An intelligent full-frequency rooftop unit with self-diagnosis for incorrect insertion of electronic expansion valve coil and its control method

Abstract

The present invention discloses an intelligent full-frequency conversion rooftop unit with self-diagnosis for incorrectly inserted electronic expansion valve coils and a control method thereof. The unit comprises an indoor heat exchanger, a first circulation system, and a second circulation system. The first circulation system and the second circulation system are both connected to the indoor heat exchanger via a pipeline. The first circulation system and the second circulation system are each provided with a diagnostic system that detects the operating parameters of the first circulation system and the second circulation system. The diagnostic system calculates the exhaust superheat of the first circulation system and the second circulation system based on the current exhaust temperature and condensation temperature, and calculates the supply air superheat of the first circulation system and the second circulation system based on the inlet and outlet temperatures of the economizer supply air circuit. The system determines whether the electronic expansion valve coil is incorrectly inserted based on the exhaust temperature, exhaust superheat, and the opening of the electronic expansion valve. This method does not require additional control resources and has the advantages of a simple judgment method and high reliability.

Description

Technical Field

[0001] The present invention relates to the field of air conditioning and control technology, and in particular to an intelligent full-frequency conversion rooftop unit capable of self-diagnosis of incorrect insertion of an electronic expansion valve coil and a control method thereof. Background Art

[0002] Currently, rooftop units are widely used in medical, industrial, and commercial purification projects because they don't require on-site copper pipes connecting the indoor and outdoor units, nor do they require complex wiring. They offer simple installation and commissioning, low installation costs, and a high cost-effectiveness. Their application scope continues to expand, and the market is experiencing rapid growth. Fully variable-frequency rooftop units typically utilize a variable-frequency compressor with air supply and heat increase. Both the main and air supply circuits of their fluorine system utilize electronic expansion valves for throttling. Furthermore, rooftop units have a wide cooling capacity range. Large-capacity rooftop units generally utilize multiple system designs. Consequently, a single rooftop unit may have a large number of electronic expansion valve coils connected to the same control board, ranging from two to four, six, or even eight. During production applications, incorrect insertion of electronic expansion valve coils is a common occurrence, leading to unit malfunction and even compressor damage.

[0003] Existing solutions rely on human experience to troubleshoot. However, the technical experience and capabilities of commissioning and maintenance personnel vary widely. Failure to promptly identify the problem can impact the unit's performance, and ultimately the user experience. Some even damage the compressor during the troubleshooting process, significantly reducing the unit's performance. To address this issue, the inventors have proposed an intelligent, fully variable-frequency rooftop unit with self-diagnosis for incorrectly inserted electronic expansion valve coils and a control method to address this problem. Summary of the Invention

[0004] In order to solve the problem that the current problem of relying on human experience to troubleshoot the wrong insertion of the electronic expansion valve coil, the technical experience and capabilities of the debugging and maintenance personnel are uneven. If the problem cannot be found in time, it will affect the use effect of the unit, and then affect the user's experience. Even in the process of troubleshooting, the compressor may be damaged, which greatly reduces the use effect of the unit; the purpose of the present invention is to provide an intelligent full-frequency rooftop unit with self-diagnosis of the wrong insertion of the electronic expansion valve coil and a control method thereof.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solution: an intelligent full-frequency rooftop unit with self-diagnosis of incorrect insertion of an electronic expansion valve coil, including an indoor heat exchanger, a first circulation system and a second circulation system, the first circulation system and the second circulation system are both connected to the indoor heat exchanger through pipes, and the first circulation system and the second circulation system are both provided with a diagnostic system, which detects the operating parameters of the first circulation system and the second circulation system.

[0006] In a preferred implementation case, the first circulation system includes a first compressor, the input end of the first compressor is connected to the outlet end of the first gas-liquid separator and the first muffler through a pipeline, the output end of the first compressor and the input end of the first gas-liquid separator are both connected to the first four-way valve through a pipeline, the first four-way valve is connected to the output end of the indoor heat exchanger and the input end of the first outdoor heat exchanger through a pipeline, the output end of the first heat exchanger is connected to the first one-way valve group through a pipeline, the one-way valve group is connected to the first economizer through a pipeline, a first main valve is installed between the first economizer and the first one-way valve group, and a first auxiliary valve is installed between the first economizer and the pipeline at one end of the first main valve away from the first one-way valve group, the first economizer is connected to the first muffler through a pipeline, the first one-way valve group is also connected to the input end of the first liquid reservoir through a pipeline, and the output end of the first liquid reservoir is connected to the input end of the indoor heat exchanger through a pipeline.

[0007] In a preferred implementation case, the second circulation system includes a second compressor, the input end of the second compressor is connected to the outlet end of the second gas-liquid separator and the second muffler through a pipeline, the output end of the second compressor and the input end of the second gas-liquid separator are both connected to the second four-way valve through a pipeline, the second four-way valve is connected to the output end of the indoor heat exchanger and the input end of the second outdoor heat exchanger through a pipeline, the output end of the second heat exchanger is connected to the second one-way valve group through a pipeline, the one-way valve group is connected to the second economizer through a pipeline, a second main valve is installed between the second economizer and the second one-way valve group, and a second auxiliary valve is installed between the second economizer and the pipelines at the two ends of the second main valve away from the second one-way valve group, the second economizer is connected to the second muffler through a pipeline, the second one-way valve group is also connected to the input end of the second liquid reservoir through a pipeline, and the output end of the second liquid reservoir is connected to the input end of the indoor heat exchanger through a pipeline.

[0008] In a preferred embodiment, a variable frequency blower is installed at the indoor heat exchanger, and condensing fans are installed at both the first outdoor heat exchanger and the second outdoor heat exchanger.

[0009] In a preferred embodiment, the condensing fan is a DC variable frequency condensing fan, and the first compressor and the second compressor are both air-supplying and enthalpy-increasing DC variable frequency compressors.

[0010] In a preferred embodiment, the diagnostic system includes a first detection module, a second detection module and a controller, wherein:

[0011] The first detection module is connected to the first circulation system and is used to detect the exhaust temperature and pressure, the supply air inlet temperature and the supply air outlet temperature of the first circulation system, and transmit the detection data to the controller;

[0012] The second detection module is connected to the second circulation system and is used to detect the exhaust temperature and pressure, the supply air inlet temperature and the supply air outlet temperature of the second circulation system, and transmit the detection data to the controller;

[0013] The controller is used to receive and process data from the first detection module and the second detection module, and to diagnose whether the electronic expansion valve coil is incorrectly inserted.

[0014] In a preferred embodiment, the first detection module includes:

[0015] a first exhaust pressure sensor, which is installed at the output end of the first compressor and is used to detect the exhaust pressure Pd1 of the first circulation system;

[0016] a first exhaust gas temperature sensor, which is installed at the output end of the first compressor and is used to detect the exhaust gas temperature Td1 of the first circulation system;

[0017] a first supplementary air inlet temperature sensor, which is installed on the pipeline between the first economizer and the first auxiliary valve and is used to detect the supplementary air inlet temperature Tv_in1 of the first circulation system;

[0018] The first supplementary air outlet temperature sensor is installed on the pipeline between the first economizer and the first muffler, and is used to detect the supplementary air outlet temperature Tv_out1 of the first circulation system.

[0019] In a preferred embodiment, the second detection module includes:

[0020] a second exhaust pressure sensor, which is installed at the output end of the second compressor and is used to detect the exhaust pressure Pd2 of the second circulation system;

[0021] a second exhaust gas temperature sensor, which is installed at the output end of the second compressor and is used to detect the exhaust gas temperature Td2 of the second circulation system;

[0022] A second air supply inlet temperature sensor, which is installed on the pipeline between the second economizer and the second auxiliary valve, and is used to detect the air supply inlet temperature Tv_in2 of the second circulation system;

[0023] The second supplementary air outlet temperature sensor is installed on the pipeline between the second economizer and the second muffler, and is used to detect the supplementary air outlet temperature Tv_out2 of the second circulation system.

[0024] A control method for an intelligent full-frequency conversion rooftop unit with self-diagnosis for incorrect insertion of an electronic expansion valve coil is characterized in that a controller calculates the exhaust superheats TdSH1=Td1-Tc1 and TdSH2=Td2-Tc2 of a first circulation system and a second circulation system according to the current exhaust temperature and condensing temperature; and calculates the supply air superheats TvSH1=Tv_out1-Tv_in1 and TvSH2=Tv_out2-Tv_in2 of the first circulation system and the second circulation system according to the inlet and outlet temperatures of the economizer supply air circuit, thereby diagnosing incorrect insertion of the electronic expansion valve coil.

[0025] In a preferred embodiment, the controller diagnosis process includes the following steps:

[0026] 1) The unit is started and running;

[0027] 2) Check the compressor startup time. If the startup time is ≥ 5s, go to step 3);

[0028] 3) If Td>Td_max, the default value is 115°C, which is adjustable, and the corresponding system main valve opening Pmain=Pmain_max, the default value is 450p, and the corresponding system auxiliary valve opening or the main and auxiliary valve openings of other systems are 0P, the compressor will be shut down for protection, and go to step 4);

[0029] If the main valve opening of one system is Pmain=Pmain_max, and the exhaust Td is greater than Tc+50°C, and the main valve opening of the other system is Pmain=Pmain_min, the default value is 70p, and the exhaust Td is less than Tc+10°C, then go to step 5);

[0030] If the auxiliary valve opening Pmain of one system is equal to Pmain_max, and the supply air superheat TvSH is greater than 10°C, and the auxiliary valve opening Pmain of the other system is equal to Pmain_min, the default value is 70p, and the supply air superheat TvSH is less than 1°C, then go to step 5);

[0031] 4) The main valves and auxiliary valves of all systems are forced to maintain their initial openings, and the openings are ≥300P; the compressors of the protected systems are started and run. If Td < Tc + 50°C and Td > Tc + 15°C, go to step 5); if Td > Td_max, go to step 6;

[0032] 5) The unit shuts down for protection and reports a fault with the electronic expansion valve coil being incorrectly inserted. Return to step 2);

[0033] 6) The unit shuts down for protection and reports an exhaust temperature over-high protection fault, and returns to step 2).

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] By detecting the exhaust temperature Td1 and Td2, the exhaust pressure Pd1 and Pd2, the air supply inlet temperature Tv_in1 and Tv_in2, and the air supply outlet temperature Tv_out1 and Tv_out2, the controller calculates the exhaust superheat TdSH1=Td1-Tc1 and TdSH2=Td2-Tc2 of the first circulation system and the second circulation system according to the current exhaust temperature and condensation temperature. The controller calculates the air supply superheat TvSH1=Tv_out1-Tv_in1 and TvSH2=Tv_out2-Tv_in2 of the first circulation system and the second circulation system according to the inlet and outlet temperatures of the economizer air supply circuit. By detecting the exhaust temperature, the exhaust superheat and the opening of the electronic expansion valve, it is determined whether the coil of the electronic expansion valve is inserted incorrectly. No additional control resources are required. The method has the advantages of simple judgment method and high reliability. Moreover, the present invention can cover all variable frequency rooftop units with electronic expansion valve throttling and has wide application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0037] Figure 1 This is a structural schematic diagram of the intelligent full-frequency rooftop unit with self-diagnosis for incorrect insertion of the electronic expansion valve coil of the present invention.

[0038] Figure 2 This is a schematic structural diagram of the first circulation system of the present invention.

[0039] Figure 3 This is a schematic structural diagram of the second circulation system of the present invention.

[0040] Figure 4 Schematic diagram of the diagnostic system structure of the present invention.

[0041] In the figure: 1. Indoor heat exchanger; 2. First circulation system; 21. First compressor; 22. First four-way valve; 23. First outdoor heat exchanger; 24. First one-way valve group; 25. First economizer; 26. First auxiliary valve; 27. First main valve; 28. First muffler; 29. ​​First liquid reservoir; 210. First gas-liquid separator; 3. Second circulation system; 31. Second compressor; 32. Second four-way valve; 33. Second outdoor heat exchanger; 34. Second one-way valve group; 35. Second economizer; 36. Second auxiliary valve; 37. 7. Second main valve; 38. Second muffler; 39. Second liquid reservoir; 310. Second gas-liquid separator; 4. First detection module; 41. First exhaust pressure sensor; 42. First exhaust temperature sensor; 43. First air supply inlet temperature sensor; 44. First air supply outlet temperature sensor; 5. Second detection module; 51. Second exhaust pressure sensor; 52. Second exhaust temperature sensor; 53. Second air supply inlet temperature sensor; 54. Second air supply outlet temperature sensor; 6. Variable frequency blower; 7. Condensing blower DETAILED DESCRIPTION

[0042] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0043] Example: Figure 1-4 As shown, the present invention provides an intelligent full-frequency conversion rooftop unit with self-diagnosis of incorrect insertion of an electronic expansion valve coil, comprising an indoor heat exchanger 1, a first circulation system 2 and a second circulation system 3, wherein the first circulation system 2 and the second circulation system 3 are both connected to the indoor heat exchanger 1 through a pipeline, and the first circulation system 2 and the second circulation system 3 are both provided with a diagnostic system, which detects the operating parameters of the first circulation system 2 and the second circulation system 3.

[0044] Through the above technical solution, the diagnostic system calculates the exhaust superheat of the first circulation system 2 and the second circulation system 3 according to the current exhaust temperature and condensing temperature, and calculates the air supply superheat of the first circulation system 2 and the second circulation system 3 according to the inlet and outlet temperatures of the economizer air supply circuit. The exhaust temperature, exhaust superheat and the opening of the electronic expansion valve are used to determine whether the coil of the electronic expansion valve is inserted incorrectly. No additional control resources are required, and the system has the advantages of simple judgment method and high reliability. Moreover, the present invention can cover all variable frequency rooftop units with electronic expansion valve throttling, and has wide application value.

[0045] Furthermore, the first circulation system 2 includes a first compressor 21, the input end of the first compressor 21 is connected to the outlet end of the first gas-liquid separator 210 and the first muffler 28 through a pipeline, the output end of the first compressor 21 and the input end of the first gas-liquid separator 210 are both connected to the first four-way valve 22 through a pipeline, the first four-way valve 22 is connected to the output end of the indoor heat exchanger 1 and the input end of the first outdoor heat exchanger 23 through a pipeline, the output end of the first heat exchanger 23 is connected to the first one-way valve group 24 through a pipeline, the one-way valve group 24 is connected to the first economizer 25 through a pipeline, a first main valve 27 is installed between the first economizer 25 and the first one-way valve group 24, and a first auxiliary valve 26 is installed between the first economizer 25 and the pipeline at the end of the first main valve 27 away from the first one-way valve group 24, the first economizer 25 is connected to the first muffler 28 through a pipeline, the first one-way valve group 24 is also connected to the input end of the first liquid reservoir 29 through a pipeline, and the output end of the first liquid reservoir 29 is connected to the input end of the indoor heat exchanger 1 through a pipeline.

[0046] Furthermore, the second circulation system 3 includes a second compressor 31, the input end of the second compressor 31 is connected to the outlet end of the second gas-liquid separator 310 and the second muffler 38 through a pipeline, the output end of the second compressor 31 and the input end of the second gas-liquid separator 310 are both connected to the second four-way valve 32 through a pipeline, the second four-way valve 32 is connected to the output end of the indoor heat exchanger 1 and the input end of the second outdoor heat exchanger 33 through a pipeline, the output end of the second heat exchanger 33 is connected to the second one-way valve group 34 through a pipeline, the one-way valve group 34 is connected to the second economizer 35 through a pipeline, a second main valve 37 is installed between the second economizer 35 and the second one-way valve group 34, and a second auxiliary valve 36 is installed between the second economizer 35 and the pipelines at the two ends of the second main valve 37 away from the second one-way valve group 34, the second economizer 35 is connected to the second muffler 38 through a pipeline, the second one-way valve group 34 is also connected to the input end of the second liquid reservoir 39 through a pipeline, and the output end of the second liquid reservoir 39 is connected to the input end of the indoor heat exchanger 1 through a pipeline.

[0047] Furthermore, a variable frequency blower 6 is installed at the indoor heat exchanger 1 , and a condensing fan 7 is installed at both the first outdoor heat exchanger 23 and the second outdoor heat exchanger 33 .

[0048] Furthermore, the condensing fan 7 is a DC variable frequency condensing fan, and the first compressor 21 and the second compressor 31 are both air-supplying and enthalpy-increasing DC variable frequency compressors.

[0049] Through the above technical solution, the first compressor 21 and the second compressor 31 compress the low-pressure and low-temperature refrigerant into a high-temperature and high-pressure superheated gas, which passes through the exhaust pipe to the first four-way valve 22 and the second four-way valve 32, and then to the first outdoor heat exchanger 23 and the second outdoor heat exchanger 33 for condensation. After condensation by the outdoor heat exchanger, the refrigerant passes through the one-way valve assembly to the economizer, and exchanges heat with the air supply circuit refrigerant after throttling by the auxiliary valve, thereby obtaining supercooled high-pressure and medium-temperature refrigerant. After throttling by the main valve, the refrigerant passes through the one-way valve assembly to the liquid reservoir. After passing through the liquid reservoir, the refrigerant reaches the indoor heat exchanger 1, which is a fin-tube heat exchanger. After the refrigerant and the indoor air are forced to exchange heat through convection by the variable frequency blower 6, low-pressure and low-temperature superheated vapor is obtained, which returns to the gas-liquid separator through the four-way valve and then returns to the compressor through the gas-liquid separator. The air supply circuit refrigerant after throttling by the auxiliary valve obtains medium-pressure and medium-temperature superheated vapor after heat exchange in the economizer, and returns to the compressor medium-pressure chamber after eliminating pulsation and noise through the muffler to complete the cycle.

[0050] Furthermore, the diagnostic system includes a first detection module 4, a second detection module 5 and a controller, wherein:

[0051] The first detection module 4 is connected to the first circulation system 2 and is used to detect the exhaust temperature and pressure, the supply air inlet temperature and the supply air outlet temperature of the first circulation system 2, and transmit the detection data to the controller;

[0052] The second detection module 5 is connected to the second circulation system 3 and is used to detect the exhaust temperature and pressure, the supply air inlet temperature and the supply air outlet temperature of the second circulation system 3, and transmit the detection data to the controller;

[0053] The controller is used to receive and process data from the first detection module 4 and the second detection module 5, and to diagnose whether the electronic expansion valve coil is incorrectly inserted.

[0054] Furthermore, the first detection module 4 includes:

[0055] A first exhaust pressure sensor 41 is installed at the output end of the first compressor 21 and is used to detect the exhaust pressure Pd1 of the first circulation system 2;

[0056] A first exhaust gas temperature sensor 42 is installed at the output end of the first compressor 21 and is used to detect the exhaust gas temperature Td1 of the first circulation system 2;

[0057] A first supplementary air inlet temperature sensor 43 , which is installed on the pipeline between the first economizer 25 and the first auxiliary valve 26 and is used to detect the supplementary air inlet temperature Tv_in1 of the first circulation system 2 ;

[0058] The first supplementary air outlet temperature sensor 44 is installed on the pipeline between the first economizer 25 and the first muffler 28 , and is used to detect the supplementary air outlet temperature Tv_out1 of the first circulation system 2 .

[0059] Furthermore, the second detection module 5 includes:

[0060] A second exhaust pressure sensor 51 is installed at the output end of the second compressor 31 and is used to detect the exhaust pressure Pd2 of the second circulation system 3;

[0061] A second exhaust gas temperature sensor 52 is installed at the output end of the second compressor 31 and is used to detect the exhaust gas temperature Td2 of the second circulation system 3;

[0062] A second air supply inlet temperature sensor 53, which is installed on the pipeline between the second economizer 35 and the second auxiliary valve 36, and is used to detect the air supply inlet temperature Tv_in2 of the second circulation system 3;

[0063] The second supplementary air outlet temperature sensor 54 is installed on the pipeline between the second economizer 35 and the second muffler 38 , and is used to detect the supplementary air outlet temperature Tv_out2 of the second circulation system 3 .

[0064] A control method for an intelligent full-frequency conversion rooftop unit with self-diagnosis for incorrect insertion of an electronic expansion valve coil is characterized in that a controller calculates the exhaust superheat TdSH1=Td1-Tc1 and TdSH2=Td2-Tc2 of a first circulation system 2 and a second circulation system 3 according to the current exhaust temperature and condensing temperature; and calculates the supply air superheat TvSH1=Tv_out1-Tv_in1 and TvSH2=Tv_out2-Tv_in2 of the first circulation system 2 and the second circulation system 3 according to the inlet and outlet temperatures of the economizer supply air circuit, thereby diagnosing incorrect insertion of the electronic expansion valve coil.

[0065] Furthermore, the controller diagnosis process includes the following steps:

[0066] 1) The unit is started and running;

[0067] 2) Check the compressor startup time. If the startup time is ≥ 5s, go to step 3);

[0068] 3) If Td>Td_max, the default value is 115°C, which is adjustable, and the corresponding system main valve opening Pmain=Pmain_max, the default value is 450p, and the corresponding system auxiliary valve opening or the main and auxiliary valve openings of other systems are 0P, the compressor will be shut down for protection, and go to step 4);

[0069] If the main valve opening of one system is Pmain=Pmain_max, and the exhaust Td is greater than Tc+50°C, and the main valve opening of the other system is Pmain=Pmain_min, the default value is 70p, and the exhaust Td is less than Tc+10°C, then go to step 5);

[0070] If the auxiliary valve opening Pmain of one system is equal to Pmain_max, and the supply air superheat TvSH is greater than 10°C, and the auxiliary valve opening Pmain of the other system is equal to Pmain_min, the default value is 70p, and the supply air superheat TvSH is less than 1°C, then go to step 5);

[0071] 4) The main valves and auxiliary valves of all systems are forced to maintain their initial openings, and the openings are ≥300P; the compressors of the protected systems are started and run. If Td < Tc + 50°C and Td > Tc + 15°C, go to step 5); if Td > Td_max, go to step 6;

[0072] 5) The unit shuts down for protection and reports a fault with the electronic expansion valve coil being incorrectly inserted. Return to step 2);

[0073] 6) The unit shuts down for protection and reports an exhaust temperature over-high protection fault, and returns to step 2).

[0074] Working principle: By detecting the exhaust temperature Td1 and Td2, the exhaust pressure Pd1 and Pd2, the air supply inlet temperature Tv_in1 and Tv_in2, and the air supply outlet temperature Tv_out1 and Tv_out2, the controller calculates the exhaust superheat TdSH1=Td1-Tc1 and TdSH2=Td2-Tc2 of the first circulation system 2 and the second circulation system 3 according to the current exhaust temperature and condensation temperature. The controller calculates the air supply superheat TvSH1=Tv_out1-Tv_in1 and TvSH2=Tv_out2-Tv_in2 of the first circulation system 2 and the second circulation system 3 according to the inlet and outlet temperatures of the economizer air supply circuit. By detecting the exhaust temperature, the exhaust superheat and the opening of the electronic expansion valve, it is determined whether the coil of the electronic expansion valve is inserted incorrectly. No additional control resources are required. It has the advantages of simple judgment method and high reliability. Moreover, the present invention can cover all variable frequency rooftop units with electronic expansion valve throttling and has wide application value.

[0075] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. An intelligent full-frequency conversion rooftop unit with self-diagnosis for incorrect insertion of an electronic expansion valve coil, comprising an indoor heat exchanger (1), a first circulation system (2) and a second circulation system (3), characterized in that: The first circulation system (2) and the second circulation system (3) are both connected to the indoor heat exchanger (1) via a pipeline, and the first circulation system (2) and the second circulation system (3) are both provided with a diagnostic system, and the diagnostic system detects the operating parameters of the first circulation system (2) and the second circulation system (3); The first circulation system (2) includes a first compressor (21), the input end of the first compressor (21) is connected to the outlet end of the first gas-liquid separator (210) and the first muffler (28) through a pipeline, the output end of the first compressor (21) and the input end of the first gas-liquid separator (210) are both connected to a first four-way valve (22) through a pipeline, the first four-way valve (22) is connected to the output end of the indoor heat exchanger (1) and the input end of the first outdoor heat exchanger (23) through a pipeline, the output end of the first outdoor heat exchanger (23) is connected to a first one-way valve group (24) through a pipeline, The one-way valve group (24) is connected to the first economizer (25) through a pipeline. A first main valve (27) is installed between the first economizer (25) and the first one-way valve group (24). A first auxiliary valve (26) is installed between the first economizer (25) and the pipeline at one end of the first main valve (27) away from the first one-way valve group (24). The first economizer (25) is connected to the first muffler (28) through a pipeline. The first one-way valve group (24) is also connected to the input end of the first liquid reservoir (29) through a pipeline. The output end of the first liquid reservoir (29) is connected to the input end of the indoor heat exchanger (1) through a pipeline. The second circulation system (3) includes a second compressor (31), the input end of the second compressor (31) is connected to the outlet end of the second gas-liquid separator (310) and the second muffler (38) through a pipeline, the output end of the second compressor (31) and the input end of the second gas-liquid separator (310) are both connected to a second four-way valve (32) through a pipeline, the second four-way valve (32) is connected to the output end of the indoor heat exchanger (1) and the input end of the second outdoor heat exchanger (33) through a pipeline, the output end of the second outdoor heat exchanger (33) is connected to a second one-way valve group (34) through a pipeline, and the The one-way valve group (34) is connected to the second economizer (35) through a pipeline, a second main valve (37) is installed between the second economizer (35) and the second one-way valve group (34), and a second auxiliary valve (36) is installed between the second economizer (35) and the pipeline at two ends of the second main valve (37) away from the second one-way valve group (34). The second economizer (35) is connected to the second muffler (38) through a pipeline, and the second one-way valve group (34) is also connected to the input end of the second liquid reservoir (39) through a pipeline, and the output end of the second liquid reservoir (39) is connected to the input end of the indoor heat exchanger (1) through a pipeline. The controller calculates the exhaust superheat TdSH1=Td1-Tc1 and TdSH2=Td2-Tc2 of the first circulation system (2) and the second circulation system (3) according to the current exhaust temperature and condensing temperature. The controller calculates the supply air superheat TvSH1=Tv_out1-Tv_in1 and TvSH2=Tv_out2-Tv_in2 of the first circulation system (2) and the second circulation system (3) according to the inlet and outlet temperatures of the economizer supply air circuit, thereby diagnosing the wrong insertion of the electronic expansion valve coil. Tv_in1 and Tv_in2 are the supply air inlet temperatures, Tv_out1 and Tv_out2 are the supply air outlet temperatures, Td1 and Td2 are the exhaust temperatures, and Tc1 and Tc2 are the condensing temperatures. The controller diagnostic process includes the following steps: 1) The unit starts running; 2) Check the compressor startup time. If the startup time is ≥ 5s, go to step 3); 3) If Td>Td_max, the default value is 115℃, which is adjustable, and the corresponding system main valve opening Pmain=Pmain_max, the default value is 450p, and the corresponding system auxiliary valve opening or the main and auxiliary valve openings of other systems are 0P, the compressor will be shut down for protection and go to step 4); If the main valve opening of one system is Pmain=Pmain_max, and the exhaust gas Td>Tc+50℃, and the main valve opening of the other system is Pmain=Pmain_min, the default value is 70p, and the exhaust gas Td<Tc+10℃, then go to step 5); If the auxiliary valve opening of one system Pmain=Pmain_max, and the supply air superheat TvSH>10℃, and the auxiliary valve opening of the other system Pmain=Pmain_min, the default value is 70p, and the supply air superheat TvSH<1℃, then go to step 5); 4) Main valves and auxiliary valves of all systems are forced to maintain their initial openings, and the openings are ≥300P; the compressors of the protected systems are started and run. If Td < Tc + 50°C, and Td > Tc + 15°C, go to step 5); if Td > Td_max, go to step 6); 5) The unit shuts down for protection and reports a fault with the electronic expansion valve coil being incorrectly inserted. Return to step 2); 6) The unit shuts down for protection and reports a high exhaust temperature protection fault, returning to step 2).

2. The intelligent full-frequency rooftop unit with self-diagnosis for incorrect insertion of electronic expansion valve coils as claimed in claim 1, characterized in that: A variable frequency blower (6) is installed at the indoor heat exchanger (1), and a condensing blower (7) is installed at both the first outdoor heat exchanger (23) and the second outdoor heat exchanger (33).

3. The intelligent full-frequency conversion rooftop unit with self-diagnosis for incorrect insertion of electronic expansion valve coils as claimed in claim 2, characterized in that: The condensing fan (7) is a DC variable frequency condensing fan, and the first compressor (21) and the second compressor (31) are both air-supplying and enthalpy-increasing DC variable frequency compressors.

4. The intelligent full-frequency rooftop unit with self-diagnosis for incorrect insertion of electronic expansion valve coils as claimed in claim 1, characterized in that: The diagnostic system comprises a first detection module (4), a second detection module (5) and a controller, wherein: The first detection module (4) is connected to the first circulation system (2) and is used to detect the exhaust temperature and pressure, the air supply inlet temperature and the air supply outlet temperature of the first circulation system (2), and transmit the detection data to the controller; The second detection module (5) is connected to the second circulation system (3) and is used to detect the exhaust temperature and pressure, the air supply inlet temperature and the air supply outlet temperature of the second circulation system (3), and transmit the detection data to the controller; The controller is used to receive data from the first detection module (4) and the second detection module (5), process the data, and diagnose the incorrect insertion of the electronic expansion valve coil.

5. The intelligent full-frequency rooftop unit with self-diagnosis for incorrect insertion of electronic expansion valve coils as claimed in claim 4, characterized in that: The first detection module (4) comprises: a first exhaust pressure sensor (41), the first exhaust pressure sensor (41) being installed at the output end of the first compressor (21) and being used to detect the exhaust pressure Pd1 of the first circulation system (2); a first exhaust gas temperature sensor (42), the first exhaust gas temperature sensor (42) being installed at the output end of the first compressor (21) and being used to detect the exhaust gas temperature Td1 of the first circulation system (2); a first air supply inlet temperature sensor (43), the first air supply inlet temperature sensor (43) being installed on a pipeline between the first economizer (25) and the first auxiliary valve (26), and being used to detect an air supply inlet temperature Tv_in1 of the first circulation system (2); A first air supply outlet temperature sensor (44) is installed on a pipeline between the first economizer (25) and the first muffler (28) and is used to detect the air supply outlet temperature Tv_out1 of the first circulation system (2).

6. The intelligent full-frequency rooftop unit with self-diagnosis for incorrect insertion of electronic expansion valve coils as claimed in claim 4, characterized in that: The second detection module (5) comprises: a second exhaust pressure sensor (51), the second exhaust pressure sensor (51) being installed at the output end of the second compressor (31) and being used to detect the exhaust pressure Pd2 of the second circulation system (3); a second exhaust gas temperature sensor (52), the second exhaust gas temperature sensor (52) being installed at the output end of the second compressor (31) and being used to detect the exhaust gas temperature Td2 of the second circulation system (3); a second air supply inlet temperature sensor (53), the second air supply inlet temperature sensor (53) being installed on a pipeline between the second economizer (35) and the second auxiliary valve (36), and being used to detect the air supply inlet temperature Tv_in2 of the second circulation system (3); A second air supply outlet temperature sensor (54) is installed on the pipeline between the second economizer (35) and the second muffler (38) and is used to detect the air supply outlet temperature Tv_out2 of the second circulation system (3).

Images