to the above embodiment will not be repeated in this embodiment.

[0124] The multi-module unit includes multiple independent refrigerant systems, each of which includes two compressors connected in parallel.

[0125] like Figure 2 As shown, taking the cooling mode as an example, the compressor control of the multi-module unit includes the following steps:

[0126] S201, turn on the computer.

[0127] S202, determine whether the current actual outlet water temperature T satisfies T≥A, if yes, proceed to S203, if not, proceed to S209. A represents the first threshold.

[0128] S203, the refrigerant system is fully opened, and all compressors are directly started for initialization.

[0129] S204: If the water temperature drop rate ΔT>ΔT1, the compressor maintains the current state. ΔT1 represents a preset rate.

[0130] S205, if the water temperature drop rate △T≤△T1, each compressor is frequency-increased in sequence, that is, the compressor frequency is increased by a1Hz and adjusted every t1 time.

[0131] S206, the current compressor has been upgraded to a frequency greater than or equal to Q and there is still a need for upgrading the frequency. Q represents a preset optimal frequency.

[0132] S207, if the frequencies of other turned-on compressors are greater than or equal to Q, then the frequencies of the turned-on compressors continue to be increased in sequence, the compressor frequencies are increased by a1 Hz, and are adjusted once every t1 time.

[0133] S208: If there is a compressor whose frequency is less than Q among other compressors that have been turned on, then the frequency increase of the current compressor is stopped, and other compressors that have been turned on and whose frequencies are less than Q are increased in sequence.

[0134] S209, judging whether the current actual outlet water temperature T satisfies B≤T<A, if so, proceeding to S210, if not, proceeding to S218. B represents the second threshold value.

[0135] S210, only one compressor is turned on for each refrigerant system, and the compressor is directly started for initialization. If the compressor is already turned on, it is maintained.

[0136] S211: If the water temperature drop rate ΔT>ΔT1, the compressor maintains the current state.

[0137] S212, if the water temperature drop rate ΔT≤ΔT1, each initialized compressor is frequency-upgraded in sequence, the compressor frequency is increased by a1Hz, and is adjusted every t1 time.

[0138] S213: The current compressor has been upgraded to a frequency greater than or equal to Q and there is still a need for frequency upgrade.

[0139] S214, if the frequencies of other turned-on compressors are greater than or equal to Q, determine whether there are compressors that are not turned on, if so, proceed to S216, if not, proceed to S215.

[0140] S215, increasing the frequency of the compressors that have been turned on in sequence, the compressor frequency increases by a1Hz, and is adjusted once every t1 time.

[0141] S216, giving priority to initializing the compressors that are not turned on.

[0142] S217: If there is a compressor whose frequency is less than Q among other compressors that have been turned on, the frequency increase of the current compressor is stopped, and other compressors that have been turned on and whose frequencies are less than Q are increased in sequence.

[0143] S218, determine whether the current actual outlet water temperature T satisfies C≤T<B, if so, proceed to S219, S220 or S225 according to the water temperature drop rate, if not, proceed to S229. C represents the third threshold.

[0144] S219, if 0.4×ΔT1≤ΔT≤ΔT1, the compressor maintains the current state, the stopped compressor remains not started, and the started compressor maintains the current frequency.

[0145] S220, if ΔT<0.4×ΔT1, the temperature drop rate is small, indicating that the capacity output is insufficient. At this time, it is necessary to continue to increase the capacity output to quickly reach the required temperature range. Specifically, according to the principle of compressor rotation start and stop, start to the initial frequency in sequence and perform the initialization process.

[0146] S221, the compressor completes initialization, and the frequency of the compressor increases by a3Hz and is adjusted every t3 time.

[0147] S222: The current compressor has been upgraded to a frequency greater than or equal to Q and there is still a need for frequency upgrade.

[0148] S223, if the frequencies of other turned-on compressors are greater than or equal to Q, the frequencies of the turned-on compressors are increased in sequence, the compressor frequencies are increased by a3Hz, and are adjusted every t3 time.

[0149] S224: If there is a compressor whose frequency is less than Q among other compressors that have been turned on, the frequency increase of the current compressor is stopped, and other compressors that have been turned on and whose frequencies are less than Q are increased in sequence.

[0150] S225, if ΔT>ΔT1, the temperature drop rate is fast, which means that the unit output capacity is greater than the load demand, and the capacity output needs to be reduced to maintain balance. Specifically, the compression is reduced in sequence, and the compressor frequency is reduced by a2Hz, and adjusted every t2 time.

[0151] S226: The current compressor has been frequency-reduced to less than or equal to Q and there is still a need for frequency reduction.

[0152] S227, if the frequencies of other turned-on compressors are all less than or equal to Q, the turned-on compressors are frequency-reduced in sequence, the compressor frequency is reduced by a2Hz, and the frequency is adjusted every t2 time.

[0153] S228, if there is a compressor whose frequency is greater than Q among other compressors that have been turned on, then stop reducing the frequency of the current compressor, and sequentially reduce the frequency of other compressors that have been turned on and whose frequency is greater than Q. If the current compressor has been reduced to the lowest frequency allowed, then maintain the lowest frequency operation.

[0154] S229, determine whether the current actual outlet water temperature T satisfies D≤T<C, if so, proceed to S230, if not, proceed to S231. D represents the fourth threshold.

[0155] S230, the number of compressors turned on and the operating frequency are maintained at the current state.

[0156] S231, current actual outlet water temperature T≤D.

[0157] S232, control the compressor frequency reduction in sequence, the compressor frequency is reduced by a4Hz, and is adjusted once every t4 time.

[0158] S233: The current compressor has been frequency-reduced to less than or equal to Q and there is still a need for frequency reduction.

[0159] S234, if the frequencies of other turned-on compressors are less than or equal to Q, the turned-on compressors are frequency-reduced in sequence, the compressor frequency is reduced by a4Hz, and the frequency is adjusted every t4 time.

[0160] S235, if the frequencies of all the compressors that have been turned on have dropped to the minimum frequency, one compressor is turned off every 30 seconds, and the stopped compressors remain as they are.

[0161] S236: If there is a compressor whose frequency is greater than Q among other compressors that have been turned on, stop reducing the frequency of the current compressor, and reduce the frequency of other compressors that have been turned on and whose frequency is greater than Q in sequence.

[0162] Among them, a1>a3, when the load demand is large, the frequency amplitude of each adjustment is large. a2<a4, when the temperature is below the required temperature range, the frequency is quickly reduced.

[0163] The difference between the heating mode and the cooling mode mainly lies in the different threshold sets and the different judgments of the actual water outlet temperature range, while the specific controls in the corresponding ranges are the same, which will not be described in detail in this embodiment.

[0164] When the load demand is very large, this embodiment directly turns on all compressors to quickly meet the load demand. When the load demand is large, half of the compressors are started to run, which can not only quickly meet the load demand, but also make full use of the heat exchanger to improve energy efficiency. Through the control strategy of this embodiment, the project can respond to the terminal load demand more quickly, shorten the unit startup time, reduce the loading and unloading time, and will not cause problems such as frequent starts and stops or large water temperature fluctuations due to rapid loading. Set the optimal frequency, and during the process of loading and unloading the compressor, ensure that the compressor runs as close to the optimal frequency as possible, which improves the operating efficiency of the unit to a certain extent and improves the energy efficiency of the unit. Example 3

[0165] Based on the same inventive concept, this embodiment provides a compressor control device for a multi-module unit, which can be used to implement the compressor control method for the multi-module unit described in the above embodiment. The device can be implemented by software and / or hardware. The multi-module unit includes at least one refrigerant system, and each refrigerant system includes at least one compressor.

[0166] Figure 3 is a block diagram of a compressor control device for a multi-module unit provided in Embodiment 3 of the present invention. Figure 3 As shown, the device comprises:

[0167] A monitoring module 31, used to monitor the actual outlet water temperature and water temperature change rate of the multi-module unit;

[0168] The control module 32 is used to control the number of compressors to be turned on and the operating frequency according to the actual water outlet temperature and the water temperature change rate, so that the actual water outlet temperature is within the required temperature range and the turned-on compressors are operated at a preset optimal frequency to the greatest extent, wherein the optimal frequency makes the compressor operate at the highest efficiency.

[0169] Optionally, the control module 32 includes:

[0170] A first determining unit, configured to determine an operating mode of the multi-module unit and determine a threshold set under the operating mode according to a current set temperature;

[0171] A second determining unit, configured to determine the interval in which the actual outlet water temperature is located according to the actual outlet water temperature and the threshold set;

[0172] The control unit is used to control the number of compressors to be turned on and the operating frequency according to the interval of the actual outlet water temperature and the water temperature change rate.

[0173] Optionally, the second determining unit is specifically configured to:

[0174] In the cooling mode, if the current actual outlet water temperature is greater than or equal to the first threshold, it is determined that the current actual outlet water temperature is in the first interval;

[0175] If the current actual outlet water temperature is greater than or equal to the second threshold and less than the first threshold, it is determined that the current actual outlet water temperature is in the second interval;

[0176] If the current actual outlet water temperature is greater than or equal to the third threshold value and less than the second threshold value, it is determined that the current actual outlet water temperature is in the third interval;

[0177] If the current actual outlet water temperature is greater than or equal to the fourth threshold value and less than the third threshold value, it is determined that the current actual outlet water temperature is in the fourth interval;

[0178] If the current actual outlet water temperature is less than the fourth threshold, it is determined that the current actual outlet water temperature is in the fifth interval.

[0179] Optionally, the second determining unit is specifically configured to:

[0180] In the heating mode, if the current actual outlet water temperature is less than or equal to the fifth threshold, it is determined that the current actual outlet water temperature is in the first interval;

[0181] If the current actual outlet water temperature is greater than the fifth threshold value and less than or equal to the sixth threshold value, it is determined that the current actual outlet water temperature is in the second interval;

[0182] If the current actual outlet water temperature is greater than the sixth threshold value and less than or equal to the seventh threshold value, it is determined that the current actual outlet water temperature is in the third interval;

[0183] If the current actual outlet water temperature is greater than the seventh threshold value and less than or equal to the eighth threshold value, it is determined that the current actual outlet water temperature is in the fourth interval;

[0184] If the current actual outlet water temperature is greater than the eighth threshold, it is determined that the current actual outlet water temperature is in the fifth interval.

[0185] Optionally, the control unit is specifically used for:

[0186] If the current actual outlet water temperature is in the first interval, all compressors are turned on and the water temperature change rate is monitored;

[0187] When the water temperature change rate is less than or equal to the preset rate, the compressor to be adjusted is determined according to the first preset rule from the compressors that are turned on and whose frequencies are less than the optimal frequency, and the frequency of the compressor to be adjusted is increased by the first frequency. After the first preset time, if the water temperature change rate is still less than or equal to the preset rate, the step of determining the compressor to be adjusted according to the first preset rule from the compressors that are turned on and whose frequencies are less than the optimal frequency is returned to the execution, and the cycle is repeated until the water temperature change rate is greater than the preset rate or until the current actual water outlet temperature is not in the first interval;

[0188] When the water temperature change rate is greater than the preset rate, the compressor is controlled to maintain the current state.

[0189] Optionally, when the frequencies of all turned-on compressors are greater than or equal to the optimal frequency and the water temperature change rate is still less than or equal to the preset rate, the compressor currently to be adjusted is determined among the turned-on compressors according to a first preset rule, and the frequency of the compressor currently to be adjusted is increased by a first frequency. After a first preset time, if the water temperature change rate is still less than or equal to the preset rate, the process returns to executing the step of determining the compressor currently to be adjusted among the turned-on compressors according to the first preset rule, and the process repeats this cycle until the water temperature change rate is greater than the preset rate or until the current actual water outlet temperature is not in the first interval.

[0190] Optionally, when each refrigerant system includes at least two compressors, the at least two compressors are connected in parallel; the control unit is specifically used to:

[0191] If the current actual outlet water temperature is in the second interval, a preset number of compressors are turned on in each refrigerant system, and the water temperature change rate is monitored;

[0192] When the water temperature change rate is less than or equal to the preset rate, the compressor to be adjusted is determined according to the first preset rule from the compressors that are turned on and whose frequencies are less than the optimal frequency, and the frequency of the compressor to be adjusted is increased by the first frequency. After the first preset time, if the water temperature change rate is still less than or equal to the preset rate, the step of determining the compressor to be adjusted according to the first preset rule from the compressors that are turned on and whose frequencies are less than the optimal frequency is returned to the execution, and the cycle is repeated until the water temperature change rate is greater than the preset rate or until the current actual water outlet temperature is not in the second interval;

[0193] When the water temperature change rate is greater than the preset rate, the compressor is controlled to maintain the current state.

[0194] Optionally, when the frequencies of all the compressors that have been turned on are greater than or equal to the optimal frequency, and the water temperature change rate is still less than or equal to the preset rate, a compressor that has not been turned on is started according to a second preset rule;

[0195] If there is no unturned compressor, the current compressor to be adjusted is determined among the turned-on compressors according to the first preset rule, and the frequency of the current compressor to be adjusted is increased by a first frequency. After the first preset time, if the water temperature change rate is still less than or equal to the preset rate, the process returns to the step of determining the current compressor to be adjusted among the turned-on compressors according to the first preset rule, and the process repeats this cycle until the water temperature change rate is greater than the preset rate or until the current actual water outlet temperature is not in the second interval.

[0196] Optionally, the control unit is specifically used for:

[0197] If the current actual outlet water temperature is in the third interval, the compressor is started according to the second preset rule, and the water temperature change rate is monitored;

[0198] When the water temperature change rate is greater than the preset rate, the compressor to be adjusted is determined from the compressors that are turned on and have a frequency greater than the optimal frequency according to the first preset rule, and the frequency of the compressor to be adjusted is reduced by a second frequency. After the second preset time, if the water temperature change rate is still greater than the preset rate, the step of determining the compressor to be adjusted from the compressors that are turned on and have a frequency greater than the optimal frequency according to the first preset rule is returned to the execution, and the cycle is repeated until the water temperature change rate is less than or equal to the preset rate or until the current actual water outlet temperature is not in the third interval;

[0199] When the water temperature change rate is greater than or equal to n times the preset rate and less than or equal to the preset rate, the compressor is controlled to maintain the current state, 0<n<1;

[0200] When the water temperature change rate is less than n times the preset rate, the frequency of the turned-on compressor is increased with the third frequency as the frequency increase amplitude. When the frequencies of all turned-on compressors are greater than or equal to the optimal frequency and the water temperature change rate is still less than n times the preset rate, an unturned compressor is started according to the second preset rule. After the compressor is initialized, the frequency of the compressor is increased by the third frequency. After the third preset time, if the water temperature change rate is still less than n times the preset rate, the step of increasing the frequency of the compressor by the third frequency is returned to execute, and the cycle is repeated until the compressor is increased to the optimal frequency or until the water temperature change rate is greater than or equal to n times the preset rate or until the current actual water outlet temperature is not in the third interval.

[0201] Optionally, when the frequencies of all turned-on compressors are less than or equal to the optimal frequency, and the water temperature change rate is still greater than the preset rate, the compressor to be adjusted currently is determined among the turned-on compressors according to the first preset rule, and the frequency of the compressor to be adjusted currently is reduced by a second frequency. After a second preset time, if the water temperature change rate is still greater than the preset rate, the step of determining the compressor to be adjusted currently among the turned-on compressors according to the first preset rule is returned to and executed, and this cycle is repeated until the water temperature change rate is less than or equal to the preset rate or until the current actual water outlet temperature is not in the third interval;

[0202] If the frequency of any compressor drops to the minimum frequency, the compressor is controlled to maintain the operation at the minimum frequency.

[0203] Optionally, the control unit is specifically used to: if the current actual water outlet temperature is in the fourth interval, control the number of compressors turned on and the operating frequency to maintain the current state.

[0204] Optionally, the control unit is specifically used for:

[0205] If the current actual outlet water temperature is in the fifth interval, the compressor to be adjusted is determined from the compressors that are turned on and have a frequency greater than the optimal frequency according to the first preset rule, and the frequency of the compressor to be adjusted is reduced by a fourth frequency. After the fourth preset time, if the current actual outlet water temperature is still in the fifth interval, the step of determining the compressor to be adjusted from the compressors that are turned on and have a frequency greater than the optimal frequency according to the first preset rule is returned to be executed, and this cycle is repeated until the current actual outlet water temperature is not in the fifth interval;

[0206] If the frequencies of all the compressors that have been turned on are reduced to the lowest frequency, and the current actual outlet water temperature is still in the fifth interval, then one compressor is turned off every fifth preset time.

[0207] The above device can execute the method provided by the embodiment of the present invention, and has the functional modules and beneficial effects corresponding to the execution method. For technical details not described in detail in this embodiment, please refer to the method provided by the embodiment of the present invention. Example 4

[0208] An embodiment of the present invention provides a multi-module unit, comprising: a compressor control device of the multi-module unit described in the above embodiment. Example 5

[0209] An embodiment of the present invention provides a computer device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method described in the above embodiment when executing the computer program. Example 6

[0210] An embodiment of the present invention provides a non-volatile computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the method described in the above embodiment are implemented.

[0211] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0212] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0213] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A compressor control method for a multi-module unit, wherein the multi-module unit comprises at least one refrigerant system, each refrigerant system comprises at least one compressor, characterized in that: The method comprises: Monitoring the actual outlet water temperature and water temperature change rate of the multi-module unit; According to the actual outlet water temperature and the water temperature change rate, the number of compressors turned on and the operating frequency are controlled so that the actual outlet water temperature is within the required temperature range and the compressors turned on are operated at a preset optimal frequency to the greatest extent, wherein the optimal frequency makes the compressors operate at the highest efficiency; According to the actual outlet water temperature and the water temperature change rate, the number of compressors turned on and the operating frequency are controlled, including: determining the working mode of the multi-module unit, and determining the threshold value set under the working mode according to the current set temperature; determining the interval of the actual outlet water temperature according to the actual outlet water temperature and the threshold value set; according to the interval of the actual outlet water temperature and the water temperature change rate, controlling the number of compressors turned on and the operating frequency; In cooling mode, the first interval, the second interval, the third interval, the fourth interval and the fifth interval are set in sequence according to the threshold from large to small; in heating mode, the first interval, the second interval, the third interval, the fourth interval and the fifth interval are set in sequence according to the threshold from small to large; According to the interval of the actual outlet water temperature and the water temperature change rate, the number of compressors to be turned on and the operating frequency are controlled, including: If the current actual outlet water temperature is in the first interval, all compressors are turned on and the water temperature change rate is monitored; When the water temperature change rate is less than or equal to the preset rate, the compressor to be adjusted is determined according to the first preset rule from the compressors that are turned on and whose frequencies are less than the optimal frequency, and the frequency of the compressor to be adjusted is increased by the first frequency. After the first preset time, if the water temperature change rate is still less than or equal to the preset rate, the step of determining the compressor to be adjusted according to the first preset rule from the compressors that are turned on and whose frequencies are less than the optimal frequency is returned to the execution, and the cycle is repeated until the water temperature change rate is greater than the preset rate or until the current actual water outlet temperature is not in the first interval; When the water temperature change rate is greater than the preset rate, the compressor is controlled to maintain the current state.

2. The method according to claim 1, characterized in that: Determining the interval of the actual outlet water temperature according to the actual outlet water temperature and the threshold set includes: In the cooling mode, if the current actual outlet water temperature is greater than or equal to the first threshold, it is determined that the current actual outlet water temperature is in the first interval; If the current actual outlet water temperature is greater than or equal to the second threshold and less than the first threshold, it is determined that the current actual outlet water temperature is in the second interval; If the current actual outlet water temperature is greater than or equal to the third threshold value and less than the second threshold value, it is determined that the current actual outlet water temperature is in the third interval; If the current actual outlet water temperature is greater than or equal to the fourth threshold value and less than the third threshold value, it is determined that the current actual outlet water temperature is in the fourth interval; If the current actual outlet water temperature is less than the fourth threshold, it is determined that the current actual outlet water temperature is in the fifth interval.

3. The method according to claim 1, characterized in that Determining the interval of the actual outlet water temperature according to the actual outlet water temperature and the threshold set includes: In the heating mode, if the current actual outlet water temperature is less than or equal to the fifth threshold, it is determined that the current actual outlet water temperature is in the first interval; If the current actual outlet water temperature is greater than the fifth threshold value and less than or equal to the sixth threshold value, it is determined that the current actual outlet water temperature is in the second interval; If the current actual outlet water temperature is greater than the sixth threshold value and less than or equal to the seventh threshold value, it is determined that the current actual outlet water temperature is in the third interval; If the current actual outlet water temperature is greater than the seventh threshold value and less than or equal to the eighth threshold value, it is determined that the current actual outlet water temperature is in the fourth interval; If the current actual outlet water temperature is greater than the eighth threshold, it is determined that the current actual outlet water temperature is in the fifth interval.

4. The method according to claim 1, characterized in that When the current actual water outlet temperature is in the first interval, when the frequencies of all turned-on compressors are greater than or equal to the optimal frequency, and the water temperature change rate is still less than or equal to the preset rate, the compressor to be adjusted is determined among the turned-on compressors according to the first preset rule, and the frequency of the compressor to be adjusted is increased by a first frequency. After a first preset time, if the water temperature change rate is still less than or equal to the preset rate, the process returns to the step of determining the compressor to be adjusted among the turned-on compressors according to the first preset rule, and the process repeats this cycle until the water temperature change rate is greater than the preset rate or the current actual water outlet temperature is no longer in the first interval.

5. The method according to claim 1, characterized in that: When each refrigerant system includes at least two compressors, the at least two compressors are connected in parallel; According to the interval of the actual outlet water temperature and the water temperature change rate, the number of compressors to be turned on and the operating frequency are controlled, including: If the current actual outlet water temperature is in the second interval, a preset number of compressors are turned on in each refrigerant system, and the water temperature change rate is monitored; When the water temperature change rate is less than or equal to the preset rate, the compressor to be adjusted is determined according to the first preset rule from the compressors that are turned on and whose frequencies are less than the optimal frequency, and the frequency of the compressor to be adjusted is increased by the first frequency. After the first preset time, if the water temperature change rate is still less than or equal to the preset rate, the step of determining the compressor to be adjusted according to the first preset rule from the compressors that are turned on and whose frequencies are less than the optimal frequency is returned to the execution, and the cycle is repeated until the water temperature change rate is greater than the preset rate or until the current actual water outlet temperature is not in the second interval; When the water temperature change rate is greater than the preset rate, the compressor is controlled to maintain the current state.

6. The method according to claim 5, characterized in that When the current actual outlet water temperature is in the second interval, when the frequencies of all the compressors that are turned on are greater than or equal to the optimal frequency, and the water temperature change rate is still less than or equal to the preset rate, start a compressor that is not turned on according to the second preset rule; If there is no unturned compressor, the current compressor to be adjusted is determined among the turned-on compressors according to the first preset rule, and the frequency of the current compressor to be adjusted is increased by a first frequency. After the first preset time, if the water temperature change rate is still less than or equal to the preset rate, the process returns to the step of determining the current compressor to be adjusted among the turned-on compressors according to the first preset rule, and the process repeats this cycle until the water temperature change rate is greater than the preset rate or until the current actual water outlet temperature is not in the second interval.

7. The method according to claim 1, characterized in that According to the interval of the actual outlet water temperature and the water temperature change rate, the number of compressors to be turned on and the operating frequency are controlled, including: If the current actual outlet water temperature is in the third interval, the compressor is started according to the second preset rule, and the water temperature change rate is monitored; When the water temperature change rate is greater than the preset rate, the compressor to be adjusted is determined from the compressors that are turned on and have a frequency greater than the optimal frequency according to the first preset rule, and the frequency of the compressor to be adjusted is reduced by a second frequency. After the second preset time, if the water temperature change rate is still greater than the preset rate, the step of determining the compressor to be adjusted from the compressors that are turned on and have a frequency greater than the optimal frequency according to the first preset rule is returned to the execution, and the cycle is repeated until the water temperature change rate is less than or equal to the preset rate or until the current actual water outlet temperature is not in the third interval; When the water temperature change rate is greater than or equal to n times the preset rate and less than or equal to the preset rate, the compressor is controlled to maintain the current state, 0<n<1; When the water temperature change rate is less than n times the preset rate, the frequency of the turned-on compressor is increased with the third frequency as the frequency increase amplitude. When the frequencies of all turned-on compressors are greater than or equal to the optimal frequency and the water temperature change rate is still less than n times the preset rate, an unturned compressor is started according to the second preset rule. After the compressor is initialized, the frequency of the compressor is increased by the third frequency. After the third preset time, if the water temperature change rate is still less than n times the preset rate, the step of increasing the frequency of the compressor by the third frequency is returned to execute, and the cycle is repeated until the compressor is increased to the optimal frequency or until the water temperature change rate is greater than or equal to n times the preset rate or until the current actual water outlet temperature is not in the third interval.

8. The method according to claim 7, characterized in that In the case where the current actual outlet water temperature is in the third interval, when the frequencies of all the turned-on compressors are less than or equal to the optimal frequency, and the water temperature change rate is still greater than the preset rate, the compressor to be adjusted currently is determined among the turned-on compressors according to the first preset rule, and the frequency of the compressor to be adjusted currently is reduced by a second frequency. After the second preset time, if the water temperature change rate is still greater than the preset rate, the step of determining the compressor to be adjusted currently among the turned-on compressors according to the first preset rule is returned to, and the cycle is repeated until the water temperature change rate is less than or equal to the preset rate or until the current actual outlet water temperature is not in the third interval; If the frequency of any compressor drops to the minimum frequency, the compressor is controlled to maintain the operation at the minimum frequency.

9. The method according to claim 1, characterized in that: According to the interval of the actual outlet water temperature and the water temperature change rate, the number of compressors to be turned on and the operating frequency are controlled, including: If the current actual outlet water temperature is in the fourth interval, the number of compressors turned on and the operating frequency are controlled to maintain the current state.

10. The method according to claim 1, characterized in that According to the interval of the actual outlet water temperature and the water temperature change rate, the number of compressors to be turned on and the operating frequency are controlled, including: If the current actual outlet water temperature is in the fifth interval, the compressor to be adjusted is determined from the compressors that are turned on and have a frequency greater than the optimal frequency according to the first preset rule, and the frequency of the compressor to be adjusted is reduced by a fourth frequency. After the fourth preset time, if the current actual outlet water temperature is still in the fifth interval, the step of determining the compressor to be adjusted from the compressors that are turned on and have a frequency greater than the optimal frequency according to the first preset rule is returned to be executed, and this cycle is repeated until the current actual outlet water temperature is not in the fifth interval; If the frequencies of all the compressors that have been turned on are reduced to the lowest frequency, and the current actual outlet water temperature is still in the fifth interval, then one compressor is turned off every fifth preset time.

11. A compressor control device for a multi-module unit, the multi-module unit comprising at least one refrigerant system, each refrigerant system comprising at least one compressor, characterized in that: The device comprises: A monitoring module, used to monitor the actual outlet water temperature and water temperature change rate of the multi-module unit; A control module, for controlling the number of compressors to be turned on and the operating frequency according to the actual outlet water temperature and the water temperature change rate, so that the actual outlet water temperature is within the required temperature range and the compressors that have been turned on are operated at a preset optimal frequency to the greatest extent, wherein the optimal frequency makes the compressors operate at the highest efficiency; The control module comprises: A first determining unit, configured to determine an operating mode of the multi-module unit and determine a threshold set under the operating mode according to a current set temperature; A second determining unit, configured to determine the interval in which the actual outlet water temperature is located according to the actual outlet water temperature and the threshold set; A control unit, used to control the number of compressors to be turned on and the operating frequency according to the interval of the actual outlet water temperature and the water temperature change rate; In cooling mode, the first interval, the second interval, the third interval, the fourth interval and the fifth interval are set in sequence according to the threshold from large to small; in heating mode, the first interval, the second interval, the third interval, the fourth interval and the fifth interval are set in sequence according to the threshold from small to large; The control unit is specifically used for: If the current actual outlet water temperature is in the first interval, all compressors are turned on and the water temperature change rate is monitored; When the water temperature change rate is less than or equal to the preset rate, the compressor to be adjusted is determined according to the first preset rule from the compressors that are turned on and whose frequencies are less than the optimal frequency, and the frequency of the compressor to be adjusted is increased by the first frequency. After the first preset time, if the water temperature change rate is still less than or equal to the preset rate, the step of determining the compressor to be adjusted according to the first preset rule from the compressors that are turned on and whose frequencies are less than the optimal frequency is returned to the execution, and the cycle is repeated until the water temperature change rate is greater than the preset rate or until the current actual water outlet temperature is not in the first interval; When the water temperature change rate is greater than the preset rate, the compressor is controlled to maintain the current state.

12. A multi-module unit, characterized in that: include: The compressor control device of the multi-module unit according to claim 11.

13. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method according to any one of claims 1 to 10 when executing the computer program.

14. A non-volatile computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 10 are implemented.

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