Triple co-generation system, control method, device and medium

Abstract

The invention discloses a triple co-generation system, a control method and device and a medium, the triple co-generation system comprises a heat pump system, a hot water system, an air conditioning system and a geothermal system, and the output end of the hot water system, the output end of the air conditioning system and the output end of the geothermal system are all connected with the input end of the heat pump system; the heat pump system comprises a compressor, a four-way valve, a condenser, an evaporator, a first electronic expansion valve, a second electronic expansion valve, an economizer and an electromagnetic valve. The control method of the triple co-generation system comprises the steps that the working state of the triple co-generation system is obtained; the working states of the first electronic expansion valve, the second electronic expansion valve and the fan are controlled according to the working state of the triple-generation system, and the energy efficiency ratio of the triple-generation system can be effectively increased.

Description

Technical Field

[0001] The present application relates to but is not limited to the field of trigeneration, and in particular to a trigeneration system, a control method, a device and a medium. Background Art

[0002] At present, air conditioning refrigeration, domestic hot water supply and winter heating all use separate units. For example, a single cooling air conditioning unit is used to meet the cooling demand in summer, and heating in winter and hot water throughout the year are provided by boilers. However, when a single cooling air conditioning unit is used to meet the cooling demand, there is no heat recovery, and the energy efficiency of the unit decreases as the condenser becomes dirty, resulting in low energy utilization. In winter, heating and domestic hot water are mainly provided by boilers, but the energy consumption of winter and domestic hot water is large, and the operating cost is high. Summary of the invention

[0003] The embodiments of the present application provide a trigeneration system, a control method, a device and a medium, which can effectively improve the energy efficiency ratio of the trigeneration system.

[0004] In a first aspect, an embodiment of the present application provides a control method for a trigeneration system, wherein the trigeneration system comprises: a heat pump system, a hot water system, an air-conditioning system, a geothermal system, a first three-way valve and a second three-way valve, wherein the output end of the heat pump system is connected to the first end of the first three-way valve, the second end of the first three-way valve is connected to the input end of the hot water system, the third end of the first three-way valve is connected to the first end of the second three-way valve, the second end of the second three-way valve is connected to the input end of the air-conditioning system, the third end of the second three-way valve is connected to the input end of the geothermal system, the output end of the hot water system, the output end of the air-conditioning system and the output end of the geothermal system are all connected to the input end of the heat pump system, and the heat pump system comprises: a compressor, a four-way valve, a condenser The compressor comprises a four-way valve, an evaporator, a first electronic expansion valve, a second electronic expansion valve, an economizer and a solenoid valve, wherein the exhaust port of the compressor is connected to the first end of the four-way valve, the second end of the four-way valve is connected to the input end of the condenser, the output end of the condenser is respectively connected to the first end of the economizer and the third end of the economizer, the second end of the economizer is connected to the first air intake port of the compressor, the second electronic expansion valve and the solenoid valve are further connected between the output end of the condenser and the third end of the economizer, the fourth end of the economizer is connected to the input end of the evaporator, the input end of the evaporator, the output end of the evaporator is connected to the third end of the four-way valve, the fourth end of the four-way valve is connected to the second air intake port of the compressor, and the evaporator is also provided with a fan;

[0005] The control method comprises:

[0006] Obtaining the working status of the trigeneration system;

[0007] The working states of the first electronic expansion valve, the second electronic expansion valve and the fan are controlled according to the working state of the trigeneration system.

[0008] According to the control method of the trigeneration system of the first aspect embodiment of the present application, there are at least the following beneficial effects: the first electronic expansion valve can be used to control the refrigerant flow entering the evaporator, and the refrigeration efficiency can be improved by controlling the refrigerant flow entering the evaporator. The second electronic expansion valve can be used to control the refrigerant diverted into the economizer and control the refrigerant delivered to the compressor. In addition, adjusting the working state of the fan can also improve the efficiency of the evaporator. Therefore, the working states of the first electronic expansion valve, the second electronic expansion valve and the fan can be controlled according to the working state of the trigeneration system to improve the energy efficiency ratio of the trigeneration system.

[0009] According to some embodiments of the first aspect of the present application, the heat pump system further includes a first temperature sensor and a second temperature sensor, the first temperature sensor is used to obtain the coil temperature of the evaporator, and the second temperature sensor is used to obtain the suction temperature of the second suction port, and the operating state of the first electronic expansion valve, the second electronic expansion valve and the fan is controlled according to the operating state of the trigeneration system, including:

[0010] The opening degree of the first electronic expansion valve is adjusted according to the coil temperature and the suction temperature.

[0011] According to some embodiments of the first aspect of the present application, adjusting the opening of the first electronic expansion valve according to the coil temperature and the suction temperature includes:

[0012] Acquiring the current opening degree of the first electronic expansion valve;

[0013] Calculating an opening adjustment parameter of the first electronic expansion valve according to the current opening, the actual target superheat, the preset target superheat and the previous target superheat;

[0014] adjusting the opening of the electronic expansion valve according to the opening adjustment parameter;

[0015] The actual target superheat is the difference between the suction temperature at the current moment and the coil temperature at the current moment, and the previous target superheat is the difference between the suction temperature at the previous moment and the coil temperature at the previous moment.

[0016] According to some embodiments of the first aspect of the present application, the opening adjustment parameter of the first electronic expansion valve is calculated based on the current opening, the actual target superheat, the preset target superheat and the previous target superheat by the following formula:

[0017] x=y+[α(gh)+γ(gf)];

[0018] Among them, x is the opening adjustment parameter, y is the current opening, g is the actual target superheat, h is the preset target superheat, f is the previous target superheat, α is the first correction parameter, and γ is the second correction parameter.

[0019] According to some embodiments of the first aspect of the present application, controlling the working states of the first electronic expansion valve, the second electronic expansion valve, and the fan according to the working state of the trigeneration system further includes:

[0020] The rotation speed of the fan is controlled according to the working state of the trigeneration system.

[0021] According to some embodiments of the first aspect of the present application, the heat pump system further includes a pressure sensor, the pressure sensor is used to obtain the suction pressure of the second suction port of the compressor, and the speed of the fan is controlled according to the working state of the trigeneration system, including:

[0022] When the trigeneration system is in a heating mode, controlling the speed of the fan according to the suction pressure and a first pressure threshold;

[0023] or,

[0024] When the trigeneration system is in cooling mode, controlling the speed of the fan according to the suction pressure and the second pressure threshold;

[0025] The first pressure threshold is smaller than the second pressure threshold.

[0026] According to some embodiments of the first aspect of the present application, the heat pump system further includes a third temperature sensor, the third temperature sensor is used to obtain the exhaust temperature of the first exhaust port, and the operating state of the first electronic expansion valve, the second electronic expansion valve and the fan is controlled according to the operating state of the trigeneration system, and further includes:

[0027] The opening degree of the second electronic expansion valve is controlled according to the exhaust gas temperature.

[0028] In a second aspect, an embodiment of the present application provides an operation control device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the control method of the three-connection system as described in the first aspect is implemented.

[0029] In a third aspect, an embodiment of the present application provides a three-connection system, including an operation control device as described in the embodiment of the second aspect.

[0030] In a fourth aspect, an embodiment of the present application further provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are used to enable a computer to execute the control method of the three-connection system as described in the embodiment of the first aspect.

[0031] Other features and advantages of the present application will be described in the following description, and partly become apparent from the description, or understood by practicing the present application. The purpose and other advantages of the present application can be realized and obtained by the structures specifically pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0033] Figure 1 A schematic diagram of the structure of a heat pump system provided in an embodiment of the present application;

[0034] Figure 2 A schematic diagram of the structure of a trigeneration system provided in an embodiment of the present application;

[0035] Figure 3 A flow chart of a control method for a three-connection system provided in an embodiment of the present application;

[0036] Figure 4 for Figure 3 Specific flow chart of step S200;

[0037] Figure 5 for Figure 3 Another specific flow chart of step S200;

[0038] Figure 6 for Figure 3 Another specific flow chart of step S200;

[0039] Figure 7 An operation control device is provided for an embodiment of the present application. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0041] It is understood that although the functional modules are divided in the device schematic diagram and the logical order is shown in the flow chart, in some cases, the steps shown or described may be performed in a different order than the module division in the device or the order in the flow chart. The terms "first", "second", etc. in the specification, claims or the above drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0042] At present, air conditioning refrigeration, domestic hot water supply and winter heating all use separate units. For example, a single cooling air conditioning unit is used to meet the cooling demand in summer, and heating in winter and hot water throughout the year are provided by boilers. However, when a single cooling air conditioning unit is used to meet the cooling demand, there is no heat recovery, and the energy efficiency of the unit decreases as the condenser becomes dirty, resulting in low energy utilization. In winter, heating and domestic hot water are mainly provided by boilers, but the energy consumption of winter and domestic hot water is large, and the operating cost is high.

[0043] Based on this, the present application provides a trigeneration system, a control method, a device and a medium. The first electronic expansion valve can be used to control the refrigerant flow entering the evaporator. By controlling the refrigerant flow entering the evaporator, the refrigeration efficiency can be improved. The second electronic expansion valve can be used to control the refrigerant diverted into the economizer and control the refrigerant delivered to the compressor. In addition, adjusting the working state of the fan can also improve the efficiency of the evaporator. Therefore, the working states of the first electronic expansion valve, the second electronic expansion valve and the fan can be controlled according to the working state of the trigeneration system to improve the energy efficiency ratio of the trigeneration system.

[0044] The embodiments of the present application are further described below in conjunction with the accompanying drawings.

[0045] Reference Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of the structure of the heat pump system provided in the embodiment of the present application. Figure 2 A schematic diagram of the structure of the trigeneration system provided in an embodiment of the present application.

[0046] It can be understood that the trigeneration system includes: a heat pump system 1100, a hot water system 1200, an air conditioning system 1300, a geothermal system 1400, a first three-way valve 1500 and a second three-way valve 1600, the output end of the heat pump system 1100 is connected to the first end of the first three-way valve 1500, the second end of the first three-way valve 1500 is connected to the input end of the hot water system 1200, the third end of the first three-way valve 1500 is connected to the first end of the second three-way valve 1600, the second end of the second three-way valve 1600 is connected to the input end of the air conditioning system 1300, the third end of the second three-way valve 1600 is connected to the input end of the geothermal system 1400, the output end of the hot water system 1200, the air conditioning system 1300, the first three-way valve 1500 and the second three-way valve 1600 are connected to the input end of the geothermal system 1400, and the output end of the hot water system 1200 and the air conditioning system 1300 are connected to the first three-way valve 1500. The output end of the system 1300 and the output end of the geothermal system 1400 are both connected to the input end of the heat pump system 1100. The heat pump system 1100 includes: a compressor 100, a four-way valve 200, a condenser 300, an evaporator 900, a first electronic expansion valve 700, a second electronic expansion valve 630, an economizer 600, a first temperature sensor 910, a second temperature sensor 120, a third temperature sensor 110, a pressure sensor 130, a gas-liquid separator 1000, a first drying filter 400, a liquid storage device 500, a second drying filter 800, a liquid injection check valve 640 and a solenoid valve 620. The first exhaust port of the compressor 100 is connected to the first end 210 of the four-way valve 200. The third temperature sensor 110 is disposed between the first exhaust port and the first end 210 of the four-way valve 200, the second end 220 of the four-way valve 200 is connected to the input end of the condenser 300, the output end of the condenser 300 is connected to one end of the first drying filter 400, the other end of the first drying filter 400 is connected to one end of the liquid reservoir 500, the other end of the liquid reservoir 500 is connected to the first end of the economizer 600 and the third end of the economizer 600, respectively, the second electronic expansion valve 630 and the solenoid valve 620 are also connected between the other end of the liquid reservoir 500 and the third end of the economizer 600, the second end of the economizer 600 is connected to the first suction port of the compressor 100 through the liquid injection check valve 640 The fourth end of the economizer 600 is connected to the input end of the evaporator 900, and the first electronic expansion valve 700, the second drying filter 800 and the first temperature sensor 910 are connected in sequence between the fourth end of the economizer 600 and the input end of the evaporator 900. The output end of the evaporator 900 is connected to the third end 240 of the four-way valve 200. The evaporator 900 is also provided with a fan. The fourth end 230 of the four-way valve 200 is connected to one end of the gas-liquid separator 1000, and the other end of the gas-liquid separator 1000 is connected to the second air intake port of the compressor 100. The second temperature sensor 120 and the pressure sensor 130 are arranged between the other end of the gas-liquid separator 1000 and the second air intake port of the compressor 100.

[0047] It should be noted that the first temperature sensor 910 is used to obtain the coil temperature of the evaporator 900, the second temperature sensor 120 is used to obtain the intake temperature of the second intake port, the third temperature sensor 110 is used to obtain the exhaust temperature of the first exhaust port, and the pressure sensor 130 is used to obtain the refrigerant pressure of the second intake port of the compressor 100.

[0048] It should be noted that the condenser 300 includes a refrigerant channel and a medium channel 310. The input end of the refrigerant channel is connected to the second end 220 of the four-way valve 200, the output end of the refrigerant channel is connected to one end of the first drying filter 400, the output end of the medium channel 310 is connected to the first end of the first three-way valve 1500, and the input end of the medium channel 310 is connected to the output end of the hot water system 1200, the output end of the air-conditioning system 1300 and the output end of the geothermal system 1400 respectively. The functions of domestic hot water preparation, cooling and heating can be achieved by controlling the working states of the first three-way valve 1500 and the second three-way valve 1600.

[0049] It should be noted that the economizer 600 is a plate heat exchanger that separates the refrigerant flowing out of the condenser 300. A portion of the refrigerant is directly delivered to the first air intake port of the compressor 100 to increase the air intake enthalpy of the compressor, and the other portion of the refrigerant is delivered to the second air intake port of the compressor 100 after passing through the evaporator 900. The refrigerant flowing into the first air intake port can be controlled by the second electronic expansion valve 630 and the solenoid valve 620.

[0050] First, refer to Figure 3 , Figure 3 A flow chart of a control method for a three-connection system provided in an embodiment of the present application, which is applied to Figure 1 and Figure 2 The three-connection system shown, the control method of the three-connection system includes but is not limited to the following steps:

[0051] Step S100, obtaining the working status of the trigeneration system;

[0052] Step S200, controlling the working states of the first electronic expansion valve, the second electronic expansion valve and the fan according to the working state of the trigeneration system.

[0053] It can be understood that by adjusting the opening of the first electronic expansion valve, the amount of refrigerant entering the evaporator can be controlled, thereby controlling the refrigeration efficiency of the evaporator, while by adjusting the second electronic expansion valve, the refrigerant diverted into the economizer can be controlled, thereby controlling the refrigerant flowing into the first air intake port. In addition, by adjusting the speed of the fan, the efficiency of the evaporator can be controlled. Therefore, the working states of the first electronic expansion valve, the second electronic expansion valve and the fan can be comprehensively controlled according to the working state of the combined power supply system to improve the energy efficiency ratio of the three-in-one system.

[0054] Reference Figure 4 , Figure 4 for Figure 3 The specific flow chart of step S200 includes but is not limited to the following steps:

[0055] Step S210, adjusting the opening of the first electronic expansion valve according to the coil temperature and the suction temperature.

[0056] It can be understood that the coil temperature is the temperature of the evaporator coil, which can reflect the heat absorption of the refrigerant in the evaporator. The suction temperature is the temperature of the refrigerant inhaled by the compressor. The refrigeration efficiency of the evaporator can be reflected by the coil temperature and the suction temperature. The opening of the first electronic expansion valve will affect the amount of refrigerant entering the evaporator, thereby controlling the refrigeration efficiency of the evaporator. Therefore, the opening of the first expansion valve can be adjusted according to the coil temperature and the suction temperature, thereby changing the refrigeration efficiency of the evaporator to improve the energy efficiency ratio of the three-way system.

[0057] Specifically, in some embodiments, the actual target superheat is a parameter for measuring the overheat state in the heat pump system at the current moment, and controlling the superheat helps to ensure the stable operation and high efficiency of the heat pump system, and the actual target superheat is the difference between the suction temperature at the current moment and the coil temperature at the current moment. Therefore, the opening adjustment parameter of the first electronic expansion valve can be calculated according to the current opening of the first electronic expansion valve, the actual target superheat, the preset target superheat and the previous target superheat, wherein the preset target superheat is a parameter for the overheat state in the heat pump system under normal conditions, and the previous target superheat is a parameter for measuring the overheat state in the heat pump system at the previous moment, which can be calculated by the suction temperature at the previous moment and the coil temperature at the previous moment. By comprehensively calculating the opening adjustment parameter of the first electronic expansion valve based on the current opening, the actual target superheat, the preset target superheat and the previous target superheat, and then adjusting the opening of the electronic expansion valve according to the opening adjustment parameter, the energy efficiency ratio of the heat pump system can be effectively improved, thereby improving the energy efficiency ratio of the three-way unit.

[0058] It should be noted that the opening adjustment parameter of the first electronic expansion valve can be calculated by formula (1):

[0059] x=y+[α(gh)+γ(gf)](1),

[0060] Among them, x is the opening adjustment parameter, y is the current opening, g is the actual target superheat, h is the preset target superheat, f is the previous target superheat, α is the first correction parameter, and γ is the second correction parameter.

[0061] It should be noted that the opening adjustment parameter is the opening of the first electronic expansion valve at the next moment. The accuracy of the calculation can be improved by setting the first correction parameter and the second correction parameter. In addition, the first correction parameter and the second correction parameter can also control the influence of each parameter on the opening adjustment parameter. The first correction parameter can be 5 and the second correction parameter can be 1. The first correction parameter can be set between 1 and 6 according to the working state of the three-connected system.

[0062] Reference Figure 5 , Figure 5 for Figure 3 Another specific flow chart of step S200 includes but is not limited to the following steps:

[0063] Step S220, controlling the speed of the fan according to the working state of the trigeneration system.

[0064] It can be understood that the evaporator fan is used to help the evaporator evaporate the low-pressure refrigerant coming out of the expansion valve. Increasing the fan speed can speed up the air flow rate, allowing more hot air to contact the evaporator and be cooled, thereby improving the working efficiency of the heat pump system. Therefore, the fan speed can be controlled according to the working status of the trigeneration system.

[0065] Specifically, the evaporation efficiency of the evaporator will change the refrigerant pressure flowing into the second air intake port of the evaporator. When the fan is a DC fan and the trigeneration system is in heating mode, the fan speed can be adjusted according to the suction pressure and the first pressure threshold, wherein the suction pressure is the refrigerant pressure of the second air intake port, and the first pressure threshold is a pre-set normal pressure value of the heating mode. In addition, since there may be certain errors in actual use, an error range can be set for the first pressure threshold, that is, the fan speed can be adjusted according to the suction pressure and the first pressure range. For example, when the suction pressure is less than the lower limit of the first pressure range, the fan speed can be adjusted to the minimum speed; when the suction pressure is in the first pressure range, the fan speed can be adjusted in sections between the minimum fan speed and the maximum fan speed; when the suction pressure is greater than the upper limit of the first pressure range, the fan speed can be adjusted to the maximum speed. Among them, within the proportional adjustment range, the current target speed is calculated according to the linear function, and then according to the absolute value of the current speed-target speed, the adjustment is performed according to the following logic: when the current speed-target speed ≥ 200 revolutions, the DC fan is adjusted by 20 revolutions per adjustment cycle; when 100≤current speed-target speed<200 revolutions, the DC fan is adjusted by 15 revolutions per adjustment cycle; when 50≤current speed-target speed<100 revolutions, the DC fan is adjusted by 10 revolutions per adjustment cycle; when 20≤current speed-target speed<50 revolutions, the DC fan is adjusted by 5 revolutions per adjustment cycle; when 5≤current speed-target speed<20 revolutions, the DC fan is adjusted by 2 revolutions per adjustment cycle.

[0066] Specifically, the working efficiency of the evaporator of the heat pump is different in the cooling mode and the heating mode. Therefore, when the fan is a DC fan and the trigeneration system is in the cooling mode, the fan speed can be adjusted according to the suction pressure and the second pressure threshold, wherein the second pressure threshold is a pre-set normal pressure value of the cooling mode and the first pressure threshold is less than the second pressure threshold. In addition, since there may be certain errors in actual use, an error range can be set for the second pressure threshold, that is, the fan speed can be adjusted according to the suction pressure and the second pressure range. For example, when the suction pressure is greater than the upper limit of the first pressure range, the fan speed can be adjusted to the minimum speed; when the suction pressure is in the second pressure range, the fan speed can be adjusted in stages between the minimum fan speed and the maximum fan speed; when the suction pressure is less than the lower limit of the second pressure range, the fan speed can be adjusted to the maximum speed.

[0067] Reference Figure 6 , Figure 6 for Figure 3 Another specific flow chart of step S200 includes but is not limited to the following steps:

[0068] Step S230, controlling the opening of the second electronic expansion valve according to the exhaust gas temperature.

[0069] It is understandable that the exhaust temperature is related to the efficiency of the compressor. When the exhaust temperature is too high, the reserved gap of the compressor may increase, resulting in gas leakage, thereby reducing the efficiency of the unit. In addition, excessively high temperatures will also cause the grease to decompose under the catalytic action of metal materials, producing harmful dispersed carbon and acidic substances, leading to carbon deposition and blockage of the oil channel, and even causing the main engine to coke and get stuck, further reducing the efficiency of the compressor. The amount of refrigerant charged also has a significant impact on the exhaust temperature of the compressor. If the refrigerant is charged too much, it will occupy too much heat exchange area, resulting in an increase in the condensation temperature, which in turn increases the exhaust temperature of the compressor. The economizer separates the refrigerant flowing out of the condenser. A part of the refrigerant is directly delivered to the first air intake port of the compressor to increase the air intake and enthalpy of the compressor. The other part of the refrigerant is delivered to the first air intake port of the compressor after passing through the evaporator. The opening of the second electronic expansion valve can control the amount of refrigerant delivered to the first air intake port. Therefore, the opening of the second electronic expansion valve can be controlled according to the exhaust temperature. In addition, when it is necessary to replenish air and increase the air intake of the compressor, the liquid injection check valve and the solenoid valve are both in the open state.

[0070] Second, refer to Figure 7 The present application embodiment provides an operation control device 1700, including a memory 1710, a processor 1720, and a computer program stored in the memory 1710 and executable on the processor 1720. The processor 1720 executes the program to implement the control method of the three-connection system of the first embodiment, for example, Figure 3Method steps S100 to S200, Figure 4 Step S210, Figure 5 Step S220 and Figure 6 Step S230.

[0071] The memory 1710 is a non-transitory computer-readable storage medium that can be used to store non-transitory software programs and non-transitory computer executable programs, such as the control method of the three-connection system in the above embodiment of the present application. The processor 1720 implements the control method of the three-connection system in the above embodiment of the present application by running the non-transitory software programs and instructions stored in the memory 1710.

[0072] The memory 1710 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and an application required by at least one function; the data storage area may store data required to execute the control method of the three-connection system in the above embodiment, etc. In addition, the memory 1710 may include a high-speed random access memory 1710, and may also include a non-transitory memory 1710, such as at least one disk storage device, a flash memory device, or other non-transitory solid-state storage device. It should be noted that the memory 1710 may optionally include a memory 1710 remotely arranged relative to the processor 1720, and these remote memories 1710 may be connected to the terminal via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0073] In a third aspect, an embodiment of the present application provides an electronic device, including an operation control device 1700 as described in the embodiment of the second aspect above.

[0074] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, and a computer-executable instruction is used to enable a computer to execute a control method for a three-connection system in accordance with an embodiment of the first aspect, for example, to execute Figure 3 Method steps S100 to S200, Figure 4 Step S210, Figure 5 Step S220 and Figure 6 Step S230.

[0075] It will be appreciated by those skilled in the art that all or some of the steps and systems in the disclosed methods above may be implemented as software, firmware, hardware and appropriate combinations thereof. Some physical components or all physical components may be implemented as software executed by a processor, such as a central processing unit, a digital signal processor or a microprocessor, or implemented as hardware, or implemented as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium or a non-transitory medium and a communication medium or a temporary medium. As known to those skilled in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information such as computer-readable instructions, data structures, program modules or other data. Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disk DVD or other optical disk storage, magnetic cassettes, magnetic tapes, disk storage or other magnetic storage devices, or any other medium that may be used to store desired information and may be accessed by a computer. Furthermore, it is well known to those skilled in the art that communication media typically embodies computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

[0076] The embodiments of the present application are described in detail above in conjunction with the accompanying drawings, but the present application is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the technical field without departing from the purpose of the present application.

Claims

1. A control method for a trigeneration system, characterized in that: The trigeneration system comprises: a heat pump system, a hot water system, an air conditioning system, a geothermal system, a first three-way valve and a second three-way valve, the output end of the heat pump system is connected to the first end of the first three-way valve, the second end of the first three-way valve is connected to the input end of the hot water system, the third end of the first three-way valve is connected to the first end of the second three-way valve, the second end of the second three-way valve is connected to the input end of the air conditioning system, the third end of the second three-way valve is connected to the input end of the geothermal system, the output ends of the hot water system, the output ends of the air conditioning system and the output ends of the geothermal system are all connected to the input end of the heat pump system, the heat pump system comprises: a compressor, a four-way valve, a condenser, an evaporator, a first electronic expansion valve, a second electronic expansion valve, a third electronic expansion valve, a fourth electronic expansion valve, a fifth ... two electronic expansion valves, an economizer and a solenoid valve, the first exhaust port of the compressor is connected to the first end of the four-way valve, the second end of the four-way valve is connected to the input end of the condenser, the output end of the condenser is respectively connected to the first end of the economizer and the third end of the economizer, the second end of the economizer is connected to the first air intake port of the compressor, the second electronic expansion valve and the solenoid valve are further connected between the output end of the condenser and the third end of the economizer, the fourth end of the economizer is connected to the input end of the evaporator, the input end of the evaporator, the output end of the evaporator is connected to the third end of the four-way valve, the fourth end of the four-way valve is connected to the second air intake port of the compressor, and the evaporator is also provided with a fan; The control method comprises: Obtaining the working status of the trigeneration system; The working states of the first electronic expansion valve, the second electronic expansion valve and the fan are controlled according to the working state of the trigeneration system.

2. The control method according to claim 1, characterized in that: The heat pump system further includes a first temperature sensor and a second temperature sensor, wherein the first temperature sensor is used to obtain the coil temperature of the evaporator, and the second temperature sensor is used to obtain the suction temperature of the second suction port. The operating states of the first electronic expansion valve, the second electronic expansion valve and the fan are controlled according to the operating state of the trigeneration system, including: The opening degree of the first electronic expansion valve is adjusted according to the coil temperature and the suction temperature.

3. The control method according to claim 2, characterized in that: The adjusting the opening of the first electronic expansion valve according to the coil temperature and the suction temperature includes: Acquiring the current opening degree of the first electronic expansion valve; Calculating an opening adjustment parameter of the first electronic expansion valve according to the current opening, the actual target superheat, the preset target superheat and the previous target superheat; adjusting the opening of the electronic expansion valve according to the opening adjustment parameter; The actual target superheat is the difference between the suction temperature at the current moment and the coil temperature at the current moment, and the previous target superheat is the difference between the suction temperature at the previous moment and the coil temperature at the previous moment.

4. The control method according to claim 3, characterized in that: The opening adjustment parameter of the first electronic expansion valve is calculated based on the current opening, the actual target superheat, the preset target superheat and the previous target superheat by the following formula: x=y+[α(gh)+γ(gf)]; Among them, x is the opening adjustment parameter, y is the current opening, g is the actual target superheat, h is the preset target superheat, f is the previous target superheat, α is the first correction parameter, and γ is the second correction parameter.

5. The control method according to claim 1, characterized in that: The controlling the working states of the first electronic expansion valve, the second electronic expansion valve and the fan according to the working state of the trigeneration system also includes: The rotation speed of the fan is controlled according to the working state of the trigeneration system.

6. The control method according to claim 5, characterized in that: The heat pump system further includes a pressure sensor, which is used to obtain the suction pressure of the second suction port of the compressor. The speed of the fan is controlled according to the working state of the trigeneration system, including: When the trigeneration system is in a heating mode, controlling the speed of the fan according to the suction pressure and a first pressure threshold; or, When the trigeneration system is in cooling mode, controlling the speed of the fan according to the suction pressure and the second pressure threshold; The first pressure threshold is smaller than the second pressure threshold.

7. The control method according to claim 1, characterized in that: The heat pump system further includes a third temperature sensor, the third temperature sensor is used to obtain the exhaust temperature of the first exhaust port, and the operating states of the first electronic expansion valve, the second electronic expansion valve and the fan are controlled according to the operating state of the trigeneration system, and further include: The opening degree of the second electronic expansion valve is controlled according to the exhaust gas temperature.

8. An operation control device, characterized in that: The invention comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the control method of the trigeneration system according to any one of claims 1 to 7 when executing the computer program.

9. A trigeneration system, characterized in that: Comprising the operation control device as claimed in claim 8.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are used to enable a computer to execute the control method of the trigeneration system according to any one of claims 1 to 7.

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