Gas supplement and enthalpy increase control method and device and central air conditioner

Abstract

The application provides a gas supplementing and enthalpy increasing control method and device and a central air conditioner. The method comprises the following steps: in a heating starting stage of the central air conditioner, a required frequency of an enthalpy injection compressor is calculated according to starting parameters, and an enthalpy injection working mode is determined according to the required frequency and a maximum frequency of the enthalpy injection compressor; in a heating running stage of the central air conditioner, when a first ratio between an actual frequency and the maximum frequency is not greater than a preset first threshold value, the enthalpy injection state is controlled according to an actual power and a corrected rated power in the first mode or the second mode. In the control mode, whether to start the enthalpy injection is determined according to the required frequency and the maximum frequency of the enthalpy injection compressor in the heating starting stage of the central air conditioner; in the heating running stage, the actual power and the corrected rated power of the central air conditioner are compared and analyzed, the running energy efficiency state of the central air conditioning system is determined in real time, and the control state of the enthalpy injection is adjusted in time, so that the energy efficiency of the central air conditioner is optimized.

Description

Technical Field

[0001] This invention relates to the field of air conditioner technology, and in particular to a method, device, and central air conditioner for controlling enthalpy increase through gas replenishment. Background Technology

[0002] With the development of multi-split air conditioning technology, central air conditioning has been widely accepted by users. However, in practical applications, central air conditioning heat pumps generally suffer from a supply-demand imbalance. That is, when the outdoor temperature is lower and the room's heat load demand is greater, the heating capacity of the air conditioner decreases and cannot meet customer needs.

[0003] To address the aforementioned issues, traditional air conditioners primarily use electric heating as an auxiliary heat source to supplement heat when the required temperature cannot be achieved. However, electric heating involves direct electrothermal conversion, resulting in low energy efficiency and violating national energy conservation and emission reduction policies. In response, some manufacturers have developed enthalpy-increasing compressors that inject gas at the compressor's mid-pressure position to increase refrigerant circulation and improve heating capacity under low-temperature conditions. However, these compressors mainly focus on improving compressor reliability and capacity, neglecting energy efficiency. Therefore, optimizing the control of enthalpy-increasing gas injection to improve product energy efficiency is a pressing problem that needs to be solved. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a gas replenishment enthalpy control method, device and central air conditioner to alleviate the above problems and achieve optimal energy efficiency of the central air conditioner.

[0005] In a first aspect, embodiments of the present invention provide a gas injection enthalpy increase control method, applied to the controller of a central air conditioner. The central air conditioner further includes an enthalpy injection compressor and multiple indoor units connected in parallel, all communicatively connected to the controller. The method includes: if the central air conditioner starts in heating mode, acquiring start-up parameters; wherein, the start-up parameters include the outdoor ambient temperature and indoor ambient temperature at start-up, and the number of indoor units in operation; calculating the total heat load of the central air conditioner based on the start-up parameters; calculating the demand frequency of the enthalpy injection compressor based on the total heat load; and determining the enthalpy injection working mode based on the demand frequency and the maximum frequency of the enthalpy injection compressor. The formula is as follows: The enthalpy injection working mode includes a first mode and a second mode. The first mode represents the enthalpy injection mode not being activated, and the second mode represents the enthalpy injection mode being activated. During the heating operation of the central air conditioner, the actual frequency of the enthalpy injection compressor is obtained; a first ratio between the actual frequency and the maximum frequency is calculated; it is determined whether the first ratio is not greater than a preset first threshold; if so, the actual power and corrected rated power of the central air conditioner are obtained; wherein, the corrected rated power is determined based on the overall rated power of the central air conditioner and a correction coefficient; in the first mode or the second mode, the enthalpy injection state is controlled according to the actual power and the corrected rated power.

[0006] The above-mentioned gas injection and enthalpy enhancement control method determines whether to activate the injection enthalpy compressor based on the demand frequency and maximum frequency of the injection enthalpy compressor during the heating start-up phase of the central air conditioner. During the heating operation phase, the actual power and corrected rated power of the injection enthalpy compressor are compared and analyzed in real time to determine the energy efficiency status of the central air conditioning system and adjust the control status of the injection enthalpy in a timely manner, thereby achieving optimal energy efficiency of the central air conditioner.

[0007] Preferably, in the first mode described above, the step of controlling the injection enthalpy state based on the actual power and the corrected rated power includes: if the actual power is not greater than the corrected rated power, controlling the injection enthalpy to remain in the off state; or, if the actual power is greater than the corrected rated power, controlling the injection enthalpy to be in the on state.

[0008] Preferably, in the second mode described above, the step of controlling the injection enthalpy state based on the actual power and the corrected rated power includes: if the actual power is not greater than the corrected rated power, controlling the injection enthalpy to remain in the on state; or, if the actual power is greater than the corrected rated power, controlling the injection enthalpy to be in the off state.

[0009] Preferably, the above method further includes: in the first mode, if the first ratio is greater than a preset first threshold, then the injection enthalpy is controlled to be in the open state.

[0010] Preferably, the step of determining the injection enthalpy operating mode based on the demand frequency and the maximum frequency includes: calculating a second ratio between the demand frequency and the maximum frequency; if the second ratio is not greater than a preset second threshold, determining the injection enthalpy operating mode as a first mode; or, if the second ratio is greater than the preset second threshold, determining the injection enthalpy operating mode as a second mode.

[0011] Preferably, the step of calculating the total heat load of the central air conditioner based on the start-up parameters includes: calculating the total heat load according to the following formula: Q 需 =[a*(5-T)] 外环 )+b*(10-T 内环 )]*ΣQ 内-ON ; where Q 需 T represents the total heat load. 外环 Indicates the outdoor ambient temperature, T 内环 Indicates indoor ambient temperature, ΣQ 内-ON This indicates the number of indoor units that are turned on, and 'a' and 'b' represent calculation coefficients.

[0012] Preferably, the aforementioned central air conditioner further includes an enthalpy-injection electronic expansion valve communicatively connected to the controller. The method further includes: acquiring the enthalpy-injection inlet pipe temperature and the enthalpy-injection outlet pipe temperature; calculating the difference between the enthalpy-injection inlet pipe temperature and the enthalpy-injection outlet pipe temperature; if the difference is not less than a first difference threshold, controlling the opening of the enthalpy-injection electronic expansion valve to increase; or, if the difference is less than the first difference threshold and not less than a second difference threshold, controlling the opening of the enthalpy-injection electronic expansion valve to remain unchanged; or, if the difference is less than the second difference threshold, controlling the opening of the enthalpy-injection electronic expansion valve to decrease; wherein the second difference threshold is less than the first difference threshold.

[0013] Secondly, embodiments of the present invention also provide a gas injection enthalpy control device, applied to the controller of a central air conditioner. The central air conditioner further includes an enthalpy-injecting compressor and multiple indoor units connected in parallel, all communicatively connected to the controller. The device includes: a first acquisition module, used to acquire start-up parameters when the central air conditioner starts in heating mode; wherein the start-up parameters include the outdoor ambient temperature and the indoor ambient temperature at start-up, and the number of indoor units in operation; a first calculation module, used to calculate the total heat load of the central air conditioner based on the start-up parameters; a second calculation module, used to calculate the demand frequency of the enthalpy-injecting compressor based on the total heat load; and a mode determination module, used to determine the enthalpy-injecting operating mode based on the demand frequency and the maximum frequency of the enthalpy-injecting compressor. The enthalpy injection operating mode includes a first mode and a second mode. The first mode represents the enthalpy injection mode not being activated, and the second mode represents the enthalpy injection mode being activated. The second acquisition module is used to acquire the actual frequency of the enthalpy injection compressor during the heating operation of the central air conditioner. The third calculation module is used to calculate a first ratio between the actual frequency and the maximum frequency. The judgment module is used to determine whether the first ratio is not greater than a preset first threshold. If so, the third acquisition module is used to acquire the actual power and the corrected rated power of the central air conditioner. The corrected rated power is determined based on the overall rated power of the central air conditioner and a correction coefficient. The status control module is used to control the enthalpy injection status based on the actual power and the corrected rated power in the first mode or the second mode.

[0014] Thirdly, embodiments of the present invention also provide a central air conditioner, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the method described in the first aspect.

[0015] Fourthly, embodiments of the present invention also provide a computer-readable storage medium storing a computer program, which, when executed by a processor, performs the steps of the method described in the first aspect.

[0016] The embodiments of the present invention bring the following beneficial effects:

[0017] This invention provides a gas injection enthalpy enhancement control method, device, and central air conditioner. During the heating start-up phase of the central air conditioner, the required frequency of the enthalpy-injecting compressor is calculated based on start-up parameters, and the enthalpy-injecting operating mode is determined based on the required frequency and the maximum frequency of the compressor. During the heating operation phase, when a first ratio between the actual frequency and the maximum frequency is not greater than a preset first threshold, the enthalpy-injecting state is controlled based on the actual power and the corrected rated power in either the first or second mode. In this control method, during the heating start-up phase, the decision to activate enthalpy injection is based on the required frequency and maximum frequency of the compressor. During the heating operation phase, the energy efficiency status of the central air conditioning system is assessed in real time by comparing and analyzing the actual power and the corrected rated power of the central air conditioner, and the control state of enthalpy injection is adjusted accordingly, achieving optimal energy efficiency for the central air conditioner.

[0018] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained through the structures particularly pointed out in the description and the drawings.

[0019] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0020] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the outdoor structure of a central air conditioner provided in an embodiment of the present invention;

[0022] Figure 2 A flowchart of a gas replenishment and enthalpy increase control method provided in an embodiment of the present invention;

[0023] Figure 3 A compressor power curve is provided for an embodiment of the present invention;

[0024] Figure 4 A flowchart of another gas replenishment enthalpy control method provided in an embodiment of the present invention;

[0025] Figure 5 This is a schematic diagram of a gas replenishment and enthalpy increase control device provided in an embodiment of the present invention;

[0026] Figure 6 This is a schematic diagram of the structure of a central air conditioner provided in an embodiment of the present invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] To facilitate understanding of this embodiment, a gas replenishment and enthalpy increase control method provided by this embodiment of the invention will be described in detail below. The executing entity is the controller of a central air conditioner. The central air conditioner also includes an outdoor side and an indoor side that are communicatively connected to the controller. The indoor side includes multiple indoor units connected in parallel. The structure of each indoor unit can refer to existing air conditioners, and will not be described in detail here.

[0029] For the outdoor side, such as Figure 1 As shown, the system includes: an enthalpy-injecting compressor 11, a gas-liquid separator 12, an oil separator 13, a four-way valve 14, a heat exchanger 15, and a throttling electronic expansion valve 16; a plate heat exchanger 17 and an enthalpy-injecting electronic expansion valve 18 for the enthalpy-injecting compressor 11; and a data acquisition device for detecting the enthalpy temperature, which includes an enthalpy inlet temperature sensor 191 and an enthalpy outlet temperature sensor 192. It should be noted that the aforementioned enthalpy-injecting compressor 11 is a variable-frequency enthalpy-injecting compressor. For parts not mentioned in the outdoor section, refer to existing air conditioners.

[0030] Based on the aforementioned central air conditioner, this embodiment of the invention provides a method for controlling enthalpy increase through gas replenishment, such as... Figure 2 As shown, the method includes the following steps:

[0031] Step S202: If the central air conditioner starts in heating mode, obtain the start-up parameters;

[0032] Among them, the startup parameters include the outdoor ambient temperature T at startup. 外环 and indoor ambient temperature T 内环 And the number of indoor units turned on; specifically, the outdoor ambient temperature T 外环 and indoor ambient temperature T 内环 This can be obtained through the corresponding temperature sensor. Since the central air conditioner is in the start-up phase, the indoor ambient temperature T corresponding to the location of each indoor unit is [temperature value]. 内环 The indoor ambient temperature T is relatively close, therefore the above indoor ambient temperature T 内环It can be set to the temperature of the room where any one of the indoor units is turned on, or it can be the average temperature of the rooms where all the indoor units are turned on. The specific setting can be adjusted according to the actual situation.

[0033] Step S204: Calculate the total heat load of the central air conditioner based on the startup parameters;

[0034] In practical applications, under the same conditions, central air conditioners improve heating capacity mainly through two methods when operating in heating mode. One method is to increase the compressor's operating frequency. The higher the compressor's operating frequency, the higher the refrigerant circulation volume, resulting in increased heating capacity, while also increasing the compressor's work. The other method is to activate enthalpy injection. When enthalpy injection is activated, the refrigerant circulation volume increases, resulting in increased heating capacity, while also increasing the compressor's work. Therefore, in heating mode, both increasing the compressor's operating frequency and activating enthalpy injection can improve heating capacity. Thus, energy efficiency should be prioritized as the control condition for operating central air conditioners.

[0035] like Figure 3 As shown, since the compressor power W increases significantly with the increase of the operating frequency F, and the energy efficiency is low at high frequencies, different methods can be used to increase the unit's heating capacity at different frequency stages to achieve optimal energy efficiency. Specifically, during the start-up phase of a central air conditioner, it is determined whether the injection enthalpy function needs to be activated to supplement heat based on the load demand.

[0036] Specifically, based on the outdoor ambient temperature T at startup 外环 and indoor ambient temperature T 内环 The total heat load is calculated based on the number of indoor units in operation, and the output ratio is predicted based on the capacity of the injection enthalpy compressor; for the outdoor ambient temperature T... 外环 Due to the outdoor ambient temperature T 外环 The lower the temperature, the lower the heating capacity of the central air conditioner. For the same heating demand, a higher output from the enthalpy-injecting compressor is required. In other words, the compressor's operating frequency is inversely proportional to the outdoor ambient temperature. Similarly, for an indoor ambient temperature T... 内环 Indoor ambient temperature T 内环 The lower the temperature, the greater the heat demand on the indoor side, requiring a higher output from the enthalpy-injected compressor. This means the compressor's operating frequency is inversely proportional to the indoor ambient temperature. Furthermore, under the same indoor and outdoor conditions, a higher load on the indoor unit requires a higher output from the enthalpy-injected compressor; this means the compressor's operating frequency is directly proportional to the load on the indoor unit. Therefore, the total heat load can be calculated using the following formula:

[0037] Q 需 =[a*(5-T)] 外环 )+b*(10-T 内环 )]*ΣQ 内-ON (1)

[0038] Among them, Q需 T represents the total heat load. 外环 Indicates the outdoor ambient temperature, T 内环 Indicates indoor ambient temperature, ΣQ 内-ON This indicates the number of indoor units in operation, with 'a' and 'b' representing calculation coefficients. It should be noted that the total heat load Q... 需 The unit is W, the value of a ranges from 0.8 to 1.5, preferably 1.3; the value of b ranges from 0.8 to 1.5, preferably 1.2.

[0039] Step S206: Calculate the required frequency of the injection enthalpy compressor based on the total heat load;

[0040] Specifically, the required frequency of the injection enthalpy compressor is calculated according to the following formula:

[0041] F 需求频率 =(Q 需 / Q 额定能力 )*F 最大频率 (2)

[0042] Among them, Q 额定能力 F indicates the temperature regulation capability of a central air conditioner. 最大频率 Q represents the maximum frequency of the injection enthalpy compressor. 额定能力 and F 最大频率 These settings are configured at the factory for both the central air conditioner and the enthalpy compressor.

[0043] Step S208: Determine the injection enthalpy operating mode based on the demand frequency and the maximum frequency of the injection enthalpy compressor;

[0044] The enthalpy injection operating mode includes a first mode and a second mode. The first mode represents the non-initiated enthalpy injection mode, meaning that during the startup phase, no enthalpy injection is required to supplement heat. The second mode represents the initiated enthalpy injection mode, meaning that during the startup phase, enthalpy injection needs to be initiated to supplement heat. The specific determination process is as follows: First, calculate the second ratio between the demand frequency and the maximum frequency, i.e., k2 = F. 需求频率 / F 最大频率 If the second ratio k2 is not greater than the preset second threshold K2, i.e., k2≤K2, it indicates that the indoor load demand is very low and there is no need to turn on the injection enthalpy, thus determining the injection enthalpy working mode as the first mode; or, if the second ratio is greater than the preset second threshold, i.e., k2>K2, it indicates that the indoor load demand is large and injection enthalpy auxiliary heating needs to be turned on, thus determining the injection enthalpy working mode as the second mode.

[0045] It should be noted that the aforementioned preset second threshold K2 can also be called the capacity requirement percentage, and its value ranges from 50% to 85%, preferably 65%, which can be set according to different injection enthalpy compressors and central air conditioning systems.

[0046] Step S210: During the heating operation of the central air conditioner, obtain the actual frequency of the injection enthalpy compressor;

[0047] Specifically, during the heating operation of the central air conditioner, i.e., the heating phase, the actual frequency F of the enthalpy compressor is detected. 实际频率 So that according to F 实际频率 The frequency stage controls the state of the injection enthalpy, and the frequency stage is determined by F. 实际频率 and the maximum frequency F of the injection enthalpy compressor 最大频率 To make distinctions.

[0048] Step S212: Calculate the first ratio between the actual frequency and the maximum frequency; that is, the first ratio k1 = F 实际频率 / F 最大频率 ;

[0049] Step S214: Determine whether the first ratio is not greater than a preset first threshold.

[0050] The preset first threshold K1 has a value range of 65% to 90%, preferably 70%.

[0051] Step S216: If yes, obtain the actual power and corrected rated power of the central air conditioner;

[0052] Specifically, when k1≤K1, the actual power W of the central air conditioner is detected at this time. 实际功率 and corrected rated power W 修正额定功率 Among them, during the operation of the central air conditioner, the actual power (W) of the central air conditioner... 实际功率 The power W can be calculated in real time according to the power calculation program in the controller. 修正额定功率 Based on the rated power (W) of the central air conditioner 整机额定功率 and correction factor K 修正系数 Confirm; and for W 实际功率 and W 修正额定功率 The analysis is performed in order to control the injection enthalpy state based on the analysis results.

[0053] Among them, the rated power of the central air conditioner unit is W 整机额定功率 The central air conditioning units are pre-set at the factory with different W values ​​for different starting loads and ambient temperatures. 整机额定功率 The controller can read this directly, such as 60Hz-30W during current operation, which means W at this time. 整机额定功率 =30W. Furthermore, due to different installation scenarios, the power of central air conditioners may deviate from the factory theoretical value. Therefore, the rated power needs to be corrected during the engineering commissioning process; that is, a correction factor K is set. 修正系数 .

[0054] Specifically, the correction coefficient K 修正系数Based on the initial rated power (W) of the central air conditioner during its first start-up operation. 初始整机额定功率 And the initial engineering commissioning power W 工程调试 Confirmed, the power (W) for engineering debugging here. 工程调试 With all indoor units turned on, the controller reads the current indoor and outdoor ambient temperatures and the total unit current, and calculates W based on these parameters. 工程调试 For example, the initial rated power of the entire machine (W) 初始整机额定功率 50Hz-20W, engineering debugging power (W) 工程调试 At 50Hz-10W, K can be calculated. 修正系数 =0.5.

[0055] In summary, during the subsequent heating operation of the central air conditioning unit, at this time, according to W 修正额定功率 =K 修正系数 *W 整机额定功率 The current corrected rated power W can be calculated. 修正额定功率 For example, K 修正系数 The value is 0.5, which corresponds to the operating load and ambient temperature in W. 整机额定功率 The value is 30W, from which the corrected rated power (W) can be calculated. 修正额定功率 The value is 30W * 0.5W = 15W, which is 60Hz - 15W.

[0056] Step S218: In the first mode or the second mode, control the injection enthalpy state according to the actual power and the corrected rated power.

[0057] In one control method, for the first mode, if the actual power is not greater than the corrected rated power, the enthalpy injection is kept in the off state; or, if the actual power is greater than the corrected rated power, the enthalpy injection is kept in the on state. That is, when the enthalpy injection is not turned on during the startup phase, if W 实际功率 ≤W 修正额定功率 If the enthalpy-injected compressor is in its high-efficiency range and meets the capacity requirements, then the enthalpy-injected compressor will not start, i.e., the enthalpy-injected compressor will be controlled to maintain its current off state; if W 实际功率 >W 修正额定功率 At this point, the enthalpy injection is activated to replenish heat.

[0058] In another control method, for the second mode, if the actual power is not greater than the corrected rated power, the enthalpy injection is kept on; or, if the actual power is greater than the corrected rated power, the enthalpy injection is kept off. That is, when the enthalpy injection is turned on during the startup phase, if W... 实际功率 ≤W 修正额定功率 Then the injection enthalpy is controlled to maintain the current on state; if W 实际功率 >W 修正额定功率At this point, the enthalpy control switch is turned off, and the heating capacity is increased by increasing the operating frequency of the compressor.

[0059] Furthermore, the method also includes: in the first mode, if the first ratio is greater than a preset first threshold, then the injection enthalpy is controlled to be in the on state. That is, when the injection enthalpy is not turned on during the startup phase, if k1 > K1, the controller does not need to detect the actual power W of the central air conditioner. 实际功率 and corrected rated power W 修正额定功率 It directly controls the opening of the injection enthalpy to improve the heating capacity.

[0060] The gas injection and enthalpy enhancement control method provided in this invention determines whether to activate the injection enthalpy based on the demand frequency and maximum frequency of the injection enthalpy compressor during the heating start-up phase of the central air conditioner. During the heating operation phase, the energy efficiency status of the central air conditioning system is judged in real time by comparing and analyzing the actual power and the corrected rated power of the central air conditioner, and the control status of the injection enthalpy is adjusted in a timely manner, thereby achieving optimal energy efficiency of the central air conditioner.

[0061] Optionally, when the enthalpy injection is activated, the enthalpy injection flow rate is also controlled via an electronic expansion valve to ensure that the enthalpy injection compressor does not return liquid. Specifically, the method further includes: acquiring the enthalpy injection inlet pipe temperature and the enthalpy injection outlet pipe temperature; calculating the difference between the enthalpy injection inlet pipe temperature and the enthalpy injection outlet pipe temperature; if the difference is not less than a first difference threshold, controlling the opening of the electronic expansion valve to increase; or, if the difference is less than the first difference threshold and not less than a second difference threshold, controlling the opening of the electronic expansion valve to remain unchanged; or, if the difference is less than the second difference threshold, controlling the opening of the electronic expansion valve to decrease; wherein the second difference threshold is less than the first difference threshold.

[0062] Specifically, such as Figure 1 As shown, the temperature T of the enthalpy injection pipe is detected by the enthalpy injection temperature sensing bulb 191. 进管 The temperature T of the enthalpy-spraying tube is detected by the enthalpy-spraying temperature sensing bulb 192. 出管 And calculate the difference ΔT = T 出管 -T 进管 The first difference threshold is △T1, and the second difference threshold is △T2. The value range of △T1 is 4℃~8℃, preferably 5℃, and the value range of △T2 is 1℃~3℃, preferably 3℃. The opening degree control of the enthalpy electronic expansion valve is as follows:

[0063] (1) When △T≥△T1, the opening of the electronic expansion valve of the enthalpy injection is increased by P1; that is, the temperature is high and the flow rate is low at this time, so the opening of the electronic expansion valve of the enthalpy injection needs to be increased. Here, the value of P1 is in the range of 2 to 5, preferably 3.

[0064] (2) When △T2≤△T<△T1, the opening of the electronic expansion valve for enthalpy injection remains unchanged; that is, the temperature and flow rate are normal at this time, and there is no need to adjust the opening of the electronic expansion valve for enthalpy injection, just maintain the current opening.

[0065] (3) When △T < △T2, the opening of the electronic expansion valve of the enthalpy injection is reduced by P2; that is, the temperature is low and the flow rate is large at this time, so the opening of the electronic expansion valve of the enthalpy injection needs to be reduced. Here, the value of P2 is in the range of 2 to 6, preferably 4.

[0066] In summary, when the enthalpy injection is activated, the opening degree of the enthalpy injection electronic expansion valve is controlled according to the enthalpy injection inlet pipe temperature and the enthalpy injection outlet pipe temperature to control the enthalpy injection flow rate. This ensures that the enthalpy injection compressor does not return liquid, thereby guaranteeing the stable operation of the central air conditioner and ensuring user comfort.

[0067] To facilitate understanding, an example is provided to illustrate the above method of controlling enthalpy increase through gas replenishment, such as... Figure 4 As shown, the method includes the following steps:

[0068] Step S402, obtain T at the start of heating. 外环 and T 内环 And the number of indoor units N that are turned on;

[0069] Step S404, according to T 外环 T 内环 And N, the total heat load Q is calculated. 需 ;

[0070] Step S406, according to Q 需 The F value of the injection enthalpy compressor is calculated based on the rated capacity. 需求频率 ;

[0071] Step S408, calculate the second ratio k2 = F 需求频率 / F 最大频率 ;

[0072] Step S410: Determine if k2 ≤ K2; if yes, proceed to step S412; if no, proceed to step S426.

[0073] Step S412, injection enthalpy not activated; i.e., first mode;

[0074] Step S414: During heating operation, obtain the F value of the injection enthalpy compressor. 实际频率 ;

[0075] Step S416, calculate the first ratio k1 = F 实际频率 / F 最大频率 ;

[0076] Step S418: Determine if k1 ≤ K1. If yes, proceed to step S420; otherwise, proceed to step S424.

[0077] Step S420, obtain W 实际功率 and W 修正额定功率 ;

[0078] Step S422, determine W 实际功率 ≤W 修正额定功率 If yes, return to step S412; otherwise, proceed to step S424.

[0079] Step S424: Control the enthalpy injection to start;

[0080] Step S426, injection enthalpy is activated; i.e., the second mode;

[0081] Step S428: During heating operation, obtain the F value of the injection enthalpy compressor. 实际频率 ;

[0082] Step S430, calculate the first ratio k1 = F 实际频率 / F 最大频率 ;

[0083] Step S432: Determine if k1 ≤ K1. If yes, execute step S432; otherwise, return to execute step S426.

[0084] Step S434, obtain W 实际功率 and W 修正额定功率 ;

[0085] Step S436, determine W 实际功率 ≤W 修正额定功率 If yes, return to step S412; otherwise, proceed to step S424.

[0086] Step S438: Control the spray enthalpy to shut off.

[0087] In summary, the above-mentioned gas replenishment and enthalpy increase control method utilizes the actual power (W) of the central air conditioner. 实际功率 With the preset theoretical power W 修正额定功率 By conducting comparative analysis, the energy efficiency status of the central air conditioning system is judged in real time, and the injection enthalpy control strategy is adjusted in a timely manner to achieve switching between injection enthalpy and frequency increase control. That is, while meeting the user's heating needs and ensuring the reliable operation of the unit, the energy efficiency of the central air conditioner is optimized by optimizing the injection enthalpy control.

[0088] Corresponding to the above method embodiments, this invention also provides a gas injection enthalpy control device, applied to the controller of a central air conditioner. The central air conditioner further includes an enthalpy-injecting compressor and multiple indoor units connected in parallel, which are communicatively connected to the controller. Figure 5As shown, the device includes: a first acquisition module 51, a first calculation module 52, a second calculation module 53, a mode determination module 54, a second acquisition module 55, a third calculation module 56, a judgment module 57, a third acquisition module 58, and a state control module 59; wherein the functions of each module are as follows:

[0089] The first acquisition module 51 is used to acquire start-up parameters if the central air conditioner starts in heating mode; wherein, the start-up parameters include the outdoor ambient temperature and the indoor ambient temperature at the time of start-up, as well as the number of indoor units turned on.

[0090] The first calculation module 52 is used to calculate the total heat load of the central air conditioner based on the start-up parameters.

[0091] The second calculation module 53 is used to calculate the required frequency of the injection enthalpy compressor based on the total heat load.

[0092] The mode determination module 54 is used to determine the injection enthalpy operating mode based on the demand frequency and the maximum frequency of the injection enthalpy compressor; wherein, the injection enthalpy operating mode includes a first mode and a second mode, the first mode is used to characterize the non-injection enthalpy mode, and the second mode is used to characterize the injection enthalpy mode.

[0093] The second acquisition module 55 is used to acquire the actual frequency of the injection enthalpy compressor during the heating operation of the central air conditioner.

[0094] The third calculation module 56 is used to calculate the first ratio between the actual frequency and the maximum frequency;

[0095] The judgment module 57 is used to determine whether the first ratio is not greater than a preset first threshold.

[0096] The third acquisition module 58 is used to acquire, if yes, the actual power and corrected rated power of the central air conditioner; wherein, the corrected rated power is determined based on the overall rated power of the central air conditioner and the correction coefficient;

[0097] The status control module 59 is used to control the injection enthalpy state according to the actual power and the corrected rated power in the first mode or the second mode.

[0098] The gas injection enthalpy control device provided in this embodiment of the invention determines whether to activate the injection enthalpy based on the required frequency and maximum frequency of the injection enthalpy compressor during the heating start-up phase of the central air conditioner; during the heating operation phase, it determines the operating energy efficiency status of the central air conditioning system in real time by comparing and analyzing the actual power and corrected rated power of the central air conditioner, and adjusts the control status of the injection enthalpy in a timely manner, thereby achieving optimal energy efficiency of the central air conditioner.

[0099] Preferably, in the first mode, the state control module 59 is further configured to: control the enthalpy injection to remain in the off state if the actual power is not greater than the corrected rated power; or control the enthalpy injection to be in the on state if the actual power is greater than the corrected rated power.

[0100] Preferably, in the second mode, the state control module 59 is further configured to: control the enthalpy injection to remain in the open state if the actual power is not greater than the corrected rated power; or, control the enthalpy injection to be in the closed state if the actual power is greater than the corrected rated power.

[0101] Preferably, the above-mentioned device further includes: in the first mode, if the first ratio is greater than a preset first threshold, the injection enthalpy is controlled to be in the open state.

[0102] Preferably, the mode determination module 54 is further configured to: calculate a second ratio between the required frequency and the maximum frequency; if the second ratio is not greater than a preset second threshold, determine the injection enthalpy working mode as the first mode; or, if the second ratio is greater than the preset second threshold, determine the injection enthalpy working mode as the second mode.

[0103] Preferably, the first calculation module 52 is further configured to: calculate the total heat load according to the following formula: Q 需 =[a*(5-T)] 外环 )+b*(10-T 内环 )]*ΣQ 内-ON ; where Q 需 T represents the total heat load. 外环 Indicates the outdoor ambient temperature, T 内环 Indicates indoor ambient temperature, ΣQ 内-ON This indicates the number of indoor units that are turned on, and 'a' and 'b' represent calculation coefficients.

[0104] Preferably, the aforementioned central air conditioner further includes an enthalpy-injection electronic expansion valve communicatively connected to the controller. This device further includes: acquiring the enthalpy-injection inlet pipe temperature and the enthalpy-injection outlet pipe temperature; calculating the difference between the enthalpy-injection inlet pipe temperature and the enthalpy-injection outlet pipe temperature; if the difference is not less than a first difference threshold, controlling the opening of the enthalpy-injection electronic expansion valve to increase; or, if the difference is less than the first difference threshold and not less than a second difference threshold, controlling the opening of the enthalpy-injection electronic expansion valve to remain unchanged; or, if the difference is less than the second difference threshold, controlling the opening of the enthalpy-injection electronic expansion valve to decrease; wherein the second difference threshold is less than the first difference threshold.

[0105] The gas replenishment and enthalpy increase control device provided in this embodiment of the invention has the same technical features as the gas replenishment and enthalpy increase control method provided in the above embodiment, so it can also solve the same technical problems and achieve the same technical effects.

[0106] This invention also provides a central air conditioner, including a processor and a memory. The memory stores machine-executable instructions that can be executed by the processor. The processor executes the machine-executable instructions to implement the above-mentioned gas replenishment and enthalpy increase control method.

[0107] See Figure 6 As shown, the central air conditioner includes a processor 100 and a memory 101. The memory 101 stores machine-executable instructions that can be executed by the processor 100. The processor 100 executes the machine-executable instructions to implement the above-mentioned gas replenishment and enthalpy increase control method.

[0108] Furthermore, Figure 6 The central air conditioner shown also includes a bus 102 and a communication interface 103. The processor 100, the communication interface 103 and the memory 101 are connected via the bus 102.

[0109] The memory 101 may include high-speed random access memory (RAM) or non-volatile memory, such as at least one disk storage device. Communication between this system network element and at least one other network element is achieved through at least one communication interface 103 (which can be wired or wireless), such as the Internet, wide area network, local area network, or metropolitan area network. The bus 102 may be an ISA (Industrial Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus, or an EISA (Enhanced Industry Standard Architecture) bus. These buses can be categorized as address buses, data buses, and control buses. For ease of representation, Figure 6 The symbol is represented by a single double-headed arrow, but this does not mean that there is only one bus or one type of bus.

[0110] Processor 100 may be an integrated circuit chip with signal processing capabilities. In implementation, each step of the above method can be completed by the integrated logic circuitry in the hardware of processor 100 or by instructions in software form. Processor 100 may be a general-purpose processor, including a Central Processing Unit (CPU), a Network Processor (NP), etc.; it may also be a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this invention. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this invention can be directly manifested as execution by a hardware decoding processor, or execution by a combination of hardware and software modules in the decoding processor. The software module can reside in a readily available storage medium in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, or registers. This storage medium is located in memory 101, and the processor 100 reads the information from memory 101 and, in conjunction with its hardware, completes the steps of the method described in the foregoing embodiments.

[0111] This embodiment also provides a machine-readable storage medium storing machine-executable instructions. When the machine-executable instructions are called and executed by the processor, the machine-executable instructions cause the processor to implement the above-mentioned gas replenishment and enthalpy increase control method.

[0112] The computer program product for the gas replenishment and enthalpy increase control method, device and central air conditioner provided in the embodiments of the present invention includes a computer-readable storage medium storing program code. The instructions included in the program code can be used to execute the methods described in the preceding method embodiments. For specific implementation, please refer to the method embodiments, which will not be repeated here.

[0113] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the system and apparatus described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0114] Furthermore, in the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0115] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a processor-executable, non-volatile, computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0116] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0117] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for controlling enthalpy increase through gas replenishment, characterized in that, A controller for a central air conditioner, the central air conditioner further comprising an enthalpy-injecting compressor and multiple indoor units connected in parallel and communicatively connected to the controller, the method comprising: If the central air conditioner starts in heating mode, the start-up parameters are obtained; wherein, the start-up parameters include the outdoor ambient temperature and the indoor ambient temperature at the time of start-up, as well as the number of indoor units turned on; The total heat load of the central air conditioner is calculated based on the aforementioned startup parameters; the total heat load is calculated using the following formula: Q 需 =[a*(5-T 外环 )+b*(10-T) 内环 )]*ΣQ 内-ON ; where Q 需 The total heat load, T, represents the total heat load. 外环 The outdoor ambient temperature, T 内环 The indoor ambient temperature is represented by ΣQ. 内-ON This indicates the number of indoor units that are turned on, and a and b represent calculation coefficients, with the unit being W / ℃; The required frequency of the injection enthalpy compressor is calculated based on the total heat load. The enthalpy injection operating mode is determined based on the required frequency and the maximum frequency of the enthalpy injection compressor; wherein, the enthalpy injection operating mode includes a first mode and a second mode, the first mode is used to characterize the enthalpy injection mode not being activated, and the second mode is used to characterize the enthalpy injection mode being activated. During the heating operation of the central air conditioner, the actual frequency of the injection enthalpy compressor is obtained; Calculate a first ratio between the actual frequency and the maximum frequency; Determine whether the first ratio is not greater than a preset first threshold; If so, obtain the actual power and corrected rated power of the central air conditioner; wherein, the corrected rated power is determined based on the overall rated power of the central air conditioner and the correction factor; In either the first or second mode, the injection enthalpy state is controlled based on the actual power and the corrected rated power.

2. The method according to claim 1, characterized in that, In the first mode, the step of controlling the injection enthalpy state based on the actual power and the corrected rated power includes: If the actual power is not greater than the corrected rated power, the injection enthalpy is controlled to remain in the off state; or... If the actual power is greater than the corrected rated power, the injection enthalpy is controlled to be in the on state.

3. The method according to claim 1, characterized in that, In the second mode, the step of controlling the injection enthalpy state based on the actual power and the corrected rated power includes: If the actual power is not greater than the corrected rated power, the injection enthalpy is controlled to remain on; or... If the actual power is greater than the corrected rated power, the injection enthalpy is controlled to be in the off state.

4. The method according to claim 1, characterized in that, The method further includes: In the first mode, if the first ratio is greater than the preset first threshold, the injection enthalpy is controlled to be in the on state.

5. The method according to claim 1, characterized in that, The step of determining the injection enthalpy operating mode based on the required frequency and the maximum frequency includes: Calculate a second ratio between the required frequency and the maximum frequency; If the second ratio is not greater than a preset second threshold, the enthalpy operating mode is determined to be the first mode; or, if the second ratio is greater than the preset second threshold, the enthalpy operating mode is determined to be the second mode.

6. The method according to claim 1, characterized in that, The central air conditioner also includes an electronic expansion valve for injection enthalpy that is communicatively connected to the controller, and the method further includes: Obtain the enthalpy inlet temperature and enthalpy outlet temperature; Calculate the difference between the enthalpy inlet temperature and the enthalpy outlet temperature; If the difference is not less than a first difference threshold, the opening of the enthalpy electronic expansion valve is increased; or, if the difference is less than the first difference threshold and not less than a second difference threshold, the opening of the enthalpy electronic expansion valve remains unchanged; or, if the difference is less than the second difference threshold, the opening of the enthalpy electronic expansion valve is decreased; wherein the second difference threshold is less than the first difference threshold.

7. A gas replenishment and enthalpy increase control device, characterized in that, A controller for a central air conditioner, the central air conditioner further comprising an enthalpy-injecting compressor and multiple indoor units connected in parallel and communicatively connected to the controller, the device comprising: The first acquisition module is used to acquire start-up parameters if the central air conditioner starts heating; wherein, the start-up parameters include the outdoor ambient temperature and the indoor ambient temperature at the time of start-up, as well as the number of indoor units turned on; The first calculation module is used to calculate the total heat load of the central air conditioner based on the startup parameters; the total heat load is calculated according to the following formula: Q 需 =[a*(5-T 外环 )+b*(10-T) 内环 )]*ΣQ 内-ON ; where Q 需 The total heat load, T, represents the total heat load. 外环 The outdoor ambient temperature, T 内环 The indoor ambient temperature is represented by ΣQ. 内-ON This indicates the number of indoor units that are turned on, and a and b represent calculation coefficients, with the unit being W / ℃; The second calculation module is used to calculate the required frequency of the injection enthalpy compressor based on the total heat load. The mode determination module is used to determine the injection enthalpy operating mode based on the demand frequency and the maximum frequency of the injection enthalpy compressor; wherein, the injection enthalpy operating mode includes a first mode and a second mode, the first mode is used to characterize the non-injection enthalpy mode, and the second mode is used to characterize the injection enthalpy mode. The second acquisition module is used to acquire the actual frequency of the injection enthalpy compressor during the heating operation of the central air conditioner. The third calculation module is used to calculate a first ratio between the actual frequency and the maximum frequency; The judgment module is used to determine whether the first ratio is not greater than a preset first threshold. The third acquisition module is used to acquire, if yes, the actual power and corrected rated power of the central air conditioner; wherein the corrected rated power is determined based on the overall rated power of the central air conditioner and a correction coefficient; A state control module is used to control the injection enthalpy state based on the actual power and the corrected rated power in the first mode or the second mode.

8. A central air conditioner, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method described in any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, which, when executed by a processor, performs the steps of the method described in any one of claims 1-6.

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