Double-evaporator refrigerating system, refrigerating equipment and control method thereof

Abstract

The invention discloses a double-evaporator refrigerating system, refrigerating equipment and a control method thereof.The double-evaporator refrigerating system is characterized in that an exhaust port of a double-cylinder compressor is communicated with two pipelines, the first pipeline is communicated with a port of a four-way valve, and a four-way port of the four-way valve is sequentially communicated with a condenser assembly and a hot runner inlet of an enthalpy-increasing heat exchanger; a hot runner outlet of the enthalpy-increasing heat exchanger is communicated with three branches; the first branch is sequentially communicated with a cold runner of the enthalpy-increasing heat exchanger and an enthalpy-increasing opening of the double-cylinder compressor; the second branch is sequentially communicated with the first evaporator assembly and a two-way port of the four-way valve, and a three-way port of the four-way valve is communicated with a first air suction port of the double-cylinder compressor; the third branch is sequentially communicated with the second evaporator assembly and a second air suction port of the double-cylinder compressor; and the second pipeline is communicated with the second evaporator assembly. When the second temperature zone is defrosted, the first temperature zone can be defrosted or refrigerated, so that the temperature of the first temperature zone is kept stable, meanwhile, the defrosting energy consumption can be reduced, and energy conservation is facilitated.

Description

Technical Field

[0001] The present invention relates to the field of cold chain technology, and more specifically, to a dual-evaporator refrigeration system. In addition, the present invention also relates to a refrigeration device including the dual-evaporator refrigeration system, and a control method applied to the dual-evaporator refrigeration system. Background Art

[0002] The dual evaporator refrigeration system uses two evaporators in one refrigeration system to achieve independent temperature control in different areas. For example, in a refrigeration and freezing equipment, one evaporator can be used in the freezing area (i.e., ultra-low temperature area), while the other evaporator can be used in the refrigeration area (i.e., low temperature area), so that the freezing area and the refrigeration area can independently control the temperature without interfering with each other.

[0003] In the process of implementing the invention of this application, the inventors found that there are at least the following problems in the prior art:

[0004] In the existing dual-evaporator refrigeration system, during refrigeration operation, when the evaporator in the low-temperature zone is defrosted, the evaporator in the ultra-low-temperature zone needs to be closed, which will cause the temperature of the ultra-low-temperature zone to fluctuate, which is not conducive to energy saving and temperature stability.

[0005] In summary, how to avoid temperature fluctuation in the ultra-low temperature zone due to defrosting in the low temperature zone is an urgent problem to be solved by those skilled in the art. Summary of the invention

[0006] In view of this, an object of the present invention is to provide a dual-evaporator refrigeration system, which can achieve defrosting or refrigeration of the first temperature zone when the second temperature zone is defrosted, so as to maintain a stable temperature in the first temperature zone.

[0007] Another object of the present invention is to provide a refrigeration device including the above-mentioned dual-evaporator refrigeration system, and also to provide a control method applied to the above-mentioned dual-evaporator refrigeration system.

[0008] In order to achieve the above object, the present invention provides the following technical solutions:

[0009] A dual-evaporator refrigeration system includes a dual-cylinder compressor, a four-way valve, a condenser assembly, an enthalpy-increasing heat exchanger, a first evaporator assembly for installation in a first temperature zone, and a second evaporator assembly for installation in a second temperature zone;

[0010] The exhaust pipe connected to the exhaust port of the twin-cylinder compressor is divided into two pipes:

[0011] The first pipeline is connected to one port of the four-way valve, the four-way port of the four-way valve is connected to the condenser assembly and the hot runner inlet of the enthalpy-increasing heat exchanger in sequence, the hot runner outlet of the enthalpy-increasing heat exchanger is connected to the connecting pipeline, and the connecting pipeline is divided into three branches: the first branch is connected to the cold runner of the enthalpy-increasing heat exchanger and the enthalpy-increasing port of the two-cylinder compressor in sequence through the throttle valve group; the second branch is connected to the first evaporator assembly and the second port of the four-way valve in sequence through the first expansion valve, and the three-way port of the four-way valve is connected to the first suction port of the two-cylinder compressor; the third branch is connected to the second evaporator assembly and the second suction port of the two-cylinder compressor in sequence through the second expansion valve;

[0012] The second pipeline is connected to the third branch between the second expansion valve and the second evaporator assembly through the first solenoid valve.

[0013] Optionally, it also includes a first indoor temperature sensor for installation in the first temperature zone and a second indoor temperature sensor for installation in the second temperature zone. The first indoor temperature sensor, the second indoor temperature sensor, the four-way valve, the throttling valve group, the first expansion valve, and the second expansion valve are all signal-connected to the control unit.

[0014] Optionally, it also includes a first coil temperature sensor provided in the first evaporator component and a second coil temperature sensor provided in the second evaporator component, and the first coil temperature sensor, the second coil temperature sensor and the first solenoid valve are all connected to the control unit through signals.

[0015] Optionally, an auxiliary pipeline is connected between the pipeline connecting the three-way port of the four-way valve and the first air intake port and the third pipeline located between the second evaporator assembly and the second air intake port, and a second solenoid valve connected to the control unit signal is provided on the auxiliary pipeline.

[0016] Optionally, the throttling valve group includes a third solenoid valve and a thermal expansion valve, which are sequentially arranged on the first branch along the direction from the hot runner outlet to the cold runner inlet of the enthalpy increase heat exchanger.

[0017] Optionally, a drying filter is provided on the connecting pipeline communicating with the hot runner outlet of the enthalpy-increasing heat exchanger.

[0018] Optionally, the condenser assembly includes a condenser and a condensing fan disposed on one side of the condenser;

[0019] And / or, the first evaporator assembly includes a first evaporator and a first evaporation fan disposed on one side of the first evaporator;

[0020] And / or, the second evaporator assembly includes a second evaporator and a second evaporation fan arranged on one side of the second evaporator.

[0021] Preferably, an exhaust gas temperature sensor and an exhaust gas pressure sensor are provided on the exhaust gas pipeline connected to the exhaust port of the dual-cylinder compressor, and both of them are connected to the control unit by signals;

[0022] And / or, a first intake air temperature sensor and a first intake air pressure sensor are provided on a pipeline connecting the three-way port of the four-way valve and the first intake port, and both of the sensors are connected to the control unit;

[0023] And / or, a second suction temperature sensor and a second suction pressure sensor are provided on the second branch between the second evaporator assembly and the second suction port, and both of the sensors are connected to the control unit.

[0024] A refrigeration device comprises the double evaporator refrigeration system described in any one of the above items.

[0025] A control method is applied to any of the above dual-evaporator refrigeration systems, the control method comprising:

[0026] Obtain the coil temperature of the second temperature zone and the coil temperature of the first temperature zone;

[0027] When the temperature of the coil in the first temperature zone is greater than or equal to the first set temperature, determine whether the temperature of the coil in the second temperature zone is less than the second set temperature. If so, open the first solenoid valve and close the second expansion valve until the temperature of the coil in the second temperature zone is greater than or equal to the second set temperature.

[0028] When the temperature of the coil in the first temperature zone is lower than the first set temperature, the first port of the four-way valve is connected to its second port, the four-way port of the four-way valve is connected to its three-way port, and the throttling valve group, the first solenoid valve, and the second expansion valve are closed;

[0029] Determine whether the coil temperature in the first temperature zone is greater than or equal to the first set temperature. If so, connect the first port of the four-way valve to its four-way port, connect the second port of the four-way valve to its three-way port, and open the throttling valve group and the second expansion valve;

[0030] While executing the step of determining whether the temperature of the coil in the first temperature zone is greater than or equal to the first set temperature, determining whether the temperature of the coil in the second temperature zone is less than the second set temperature, and if so, opening the first solenoid valve;

[0031] Determine whether the coil temperature in the second temperature zone is greater than or equal to the second set temperature, and if so, close the first solenoid valve;

[0032] While executing the step of determining whether the temperature of the coil in the second temperature zone is greater than or equal to the second set temperature, determine whether the temperature of the coil in the first temperature zone is greater than or equal to the first set temperature. If so, one port of the four-way valve is connected to its four-way port, the second port of the four-way valve is connected to its three-way port, the throttling valve group and the second expansion valve are opened, and the first solenoid valve is closed.

[0033] As can be seen from the above, the first temperature zone can be used as an ultra-low temperature zone, and the second temperature zone can be used as a low temperature zone. During the operation of the refrigeration mode, the dual evaporator refrigeration system provided by the present invention can realize the following four defrosting modes:

[0034] Second temperature zone - first temperature zone defrost mode: high-temperature gaseous refrigerant is discharged from the exhaust port of the twin-cylinder compressor and divided into two paths. The first path passes through the four-way valve and enters the first evaporator assembly to release heat and defrost, and then passes through the first expansion valve throttling and then passes through the enthalpy increase heat exchanger and the condenser assembly in sequence into the four-way valve and flows back to the first suction port of the twin-cylinder compressor, thus realizing defrosting in the first temperature zone; the second path directly enters the second evaporator assembly to release heat and defrost, and then directly flows back to the second suction port of the twin-cylinder compressor, thus realizing defrosting in the second temperature zone.

[0035] Second temperature zone single opening defrost mode: In the above-mentioned second temperature zone-first temperature zone co-opening defrost mode, close the first expansion valve and the condenser assembly, and only run the second process, that is, realize the second temperature zone single opening defrost mode.

[0036] First temperature zone single opening defrost mode: In the above-mentioned second temperature zone-first temperature zone co-opening defrost mode, closing the first solenoid valve will only run the first process, that is, realizing the first temperature zone single opening defrost mode.

[0037] Second temperature zone defrosting - first temperature zone refrigeration mode: The exhaust port of the twin-cylinder compressor discharges high-temperature gaseous refrigerant and is divided into two paths. The first path passes through the four-way valve and then passes through the condenser assembly and the hot runner of the enthalpy-increasing heat exchanger to cool down and form a low-temperature liquid refrigerant. Part of the low-temperature liquid refrigerant flows into the first branch and then flows into the cold runner of the enthalpy-increasing heat exchanger after throttling by the throttle valve group, and then absorbs the heat of the refrigerant in the hot runner of the enthalpy-increasing heat exchanger and flows into the enthalpy-increasing port of the twin-cylinder compressor. The other part of the low-temperature liquid refrigerant flows into the second branch and then flows into the first evaporator assembly after throttling by the first expansion valve, and then absorbs the heat of the air in the first temperature zone to form a high-temperature gaseous refrigerant, and then flows back to the first air intake port of the twin-cylinder compressor after passing through the four-way valve, completing the refrigeration of the first temperature zone. The second path directly enters the second evaporator assembly to release heat and defrost, and then directly flows back to the second air intake port of the twin-cylinder compressor, realizing the defrosting of the second temperature zone.

[0038] To sum up, the present invention can realize defrosting of two temperature zones separately, and when the second temperature zone is defrosted, the first temperature zone can be defrosted or cooled, which can avoid temperature fluctuations in the first temperature zone and keep the temperature of the first temperature zone stable. At the same time, it can also reduce defrosting energy consumption, which is beneficial to energy saving. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0040] Figure 1 A schematic diagram of a dual-evaporator refrigeration system provided by the present invention;

[0041] Figure 2 It is a schematic diagram of a dual evaporator refrigeration system in a second temperature zone-first temperature zone simultaneous defrosting mode;

[0042] Figure 3 It is a schematic diagram of a dual evaporator refrigeration system in a second temperature zone single open defrost mode;

[0043] Figure 4 It is a schematic diagram of a dual-evaporator refrigeration system in a single-opening defrost mode in the first temperature zone;

[0044] Figure 5 It is a schematic diagram of a dual evaporator refrigeration system in a second temperature zone defrosting-first temperature zone refrigeration mode;

[0045] Figure 6 Defrost mode control logic diagram for dual evaporator refrigeration system.

[0046] Reference numerals:

[0047] 1-two-cylinder compressor; 2-four-way valve; 3-condensing fan; 4-condenser; 5-enthalpy increase heat exchanger; 6-drying filter; 7-second solenoid valve; 8-thermal expansion valve; 9-first expansion valve; 10-first evaporator; 11-first evaporating fan; 12-first indoor temperature sensor; 13-first coil temperature sensor; 14-second expansion valve; 15-second evaporator; 16-second evaporating fan; 17-second indoor temperature sensor; 18-second coil temperature sensor; 19-third solenoid valve; 20-first solenoid valve; 21-exhaust temperature sensor; 22-exhaust pressure sensor; 23-first suction temperature sensor; 24-first suction pressure sensor; 25-second suction temperature sensor; 26-second suction pressure sensor;

[0048] D-one-way port; E-two-way port; S-three-way port; C-four-way port. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work are within the scope of protection of the present invention.

[0050] The core of the present invention is to provide a dual-evaporator refrigeration system, which can realize that when the second temperature zone is defrosted, the first temperature zone can be defrosted or refrigerated to maintain a stable temperature in the first temperature zone.

[0051] Another core of the present invention is to provide a refrigeration device including the above-mentioned dual-evaporator refrigeration system, and also to provide a control method applied to the above-mentioned dual-evaporator refrigeration system.

[0052] Please refer to Figure 1 The present invention provides a dual-evaporator refrigeration system, including a dual-cylinder compressor 1, a four-way valve 2, a condenser assembly, an enthalpy-increasing heat exchanger 5, a first evaporator assembly for installation in a first temperature zone, and a second evaporator assembly for installation in a second temperature zone. It can be understood that the first temperature zone can be used as an ultra-low temperature zone (or freezing zone), and the second temperature zone can be used as a low temperature zone (or refrigeration zone). Here, the low temperature zone and the ultra-low temperature zone are relative, and the temperature of the low temperature zone will be higher than the temperature of the ultra-low temperature zone.

[0053] The exhaust port of the twin-cylinder compressor 1 is connected to an exhaust pipeline. Specifically, the exhaust pipeline connected to the exhaust port of the twin-cylinder compressor 1 can be divided into two pipelines.

[0054] It should be noted that the twin-cylinder compressor 1 has an enthalpy increase port for introducing enthalpy increase gas to reduce the work done by the compressor, thereby facilitating the stable operation of the refrigeration system with dual temperature zones and saving system energy consumption. In addition, the twin-cylinder compressor 1 has a first air intake port and a second air intake port, which are respectively connected to two independent cylinders. The two cylinders can compress the refrigerant at the same time, thereby improving the efficiency of the compressor, which is further conducive to improving the refrigeration efficiency of the refrigeration system.

[0055] The first pipeline is connected to a port D of the four-way valve 2, and the four-way port C of the four-way valve 2 is connected to the condenser assembly and the hot runner inlet of the enthalpy increasing heat exchanger 5 in sequence. The hot runner outlet of the enthalpy increasing heat exchanger 5 is connected to the connecting pipeline, and the connecting pipeline is divided into three branches: the first branch is connected to the cold runner of the enthalpy increasing heat exchanger 5 and the enthalpy increasing port of the two-cylinder compressor 1 in sequence through the throttle valve group; the second branch is connected to the first evaporator assembly and the second port E of the four-way valve 2 in sequence through the first expansion valve 9, and the three-way port S of the four-way valve 2 is connected to the first suction port of the two-cylinder compressor 1; the third branch is connected to the second evaporator assembly and the second suction port of the two-cylinder compressor 1 in sequence through the second expansion valve 14.

[0056] It should be noted that the four-way valve 2 includes four ports, namely, port D, port E, port S and port C. The four ports can be switched to be connected to change the flow direction of the refrigerant. The function of the condenser assembly is to cool the high-temperature gaseous refrigerant and convert it into a liquid state to achieve a refrigeration effect. The enthalpy-increasing heat exchanger 5 includes a hot runner and a cold runner that are adjacently arranged and can exchange heat with each other. The two respectively allow hot fluid and cold fluid to pass through and achieve efficient heat exchange between hot fluid and cold fluid. Exemplarily, the enthalpy-increasing heat exchanger 5 can adopt a plate heat exchanger. The function of the evaporator assembly is to evaporate the low-temperature refrigerant and convert it into a gaseous state, so that the indoor gas is cooled and cooled, thereby achieving an indoor refrigeration effect. Therefore, the first evaporator assembly is used to be installed in the first temperature zone, so that the first temperature zone refrigeration can be achieved, and the second evaporator assembly is used to be installed in the second temperature zone, so that the second temperature zone refrigeration can be achieved. The throttling valve group, the first expansion valve 9 and the second expansion valve 14 can all play a throttling and pressure-reducing role, that is, the liquid refrigerant is throttled through them to become low-temperature and low-pressure wet steam (or gas-liquid mixture).

[0057] The second pipeline is connected to the third branch between the second expansion valve 14 and the second evaporator assembly through the first solenoid valve 20.

[0058] It should be noted that if the first solenoid valve 20 is opened, the exhaust port of the two-cylinder compressor 1 can directly flow into the second evaporator assembly to release heat and defrost, that is, to achieve defrosting in the second temperature zone.

[0059] Regarding the specific configuration of the condenser assembly, based on the above embodiments, please refer to Figure 1 The condenser assembly includes a condenser 4 and a condensing fan 3 arranged on one side of the condenser 4.

[0060] Among them, the condensing fan 3 and the condenser 4 can both be installed on the outdoor side. The four-way port C of the four-way valve 2 is connected to the condenser 4 and the hot runner inlet of the enthalpy increase heat exchanger 5 in sequence. The condensing fan 3 can be set on the air inlet side or the air outlet side of the condenser 4. The outdoor air is sucked into the condenser 4 through high-speed rotation, taking away the heat generated by the refrigerant in the condensation process, and changing the refrigerant from gas to liquid to achieve a cooling effect.

[0061] Regarding the specific configuration of the first evaporator assembly, based on the above embodiment, please refer to Figure 1 The first evaporator assembly includes a first evaporator 10 and a first evaporation fan 11 arranged at one side of the first evaporator 10 .

[0062] Among them, the first evaporation fan 11 and the first evaporator 10 can both be installed on the indoor side (that is, in the first temperature zone), and the second branch is connected to the first evaporator 10 and the second port E of the four-way valve 2 in sequence through the first expansion valve 9. The first evaporation fan 11 can be set on the air inlet side or the air outlet side of the first evaporator 10, and introduces the hot air in the first temperature zone into the first evaporator 10 through high-speed rotation. The hot air is released into the room after heat exchange with the first evaporator 10, thereby achieving the effect of cooling the first temperature zone.

[0063] Regarding the specific configuration of the second evaporator assembly, based on the above embodiment, please refer to Figure 1 The second evaporator assembly includes a second evaporator 15 and a second evaporation fan 16 disposed on one side of the second evaporator 15 .

[0064] Among them, the second evaporator fan 16 and the second evaporator 15 can be installed on the indoor side (that is, in the second temperature zone), and the third branch connects the second evaporator 15 and the second air intake port of the two-cylinder compressor 1 in sequence through the second expansion valve 14. The second evaporator fan 16 can be set on the air inlet side or the air outlet side of the second evaporator 15, and introduces the hot air in the second temperature zone into the second evaporator 15 through high-speed rotation. The hot air is released into the room after heat exchange with the second evaporator 15, thereby achieving the effect of cooling the second temperature zone.

[0065] It should be noted that the two-cylinder compressor 1 has two cylinder bodies. If in the second temperature zone independent refrigeration mode or the first temperature zone independent refrigeration mode, one cylinder body inhales gas through its corresponding air intake port for compression, and the other cylinder body has no air intake for compression or is directly closed, the other cylinder body is frequently started and stopped or the internal pressure is unbalanced, which will shorten the service life of the compressor.

[0066] In order to effectively avoid the above situation and increase the service life of the compressor, based on the above embodiment, please refer to Figure 1 An auxiliary pipeline is connected between the pipeline connecting the three-way port S of the four-way valve 2 and the first air intake port and the third pipeline located between the second evaporator assembly and the second air intake port. The auxiliary pipeline is provided with a second solenoid valve 7 connected to the control unit signal.

[0067] Therefore, in the second temperature zone single open defrost mode or the first temperature zone single open defrost mode, opening the second solenoid valve 7 can make both air intake ports of the twin-cylinder compressor 1 suck gas, and then make both cylinders of the twin-cylinder compressor 1 suck gas and cooperate to perform compression action, which is beneficial to improve the working efficiency and service life of the compressor. It should be noted that in the second temperature zone-first temperature zone simultaneous open defrost mode and the second temperature zone defrost-first temperature zone refrigeration mode, the second solenoid valve 7 remains closed.

[0068] Regarding the specific setting of the throttle valve group, based on the above embodiment, please refer to Figure 1 The throttle valve group includes a third solenoid valve 19 and a thermal expansion valve 8, which are arranged on the first branch in sequence along the direction from the hot runner outlet to the cold runner inlet of the enthalpy increase heat exchanger 5.

[0069] Specifically, the thermal expansion valve 8 is installed on the first branch, and a part of the liquid refrigerant discharged from the hot flow channel of the enthalpy-increasing heat exchanger 5 is throttled by the thermal expansion valve 8 to become low-temperature and low-pressure wet steam (or gas-liquid mixture), and then flows into the cold flow channel of the enthalpy-increasing heat exchanger 5 to absorb heat and evaporate into low-temperature and low-pressure gaseous refrigerant. The low-temperature and low-pressure gaseous refrigerant flows into the two-cylinder compressor 1 through the enthalpy-increasing port to achieve the enthalpy-increasing function. The thermal expansion valve 8 maintains a certain degree of superheat to prevent liquid refrigerant from entering the two-cylinder compressor 1 and causing liquid hammer. Since the thermal expansion valve 8 maintains a certain degree of superheat, the thermal expansion valve 8 cannot be completely closed. Therefore, a third solenoid valve 19 located before the thermal expansion valve 8 is provided on the first branch to control the on-off of the first branch.

[0070] During the operation of the refrigeration mode of the dual-evaporator refrigeration system provided in the above embodiment, the following four defrosting modes can be implemented:

[0071] Please refer to Figure 2 , the second temperature zone-the first temperature zone is open at the same time defrosting mode: the exhaust port of the twin-cylinder compressor 1 discharges high-temperature gaseous refrigerant and is divided into two paths. The first path passes through the first port D and the second port E of the four-way valve 2 to enter the first evaporator assembly to release heat and defrost, and then passes through the first expansion valve 9 to throttle and then passes through the enthalpy increase heat exchanger 5 and the condenser assembly to enter the four-way port C and the three-way port S of the four-way valve 2 to return to the first air intake port of the twin-cylinder compressor 1, that is, to achieve defrosting in the first temperature zone; the second path directly enters the second evaporator assembly to release heat and defrost, and then directly returns to the second air intake port of the twin-cylinder compressor 1, that is, to achieve defrosting in the second temperature zone. It should be noted that at this time, the first port D of the four-way valve 2 is connected to its second port E, the four-way port C of the four-way valve 2 is connected to its three-way port S, the second solenoid valve 7, the third solenoid valve 19, the second expansion valve 14, the first evaporation fan 11, and the second evaporation fan 16 are all closed, and the first solenoid valve 20 is opened.

[0072] Please refer to Figure 3, Second temperature zone single open defrost mode: In the above-mentioned second temperature zone-first temperature zone co-open defrost mode, close the first expansion valve 9 and the second condensing fan 3, and only run the second process, that is, realize the second temperature zone single open defrost mode.

[0073] Please refer to Figure 4 , first temperature zone single open defrost mode: in the above-mentioned second temperature zone-first temperature zone both open defrost mode, close the first solenoid valve 20, open the third solenoid valve 19, and only run the first process, that is, realize the first temperature zone single open defrost mode.

[0074] Please refer to Figure 5 , second temperature zone defrosting-first temperature zone refrigeration mode: the exhaust port of the twin-cylinder compressor 1 discharges high-temperature gaseous refrigerant and is divided into two paths. The first path passes through the four-way valve 2 and then passes through the condenser assembly and the hot runner of the enthalpy-increasing heat exchanger 5 in turn to form a low-temperature liquid refrigerant after cooling. Part of the low-temperature liquid refrigerant flows into the first branch and is throttled by the throttle valve group and then flows into the cold runner of the enthalpy-increasing heat exchanger 5, and then absorbs the heat of the refrigerant in the hot runner of the enthalpy-increasing heat exchanger 5 and flows into the enthalpy-increasing port of the twin-cylinder compressor 1. The other part of the low-temperature liquid refrigerant flows into the second branch and passes through the first expansion valve 9 and then flows into the first evaporator assembly, and then absorbs the heat of the air in the first temperature zone and evaporates into a gaseous refrigerant, and then flows back to the first air intake port of the twin-cylinder compressor 1 after passing through the four-way valve 2, that is, the first temperature zone refrigeration is completed. The second path directly enters the second evaporator assembly to release heat and defrost, and then directly flows back to the second air intake port of the twin-cylinder compressor 1, that is, the second temperature zone defrosting is achieved. It should be noted that, at this time, the first port D of the four-way valve 2 is connected to its four-way port C, the second port E of the four-way valve 2 is connected to its three-way port S, the third solenoid valve 19 is closed, the second solenoid valve 7 is opened, the first solenoid valve 20 is opened, and the second evaporating fan 16 is closed.

[0075] Therefore, the present invention can defrost or cool the first temperature zone when the second temperature zone is defrosting, which can avoid temperature fluctuations in the first temperature zone and keep the temperature of the first temperature zone stable. It can also reduce defrosting energy consumption, which is beneficial to energy saving.

[0076] To realize automatic control of the refrigeration mode of the refrigeration system, based on the above embodiment, please refer to Figure 1 The present invention also includes a first indoor temperature sensor 12 for installation in the first temperature zone and a second indoor temperature sensor 17 for installation in the second temperature zone. The first indoor temperature sensor 12, the second indoor temperature sensor 17, the four-way valve 2, the throttle valve group, the first expansion valve 9, and the second expansion valve 14 are all signal-connected to the control unit.

[0077] Specifically, the first indoor temperature sensor 12 is used to detect the indoor temperature of the first temperature zone in real time, and transmit the signal to the control unit. The second indoor temperature sensor 17 is used to detect the indoor temperature of the second temperature zone in real time, and transmit the signal to the control unit. The control unit can determine whether the temperature zone enters the cooling mode according to the indoor temperature of the temperature zone. For example, if the first indoor temperature sensor 12 detects that the temperature of the first temperature zone is greater than the set temperature of the first temperature zone, it means that the first temperature zone needs to turn on the cooling mode, then the first port D of the four-way valve 2 is controlled to be connected with its four-way port C, the second port E of the four-way valve 2 is connected with its three-way port S, and the condensing fan 3, the third solenoid valve 19, the first expansion valve 9, and the first evaporating fan 11 are turned on, so that the first temperature zone cooling mode can be realized. Therefore, the above-mentioned setting can realize the automatic control of the cooling mode of the refrigeration system, so that the refrigeration system has better intelligence and stability.

[0078] To realize the automatic control of the defrost mode of the refrigeration system, based on the above embodiment, please refer to Figure 1 The present invention further includes a first coil temperature sensor 13 provided in the first evaporator assembly and a second coil temperature sensor 18 provided in the second evaporator assembly. The first coil temperature sensor 13, the second coil temperature sensor 18 and the first solenoid valve 20 are all connected to the control unit through signals.

[0079] Specifically, frost on the evaporator usually occurs on the coil. The first coil temperature sensor 13 is arranged on the coil of the first evaporator 10, and is used to detect the coil temperature of the first evaporator 10, that is, the coil temperature of the first temperature zone, in real time, and transmit the signal to the control unit. The control unit can determine whether the first temperature zone enters the defrost mode according to the coil temperature of the first temperature zone. If the defrost mode is required, the opening and closing of the valve components required for the defrost mode of the first temperature zone are controlled, for example, the third solenoid valve 19 and the condensing fan 3 are closed, and the first port D of the four-way valve 2 and its second port E are connected, and the four-way port C of the four-way valve 2 and its three-way port S are connected. Similarly, the second coil temperature sensor 18 is arranged on the coil of the second evaporator 15, and is used to detect the coil temperature of the second evaporator 15, i.e., the coil temperature of the second temperature zone, in real time, and transmit the signal to the control unit. The control unit can determine whether the second temperature zone enters the defrost mode according to the coil temperature of the second temperature zone. If it is necessary to enter the defrost mode, the opening and closing of the valve components required for the defrost mode of the second temperature zone is controlled, for example, the first solenoid valve 20 is opened, and the second evaporation fan 16 is closed. Therefore, the above arrangement can realize the automatic control of the defrost mode of the refrigeration system, so that the refrigeration system has better intelligence and stability.

[0080] Based on the above examples, please refer to Figure 1 A drying filter 6 is provided on the connecting pipeline communicating with the hot runner outlet of the enthalpy-increasing heat exchanger 5 .

[0081] Specifically, the filter drier 6 mainly plays the role of impurity filtering and water absorption. It can remove mechanical impurities in the refrigerant and prevent the mechanical impurities from entering the evaporator in different temperature zones, thereby ensuring the safe and stable operation of the refrigeration system.

[0082] To ensure the safe and stable operation of the refrigeration system, please refer to Figure 1 An exhaust temperature sensor 21 and an exhaust pressure sensor 22 are provided on the exhaust pipe connected to the exhaust port of the twin-cylinder compressor 1, and both of them are connected to the control unit.

[0083] Specifically, the exhaust temperature sensor 21 is used to detect the exhaust temperature of the twin-cylinder compressor 1 in real time, and transmit the signal to the control unit. The control unit will adjust the operating state of the twin-cylinder compressor 1 according to the exhaust temperature obtained to ensure that the exhaust gas is within a reasonable temperature range. The exhaust pressure sensor 22 is used to detect the exhaust pressure of the twin-cylinder compressor 1 in real time, and transmit the signal to the control unit. The control unit will adjust the operating state of the twin-cylinder compressor 1 according to the exhaust pressure obtained to ensure that the exhaust gas pressure is within a reasonable pressure range. Therefore, the above settings can ensure that the control system operates within a stable temperature and pressure range, thereby ensuring the safe and stable operation of the refrigeration system.

[0084] For further information, please refer to Figure 1 A first intake air temperature sensor 23 and a first intake air pressure sensor 24 are provided on the pipeline connecting the three-way port S of the four-way valve 2 and the first intake air port, and both of their signals are connected to the control unit; and / or, a second intake air temperature sensor 25 and a second intake air pressure sensor 26 are provided on the second branch between the second evaporator assembly and the second intake air port, and both of their signals are connected to the control unit.

[0085] Specifically, the first suction pressure sensor 24 is used to detect the suction pressure of the first suction port in real time, and transmit the signal to the control unit. The second suction pressure sensor 26 is used to detect the suction pressure of the second suction port in real time, and transmit the signal to the control unit. Since the suction pressures of the first suction port and the second suction port are both related to the refrigerant flow rate, the suction pressure can reflect the refrigeration effect or defrosting effect in the temperature zone. For example, if the suction pressure is too low, it indicates insufficient refrigerant and the evaporator refrigeration or defrosting effect is poor. The control unit can adjust the operating state of the two-cylinder compressor 1 according to the suction pressure of the first suction port and / or the second suction port, thereby ensuring safe and stable operation of the refrigeration system.

[0086] The present invention also provides a refrigeration device including the dual evaporator refrigeration system disclosed in the above embodiment. The refrigeration device is suitable for scenarios with a second temperature zone and a first temperature zone, for example, a refrigerator or a refrigeration truck, wherein the freezing zone of the two is the first temperature zone and the refrigeration zone is the second temperature zone.

[0087] The present invention also provides a control method, which is applied to the dual-evaporator refrigeration system disclosed in the above embodiments. Please refer to Figure 6 , and the specific steps of the control method include:

[0088] S1: Obtain the temperature of the coil in the second temperature zone (denoted as the temperature of the coil in the low-temperature zone in the attached drawing, that is, the second temperature zone can be used as the low-temperature zone) and the temperature of the coil in the first temperature zone (denoted as the temperature of the coil in the ultra-low temperature zone in the attached drawing, that is, the first temperature zone can be used as the ultra-low temperature zone); it can be understood that the low-temperature zone and the ultra-low temperature zone here are relative, and the temperature of the low-temperature zone will be higher than that of the ultra-low temperature zone;

[0089] Specifically, whether the second temperature zone and the first temperature zone are operating in the refrigeration mode simultaneously or separately, the control unit will input the first set temperature Td and the second set temperature Tc in advance. The first coil temperature sensor 13 is used to detect the temperature T1 of the coil in the first temperature zone in real time and transmit it to the control unit, and the second coil temperature sensor 18 is used to detect the temperature T2 of the coil in the second temperature zone in real time.

[0090] S2: Determine whether the temperature of the coil in the first temperature zone is less than the first set temperature;

[0091] S3: If the temperature of the coil in the first temperature zone is greater than or equal to the first set temperature, determine whether the temperature of the coil in the second temperature zone is less than the second set temperature;

[0092] It should be noted that if T1≥Td, it means that defrosting is not required in the first temperature zone, and continue to determine whether the temperature of the coil in the second temperature zone is less than the second set temperature.

[0093] S4: If the temperature of the coil in the second temperature zone is greater than or equal to the second set temperature, return to step S1;

[0094] It should be noted that if T2≥Tc, it means that defrosting is not required in the second temperature zone, and return to step S1 to execute the next round of control.

[0095] S5: If the temperature of the coil in the second temperature zone is less than the second set temperature, open the first solenoid valve 20 and close the second expansion valve 14 until the temperature T2 of the coil in the second temperature zone is greater than or equal to the second set temperature Tc.

[0096] Specifically, if T2<Tc, it means that defrosting is required in the second temperature zone. At this time, during the operation of the refrigeration system, directly open the first solenoid valve 20, close the second expansion valve 14 and the second evaporation fan 16, that is, operate the defrosting mode of the second temperature zone - the refrigeration mode of the first temperature zone.

[0097] S6: After executing step S5, determine whether the temperature of the coil in the second temperature zone is greater than or equal to the second set temperature. If so, close the first solenoid valve 20 and open the second expansion valve 14. If not, continue to execute step S5.

[0098] Specifically, during the operation of the second temperature zone defrosting - first temperature zone refrigeration mode, if T2 ≥ Tc, it indicates that the defrosting of the second temperature zone needs to end. Close the first solenoid valve 20, open the second expansion valve 14 and the second evaporation fan 16, and the second temperature zone can enter the refrigeration mode from the defrosting mode and return to step S1. If T2 < Tc, it indicates that the second temperature zone still needs to be defrosted, and continue to operate the second temperature zone defrosting - first temperature zone refrigeration mode.

[0099] S7: After executing step S2, if the coil temperature of the first temperature zone is less than the first set temperature, one port D of the four-way valve is connected to its second port E, the four-port C of the four-way valve is connected to its three-port S, and the throttle valve group, the first solenoid valve 20, and the second expansion valve 14 are closed;

[0100] Specifically, if T1 < Td, it indicates that the first temperature zone needs to be defrosted. At this time, the refrigeration mode needs to be stopped, that is, one port D of the four-way valve 2 is connected to its second port E, the four-port C of the four-way valve 2 is connected to its three-port S, and the third solenoid valve 19, the first solenoid valve 20, and the second expansion valve 14 are closed to achieve the single-zone defrosting mode of the first temperature zone.

[0101] S8: After executing step S7, determine whether the coil temperature of the first temperature zone is greater than or equal to the first set temperature. If so, one port D of the four-way valve is connected to its four-port C, the second port E of the four-way valve is connected to its three-port S, and the throttle valve group and the second expansion valve 14 are opened; if not, continue to execute step S7;

[0102] Specifically, during the operation of the single-zone defrosting mode of the first temperature zone, if T1 ≥ Td, it indicates that the defrosting of the first temperature zone needs to end. One port D of the four-way valve 2 is connected to its four-port C, the second port E of the four-way valve 2 is connected to its three-port S, and the third solenoid valve 19 and the second expansion valve 14 are opened, that is, directly close the single-zone defrosting mode of the first temperature zone, open the refrigeration mode and return to step S2. If T1 < Td, it indicates that the first temperature zone still needs to be defrosted, and continue to operate the single-zone defrosting mode of the first temperature zone.

[0103] S9: After executing step S7, it is also necessary to determine whether the coil temperature of the second temperature zone is less than the second set temperature;

[0104] It should be noted that during the operation of the single-zone defrosting mode of the first temperature zone, there is also a situation where the second evaporator 15 in the second temperature zone frosts. In addition, step S9 is executed synchronously with step S8.

[0105] S10: If the coil temperature of the second temperature zone is greater than or equal to the second set temperature, execute the above step S8.

[0106] It should be noted that during the operation of the single-defrost mode in the first temperature zone, if T2≥Tc, it indicates that the second temperature zone does not require defrosting, and step S8 is executed to determine whether the first temperature zone has ended the defrost mode.

[0107] S11: If the temperature of the coil in the second temperature zone is less than the second set temperature, the first solenoid valve is opened;

[0108] Specifically, during the operation of the single-defrost mode in the first temperature zone, if T2<Tc, it indicates that the second temperature zone requires defrosting. The first solenoid valve 20 is opened and the second solenoid valve 7 is closed, that is, the co-defrost mode of the second temperature zone - the first temperature zone is operated.

[0109] S12: Determine whether the temperature of the coil in the second temperature zone is greater than or equal to the second set temperature. If so, the first solenoid valve 20 is closed; if not, the above step S11 is continued to be executed;

[0110] Specifically, during the operation of the co-defrost mode of the second temperature zone - the first temperature zone, if T2≥Tc, it indicates that the second temperature zone does not require defrosting. The first solenoid valve 20 is closed and the second solenoid valve 7 is opened, that is, the single-defrost mode of the first temperature zone is operated, and then it returns to step S8 to determine whether the first temperature zone has ended the defrost mode; if T2<Tc, it indicates that the second temperature zone still requires defrosting, and the co-defrost mode of the second temperature zone - the first temperature zone is continued to be operated.

[0111] S13: After executing step S11, it is also necessary to determine whether the temperature of the coil in the first temperature zone is greater than or equal to the first set temperature. If so, one port D of the four-way valve is connected to its four-way port C, the two-way port E of the four-way valve is connected to its three-way port S, the throttle valve group and the second expansion valve 14 are opened, and the first solenoid valve 20 is closed; if not, the above step S11 is continued to be executed;

[0112] Specifically, during the operation of the co-defrost mode of the second temperature zone - the first temperature zone, if T1≥Td, it indicates that defrosting of the first temperature zone needs to be ended, the co-defrost mode of the second temperature zone - the first temperature zone is stopped, and the refrigeration mode is started, that is, one port D of the four-way valve 2 is connected to its four-way port C, the two-way port E of the four-way valve 2 is connected to its three-way port S, the third solenoid valve 19 and the second expansion valve 14 are opened, and then it returns to step S2. If T1<Td, it indicates that the first temperature zone still requires defrosting, and the co-defrost mode of the second temperature zone - the first temperature zone is continued to be operated. It should be noted that steps S12 and S13 are executed synchronously.

[0113] Therefore, the above control method can realize the co-defrost mode of the second temperature zone - the first temperature zone, the defrost mode of the second temperature zone - the refrigeration mode of the first temperature zone, the single-defrost mode of the second temperature zone, and the single-defrost mode of the first temperature zone. When the second temperature zone is defrosted, the first temperature zone can be defrosted or refrigerated, avoiding fluctuations in the temperature of the first temperature zone and keeping the temperature of the first temperature zone stable.

[0114] It should be noted that, in this specification, relational terms such as first and second are merely used to distinguish one entity from other entities, but do not necessarily require or imply any actual relationship or order between these entities.

[0115] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0116] The above is a detailed introduction to a dual-evaporator refrigeration system, refrigeration equipment and control method thereof provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A dual evaporator refrigeration system, characterized in that: It comprises a double-cylinder compressor (1), a four-way valve (2), a condenser assembly, an enthalpy-increasing heat exchanger (5), a first evaporator assembly for installation in a first temperature zone, and a second evaporator assembly for installation in a second temperature zone; The exhaust pipeline connected to the exhaust port of the dual-cylinder compressor (1) is divided into two pipelines: The first pipeline is connected to a port (D) of the four-way valve (2), the four-way port (C) of the four-way valve (2) is connected in sequence to the condenser assembly and the hot runner inlet of the enthalpy-increasing heat exchanger (5), the hot runner outlet of the enthalpy-increasing heat exchanger (5) is connected to the connecting pipeline, and the connecting pipeline is divided into three branches: the first branch is connected in sequence to the cold runner of the enthalpy-increasing heat exchanger (5) and the enthalpy-increasing port of the two-cylinder compressor (1) through the throttle valve group; the second branch is connected in sequence to the first evaporator assembly and the second port (E) of the four-way valve (2) through the first expansion valve (9), and the three-way port (S) of the four-way valve (2) is connected to the first air intake port of the two-cylinder compressor (1); the third branch is connected in sequence to the second evaporator assembly and the second air intake port of the two-cylinder compressor (1) through the second expansion valve (14); The second pipeline is connected to the third branch between the second expansion valve (14) and the second evaporator assembly through a first solenoid valve (20).

2. The dual evaporator refrigeration system according to claim 1, characterized in that: It also includes a first indoor temperature sensor (12) for installation in the first temperature zone and a second indoor temperature sensor (17) for installation in the second temperature zone, wherein the first indoor temperature sensor (12), the second indoor temperature sensor (17), the four-way valve (2), the throttling valve group, the first expansion valve (9), and the second expansion valve (14) are all connected to the control unit through signals.

3. The dual evaporator refrigeration system according to claim 2, characterized in that: The device also comprises a first coil temperature sensor (13) provided on the first evaporator component and a second coil temperature sensor (18) provided on the second evaporator component, wherein the first coil temperature sensor (13), the second coil temperature sensor (18) and the first solenoid valve (20) are all connected to a control unit via signals.

4. The dual evaporator refrigeration system according to claim 1, characterized in that: An auxiliary pipeline is connected between the pipeline connecting the three-way port (S) of the four-way valve (2) and the first air intake port and the third pipeline located between the second evaporator assembly and the second air intake port, and a second solenoid valve (7) connected to a control unit signal is provided on the auxiliary pipeline.

5. The dual evaporator refrigeration system according to claim 1, characterized in that: The throttle valve group comprises a third solenoid valve (19) and a thermal expansion valve (8), which are arranged in sequence on the first branch along the direction from the hot runner outlet to the cold runner inlet of the enthalpy increasing heat exchanger (5).

6. The dual evaporator refrigeration system according to claim 1, characterized in that: A drying filter (6) is provided on a connecting pipeline communicating with the hot runner outlet of the enthalpy-increasing heat exchanger (5).

7. The dual evaporator refrigeration system according to claim 1, characterized in that: The condenser assembly comprises a condenser (4) and a condensing fan (3) arranged on one side of the condenser (4); And / or, the first evaporator assembly comprises a first evaporator (10) and a first evaporation fan (11) arranged on one side of the first evaporator (10); And / or, the second evaporator assembly comprises a second evaporator (15) and a second evaporation fan (16) arranged on one side of the second evaporator (15).

8. The dual evaporator refrigeration system according to any one of claims 1 to 7, characterized in that: An exhaust temperature sensor (21) and an exhaust pressure sensor (22) are provided on an exhaust pipeline connected to the exhaust port of the dual-cylinder compressor (1), and both of the sensors are connected to a control unit; and / or, a first intake air temperature sensor (23) and a first intake air pressure sensor (24) are provided on a pipeline connecting the three-way port (S) of the four-way valve (2) and the first intake port, and both of the sensors are connected to the control unit; And / or, a second suction temperature sensor (25) and a second suction pressure sensor (26) are provided on the second branch between the second evaporator assembly and the second suction port, and both of the sensors are connected to the control unit.

9. A refrigeration device, characterized in that: A dual evaporator refrigeration system comprising any one of claims 1 to 8.

10. A control method, characterized in that: Applied to the dual evaporator refrigeration system according to any one of claims 1 to 8 above, the control method comprises: Obtain the coil temperature of the second temperature zone and the coil temperature of the first temperature zone; When the temperature of the coil in the first temperature zone is greater than or equal to the first set temperature, determine whether the temperature of the coil in the second temperature zone is less than the second set temperature. If so, open the first solenoid valve and close the second expansion valve until the temperature of the coil in the second temperature zone is greater than or equal to the second set temperature. When the temperature of the coil in the first temperature zone is lower than the first set temperature, the first port of the four-way valve is connected to its second port, the four-way port of the four-way valve is connected to its three-way port, and the throttling valve group, the first solenoid valve, and the second expansion valve are closed; Determine whether the coil temperature in the first temperature zone is greater than or equal to the first set temperature. If so, connect the first port of the four-way valve to its four-way port, connect the second port of the four-way valve to its three-way port, and open the throttling valve group and the second expansion valve; While executing the step of determining whether the temperature of the coil in the first temperature zone is greater than or equal to the first set temperature, determining whether the temperature of the coil in the second temperature zone is less than the second set temperature, and if so, opening the first solenoid valve; Determine whether the coil temperature in the second temperature zone is greater than or equal to the second set temperature, and if so, close the first solenoid valve; While executing the step of determining whether the temperature of the coil in the second temperature zone is greater than or equal to the second set temperature, determine whether the temperature of the coil in the first temperature zone is greater than or equal to the first set temperature. If so, one port of the four-way valve is connected to its four-way port, the second port of the four-way valve is connected to its three-way port, the throttling valve group and the second expansion valve are opened, and the first solenoid valve is closed.

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