Control method of high-compatibility single-circulation cooling-water machine

Abstract

The invention discloses a control method of a high-compatibility single-circulation cooling-water machine, which is characterized in that control components are divided into three categories of refrigeration, heating or flow control, and each category is uniformly controlled by a refrigeration proportion parameter, a heating proportion parameter or a flow control proportion parameter, so that integrated and unified control of components with similar functions is realized; the number of parts can be adjusted in a self-adaptive mode, only related functions are increased or decreased without affecting overall temperature control, new control logic does not need to be written, the system can adapt to most of single refrigeration cycle products with any cooling capacity, and the cooling and heating functions of all the parts are achieved while the cooling and heating functions of all the parts are achieved. Conflicts among the components caused by different component models are avoided, and therefore the purpose of adding or reducing the components is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of low-temperature chillers, and in particular to a control method for a high-compatibility single-cycle chiller. Background Art

[0002] With the progress of the times, the requirements for various temperatures in industrial production are increasing, and the chiller business is also booming. A chiller is an energy-saving machine that achieves refrigeration through steam compression or absorption circulation. The full name of a chiller is a cooling water circulation machine, also known as a refrigerator, a cooling machine, a freezer, a chiller, an ice machine, etc. Because it is widely used in various industries, it has countless aliases depending on the industry.

[0003] The water-cooled unit consists of four main components: compressor, evaporator, condenser, and expansion valve, which realize the cooling and heating effects of the unit. The refrigerant (i.e., refrigerant) absorbs the heat of the cooled object in the evaporator and vaporizes into steam. The compressor continuously extracts the generated steam from the evaporator and compresses it. The compressed high-temperature and high-pressure steam is sent to the condenser, and then releases heat to the cooling medium (such as water, air, etc.) and condenses into high-pressure liquid. After the pressure is reduced by the throttling mechanism, it enters the evaporator, vaporizes again, and absorbs the heat of the cooled object. This cycle repeats over and over again. Data shows that, for now, conventional single-cycle, single-compressor chillers still dominate the market, so designing a chiller control method with strong compatibility is of great help in meeting the needs of current customers, improving production efficiency and shortening the R&D cycle. At the same time, applying the same set of control methods, product optimization is also relatively simple, which is conducive to improving product quality and reducing various costs.

[0004] Chinese patent document CN107671414A discloses a "water chiller". It includes a condenser, a coolant pipeline, a variable frequency compressor, a water pump, a drying filter, a solenoid valve, a liquid reservoir, an expansion valve, an evaporator, a water pipeline, a water tank, a rack, a high-pressure coolant gauge, a low-pressure coolant gauge, an outlet pressure gauge, and an integrated circuit controller; a variable frequency compressor is used to control the compressor speed through analog electrical signal output, eliminate the frequent start-up of the fixed frequency compressor, reduce energy loss during over-operation, and reduce machine noise; the control of the integrated circuit controller enables the control of electrical components in the entire system, more control variables, and effectively reduces the use of electrical components. The above technical solution is complex to control, and it is difficult to increase or reduce configuration in a timely manner. Summary of the invention

[0005] The present invention mainly solves the technical problems that the original technical solution is complex to control and difficult to realize addition or reduction of configuration in time, and provides a control method for a highly compatible single-cycle chiller. By dividing the control components into three categories of refrigeration, heating or flow control, each category is uniformly controlled by a refrigeration ratio parameter, a heating ratio parameter or a flow control ratio parameter, thereby realizing integrated and unified control of components with similar functions, and adaptively adjusting the increase or decrease of components, only increasing or decreasing related functions without affecting the overall temperature control, without the need to write new control logic, and being able to adapt to most single refrigeration cycle products of any cooling capacity, while giving full play to the refrigeration and heating functions of each component, it avoids conflicts between components due to different component models, thereby achieving the purpose of increase or reduction of configuration.

[0006] The above technical problem of the present invention is mainly solved by the following technical solution: The present invention comprises the following steps: S1. Performing a highly compatible single-cycle chiller architecture; S2. Classify the control components in the architecture according to the parameter categories they affect; S3. Set uniform control ratio parameters according to the control component categories; S4. Set the overall temperature control logic and adjust the control ratio parameters of each category to achieve temperature control.

[0007] Firstly, the purpose of liquid discharge from low temperature to high temperature is achieved through a single refrigeration cycle, and then the overall circulation components are divided into three categories: refrigeration components, heating components, and flow control components; the variable frequency compressor, cold valve and other refrigeration components are uniformly integrated and regulated by the refrigeration proportional coefficient α, and similarly, the heating components are integrated and regulated by the heating proportional coefficient β; the flow control component is regulated by the flow control proportional coefficient γ.

[0008] In this way, electronic expansion valves or other control components can be added or reduced according to demand without affecting the overall program logic. In addition, since the upper and lower limits of the adjustment are selected by the relevant system engineers, the cooling and heating functions of each component can be brought into play while avoiding conflicts between components due to different component models, thereby achieving the purpose of adding configuration (increasing functions) or reducing configuration (saving costs); Preferably, the chiller architecture comprises a compressor, an output end of the compressor is connected to a condenser and an evaporator in sequence, and an output end of the evaporator is connected to an input end of the compressor to form a circulation loop.

[0009] Preferably, the condenser comprises a circulation loop condensation input end and a circulation loop condensation output end, and also comprises a cooling water input end and a cooling water output end for heat transfer.

[0010] Preferably, the evaporator comprises a circulating loop evaporation input end and a circulating loop evaporation output end, and also comprises a refrigerant input end and a refrigerant output end, and the refrigerant input end is connected to the refrigerant output end through a refrigerant system and a water pump.

[0011] Preferably, an electronic expansion valve hot valve is provided between the output end of the compressor and the circulation loop evaporation input end, an electronic expansion valve pressure regulating valve is provided between the circulation loop condensation output end and the circulation loop evaporation output end, and an electronic expansion valve cold valve is provided between the circulation loop condensation output end and the circulation loop evaporation input end.

[0012] Preferably, the control components are classified into refrigeration components and heating components, and also include circulating liquid flow control components and optional components.

[0013] Preferably, both the refrigeration component and the heating component need to have at least one main control component, and the fixed frequency component does not exist by default.

[0014] As a preference, the refrigeration components uniformly use a refrigeration ratio coefficient α, with a setting range of 0-100%. The refrigeration capacity becomes stronger as the number increases. The compressor: P(α)=A1+α(B1–A1) Among them, P(α) is the actual output frequency of the variable frequency compressor, α is the refrigeration proportional coefficient, A1 is the set frequency lower limit, and B1 is the set frequency upper limit; Electronic expansion valve cold valve: C(α)=A2+α(B2-A2) Among them, C(α) is the actual opening of the cold valve, α is the cooling proportional coefficient, A2 is the lower limit of the cold valve opening, and B2 is the upper limit of the cold valve opening; Electronic expansion valve thermal valve: H(α)=A3+(100%-α)(B3-A3) Among them, H(α) is the actual opening of the cold valve, α is the cooling proportional coefficient, A3 is the lower limit of the hot valve opening, and B3 is the upper limit of the hot valve opening; Electronic expansion valve pressure regulating valve: A(α)=A4+(100%-α)(B4-A4) Among them, A(α) is the actual opening of the pressure regulating valve, α is the proportional coefficient, A4 is the lower limit of the opening of the pressure regulating valve, and B4 is the upper limit of the opening of the pressure regulating valve.

[0015] As a preference, the heating components uniformly use a heating ratio coefficient β, with a setting range of 0-100%. The larger the number, the stronger the heating capacity. The electric heater manually sets the adjustment range, with a fixed lower limit starting from 0. E(β)=0+β(B5) Among them, E(β) is the actual power of the electric heater, β is the heating ratio coefficient, 0 is the lower limit of the heater power, and B5 is the upper limit of the heater power.

[0016] Preferably, the circulating fluid outlet temperature sensor is used as the temperature control point. When the set temperature differs from the outlet temperature, the cooling proportional coefficient α and the heating proportional coefficient β are adjusted according to the PID algorithm to stabilize the outlet temperature.

[0017] The beneficial effects of the present invention are as follows: by dividing the control components into three categories of cooling, heating or flow control, each category is uniformly controlled by a cooling ratio parameter, a heating ratio parameter or a flow control ratio parameter, thereby realizing integrated and unified control of components with similar functions, and adaptively adjusting the increase or decrease of components, only increasing or decreasing related functions without affecting the overall temperature control, without the need to write new control logic, and being able to adapt to most single refrigeration cycle products of any cooling capacity, while giving full play to the cooling and heating functions of each component, avoiding conflicts between components due to different component models, thereby achieving the purpose of increasing or reducing configuration. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a flow chart of the present invention.

[0019] Figure 2 It is a principle connection structure diagram of the present invention.

[0020] In the figure, 1 is a compressor, 2 is an electronic expansion valve hot valve, 3 is a condenser, 4 is an electronic expansion valve pressure regulating valve, 5 is an electronic expansion valve cold valve, 6 is an evaporator, 7 is a circulating liquid water pump, and 8 is a refrigerant system. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the technical solution of the present invention is further described in detail below through embodiments and in combination with the accompanying drawings. It should be understood that the specific implementation method described here is only an optimal embodiment of the present invention, which is only used to explain the present invention and does not limit the scope of protection of the present invention. All other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0022] In a single-cycle chiller system, the simplest refrigeration control component is a compressor + water pump.

[0023] According to different customer needs, add variable frequency compressor to control the cooling capacity control range, add cold valve to adjust the control temperature, add hot valve so that the cooling capacity can be increased from 0, add pressure regulating valve to reduce the exhaust pressure under high temperature, add electric heater to improve heating capacity, add flow controller, solenoid valve and other components to control the water outlet flow of the chiller... Each of these new functions requires additional program adjustment work.

[0024] Therefore, by integrating these components and adjusting them through three coefficients (cooling proportional coefficient α, heating proportional coefficient β, flow regulation proportional coefficient γ), on the one hand, the program adjustment work caused by the addition of new functions can be reduced, and on the other hand, the control logic can be simplified to increase the stability of the system, and reduce the unpredictable bugs caused by the complexity of system control due to multiple components. At the same time, the newly added new functional components can also be directly added to these coefficients for joint control without affecting the main control logic, thus improving the R&D efficiency. When it is necessary to reduce non-core components, as long as the main control board cannot detect this component, the corresponding component logic will not operate and will not affect the basic functions of the overall chiller. At the same time, the same components are all adjusted in proportion, and this control method is also very compatible. For example, if the original chiller with a cooling capacity of 2000W needs to increase the cooling capacity to 8000W, it only needs to replace the compressor and solenoid valve models, and it can be automatically compatible with the control without adjusting the program. Finally, the cooling proportional coefficient and the heating proportional coefficient are adjusted by PID to achieve the effect of stabilizing the temperature.

[0025] Before discussing the exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flow charts. Although the flow charts describe the operations (or steps) as sequential processes, many of the operations (or steps) therein can be implemented in parallel, concurrently, or simultaneously. In addition, the order of the operations can be rearranged. The process can be terminated when its operation is completed, but can also have additional steps not included in the drawings; the process can correspond to a method, function, procedure, subroutine, subprogram, etc.

[0026] The technical solution of the present invention is further specifically described below through embodiments and in conjunction with the accompanying drawings.

[0027] Example 1 A control method for a highly compatible single-cycle chiller in this embodiment is as follows: Figure 1 As shown, the following steps are included: S1. Carry out a highly compatible single-cycle chiller architecture; Figure 2As shown, the chiller architecture includes a compressor 1, the output end of the compressor is connected to the condenser 3 and the evaporator 6 in sequence, and the output end of the evaporator 6 is connected to the input end of the compressor to form a circulation loop. The condenser 3 includes a circulation loop condensation input end and a circulation loop condensation output end, and also includes a cooling water input end and a cooling water output end for heat transfer. The evaporator 6 includes a circulation loop evaporation input end and a circulation loop evaporation output end, and also includes a refrigerant input end and a refrigerant output end, and the refrigerant input end is connected to the refrigerant output end through a refrigerant system 8 and a water pump 7. An electronic expansion valve hot valve 2 is provided between the output end of the compressor and the circulation loop evaporation input end, an electronic expansion valve pressure regulating valve 4 is provided between the circulation loop condensation output end and the circulation loop evaporation output end, and an electronic expansion valve cold valve 5 is provided between the circulation loop condensation output end and the circulation loop evaporation input end.

[0028] S2. Classify the control components in the architecture. The control component classification includes cooling components and heating components, as well as circulating fluid flow control components and optional components. Both cooling components and heating components need to have at least one main control component, and the fixed frequency component does not exist by default.

[0029] All control components will be divided into three categories: 1. Refrigeration components: (Main control components) variable frequency compressor, electronic expansion valve (cold valve), (Secondary control components) Electronic expansion valve (thermal valve), electronic expansion valve (pressure regulating valve) (Additional component types can be added upon request) 2. Heating components: (Main control component) Electric heater (component types can be added according to requirements) 3. Circulating fluid flow control and other components (optional) Water pump (frequency conversion), solenoid valve (export flow control) (Additional component types can be added upon request) In order to ensure high-precision control, both the refrigeration component and the heating component need to have at least one main control component. For example: when the program detects that the variable frequency compressor and the electric heater exist at the same time, the machine can start normally. On the contrary, when the program detects the variable frequency compressor (existence), the thermal valve (non-existence), and the electric heater (non-existence), the machine cannot start.

[0030] S3. Set uniform control ratio parameters according to the control component category.

[0031] Refrigeration components In order to unify program control, all refrigeration components use the refrigeration proportional coefficient α uniformly, with a setting range of 0 to 100%. The refrigeration capacity becomes stronger as the number increases.

[0032] (Note: When the cooling coefficient is 0%, it means that the refrigeration system is running at the lowest cooling power, and whether to shut down or not is determined by the upper and lower limits set by the engineer) Variable frequency compressor (fixed frequency is not recognized and does not exist by default): The frequency of the compressor can be adjusted from 0-100% in a proportional manner (to adapt to different types of compressors). The adjustment range can be manually changed in the setting interface. When the program detects that the cooling capacity needs to be increased, the percentage of the cooling ratio is increased until the upper limit of the range is reached.

[0033] P(α)=A1+α(B1–A1) ——P(α) is the actual output frequency of the variable frequency compressor ——α is the refrigeration proportional coefficient ——A1 is to set the frequency lower limit ——B1 is for setting the upper frequency limit. For example: manually set the compressor adjustment range to 70-310HZ. At this time, the program determines that the required refrigeration ratio coefficient α is 20%, and the compressor starts. At this time, the actual frequency of the compressor is 70+20%*(310-70)=118HZ.

[0034] Electronic expansion valve (cold valve) Similar to the compressor adjustment method, the upper and lower limits of the electronic expansion valve opening are also adjusted from 0-100% in a proportional adjustment manner. However, since the adjustment of the cooling capacity by the cold valve is a parabola, only the part with the same monotonicity is taken, that is, the greater the cooling capacity, the greater the cold valve opening.

[0035] C(α)=A2+α(B2-A2) ——C(α) is the actual opening of the cold valve ——α is the refrigeration proportional coefficient ——A2 is to set the lower limit of the cold valve opening ——B2 is to set the upper limit of the cold valve opening. For example: manually set the upper and lower limits of the cold valve opening to 80-200. The larger the cooling ratio coefficient α is, the larger the cold valve opening is. When the cooling ratio is 30%, the actual opening is 80+50%*(200-80)=140 Electronic expansion valve (thermal valve): Similarly, manually set the adjustment range to maintain the cooling ratio parameter. The larger the cooling capacity, the greater the opening of the thermal valve, the smaller the adjusted cooling capacity.

[0036] H(α)=A3+(100%-α)(B3-A3) ——H(α) is the actual opening of the cold valve ——α is the refrigeration proportional coefficient ——A3 is to set the lower limit of the thermal valve opening ——B3 is to set the upper limit of the thermal valve opening Example: Manually set the upper and lower limits of the heat valve opening to 0-300, and the cooling ratio to 30%. Actual opening = 0 + (100% - 30%) * (300 - 0) = 210 That is, when the cooling ratio is 100%, the thermal valve is fully closed.

[0037] Electronic expansion valve (pressure regulating valve) Start when the circulating fluid outlet temperature is above 20℃ The adjustment method is similar to that of the thermal valve, ensuring that the larger the cooling ratio, the greater the cooling capacity.

[0038] A(α)=A4+(100%-α)(B4-A4) ——A(α) is the actual opening of the pressure regulating valve ——α is the proportional coefficient ——A4 is to set the lower limit of the pressure regulating valve opening ——B4 is to set the upper limit of the pressure regulating valve opening Example: When the upper and lower limits of the pressure regulating valve opening are set to 0-100 and the cooling ratio is 50%, Actual opening = 0 + (100% - 50%) * (100 - 0) = 50 That is, when the refrigeration proportional coefficient is 100%, the pressure regulating valve is fully closed.

[0039] Heating components: Heating component setting, heating ratio coefficient β ranges from 0 to 100%, the larger the number, the stronger the heating capacity.

[0040] Electric heater Manually set the adjustment range, and adjust the electric heater power in a proportional adjustment mode of 0-100%. The larger the percentage, the stronger the heating capacity. (To ensure safety, the fixed lower limit starts from 0).

[0041] E(β)=0+β(B5) ——E(β) is the actual power of the electric heater ——β is the heating ratio coefficient ——0 is to set the lower limit of heater power ——B5 is to set the upper limit of heater power Circulating fluid flow control components (optional) The flow control component is set, and the flow ratio coefficient γ ranges from 0 to 100%. The larger the number, the greater the flow.

[0042] These components are optional and may have some impact on performance, but they are not included in the main control components and do not affect the normal startup of the program. The fluctuations in machine performance caused by adding or removing these components are adaptively adjusted through the main control components.

[0043] Variable frequency water pump (fixed frequency is not recognized and does not exist by default) Similar to the compressor, the frequency adjustment range is manually set and then adjusted in a ratio of 0 to 100%.

[0044] F(γ)=A6+γ(B6-A6) ——F(γ) is the actual frequency of the variable frequency water pump ——γ is the flow rate proportional coefficient ——A6 is to set the lower limit of the water pump frequency ——B6 is to set the upper limit of the water pump frequency. For example: the frequency adjustment range is set to 20~60HZ. When the flow rate ratio is 20%, the water pump frequency is 20+20%*(60-20)=28HZ. Solenoid valve (export flow control) Manually set the adjustment opening range and adjust it in the proportion of 0 to 100% in the same way as above.

[0045] Example: When the opening range is set to 0-100 and the flow rate ratio is 50%, the actual opening = 0 + 50% * (100-0) = 50e (γ) = A7 + γ (B7-A7) ——e(γ) is the actual opening of the solenoid valve ——γ is the flow rate proportional coefficient ——A7 is to set the lower limit of the solenoid valve opening ——B7 is to set the upper limit of the solenoid valve opening S4. Set the overall temperature control logic to perform temperature control.

[0046] Temperature Control: The circulating fluid outlet temperature sensor (adjustable as needed) is used as the temperature control point. When the set temperature differs from the outlet temperature, the program automatically adjusts the cooling proportional coefficient α and the heating proportional coefficient β according to the PID algorithm (the heating coefficient value in the PID program is positive, and the cooling coefficient value is negative, and the output is positive and negative according to the PID algorithm control) to stabilize the outlet temperature.

[0047] PID control formula: Egress flow control: According to the settings, the program automatically adjusts the flow rate proportional coefficient γ.

[0048] (Note: According to the temperature control accuracy requirements, the control accuracy of the relevant proportional coefficient can be changed from 1% to 0.1% or 0.01%, and there is no need to adjust the other programs.) Example 2 The solution of Example 1 is applied to our company's single-channel 2200W, -10℃ chiller.

[0049] In the refrigeration components, three types of Danfoss electronic expansion valves are used: cold valve, hot valve, and pressure regulating valve. The upper and lower limits of the cold valve are (60-140), the hot valve is (0-300), and the pressure regulating valve is (0-50). The compressor uses Highly's WHP05600VUKQA7JG6 variable frequency compressor, with a frequency adjustment range of 70-310HZ (that is, when the cooling coefficient α is 0%, the compressor is still started), the heating component is a 3000W electric heater, the power range is 0-3000W (when the heating coefficient β is 0%, the heater is not started), and there is no flow control component. The cooling and heating ratio is adjusted through PID control.

[0050] The chiller architecture includes a compressor 1, the output end of the compressor is connected to a condenser 3 and an evaporator 6 in sequence, and the output end of the evaporator 6 is connected to the input end of the compressor to form a circulation loop. The condenser 3 includes a circulation loop condensation input end and a circulation loop condensation output end, and also includes a cooling water input end and a cooling water output end for heat transfer. The evaporator 6 includes a circulation loop evaporation input end and a circulation loop evaporation output end, and also includes a refrigerant input end and a refrigerant output end, and the refrigerant input end is connected to the refrigerant output end through a refrigerant system 8 and a water pump 7. An electronic expansion valve hot valve 2 is provided between the output end of the compressor and the circulation loop evaporation input end, an electronic expansion valve pressure regulating valve 4 is provided between the circulation loop condensation output end and the circulation loop evaporation output end, and an electronic expansion valve cold valve 5 is provided between the circulation loop condensation output end and the circulation loop evaporation input end.

[0051] The customer requires the refrigeration circulation liquid to be -10℃, and the customer instrument load is 1KW. After the chiller is started at room temperature of 25℃, the outlet circulation liquid temperature is set to -10℃. At this time, the set temperature is lower than the actual outlet temperature, and the refrigeration is started. The refrigeration proportional coefficient α is increased, and the heating proportional coefficient β is 0%. According to the PID adjustment calculation (the PID parameters of each temperature have been set), the refrigeration proportional parameter starts to rise parabolically from 0% to 100% within 2 minutes (rapid cooling). When the refrigeration proportional coefficient is 100%, the cold valve opening is 140, the hot valve opening is 0, and the pressure regulating valve opening is 0. When the outlet circulation temperature approaches the set temperature, the refrigeration proportional coefficient α gradually decreases. The refrigeration coefficient α in the final stable state controlled by PID is 40%, and the heating coefficient β is 0%.

[0052] Example 3 The solution of Example 1 is applied to our company's single-channel 2200W, -10℃ chiller.

[0053] In the refrigeration components, three types of Danfoss electronic expansion valves are used: cold valve, hot valve, and pressure regulating valve. The upper and lower limits of the cold valve are (60-140), the hot valve is (0-300), and the pressure regulating valve is (0-50). The compressor uses Highly's WHP05600VUKQA7JG6 variable frequency compressor, with a frequency adjustment range of 70-310HZ (that is, when the cooling coefficient α is 0%, the compressor is still started), the heating component is a 3000W electric heater, the power range is 0-3000W (when the heating coefficient β is 0%, the heater is not started), and there is no flow control component. The cooling and heating ratio is adjusted through PID control.

[0054] The chiller architecture includes a compressor 1, the output end of the compressor is connected to a condenser 3 and an evaporator 6 in sequence, and the output end of the evaporator 6 is connected to the input end of the compressor to form a circulation loop. The condenser 3 includes a circulation loop condensation input end and a circulation loop condensation output end, and also includes a cooling water input end and a cooling water output end for heat transfer. The evaporator 6 includes a circulation loop evaporation input end and a circulation loop evaporation output end, and also includes a refrigerant input end and a refrigerant output end, and the refrigerant input end is connected to the refrigerant output end through a refrigerant system 8 and a water pump 7. An electronic expansion valve hot valve 2 is provided between the output end of the compressor and the circulation loop evaporation input end, an electronic expansion valve pressure regulating valve 4 is provided between the circulation loop condensation output end and the circulation loop evaporation output end, and an electronic expansion valve cold valve 5 is provided between the circulation loop condensation output end and the circulation loop evaporation input end.

[0055] The customer requires the refrigeration circulation liquid to be -10℃, and the customer instrument load is 0.1KW. After starting the chiller, refrigeration starts, and the refrigeration coefficient α rises. When the outlet temperature approaches the set temperature, the refrigeration coefficient decreases. Because the customer load is too small, when the refrigeration coefficient α drops to 0%, the cold valve opening is 60, the hot valve opening is 300, and the pressure regulating valve opening is 0 (the actual outlet temperature is lower than 20℃ and the pressure regulating valve does not open). The temperature is still falling, and heating is started. The heating coefficient β slowly increases from 0%, and the rising speed is controlled by PID until the temperature stabilizes, and finally stabilizes at a cooling coefficient α of 0% and a heating coefficient β of 5%.

[0056] Example 4 The solution of Example 1 is applied to our company's single-channel 2200W, -10℃ chiller.

[0057] In the refrigeration components, three types of Danfoss electronic expansion valves are used: cold valve, hot valve, and pressure regulating valve. The upper and lower limits of the cold valve are (60-140), the hot valve is (0-300), and the pressure regulating valve is (0-50). The compressor uses Highly's WHP05600VUKQA7JG6 variable frequency compressor, with a frequency adjustment range of 70-310HZ (that is, when the cooling coefficient α is 0%, the compressor is still started), the heating component is a 3000W electric heater, the power range is 0-3000W (when the heating coefficient β is 0%, the heater is not started), and there is no flow control component. The cooling and heating ratio is adjusted through PID control.

[0058] The chiller architecture includes a compressor 1, the output end of the compressor is connected to a condenser 3 and an evaporator 6 in sequence, and the output end of the evaporator 6 is connected to the input end of the compressor to form a circulation loop. The condenser 3 includes a circulation loop condensation input end and a circulation loop condensation output end, and also includes a cooling water input end and a cooling water output end for heat transfer. The evaporator 6 includes a circulation loop evaporation input end and a circulation loop evaporation output end, and also includes a refrigerant input end and a refrigerant output end, and the refrigerant input end is connected to the refrigerant output end through a refrigerant system 8 and a water pump 7. An electronic expansion valve hot valve 2 is provided between the output end of the compressor and the circulation loop evaporation input end, an electronic expansion valve pressure regulating valve 4 is provided between the circulation loop condensation output end and the circulation loop evaporation output end, and an electronic expansion valve cold valve 5 is provided between the circulation loop condensation output end and the circulation loop evaporation input end.

[0059] The customer requires the refrigeration cycle liquid to be 60℃, and the customer instrument load is -1.5KW. After starting the chiller, set the temperature higher than the actual outlet temperature, start heating, and the cooling coefficient is 0%. The heating coefficient β slowly increases from 0%, and the rising speed is controlled by PID until the temperature stabilizes, and finally stabilizes at a heating coefficient β of 60% and a cooling coefficient α of 0%.

[0060] The specific embodiments described herein are merely examples of the spirit of the present invention. The above embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that technicians in the technical field to which the present invention belongs can make various modifications or supplements to the described specific embodiments or replace them in a similar manner, but will not deviate from the spirit of the present invention or exceed the scope defined in the attached claims. For ordinary technicians in this field, multiple deformations and improvements can also be made without departing from the concept of the present invention. Therefore, the scope of protection of the patent of the present invention shall be based on the attached claims.

Claims

1. A control method for a highly compatible single-cycle chiller, characterized in that: The following steps are involved: S1. Implement a highly compatible single-cycle chiller architecture; S2. Classify the control components in the architecture according to the parameter categories they affect; S3. Set uniform control ratio parameters according to the control component categories; S4. Set the overall temperature control logic and adjust the control ratio parameters of each category to achieve temperature control.

2. A control method for a highly compatible single-cycle chiller according to claim 1, characterized in that: The chiller architecture comprises a compressor (1), the output end of the compressor is connected to a condenser (3) and an evaporator (6) in sequence, and the output end of the evaporator (6) is connected to the input end of the compressor to form a circulation loop.

3. A control method for a highly compatible single-cycle chiller according to claim 2, characterized in that: The condenser (3) comprises a circulation loop condensation input end and a circulation loop condensation output end, and also comprises a cooling water input end and a cooling water output end for heat transfer.

4. A control method for a high-compatibility single-cycle chiller according to claim 3, characterized in that: The evaporator (6) comprises a circulating loop evaporation input end and a circulating loop evaporation output end, and also comprises a refrigerant input end and a refrigerant output end, wherein the refrigerant input end is connected to the refrigerant output end via a refrigerant system (8) and a water pump (7).

5. The control method of a highly compatible single-cycle chiller according to claim 4, characterized in that: An electronic expansion valve hot valve (2) is provided between the output end of the compressor and the evaporation input end of the circulation loop, an electronic expansion valve pressure regulating valve (4) is provided between the condensation output end of the circulation loop and the evaporation output end of the circulation loop, and an electronic expansion valve cold valve (5) is provided between the condensation output end of the circulation loop and the evaporation input end of the circulation loop.

6. The control method of a highly compatible single-cycle chiller according to claim 1, characterized in that: The control components are classified into refrigeration components and heating components, and also include circulating liquid flow control components and optional components.

7. A control method for a high-compatibility single-cycle chiller according to claim 6, characterized in that: Both the cooling component and the heating component need to have at least one main control component, and the fixed frequency component does not exist by default.

8. The control method of a highly compatible single-cycle chiller according to claim 6, characterized in that: The refrigeration components uniformly use a refrigeration proportional coefficient α, with a setting range of 0-100%, and the refrigeration capacity becomes stronger as the number becomes larger.

9. The control method of a highly compatible single-cycle chiller according to claim 6, characterized in that: The heating components uniformly use a heating ratio coefficient β, with a setting range of 0-100%. The larger the number, the stronger the heating capacity. The electric heater manually sets the adjustment range, and the fixed lower limit starts from 0.

10. A control method for a highly compatible single-cycle chiller according to claim 1 or 8 or 9, characterized in that: In step S5, the circulating fluid outlet temperature sensor is used as the temperature control point. When the set temperature differs from the outlet temperature, the cooling proportional coefficient α and the heating proportional coefficient β are adjusted according to the PID algorithm to stabilize the outlet temperature.

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