A control system and method for suppressing slush ice

Abstract

The present invention discloses a control system and method for suppressing slush ice, belonging to the technical field of ice makers. It includes a water tank, an evaporator arranged above the water tank, and a water pump for pumping the water in the water tank to the top of the evaporator. An ice-making tray is arranged outside the evaporator. The water outlet end of the water pump is connected with a water distribution pipe for evenly distributing the outlet water and flowing it through the ice-making tray. It also includes a controller and a temperature sensor. The temperature sensor is arranged at the refrigerant outlet end of the evaporator. The controller is electrically connected to the temperature sensor and the water pump. By detecting the refrigerant temperature through the temperature sensor installed at the refrigerant outlet end of the evaporator, when the refrigerant temperature of the evaporator is around 0°C where slush ice is likely to be generated, the control program stops the operation of the water pump, cuts off the water source, and prevents the generation of slush ice. The stop of the water pump allows the evaporator to continue cooling. When the refrigerant temperature of the evaporator is lower than 0°C, the water pump starts to operate. At this time, the water flowing through the evaporator will condense into ice without generating slush ice.

Description

Technical Field

[0001] The present invention relates to a control system and method for suppressing cotton ice, belonging to the technical field of ice makers. Background Art

[0002] An ice maker is a device that condenses water into ice through an evaporator. The main structure of the ice maker includes a water tank, an evaporator arranged above the water tank, and a water pump for pumping the water in the water tank to the top of the evaporator. A grid-shaped ice making tray is arranged outside the evaporator, and a water distributing pipe for evenly distributing and flowing the discharged water through the ice making tray is connected to the water outlet end of the water pump. When making ice, the water in the water tank is pumped to the water distributing pipe by the water pump, the water distributing pipe evenly distributes the water and flows it through the ice making tray, and it is condensed by the evaporator on the back of the ice making tray to form ice cubes in the ice making tray.

[0003] In the initial stage of ice making of the ice maker, the temperature of the evaporator needs to be slowly reduced from room temperature to the ice making temperature of -10 to -18°C. During this temperature reduction process, when the temperature of the evaporator is around 0°C, the water circulating through the evaporator by the water pump will condense into a cotton-like ice-water mixture (water freezes at 0°C, melts slightly above 0°C, and cotton ice formed by the ice-water mixture will be generated around 0°C). This cotton-like ice-water mixture circulates back to the water tank with the water pump and accumulates over time, causing blockage of the water suction port of the water pump and the water distributing pipe at the top of the ice making tray, and finally causing the water pump motor to overheat and stop due to overload.

[0004] Therefore, a control system and method for suppressing cotton ice are designed. By detecting the temperature at the refrigerant outlet end of the evaporator with a temperature sensor, when the refrigerant temperature is around 0°C where cotton ice is likely to be generated, the water pump is stopped to avoid the generation of cotton ice. Summary of the Invention

[0005] The technical problem to be solved by the present invention is as follows: to provide a control system and method for suppressing cotton ice, which solves the problem that when the evaporator cools down to around 0°C in the initial stage of ice making of the current ice maker, cotton ice is likely to be generated, resulting in blockage of the water suction port of the water pump.

[0006] The technical problem to be solved by the present invention is achieved by adopting the following technical solutions:

[0007] First solution, a control system for suppressing cotton ice, which includes a water tank, an evaporator arranged above the water tank, and a water pump for pumping the water in the water tank to the top of the evaporator. An ice making tray is arranged outside the evaporator, and a water distributing pipe for evenly distributing and flowing the discharged water through the ice making tray is connected to the water outlet end of the water pump. It further includes a controller and a temperature sensor; the temperature sensor is arranged at the refrigerant outlet end of the evaporator; the controller is electrically connected to the temperature sensor and the water pump.

[0008] By setting a temperature sensor at the refrigerant outlet end of the evaporator of an existing ice maker, the refrigerant temperature can be detected, and this temperature can relatively accurately reflect the ice-making temperature of the ice-making tray. Detecting the temperature at the refrigerant outlet end can relatively accurately detect that the refrigerant temperature inside the evaporator is not higher than the detected temperature. If the detected temperature is less than 0°C, it is not easy for the evaporator to produce slush ice, which is beneficial for judging whether slush ice is generated.

[0009] By transmitting the current refrigerant temperature to the controller, the controller judges whether the refrigerant temperature is near 0°C. If the refrigerant temperature is near 0°C, it means that slush ice is likely to be generated at the ice-making tray, and the controller does not start the water pump, so that the water source of the ice-making tray is cut off, and there is no condition for generating slush ice; if the refrigerant temperature is lower than 0°C, the controller starts the water pump, and the water flowing through the ice-making tray can condense into ice, and it is not easy to generate slush ice, which can achieve the purpose of preventing blockage.

[0010] In the second solution, based on the first solution, the temperature sensor is arranged inside the pipe at the refrigerant outlet end of the evaporator.

[0011] The temperature sensor is located inside the pipe at the refrigerant outlet end of the evaporator, which can measure the refrigerant temperature more accurately, is beneficial for more accurately controlling the start and stop of the water pump according to the refrigerant temperature, and preventing the generation of slush ice.

[0012] In the third solution, based on the first solution, the outside of the pipe at the refrigerant outlet end of the evaporator is wrapped with heat-insulating sponge.

[0013] The heat-insulating sponge has the same function as the second solution. It can prevent the temperature at the refrigerant outlet end of the evaporator from dropping too fast. After heat preservation, the refrigerant temperature can be measured more accurately.

[0014] A control method for suppressing slush ice includes the slush ice suppression control system of the first solution, and also includes the following control steps:

[0015] (1) At the moment when the running time t = 0, the evaporator starts to operate, the refrigerant enters the inside from the refrigerant inlet end of the evaporator, cools the ice-making tray on the side of the evaporator, and the refrigerant that has completed the refrigeration and heat absorption flows back from the refrigerant outlet end of the evaporator. At this time, the water pump is in a stopped state;

[0016] (2) Starting from the moment t = 0, the temperature sensor periodically measures the refrigerant temperature T at the refrigerant outlet every Δt, and transmits the numerical value of the refrigerant temperature T to the controller. The controller compares the refrigerant temperature T with the upper temperature threshold T1 and the lower temperature threshold T2 once in each cycle, and controls the periodic start and stop of the water pump (the duration of each cycle is Δt);

[0017] At the moment t = N*Δt (N is a positive integer greater than 0, representing the Nth cycle), the refrigerant temperature T measured by the temperature sensor is Tn;

[0018] When Tn ≥ T1, the controller controls the water pump to stop in the (N + 1)-th cycle, and the stop time is one cycle Δt;

[0019] When Tn < T2, the controller controls the water pump to start in the (N + 1)-th cycle, and the start time is one cycle Δt;

[0020] When T1 > Tn ≥ T2, the controller keeps the start-stop state of the water pump unchanged in the (N + 1)-th cycle, and the maintenance time is one cycle Δt;

[0021] Among them, the upper temperature threshold T1 ≤ 0°C, and the lower temperature threshold T2 ≤ -3°C.

[0022] The water pump in the existing ice maker keeps working continuously from the operation of the evaporator. During the process of the evaporator cooling from room temperature to the ice-making temperature (-10 to -18°C), slush ice will be generated during the period when the temperature of the evaporator is around 0°C, blocking the water inlet of the water pump. Therefore, by adopting this control method, the water pump is set to operate periodically (each cycle is 5 - 30 seconds). Before one operation cycle, the refrigerant temperature at the refrigerant outlet end of the evaporator is measured by a temperature sensor to provide data for judging whether to start the water pump. The advantage of the periodic operation of the water pump is that once the refrigerant temperature of the evaporator reaches around 0°C, the water pump can be stopped in time in the next cycle, cutting off the water source to prevent the generation of slush ice.

[0023] Preferably, the upper temperature threshold T1 = 0°C, and the lower temperature threshold T2 = -5°C.

[0024] In this control method, T1 needs to be less than or equal to 0°C to achieve the effect of reducing the generation of slush ice. If the value of T2 is too close to the value of T1, it will cause the water pump to start and stop frequently. Therefore, the upper temperature threshold T1 = 0°C and the lower temperature threshold T2 = -5°C. When the refrigerant temperature at the refrigerant outlet end of the evaporator is lower than -5°C, the water pump is started. After the flowing water contacts the evaporator, within one cycle, the evaporator refrigerant is still continuously cooling, and the evaporator will not immediately rise to 0°C. It may take multiple cycles for the refrigerant temperature to return to around 0°C, and then the water pump is turned off, reducing the start-stop times of the water pump, which is beneficial to extending the service life of the water pump.

[0025] The beneficial effects of the present invention are:

[0026] (1) The refrigerant temperature is detected by a temperature sensor installed at the refrigerant outlet end of the evaporator. When the refrigerant temperature of the evaporator is around 0°C where slush ice is likely to be generated, the control program stops the operation of the water pump, cuts off the water source, and prevents the generation of slush ice. The stop of the water pump allows the evaporator to continue cooling; when the refrigerant temperature of the evaporator is lower than 0°C, the water pump starts to operate. At this time, the water flowing through the evaporator will freeze into ice, rather than generating slush ice;

[0027] (2) A temperature sensor is used to obtain the refrigerant temperature at the refrigerant outlet end. The water pump is set to operate periodically. Before one operating cycle, the refrigerant temperature at the refrigerant outlet end of the evaporator is measured by the temperature sensor to provide data for judging whether to start the water pump. The advantage of the periodic operation of the water pump is that once the refrigerant temperature of the evaporator reaches around 0°C, the water pump can be stopped in time in the next cycle, cutting off the water source to prevent the generation of cotton ice. Description of the Drawings

[0028] Figure 1 It is a schematic structural diagram of the present invention;

[0029] Figure 2 It is a schematic structural diagram of one side of the ice-making tray of the present invention;

[0030] Figure 3 It is a schematic circuit principle diagram of the present invention;

[0031] Figure 4 It is a schematic diagram of the temperature curve at the refrigerant outlet of the evaporator when the ice maker operates without enabling the water pump start-stop control;

[0032] Figure 5 It is a schematic diagram of the temperature curve at the refrigerant outlet of the evaporator when the ice maker operates with the water pump start-stop control enabled.

[0033] In the figure: 1, water tank; 2, evaporator; 201, refrigerant outlet end; 202, heat insulation sponge; 3, water pump; 4, ice-making tray; 5, water dispersing pipe. Detailed Embodiment

[0034] In order to make the technical means, creative features, achieved purposes and effects of the present invention easy to understand, the present invention will be further described below in conjunction with specific embodiments.

[0035] Embodiment 1

[0036] As Figure 1 、 Figure 2 shown, the control system for suppressing cotton ice of the present invention includes a water tank 1 in the prior art, an evaporator 2 arranged above the water tank 1, and a water pump 3 for pumping the water in the water tank 1 to the top of the evaporator 2. An ice-making tray 4 is arranged outside the evaporator 2. The water outlet end of the water pump 3 is connected with a water dispersing pipe 5 for evenly dispersing the water outlet and flowing through the ice-making tray 4;

[0037] It further includes an added controller and temperature sensor for suppressing the generation of cotton ice; the temperature sensor is arranged at the refrigerant outlet end 201 of the evaporator 2;

[0038] As Figure 3As shown in the figure, the controller is electrically connected to the temperature sensor and the water pump 3. The temperature sensor uses a thermistor to collect the temperature data of the refrigerant outlet end 201 of the evaporator 2 and transmit the refrigerant temperature T value to the controller. The controller is electrically connected to the water pump 3 through an electromagnetic relay to control the start and stop of the water pump 3.

[0039] By arranging a temperature sensor at the refrigerant outlet end 201 of the evaporator 2 of the existing ice maker, the refrigerant temperature can be detected, and this temperature can more accurately reflect the ice-making temperature of the ice-making tray 4.

[0040] By transmitting the current refrigerant temperature to the controller, the controller determines whether the refrigerant temperature is near 0°C. If the refrigerant temperature is near 0°C, it means that slush ice is likely to be generated at the ice-making tray 4, and the controller does not start the water pump 3, so that the ice-making tray 4 is cut off from the water source and there is no condition for generating slush ice. If the refrigerant temperature is lower than 0°C, the controller starts the water pump 3, and the water flowing through the ice-making tray 4 can condense into ice, and it is not easy to generate slush ice, which can achieve the purpose of preventing blockage.

[0041] This control method for suppressing slush ice includes the above-mentioned control system for suppressing slush ice, and also includes the following control steps:

[0042] (1) At the moment when the running time t = 0, the evaporator 2 starts to operate, the refrigerant enters the interior from the refrigerant inlet end of the evaporator 2, cools the ice-making tray 4 on the side of the evaporator 2, and the refrigerant that has completed cooling and heat absorption flows back from the refrigerant outlet end 201 of the evaporator 2. At this time, the water pump 3 is in a stopped state;

[0043] (2) Starting from the moment t = 0, the temperature sensor periodically measures the refrigerant temperature T at the refrigerant outlet every Δt and transmits the refrigerant temperature T value to the controller. The controller compares the refrigerant temperature T with the temperature threshold upper limit T1 and the temperature threshold lower limit T2 once in each cycle to control the periodic start and stop of the water pump 3 (the duration of each cycle is Δt);

[0044] At the moment t = N*Δt (N is a positive integer greater than 0, representing the Nth cycle), the refrigerant temperature T measured by the temperature sensor is Tn;

[0045] When Tn ≥ T1, the controller controls the water pump 3 to stop in the (N + 1)th cycle, and the stop time is one cycle Δt;

[0046] When Tn < T2, the controller controls the water pump 3 to start in the (N + 1)th cycle, and the start time is one cycle Δt;

[0047] When T1 > Tn ≥ T2, the controller keeps the start and stop state of the water pump 3 unchanged in the (N + 1)th cycle, and the maintenance time is one cycle Δt;

[0048] Among them, the upper temperature threshold T1 ≤ 0°C, the lower temperature threshold T2 ≤ -3°C, and the upper temperature threshold T1 is greater than the lower temperature threshold T2.

[0049] The water pump 3 in the existing ice maker continuously operates from the moment the evaporator 2 starts running. During the process of the evaporator 2 cooling down from room temperature to the ice-making temperature (-10 to -18°C), slush ice is generated during the period when the refrigerant temperature at the outlet end of the evaporator 2 is around 0°C, and the accumulated slush ice will block the water suction port of the water pump 3. Therefore, with this control method, the water pump 3 is set to a periodic operation mode (each cycle is 5 - 30 seconds). Before one operation cycle, the refrigerant temperature at the refrigerant outlet end 201 of the evaporator 2 is measured by a temperature sensor to provide data for judging whether to start the water pump 3. The advantage of the periodic operation of the water pump 3 is that once the refrigerant temperature of the evaporator 2 reaches around 0°C, the water pump 3 can be stopped in time in the next cycle to cut off the water source and prevent the generation of slush ice.

[0050] As Figure 4 shown, at the initial operation, the temperature is 10°C, and the start-stop control of the water pump 3 is not enabled, which is equivalent to the operation state of the existing ice maker. At the initial stage of startup, the evaporator 2 starts, and then the water pump 3 starts, and the water pump 3 maintains a continuous startup state. Since the evaporator 2 is not fully cooled at the initial stage of startup, the refrigerant temperature will rise during the initial stage of starting the water pump 3. However, as the evaporator 2 is fully cooled, the refrigerant temperature at the outlet end of the evaporator 2 gradually decreases; during this period, due to the continuous operation of the water pump 3 taking away heat, the temperature of the evaporator 2 drops relatively slowly, and the state of the temperature being around 0°C lasts for a long time. At this time, the water flowing through the ice-making tray 4 is likely to generate slush ice at 0°C, and the slush ice flows back to the water tank 1, resulting in the blockage of the water suction port of the water pump 3..

[0051] As Figure 5 shown, at the initial operation, the temperature is 10°C, and with this slush-ice suppression control system and method, the upper temperature threshold T1 = 0°C, and the lower temperature threshold T2 = -5°C.

[0052] (1) In the first cycle, the evaporator 2 operates alone, and the refrigerant temperature at the outlet continuously drops;

[0053] (2) Since the water pump 3 does not work, the refrigerant temperature at the outlet drops rapidly, Figure 5 and drops below -5°C in the second cycle. Therefore, the water pump 3 is started in the third cycle;

[0054] (3) At the end of the third cycle, since the evaporator 2 is not fully cooled at the initial stage of startup, only the refrigerant temperature at the outlet drops below -5°C, and the refrigerant temperature is greatly affected by the flowing water of the water pump 3 and rises above 0°C again. Therefore, the water pump 3 stops working in the fourth cycle to avoid the long-term operation of the water pump 3 around 0°C and prevent the generation of slush ice;

[0055] (4) At the end of the fourth cycle, since evaporator 2 works alone and cools down quickly, the refrigerant temperature at the outlet quickly drops to below -5°C (lower than the lowest point in the second cycle). Therefore, water pump 3 is started in the fifth cycle.

[0056] (5) At the end of the fifth cycle, since the evaporator 2 has not been completely cooled, the refrigerant temperature at the outlet is still greatly affected by the water flow of the water pump 3 and rises again to above 0°C (lower than the highest point in the third cycle). Therefore, the water pump 3 stops working in the fourth cycle to prevent the water pump 3 from running near 0°C for a long time to prevent the formation of soft ice;

[0057] (6) At the end of the sixth cycle, since evaporator 2 works alone and cools down quickly, the refrigerant temperature at the outlet quickly drops to below -5°C (lower than the lowest point in the fourth cycle). Therefore, water pump 3 is started in the seventh cycle.

[0058] (7) At the end of the 7th cycle, the evaporator 2 has been completely cooled. Although the refrigerant temperature is still affected by the water flow of the water pump 3, the power of the evaporator 2 is sufficient to slowly cool down the temperature when the water pump 3 is started. At this moment, the 0°C interval has been deviated and the refrigerant temperature can no longer rise above 0°C (between -5 and 0°C). Therefore, in the 8th cycle and subsequent cycles, the water pump 3 can resume the continuous start state.

[0059] In this control method, T1 needs to be less than or equal to 0°C to achieve the effect of reducing the production of cotton ice. If the T2 value is too close to the T1 value, the transition interval is too small, which will cause the water pump 3 to start and stop frequently. Therefore, the upper limit of the temperature threshold T1 = 0°C, and the lower limit of the temperature threshold T2 = -5°C. When the temperature of the refrigerant outlet 201 of the evaporator 2 is lower than -5°C, the water pump 3 is started. After the flowing water contacts the evaporator 2, the refrigerant in the evaporator 2 is still cooling continuously within one cycle. The evaporator 2 will not rise to 0°C immediately. It may take multiple cycles for the refrigerant temperature to return to near 0°C. At this time, the water pump 3 is turned off, and the number of starts and stops of the water pump 3 is reduced, which is conducive to extending the service life of the water pump 3.

[0060] Example 2

[0061] The other structures are the same as those in Embodiment 1, and the temperature sensor is arranged in the tube at the refrigerant outlet end 201 of the evaporator 2 .

[0062] The temperature sensor is located in the tube at the refrigerant outlet end 201 of the evaporator 2, and can measure the refrigerant temperature more accurately, which is conducive to more accurately controlling the start and stop of the water pump 3 according to the refrigerant temperature to prevent the generation of cotton ice.

[0063] Example 3

[0064] Other structures are the same as those in Embodiment 1. An insulating sponge 202 is wrapped outside the pipe of the refrigerant outlet end 201 of the evaporator 2.

[0065] Similar to the function of the second solution, the insulating sponge 202 can prevent the temperature of the refrigerant outlet end 201 of the evaporator 2 from dropping too fast, and after heat preservation, the refrigerant temperature can be measured more accurately.

[0066] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and all these changes and improvements fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. A control method for suppressing slush ice, characterized in that, A control system for inhibiting slush ice, the control system comprising a water tank, an evaporator disposed above the water tank, and a water pump for pumping water in the water tank to the top of the evaporator. An ice-making tray is disposed outside the evaporator. The water outlet end of the water pump is connected to a water distribution pipe for evenly distributing and flowing the outlet water through the ice-making tray. It is characterized in that it further comprises a controller and a temperature sensor; The temperature sensor is disposed at the refrigerant outlet end of the evaporator; The controller is electrically connected to the temperature sensor and the water pump; The temperature sensor is disposed inside the pipe at the refrigerant outlet end of the evaporator; The outside of the pipe at the refrigerant outlet end of the evaporator is wrapped with heat-insulating sponge; It further comprises the following control steps: (1) At the moment when the running time t = 0, the evaporator starts to operate. The refrigerant enters the interior from the refrigerant inlet end of the evaporator, cools the ice-making tray on the side of the evaporator, and the refrigerant that has completed the refrigeration and heat absorption flows back from the refrigerant outlet end of the evaporator. At this time, the water pump is in a stopped state; (2) Starting from the moment t = 0, the temperature sensor periodically measures the refrigerant temperature T at the refrigerant outlet every ∆t and transmits the value of the refrigerant temperature T to the controller. The controller compares the refrigerant temperature T with the upper temperature threshold T1 and the lower temperature threshold T2 once in each cycle to control the periodic start and stop of the water pump. The duration of each cycle is ∆t; At the moment t = N*∆t, N is a positive integer greater than 0, representing the Nth cycle, and the refrigerant temperature T measured by the temperature sensor is Tn; When Tn ≥ T1, the controller controls the water pump to stop in the (N + 1)th cycle, and the stop time is one cycle ∆t; When Tn < T2, the controller controls the water pump to start in the (N + 1)th cycle, and the start time is one cycle ∆t; When T1 > Tn ≥ T2, the controller keeps the start and stop state of the water pump unchanged in the (N + 1)th cycle, and the maintenance time is one cycle ∆t; Among them, the upper temperature threshold T1 ≤ 0°C, and the lower temperature threshold T2 ≤ -3°C.

2. The control method for suppressing cotton ice according to claim 1, wherein, The upper temperature threshold T1 = 0°C, and the lower temperature threshold T2 = -5°C.

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