A control system and control method applied to auxiliary defrosting of a dual-temperature refrigerator

Abstract

A kind of control system and control method applied to the auxiliary defrosting of dual-temperature refrigerator, by real-time acquisition environment temperature, high-temperature evaporator and low-temperature evaporator refrigeration cycle, control auxiliary defrosting system after certain refrigeration cycle as the mode of auxiliary defrosting is evaporator upper surface defrosting, and with environment temperature parameter is divided into four auxiliary defrosting modes, according to the change of environment temperature enters different auxiliary defrosting mode, cooperate dual-temperature refrigerator electric heating defrosting mode to achieve the purpose of refrigerator evaporator defrosting, the auxiliary defrosting control method proposed in the application can reduce the input power of dual-temperature refrigerator electric heating defrosting device, achieve the purpose of reducing the energy consumption of system, improve the energy saving of system.

Description

Technical Field

[0001] This invention relates to the field of dual-temperature refrigerator technology, and specifically to a control system and control method for auxiliary defrosting in dual-temperature refrigerators. Background Technology

[0002] Dual-temperature refrigerators are now widely used in food storage, scientific research, medical supplies, and biological product storage. However, when operating in environments with high humidity and low temperature, frost will form on the evaporator surface. The growth of frost will lead to a decrease in the heat exchange performance of the evaporator. Therefore, defrosting the evaporator surface of dual-temperature refrigerators is an important means to ensure the efficient operation of the refrigerator.

[0003] Currently, refrigerators employ a series-parallel high-temperature compartment temperature priority control principle. Based on this principle, there are three operating modes: 1) High-temperature evaporator cooling, low-temperature evaporator cooling; 2) High-temperature evaporator not cooling, low-temperature evaporator cooling; 3) High-temperature evaporator not cooling, low-temperature evaporator not cooling. Correspondingly, the system's defrosting modes are divided into three types: 1) No defrosting; 2) High-temperature evaporator defrosting, low-temperature evaporator not defrosting; 3) High-temperature evaporator defrosting, low-temperature evaporator defrosting. Refrigerator defrosting often uses an electric heating device placed at the bottom of the evaporator. During the refrigerator's periodic defrosting phase, the electric heater is activated, using thermal radiation to melt the frost layer on the evaporator surface. However, electric heating is an additional energy input, consuming a portion of the system's energy consumption. Furthermore, after defrosting, the refrigerator needs to provide more cooling to maintain the set internal temperature. With changes in ambient temperature, the compressor's start-stop frequency changes accordingly, resulting in varying frost conditions. For example, when the ambient temperature rises, the compressor starts and stops more frequently, resulting in more frost buildup. This requires more energy input to defrost, increasing the refrigerator's energy consumption and affecting the temperature distribution inside the refrigerator. Summary of the Invention

[0004] To address the issue that dual-temperature refrigerators require significant additional energy input during the defrosting phase, which also affects the internal temperature distribution, this invention aims to provide a control method for auxiliary defrosting in dual-temperature refrigerators. This method collects real-time data on ambient temperature and the cooling cycles of the high-temperature and low-temperature evaporators, controlling the auxiliary defrosting system to enter different defrosting modes. Combined with an electric heating defrosting mode, this reduces the input power of the electric heating defrosting device, achieving system energy savings.

[0005] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution:

[0006] A control system for auxiliary defrosting of a dual-temperature refrigerator includes a phase change material heat storage device and a thermosiphon connected together, and a control device connecting the phase change material heat storage device and the thermosiphon. The phase change material heat storage device is arranged at the condenser outlet of the dual-temperature refrigerator, and the thermosiphon is arranged on the upper half of the windward side of the high-temperature evaporator and the low-temperature evaporator of the dual-temperature refrigerator.

[0007] The thermosiphon includes a thermosiphon gas phase pipe located at the top and a thermosiphon liquid phase pipe located at the bottom, which are connected to each other. The thermosiphon liquid phase pipe is connected to the inlet of the phase change material heat storage device, and the thermosiphon gas phase pipe is connected to the outlet of the phase change material heat storage device.

[0008] The control method for a control system applied to auxiliary defrosting in a dual-temperature refrigerator includes the following steps:

[0009] Step 1: Set the operating parameters of the dual-temperature refrigerator: When there is no auxiliary defrosting, the input power of the first electric heating device P1 and the input power of the second electric heating device P2 of the dual-temperature refrigerator; the defrosting cycle t1 of the high-temperature evaporator is 80 to 120 cooling cycles of the high-temperature evaporator, and the defrosting cycle t2 of the low-temperature evaporator is 80 to 120 cooling cycles of the low-temperature evaporator, t1 = t2;

[0010] Step 2: Real-time parameter acquisition: Real-time acquisition of ambient temperature T, high-temperature evaporator cooling cycle T1, and low-temperature evaporator cooling cycle T2; T1 and T2 are variable values ​​under different ambient temperatures; number of high-temperature evaporator cooling cycles n1 and number of low-temperature evaporator cooling cycles m1;

[0011] Step 3: Based on the ambient temperature T, the control device adjusts the auxiliary defrosting control system to enter different auxiliary defrosting modes; T < 16℃ is the low-temperature defrosting mode; 16 ≤ T < 24℃ is the medium-low temperature defrosting mode; 24 ≤ T < 32℃ is the medium-high temperature defrosting mode; T ≥ 32℃ is the high-temperature defrosting mode; simultaneously, the control device counts the cooling cycle T1 of the high-temperature evaporator and the cooling cycle T2 of the low-temperature evaporator; after the auxiliary defrosting control system defrosts the high-temperature or low-temperature evaporator, the control device resets the corresponding evaporator cooling cycle count to zero; during the auxiliary defrosting operation phase, the thermosiphon absorbs heat from the phase change material heat storage device and transfers it to the upper half of the windward surface of the low-temperature and high-temperature evaporators to defrost stubborn points; auxiliary defrosting combined with electric heating defrosting achieves the purpose of defrosting both the low-temperature and high-temperature evaporators.

[0012] A control method for auxiliary defrosting in a dual-temperature refrigerator, wherein in step 3, under low-temperature defrosting mode, the cooling cycle of the high-temperature evaporator is T1, the cooling cycle of the low-temperature evaporator is T2, and the heat storage cycle of the phase change material heat storage device is t1 / 2. When the control device counts n cooling cycles of the low-temperature evaporator, the thermosiphon is activated to defrost the low-temperature evaporator, and the recommended value of n is 40-60; when the control device counts m cooling cycles of the high-temperature evaporator, the thermosiphon is activated to defrost the high-temperature evaporator, and the recommended value of m is 80-120. The input power of the first electric heater and the second electric heater is reduced to 0.5P1 and 0.5P2, respectively.

[0013] A control method for auxiliary defrosting in a dual-temperature refrigerator, wherein in step 3, under the medium-low temperature defrosting mode, the cooling cycle of the high-temperature evaporator is T1, the cooling cycle of the low-temperature evaporator is T2, and the heat storage cycle of the phase change material heat storage device is t1 / 2. When the control device counts n cooling cycles of the low-temperature evaporator, the thermosiphon is activated to defrost the low-temperature evaporator, and the recommended value of n is 40-60; when the control device counts m cooling cycles of the high-temperature evaporator, the thermosiphon is activated to defrost the high-temperature evaporator, and the recommended value of m is 80-120. The input power of the first electric heater and the second electric heater are reduced to 0.6P1 and 0.6P2, respectively.

[0014] A control method for auxiliary defrosting in a dual-temperature refrigerator, wherein in step 3, under the medium-high temperature defrosting mode, the cooling cycle of the high-temperature evaporator is T1, the cooling cycle of the low-temperature evaporator is T2, and the heat storage cycle of the phase change material heat storage device is t1 / 2. When the control device counts n cooling cycles of the low-temperature evaporator, the thermosiphon is activated to defrost the low-temperature evaporator, and the recommended value of n is 40-60; when the control device counts m cooling cycles of the high-temperature evaporator, the thermosiphon is activated to defrost the high-temperature evaporator, and the recommended value of m is 80-120. The input power of the first electric heater and the second electric heater is reduced to 0.7P1 and 0.7P2, respectively.

[0015] A control method for auxiliary defrosting in a dual-temperature refrigerator, wherein in step 3, under high-temperature defrosting mode, the cooling cycle of the high-temperature evaporator is T1, the cooling cycle of the low-temperature evaporator is T2, and the heat storage cycle of the phase change material heat storage device is t1 / 2. When the control device counts n cooling cycles of the low-temperature evaporator, the thermosiphon is activated to defrost the low-temperature evaporator, and the recommended value of n is 40-60; when the control device counts m cooling cycles of the high-temperature evaporator, the thermosiphon is activated to defrost the high-temperature evaporator, and the recommended value of m is 80-120. The input power of the first electric heater and the second electric heater are reduced to 0.8P1 and 0.8P2, respectively.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] 1. Considering that the electric heating defrosting device of the dual-temperature refrigerator has a large input power and affects the temperature distribution inside the refrigerator, it is proposed to use an auxiliary defrosting method in conjunction with the electric heating defrosting method, which is beneficial to reduce the input power of the electric heating device;

[0018] 2. Based on changes in ambient temperature, the auxiliary defrosting mode is divided into four different defrosting modes. In different defrosting modes, the input power of electric heating defrosting is different, which helps to improve the defrosting efficiency of the refrigerator.

[0019] 3. The auxiliary defrosting method transfers the heat stored in the phase change material heat storage device to the upper half of the windward side surface of the evaporator. Combined with the electric heating defrosting method, it is beneficial to completely defrost the stubborn defrost points on the evaporator surface. Attached Figure Description

[0020] Figure 1 This is a flowchart of the control method for auxiliary defrosting of a dual-temperature refrigerator as described in this invention.

[0021] Figure 2 This is an implementation example of the control system for auxiliary defrosting of a dual-temperature refrigerator as described in this invention.

[0022] 1. Compressor; 2. Condenser; 3. High-temperature evaporator; 4. Low-temperature evaporator; 5. Capillary tube 1; 6. Capillary tube 2; 7. Dryer filter; 8. Electric heating device; 9. Phase change material heat storage device; 10. Thermosiphon gas phase tube; 11. Thermosiphon liquid phase tube; 12. Three-way valve; 13. First solenoid valve; 14. Second solenoid valve; 15. Regenerator; 101. First phase change heat storage device interface; 111. Second phase change heat storage device interface; 120. First port of three-way valve; 121. Second port of three-way valve; 122. Third port of three-way valve; C1. Control device. Detailed Implementation

[0023] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and an embodiment. It should be understood that the embodiment described herein is only for explaining the invention and is not intended to limit the invention.

[0025] Implementation Cases

[0026] A control system for auxiliary defrosting of a dual-temperature refrigerator includes: a phase change material heat storage device and a thermosiphon connected together, and a control device connecting the phase change material heat storage device and the thermosiphon; the phase change material heat storage device is arranged at the condenser outlet of the dual-temperature refrigerator, and the thermosiphon is arranged on the upper half of the windward side of the high-temperature evaporator and the low-temperature evaporator of the dual-temperature refrigerator.

[0027] like Figure 1 As shown, a control method for a control system applied to auxiliary defrosting in a dual-temperature refrigerator includes:

[0028] Step 1: Set the operating parameters of the dual-temperature refrigerator: When there is no auxiliary defrosting, the input power of the first electric heating device P1 and the input power of the second electric heating device P2 of the dual-temperature refrigerator; the defrosting cycle t1 of the high-temperature evaporator is 80 to 120 cooling cycles of the high-temperature evaporator, and the defrosting cycle t2 of the low-temperature evaporator is 80 to 120 cooling cycles of the low-temperature evaporator, t1 = t2;

[0029] Step 2: Real-time parameter acquisition: Real-time acquisition of ambient temperature T, high-temperature evaporator cooling cycle T1, and low-temperature evaporator cooling cycle T2; T1 and T2 are variable values ​​under different ambient temperatures; number of high-temperature evaporator cooling cycles n1 and number of low-temperature evaporator cooling cycles m1;

[0030] Step 3: Based on the ambient temperature T, the control device adjusts the auxiliary defrosting control system to enter different auxiliary defrosting modes; T < 16℃ is the low-temperature defrosting mode; 16 ≤ T < 24℃ is the medium-low temperature defrosting mode; 24 ≤ T < 32℃ is the medium-high temperature defrosting mode; T ≥ 32℃ is the high-temperature defrosting mode; simultaneously, the control device counts the cooling cycle T1 of the high-temperature evaporator and the cooling cycle T2 of the low-temperature evaporator; after the auxiliary defrosting control system defrosts the high-temperature or low-temperature evaporator, the control device resets the corresponding evaporator cooling cycle count to zero; during the auxiliary defrosting operation phase, the thermosiphon absorbs heat from the phase change material heat storage device and transfers it to the upper half of the windward surface of the low-temperature and high-temperature evaporators to defrost stubborn points; auxiliary defrosting combined with electric heating defrosting achieves the purpose of defrosting both the low-temperature and high-temperature evaporators.

[0031] Figure 2 This is a schematic diagram of the auxiliary defrosting control system for a dual-temperature refrigerator using the aforementioned auxiliary defrosting control method. The control system includes a phase change material (PCM) heat storage device 9 located at the outlet of the condenser 2 in the dual-temperature refrigerator; a thermosiphon consisting of a thermosiphon vapor phase pipe 10 and a thermosiphon liquid phase pipe 11 connected together; and a control device C1 connecting the PCM heat storage device 9 and the thermosiphon. The thermosiphon is located on the upper part of the windward side of the high-temperature evaporator 3 and the low-temperature evaporator 4 in the dual-temperature refrigerator. The thermosiphon liquid phase pipe 11 is connected to the inlet of the PCM heat storage device 9, and the thermosiphon vapor phase pipe 10 is connected to the outlet of the PCM heat storage device 9.

[0032] The phase change material heat storage device 9 absorbs and stores the heat from the refrigerant at the outlet of the condenser 2. The control device C1 collects the ambient temperature T, the cooling cycle T1 of the high-temperature evaporator 3, and the cooling cycle T2 of the low-temperature evaporator 4 in real time. The defrosting cycles of the electric heating devices 8 of the high-temperature evaporator 3 and the low-temperature evaporator 4 are 100 T1 cycles and 100 T2 cycles, respectively. Without auxiliary defrosting, the input power of the first electric heating device of the high-temperature evaporator 3 is P1, which is 200W, and the input power of the third electric heating device of the low-temperature evaporator 4 is P2, which is 300W.

[0033] Control device C1 collects ambient temperature T in real time and divides the system into four defrosting modes based on ambient temperature T. Under different defrosting modes, based on real-time data collected at different ambient temperatures T, namely the cooling cycle T1 of the high-temperature evaporator 3 and the cooling cycle T2 of the low-temperature evaporator 4, the number of cooling cycles n1 of the high-temperature evaporator, and the number of cooling cycles m1 of the low-temperature evaporator, the phase change material heat storage device 9 has a heat storage cycle of 50 T2 cycles. When the number of cooling cycles n1 of the low-temperature evaporator reaches 50, control device C1 controls the second solenoid valve 14 to open, and the thermosiphon transfers heat to the upper half of the windward surface of the low-temperature evaporator 4 for defrosting. When the number of cooling cycles m1 of the high-temperature evaporator reaches 100, control device C1 controls the first solenoid valve 13 to open, and the thermosiphon transfers heat to the upper half of the windward surface of the high-temperature evaporator 3 for defrosting. Under the four different defrosting modes, the input power of the electric heating device 8 is as follows: 1. In the low-temperature defrosting mode, the input power of the first electric heating device 8 of the high-temperature evaporator 3 and the low-temperature evaporator... The input power of the second electric heating device 8 of evaporator 4 is 0.5P1 and 0.5P2 respectively; 2. In the low-temperature defrosting mode, the input power of the first electric heating device 8 of high-temperature evaporator 3 and the second electric heating device 8 of low-temperature evaporator 4 is 0.6P1 and 0.6P2 respectively; 3. In the high-temperature defrosting mode, the input power of the first electric heating device 8 of high-temperature evaporator 3 and the second electric heating device 8 of low-temperature evaporator 4 is 0.7P1 and 0.7P2 respectively; 4. In the high-temperature defrosting mode, the input power of the first electric heating device 8 of high-temperature evaporator 3 and the second electric heating device 8 of low-temperature evaporator 4 is 0.8P1 and 0.8P2 respectively.

Claims

1. A control method for a control system for auxiliary defrosting of a dual-temperature refrigerator, wherein the auxiliary defrosting control system includes a phase change material heat storage device and a thermosiphon connected together, and a control device connecting the phase change material heat storage device and the thermosiphon; the phase change material heat storage device is arranged at the condenser outlet of the dual-temperature refrigerator, and the thermosiphon is arranged on the upper half of the windward side of the high-temperature evaporator and the low-temperature evaporator of the dual-temperature refrigerator. Its features are, The control method includes the following steps: Step 1: Set the operating parameters of the dual-temperature refrigerator: When there is no auxiliary defrosting, the input power of the first electric heating device of the dual-temperature refrigerator is P1, and the input power of the second electric heating device is P2; the defrosting cycle t1 of the high-temperature evaporator is 80 to 120 cooling cycles of the high-temperature evaporator, and the defrosting cycle t2 of the low-temperature evaporator is 80 to 120 cooling cycles of the low-temperature evaporator, t1=t2; Step 2: Real-time parameter acquisition: Real-time acquisition of ambient temperature T, high-temperature evaporator cooling cycle T1, and low-temperature evaporator cooling cycle T2; T1 and T2 are variable values ​​under different ambient temperatures; Step 3: Based on the ambient temperature T, the control device adjusts the auxiliary defrosting control system to enter different auxiliary defrosting modes; T < 16℃ is the low-temperature defrosting mode; 16 ≤ T < 24℃ is the medium-low temperature defrosting mode; 24 ≤ T < 32℃ is the medium-high temperature defrosting mode; T ≥ 32℃ is the high-temperature defrosting mode; simultaneously, the control device counts the cooling cycle T1 of the high-temperature evaporator and the cooling cycle T2 of the low-temperature evaporator; after the auxiliary defrosting control system defrosts the high-temperature or low-temperature evaporator, the control device resets the corresponding evaporator cooling cycle count to zero; during the auxiliary defrosting operation phase, the thermosiphon absorbs heat from the phase change material heat storage device and transfers it to the upper half of the windward surface of the low-temperature and high-temperature evaporators to defrost stubborn points; auxiliary defrosting combined with electric heating defrosting achieves the purpose of defrosting both the low-temperature and high-temperature evaporators.

2. The control method according to claim 1, characterized in that: The thermosiphon includes a thermosiphon gas phase pipe located at the top and a thermosiphon liquid phase pipe located at the bottom, which are connected to each other. The thermosiphon liquid phase pipe is connected to the inlet of the phase change material heat storage device, and the thermosiphon gas phase pipe is connected to the outlet of the phase change material heat storage device.

3. The control method according to claim 1, characterized in that, In step 3, under the low-temperature defrosting mode, the cooling cycle of the high-temperature evaporator is T1, the cooling cycle of the low-temperature evaporator is T2, and the heat storage cycle of the phase change material heat storage device is t1 / 2. When the control device counts the cooling cycles of the low-temperature evaporator to n, the thermosiphon is activated to defrost the low-temperature evaporator, where n is 40 to 60. When the control device counts the cooling cycles of the high-temperature evaporator to m, the thermosiphon is activated to defrost the high-temperature evaporator, where m is 80 to 120. The input power of the first electric heater and the second electric heater is reduced to 0.5P1 and 0.5P2, respectively.

4. The control method according to claim 1, characterized in that, In step 3, under the medium-low temperature defrosting mode, the cooling cycle of the high-temperature evaporator is T1, the cooling cycle of the low-temperature evaporator is T2, and the heat storage cycle of the phase change material heat storage device is t1 / 2. When the control device counts the cooling cycles of the low-temperature evaporator to n, the thermosiphon is activated to defrost the low-temperature evaporator, where n is 40 to 60. When the control device counts the cooling cycles of the high-temperature evaporator to m, the thermosiphon is activated to defrost the high-temperature evaporator, where m is 80 to 120. The input power of the first electric heater and the second electric heater is reduced to 0.6P1 and 0.6P2, respectively.

5. The control method according to claim 1, characterized in that, In step 3, under the medium-high temperature defrosting mode, the cooling cycle of the high-temperature evaporator is T1, the cooling cycle of the low-temperature evaporator is T2, and the heat storage cycle of the phase change material heat storage device is t1 / 2. When the control device counts the cooling cycles of the low-temperature evaporator to n, the thermosiphon is activated to defrost the low-temperature evaporator, where n is 40 to 60. When the control device counts the cooling cycles of the high-temperature evaporator to m, the thermosiphon is activated to defrost the high-temperature evaporator, where m is 80 to 120. The input power of the first electric heater and the second electric heater is reduced to 0.7P1 and 0.7P2, respectively.

6. The control method according to claim 1, characterized in that, In step 3, under the high-temperature defrosting mode, the cooling cycle of the high-temperature evaporator is T1, the cooling cycle of the low-temperature evaporator is T2, and the heat storage cycle of the phase change material heat storage device is t1 / 2. When the control device counts the cooling cycles of the low-temperature evaporator to n, the thermosiphon is activated to defrost the low-temperature evaporator, where n is 40 to 60. When the control device counts the cooling cycles of the high-temperature evaporator to m, the thermosiphon is activated to defrost the high-temperature evaporator, where m is 80 to 120. The input power of the first electric heater and the second electric heater is reduced to 0.8P1 and 0.8P2, respectively.

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