JP2008133976A - Method of operating automatic ice making machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently perform deicing even when an ambient temperature is in a low temperature range. <P>SOLUTION: A refrigerating mechanism 20 is constituted to open a hot gas valve HV to continuously supply hot gas to an evaporator 14 until detecting a deicing completion temperature from the start of deicing operation when the ambient temperature detected by a temperature detecting means TH exceeds a predetermined set temperature. The refrigerating mechanism 20, on the other hand, is provided with a time zone where a refrigerant is supplied to a condenser CD in the stop state of a cooling fan FM by closing the hot gas valve HV only for a closing time after opening the hot gas valve HV only for an opening time from the start of the deicing operation when the ambient temperature detected by the temperature detecting means TH is not higher than the set temperature. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an operation method of an automatic ice making machine that performs ice removal with hot gas supplied to an evaporator disposed in an ice making unit during a deicing operation.

  As shown in FIG. 8, an ice making mechanism 10 is provided that continuously produces ice blocks by spraying and supplying ice making water from below to a large number of ice making chambers 12 a that open downward in an ice making chamber (ice making section) 12. An automatic ice making machine is suitably used in facilities such as a coffee shop and a restaurant, and other kitchens (see, for example, Patent Document 1). The ice making mechanism 10 is integrally provided immediately below an ice making chamber 12 horizontally disposed in the main body, and is pivotally supported by a pivot 16a so as to be tiltable, and a lower portion of the water tray 16. And an ice making water tank 18 for storing a fixed amount of ice making water. Further, on the upper surface of the ice making chamber 12, an evaporator 14 forming a part of a refrigeration mechanism 20 including a compressor CM, a condenser CD, an expansion means EV, a cooling fan FM, and the like is closely and meandered. .

  The refrigerating mechanism 20 includes a refrigerating circuit 22 that supplies the refrigerant from the compressor CM to the evaporator 14 through the condenser CD and the expansion valve EV cooled by the cooling fan FM, and the compressor CM through the bypass pipe 24a. And a bypass circuit 24 for directly supplying high-temperature and high-pressure vaporized refrigerant (hot gas) discharged from the evaporator 14 to the evaporator 14. The refrigeration mechanism 20 is provided with a hot gas valve HV that opens and closes the pipeline in the middle of the bypass pipe 24a. By closing the hot gas valve HV during the ice making operation, the refrigerant circulates in the refrigeration circuit 22, and the condenser A refrigeration cycle is formed to cool the evaporator 14 under the action of the CD and the expansion valve EV. At this time, in the ice making mechanism 10, the ice making water in the ice making water tank 18 is supplied to each cooled ice making chamber 12a in a state where the water tray 16 is held in a closed position where the ice making chamber 12a is closed from below. By injecting and supplying from 16, ice blocks are generated in each ice making chamber 12a.

In the refrigeration mechanism 20, hot gas is circulated through the bypass circuit 24 by opening the hot gas valve HV during the deicing operation, and a deicing cycle is formed in which the evaporator 14 is heated by the hot gas. At this time, the ice making mechanism 10 drives the opening / closing motor AM of the water tray opening / closing mechanism 28 to tilt the water tray 16 to the open position obliquely downward with the support shaft 16a as the center, thereby opening the ice making chamber 12a. Composed. Then, the supply of hot gas to the evaporator 14 melts the icing portion of the ice block with the ice making chamber 12 a, and the ice block that is detached from the ice making chamber 12 a by its own weight and slides down on the water tray 16 in the open position is stored in the stocker 26. Stored. Switching between the ice making operation and the deicing operation is performed based on the temperature detection of the operation switching means TP such as a thermistor disposed in the ice making chamber 12. When the ice making completion temperature is detected in the ice making operation, the ice making operation is switched to the deicing operation. When the deicing completion temperature is detected in the ice operation, the water tray 16 is raised and then the ice making operation is switched.
JP 2006-52879 A

  By the way, not all of the hot gas discharged from the compressor CM during the deicing operation circulates through the bypass circuit 24. A small amount of hot gas is liquefied after flowing into the condenser CD. A so-called stagnation phenomenon may occur. As described above, when a part of the hot gas stays in the condenser CD, the circulation amount of the hot gas in the bypass circuit 24 is reduced by the amount of the refrigerant stagnation as time elapses. The problem gradually decreases and a problem that requires a long time for deicing operation occurs. In particular, when the ambient temperature of the automatic ice making machine is lowered, the temperature of the hot gas discharged from the compressor CM is also lowered, so that the refrigerant stagnation may occur not only in the condenser CD but also in the evaporator 14. The above-mentioned problems are noticeable. When the temperature and supply amount of hot gas supplied to the evaporator 14 are reduced during the deicing operation, the temperature difference between the inlet side and the outlet side of the refrigerant in the evaporator 14 becomes significant, and each ice making chamber 12a Variations in the de-icing timing will increase. That is, although the ice block remains in the ice making chamber 12a, the operation switching means TP may erroneously detect the deicing completion temperature, and the ice block is caught between the ice making chamber 12 and the water dish 16. Occurs, which leads to breakage of the ice making chamber 12, the water tray 16, the water tray opening / closing mechanism 28, or the like.

  That is, the present invention has been proposed in order to suitably solve these problems inherent in the operation method of the automatic ice making machine according to the prior art, and the ambient temperature is in a low temperature range. Another object of the present invention is to provide a method of operating an automatic ice making machine that can perform deicing efficiently.

In order to overcome the above-mentioned problems and achieve the intended purpose, an operation method of the automatic ice maker according to claim 1 of the present application is as follows:
During ice making operation, the refrigerant is supplied from the compressor to the evaporator through the condenser cooled by the cooling fan and the expansion means, and the ice making water is supplied to the ice making part cooled by the evaporator to generate ice blocks. In the operation method of the automatic ice maker, the hot gas is directly supplied from the compressor to the evaporator by opening the hot gas valve during the deicing operation, so that the ice making unit is deiced by heating the evaporator.
During the deicing operation, if the ambient temperature detected by the temperature detecting means is equal to or lower than a preset temperature, the hot gas valve is closed for a predetermined time during the deicing process, and the cooling fan is stopped. In this state, a time zone for supplying hot gas to the evaporator via the condenser and expansion means is provided.
According to the first aspect of the present invention, when the ambient temperature is equal to or lower than the set temperature, the pressure of the condenser is increased by supplying hot gas to the condenser while the cooling fan is stopped during the deicing process. Can be made. Thereby, vaporization of the liquefied refrigerant staying in the condenser can be promoted, and a decrease in the circulation amount of the hot gas due to the staying liquefied refrigerant can be eliminated.

According to a second aspect of the present invention, when the ambient temperature detected by the temperature detecting means is equal to or lower than the set temperature, the hot gas valve is opened simultaneously with the start of the deicing operation, and then the hot gas valve is closed and opened. The gist is to set the process to repeat a predetermined number of times.
According to the second aspect of the present invention, the circulation of the liquefied refrigerant staying in the evaporator can be promoted by opening the hot gas valve simultaneously with the start of the deicing operation. Thereafter, a sufficient amount of hot gas can be supplied to the condenser by closing the hot gas valve. That is, a large supply amount of hot gas can be secured, and the liquefied refrigerant staying state in the condenser can be eliminated more smoothly.

According to a third aspect of the present invention, in the deicing operation at the time of starting the compressor, if the ambient temperature detected by the temperature detecting means is equal to or lower than a set temperature, the hot gas valve is delayed from the start of the deicing operation. The gist is to set it to open.
According to the third aspect of the invention, in the deicing operation at the time of starting the compressor, the temperature of the evaporator is higher than that at the completion of ice making, and the amount of liquefied refrigerant remaining in the evaporator is small. By setting so that the hot gas valve is opened after being delayed, the staying state of the liquefied refrigerant in the condenser can be eliminated without waste.

  According to the operation method of the automatic ice maker according to the present invention, when the ambient temperature is equal to or lower than the set temperature, it is possible to eliminate the decrease in the circulation amount of the hot gas caused by the accumulated liquefied refrigerant. It can be heated appropriately. Therefore, the ice removal from the ice making unit can be smoothly performed in the deicing operation regardless of the ambient temperature.

  Next, the operation method of the automatic ice making machine according to the present invention will be described below with reference to the accompanying drawings by giving a preferred embodiment. For convenience of explanation, the same reference numerals are used for the same elements as those of the automatic ice making machine shown in FIG.

  FIG. 1 is a schematic diagram showing an ice making mechanism 10 of an automatic ice maker according to an embodiment and a refrigeration mechanism 20 that supplies a refrigerant to an evaporator 14 that cools and heats an ice making chamber (ice making part) 12 of the ice making mechanism 10. It is. In the automatic ice making machine, as shown in FIG. 2, the ice making mechanism 10 and the refrigeration mechanism 20 are configured by the control means C based on inputs from sensors such as the operation switching means TP and the temperature detecting means TH and the time measuring means TM. Devices such as the compressor CM are driven and controlled so that the ice making operation and the deicing operation are repeated alternately. Here, when the automatic ice maker starts up the compressor CM by turning on the power, it restarts the compressor CM based on the input from the control means C or the operating means (not shown), and recovers from an abnormality or failure. Then, when the compressor CM is restarted (both are simply referred to as starting), it is set to start from the deicing operation with a delay of a certain protection time (see FIGS. 6 and 7). In other words, when the automatic ice maker stops during an ice making operation due to a power failure or the like, ice blocks may remain in the ice making chamber 12, and problems such as ice biting may occur if the ice making operation is started as it is. Start with ice driving.

  The ice making mechanism 10 is horizontally arranged inside the main body and has an ice making chamber 12 having a large number of ice making chambers 12a that open downward, and an ice making water tank that closes the ice making chambers 12a so that the ice making chambers 12a can be opened and closed and store ice making water. It is basically composed of a water dish 16 provided integrally with 18 downward. On the upper surface of the ice making chamber 12, an evaporator 14 constituting a part of the refrigeration mechanism 20 is closely and meanderingly arranged. The evaporator 14 forcibly cools each ice making chamber 12a during the ice making operation and also during the deicing operation. Each ice making chamber 12a is heated. The water tray 16 is pivotally supported by the support shaft 16a so as to be tiltable with respect to the ice making chamber 12. The water tray 16 and the ice making water tank 18 are positioned horizontally in the ice making operation and are held parallel to the ice making chamber 12 to make ice. The opening of the small chamber 12a is configured to be closed. The water tray 16 is tilted by the bias of the water tray opening / closing mechanism 28 based on the driving of the opening / closing motor AM, and is tilted downward about the support shaft 16a by the water tray opening / closing mechanism AM at the start of the deicing operation. Is to be released. Further, the water tray 16 is configured to be tilted upward about the support shaft 16a by the water tray opening / closing mechanism 28 to close the ice making chamber 12a on the condition that the ice tray 16 is deiced in the deicing operation. The And ice making water is supplied to the ice making water tank 18 from the water supply pipe 30 in which the water supply valve WV is inserted, and a predetermined amount of ice making water is stored. During the ice making operation, the ice making water pump PM communicated with the ice making water tank 18 is driven, whereby ice making water is supplied to each ice making chamber 12a from the water tray 16 that closes the ice making chamber 12a. The ice making chamber 12 is provided with operation switching means TP for detecting the temperature of the ice making chamber 12, and based on the temperature detection result of the operation switching means TP, completion of ice making in ice making operation or deicing operation in ice removing operation is completed. Determined.

  The water tray opening / closing mechanism 28 tilts the water tray 16 downward by an opening / closing motor AM driven simultaneously with the start of the deicing operation, and when the changeover switch SW detects the arrival of the water tray 16 at the open position, the opening / closing motor The AM is configured to be stopped. Further, when the operation switching means TP detects the deicing completion temperature in the deicing operation, the water dish opening / closing mechanism 28 tilts the water dish 16 upward from the open position by driving the opening / closing motor AM to close the water dish 16. The opening / closing motor AM is stopped when the change-over switch SW detects arrival at the formation position.

  In the refrigeration mechanism 20, a compressor CM, a condenser CD, a cooling fan FM that cools the condenser CD, an expansion valve (expansion means) EV, and an ice making chamber 12 are disposed in a machine room (not shown). The refrigeration circuit 22 is configured by connecting the evaporators 14 with refrigerant piping. In the refrigeration circuit 22, each device is connected by a refrigerant pipe 23 so that the refrigerant circulates in the order of the compressor CM, the condenser CD, the expansion means EV, the evaporator 14, and the compressor CM. In the refrigeration circuit 22, during the ice making operation, the refrigerant compressed by the compressor CM is supplied to the evaporator 14 through condensation in the condenser CD cooled by the cooling fan FM and decompression by the expansion means EV. As a result, the refrigerant takes heat from the ice making chamber 12 by the evaporator 14 and evaporates to forcibly cool the ice making chamber 12 to below the freezing point, and then repeats the refrigeration cycle returning to the compressor CM. The compressor CM in the stopped state is driven simultaneously with the start of the deicing operation, and is continuously driven in the deicing operation and the ice making operation.

  As the expansion valve EV of the embodiment, a temperature operation type valve that adjusts the opening degree of the valve in accordance with the temperature is adopted. The expansion valve EV includes a temperature detection unit TK disposed on the outlet side of the evaporator 14 (see FIG. 1). When the temperature detected by the temperature detection unit TK decreases, the opening degree of the valve increases while the temperature increases. When it becomes higher, the opening degree of the valve becomes smaller, and when the temperature reaches a predetermined temperature, the pipe line is completely closed. That is, in the deicing operation, when the temperature on the outlet side of the evaporator 14 becomes higher than a predetermined temperature by opening the hot gas valve HV, a circuit on the high-pressure side in the refrigeration circuit 22 (from the compressor CM to the condenser CD). The path to the expansion valve EV via is closed.

  The refrigeration mechanism 20 includes a bypass circuit 24 that supplies hot gas to the evaporator 14 during the deicing operation in addition to the refrigeration circuit 22 described above. The bypass circuit 24 has a bypass pipe 24 a having a start end connected to the refrigerant pipe 23 between the discharge side of the compressor CM and the suction side of the condenser CD and a terminal connected to the refrigerant pipe 23 on the suction side of the evaporator 14. Have. A hot gas valve HV that operates under the control of the control means C and opens and closes the conduit of the bypass pipe 24a is inserted in the bypass pipe 24a. In the refrigeration mechanism 20, when the hot gas valve HV is opened (ON), the hot gas circulates in the bypass circuit 24, and the hot gas is directly supplied to the evaporator 14 without passing through the condenser CD and the expansion valve EV. Thus, a deicing cycle for heating the ice making chamber 12 is performed. On the other hand, in the refrigeration mechanism 20, the refrigerant is circulated through the refrigeration circuit 22 by closing (OFF) the hot gas valve HV.

  The cooling fan FM is controlled by the control means C so as to be driven when the hot gas valve HV is closed and to be stopped when the hot gas valve HV is opened. In the refrigeration mechanism 20, when the deicing operation is started, the driven cooling fan FM is stopped, and the stopped cooling fan FM is maintained in the stopped state, and the deicing completion temperature by the operation switching means TP is maintained. As a condition, the cooling fan FM starts to be driven. That is, the cooling fan FM is continuously driven from the time when the water pan 16 is tilted upward to the ice making operation.

  The automatic ice making machine includes temperature detection means TH for detecting the ambient temperature in the installation environment, and the operating condition of the refrigeration mechanism 20 in the deicing operation is switched by the control means C based on the detection result of the temperature detection means TH. . That is, when the temperature detection result of the temperature detection means TH exceeds a preset temperature (for example, about 10 ° C.) preset in the control means C, the refrigeration mechanism 20 performs a normal startup process in the deicing operation at startup, In the deicing operation, the normal deicing process is controlled. On the other hand, when the temperature detection result of the temperature detection means TH is equal to or lower than the set temperature, the refrigeration mechanism 20 performs the low temperature start process in the deicing operation at the start, and performs the low temperature deicing process in the other deicing operations. To be controlled. The temperature detection means TH is provided around the condenser CD, and is particularly preferably arranged on the refrigerant inflow side in the condenser CD. This is because the temperature of the machine room in which the condenser CD is installed is raised by the exhaust heat of the compressor CM, and therefore does not always coincide with the temperature outside the machine. For the purpose of eliminating it, it is optimal to detect the ambient temperature around the condenser CD.

  In the normal start-up process and the normal deicing process, the refrigeration mechanism 20 opens the hot gas valve HV immediately after starting the deicing operation until the deicing completion temperature is detected by the operation switching means TP from the start of the deicing operation. The hot gas valve HV is controlled to be kept open during the period (deicing process). When the deicing completion temperature is detected by the operation switching means TP, the hot gas valve HV is closed and the cooling fan FM is driven in the refrigeration mechanism 20, and the ice making mechanism 10 in the water dish 16 by the changeover switch SW. The deicing operation is switched to the ice making operation based on the detection of the completion of the upward tilt.

  In the cold start process and the low temperature deicing process, the refrigeration mechanism 20 closes the hot gas valve HV for a predetermined time (closing time) during the deicing process and stops the cooling fan FM, and then the condenser. A time zone for supplying the refrigerant to the evaporator 14 via the CD and the expansion valve EV is provided. As a result, a pressure increase cycle for supplying hot gas having a high temperature and pressure to the condenser CD is performed. In the cold start process, the refrigeration mechanism 20 does not immediately open the hot gas valve HV even after the deicing operation is started, and after performing the refrigerant pressure increase cycle in the refrigeration circuit 22 for the required time, the hot gas valve HV is turned on. It is set to be opened and deiced by heating with hot gas. In the embodiment, the opening timing of the hot gas valve HV in the low temperature starting process is linked to the water tray opening / closing mechanism 28 that tilts the water tray 16. That is, the hot gas valve HV is opened and the operation switching means TP is provided on condition that the water pan 16 is tilted downward by the energization of the water pan opening / closing mechanism 28 driven by the opening / closing motor AM and is detected by the changeover switch SW. The hot gas valve HV is closed when the deicing completion temperature is detected by.

  In the low-temperature deicing step, the refrigeration mechanism 20 is configured to open and close the hot gas valve HV a predetermined number of times (in the embodiment, open-close-open-open) by the control means C based on the time measured by the time measuring means TM. Closed operation) Repeatedly. The time measuring means TM connected to the control means C is activated when the detection result of the temperature detecting means TH is equal to or lower than the set temperature, and the opening time for maintaining the open state of the hot gas valve HV at the beginning of the deicing operation and It is configured to time the closing time for maintaining the closed state of the hot gas valve HV during the deicing process (see FIG. 7). The time measuring means TM is set to start counting the opening time from the start of the deicing operation, start the closing time when the opening time elapses, and reset when the closing time elapses, The opening time and closing time are counted once.

  In the low-temperature deicing process, when the deicing operation is started, the hot gas valve HV is opened for the opening time and the degassing cycle for circulating the hot gas to the bypass circuit 24 is performed, and then the hot gas valve HV is turned on for the closing time. It is set to perform a pressure increase cycle in which the refrigerant is circulated through the refrigeration circuit 22 with the cooling fan FM stopped while being closed (see FIG. 7). Then, the hot gas valve HV is opened again to perform a deicing cycle in which the hot gas circulates in the bypass circuit 24, and the operation switching means TP detects the deicing completion temperature, whereby the hot gas valve HV is closed. . In the embodiment, the time for the water pan 16 to reach from the closed position to the open position (driving time of the opening / closing motor AM) is set to be the same as the open time of the hot gas valve HV at the beginning of the deicing operation. Has been. The closing time of the hot gas valve HV is set to about 40 seconds to 90 seconds.

(Effects of Example)
Next, the operation of the operation method of the automatic ice maker according to the embodiment will be described with reference to the flowcharts of FIGS. 3 to 5 and the timing charts of FIGS. 6 and 7. As shown in FIG. 3, when the automatic ice making machine is activated, the deicing operation is started (step S10) with a delay of the protection time set in the control means C to protect the components (step S1). First, it is determined whether or not the ambient temperature detected by the temperature detection means TH is equal to or lower than a set temperature (step S11). When the detection result of the ambient temperature by the temperature detection means TH exceeds the set temperature, the process proceeds to the normal startup process (step S12), and when the automatic ice maker installation environment is in the low temperature range and is below the set temperature, the temperature is low. The process proceeds to the starting process (step S16). In the normal starting process, the cooling fan FM and the ice making water pump PM are kept stopped, and the compressor CM is driven (step S13). Further, the hot gas valve HV is opened and hot gas is supplied to the evaporator 14 via the bypass pipe 24a, and the open / close motor AM is driven and the water pan 16 is moved downward by the energization of the water pan open / close mechanism 28. It is tilted toward (step S13). When the water pan 16 reaches the open position, the open / close motor AM is stopped by the detection of the changeover switch SW (steps S14 and S15), and the water tray 16 is stopped at the open position where the ice making chamber 12a is opened. By circulating the hot gas through the bypass circuit 24, the evaporator 14 is heated by the hot gas and the temperature of the ice making chamber 12 is gradually increased.

  When the operation switching means TP detects the deicing completion temperature (step S20), it is determined that the deicing is completed (step S21), and the hot gas valve HV is closed (step S22). At the same time, the opening / closing motor AM of the water tray opening / closing mechanism 28 is driven to tilt the water tray 16 in the open position upward, thereby closing the ice making chamber 12a and driving the cooling fan FM. A refrigerant refrigeration cycle is performed (step S22). Thus, in the normal startup process, the hot gas valve HV is in an open state from the start of the deicing operation to the detection of the deicing completion temperature, and deicing with the hot gas is continuously performed ( (See FIG. 6). When the changeover switch SW detects that the water pan 16 has reached the closed position (step S23), the process proceeds to the ice making operation (step S30).

  On the other hand, when the process proceeds to the low temperature starting process (step S16), the open / close motor AM is driven and the water tray 16 is tilted downward by the bias of the water tray opening / closing mechanism 28, but the hot gas valve HV is closed. And the stop state of the cooling fan FM is maintained (step S17). Although the hot gas discharged from the compressor CM circulates in the refrigeration circuit 22, the condenser CD is not cooled by the cooling fan FM, so that the hot gas is not condensed and liquefied in the condenser CD. . That is, in the refrigeration circuit 22, a pressure increase cycle is performed in which the refrigerant is circulated in a hot gas state to increase the pressure of the condenser CD. Here, in the deicing operation at the time of starting the compressor CM, the temperature of the evaporator 14 is higher than that at the completion of the ice making operation, the amount of liquefied refrigerant remaining in the evaporator 14 is small, and starting from a normal stop state in particular. At this time, since the liquefied refrigerant does not stay in the evaporator 14, there is no time zone for opening the hot gas valve HV and supplying hot gas to the evaporator 14 at the start of the deicing operation. Therefore, by setting the hot gas valve HV to be delayed and opened from the start of the deicing operation, the liquefied refrigerant staying state in the condenser CD can be eliminated without waste.

  When the water pan 16 reaches the open position (step S18), the open / close motor AM is stopped (step S19), and the water tray 16 is stopped at the open position where the ice making chamber 12a is opened. At the same time, by opening the hot gas valve HV, the hot gas is circulated to the bypass circuit 24, and the hot gas is directly supplied to the evaporator 14, whereby the evaporator 14 is further heated. Here, in the low temperature starting process, the opening / closing timing of the hot gas valve HV is linked to the downward tilt of the water pan 16 by driving the opening / closing motor AM. It is not necessary to provide another means such as, and the cost can be reduced. In the low temperature startup process, the steps after the detection of the deicing completion temperature by the operation switching means TP (steps S20 to S23) are the same as the normal startup process described above.

  In the ice making operation, the opening / closing motor AM is stopped by detecting the closed position of the water tray 16 by the changeover switch SW, and the ice making water pump PM is driven to supply ice making water from the water tray 16 to the ice making chamber 12a (step). S31). At this time, the ice-making chamber 12 is forcibly cooled by the evaporator 14 by supplying the evaporator 14 with the refrigerant circulating in the refrigeration circuit 22 under a predetermined refrigeration action while the cooling fan FM is driven. Therefore, an ice block M is generated in the ice making chamber 12a. In the ice making operation, when the ice making completion temperature detected in advance by the operation switching means TP is detected, the ice making operation is completed and the operation proceeds to the ice removing operation (steps S32 and S33). In the ice making operation, the ice making chamber 12 that has become hot during the deicing operation becomes a resistance and the pressure rises once. However, as the temperature of the ice making chamber 12 decreases, the compressor CM is also cooled, so that the pressure gradually increases. It decreases (see FIG. 7).

  When the deicing operation is started (step S40), it is determined whether or not the ambient temperature detected by the temperature detecting means TH is equal to or lower than the set temperature (step S41). When the detection result of the ambient temperature by the temperature detecting means TH exceeds the set temperature, the process moves to the normal deicing process (step S42), and when the installation environment of the automatic ice making machine is in the low temperature range and becomes lower than the set temperature, The process proceeds to a low temperature deicing process (step S46). In the normal deicing process, the ice making water pump PM that has supplied ice making water to the ice making chamber 12a and the cooling fan FM that has cooled the condenser CD are stopped, and the hot gas valve HV is opened to open the evaporator 14. Is supplied with hot gas via the bypass pipe 42 (step S43). Further, when the opening / closing motor AM of the water tray opening / closing mechanism 28 is driven, the water tray 16 is tilted downward (step S43), and the ice making chamber 12a is opened. When the water pan 16 arrives at the open position, the switch SW is detected (step S44), the open / close motor AM is stopped (step S45), and the water pan 16 is stopped at the open position where the ice making chamber 12a is opened. When the ice formation surface of the ice making chamber 12a and the ice block is melted, the ice making chamber 12a is deiced by its own weight. Thus, when the operation switching means TP detects the deicing completion temperature (step S20), the steps after the detection of the deicing completion temperature by the operation switching means TP (steps S20 to S23) are performed in the same manner as the normal activation process described above. ) Is implemented.

  In the low temperature deicing step, the ice making water pump PM that has supplied ice making water to the ice making chamber 12a and the cooling fan FM that has cooled the condenser CD are stopped, and the hot gas valve HV is opened to open the evaporator 14. Is supplied with hot gas via the bypass pipe 42 (step S47). Further, by driving the opening / closing motor AM of the water tray opening / closing mechanism 28, the water tray 16 is tilted downward (step S47), and the ice making chamber 12a is opened. At the same time, the timing of the opening time of the hot gas valve HV by the timing means TM is started (step S47). When the timing means TM measures the opening time (step S48), the hot gas valve HV is closed to stop the supply of hot gas to the evaporator 14, and the refrigeration is performed while the fan motor FM is kept stopped. Hot gas is circulated to the circuit 22 (step S49). Further, the time measuring means TM that measures the opening time starts measuring the closing time of the hot gas valve HV. At this time, since the temperature of the evaporator 14 and the outlet side of the evaporator 14 is increased by the hot gas, the expansion valve EV is in a closed state based on detection of a predetermined temperature by the temperature detection unit TK. Then, the liquefied refrigerant staying in the evaporator 14 evaporates and circulates as a vaporized refrigerant in the low-pressure side circuit (path from the evaporator 14 to the compressor CM) in the refrigeration circuit 22. The amount of hot gas to be circulated can be ensured.

  When the opening time elapses after the hot gas valve HV is opened (time measurement of the opening time by the time measuring means TM is completed: step S48), the hot gas valve HV is closed with the cooling fan FM stopped (step S49). The hot gas is supplied to the high-pressure circuit in the refrigeration circuit 22. At this time, the expansion valve EV is closed by detecting a predetermined temperature by the temperature detection unit TK, and the hot gas valve HV is closed, so that hot gas is pushed in from the compressor CM and condensed. In the vessel CD (high-pressure side circuit), the pressure rises. And since the temperature of the condenser CD also rises with the rise in the pressure of the condenser CD, the liquefied refrigerant staying in the condenser CD can be vaporized. At this time, in the circuit on the low pressure side in the refrigeration circuit 22, changes in pressure and temperature do not occur much. As described above, in the refrigeration mechanism 20, after the deicing operation is started, the hot gas is circulated through the bypass circuit 24 for the open time and the hot gas is directly supplied to the evaporator 14, and then the hot gas is supplied to the bypass circuit 24. Supply is stopped and a pressure rise cycle is performed in the refrigeration circuit 22 over the closing time.

  When the closing time elapses after the hot gas valve HV is closed (closing time measurement by the time measuring means TM is completed: step S50), the hot gas valve HV is opened and the operation switching means TP is at the deicing completion temperature. The hot gas is supplied directly to the evaporator 14 until it is detected (step S51). That is, since the pressure of the high pressure side circuit in the refrigeration circuit 22 is high, when the hot gas valve HV is opened, the pushed hot gas is supplied to the evaporator 14 at once. Thereby, the hot gas can surely reach the outlet side of the evaporator 14.

  When the water pan 16 reaches the open position (step S52), the opening / closing motor AM is stopped (step S53), and the water tray 16 is stopped at the open position where the ice making chamber 12a is opened. In the low-temperature deicing process, the steps after the detection of the deicing completion temperature by the operation switching means TP (steps S20 to S23) are the same as the normal activation process described above.

  According to the automatic ice maker of the embodiment, in the deicing process in the deicing operation, the hot gas is circulated through the refrigeration circuit 22 with the cooling fan FM stopped, so that the condensation occurs as the pressure of the condenser CD increases. The vessel CD can be heated (see FIG. 7). As a result, the liquefied refrigerant staying in the condenser CD can be vaporized. When the refrigerant circulation path is switched to the bypass circuit 24, the liquefied refrigerant stagnation state in the condenser CD is eliminated, so that a sufficient amount of hot gas circulates in the bypass circuit 24. That is, the hot gas is appropriately supplied to the evaporator 14 to avoid an excessive temperature difference between the inflow side and the outflow side of the evaporator 14 and balance the ice making chamber 12 as a whole. Can be heated well. Moreover, since the hot gas valve HV is opened by ending the pressure increase cycle, hot gas is vigorously supplied to the evaporator 14 and reaches the outlet side, so that the entire evaporator 14 can be heated evenly. Therefore, it is possible to prevent the ice block from being abnormally melted in the specific ice making chamber 12a, to prevent the generation of deformed ice and to obtain an ice block having a desired shape. Further, since the ice can be removed from each ice making chamber 12a at the same timing, the deicing time can be shortened and the ice making ability is improved. Moreover, since erroneous detection of the deicing completion temperature by the operation switching means TP can be suppressed, the ice making chamber 12, the water tray 16 or the water tray opening / closing mechanism 28 is caused by the biting of ice blocks between the ice making chamber 12 and the water tray 16. Etc. can be prevented from being damaged.

  Since the refrigeration mechanism 20 is set to selectively perform a pressure increase cycle only when the ambient temperature is equal to or lower than the set temperature, the refrigerant stagnation phenomenon that is manifested particularly when the ambient temperature is in the low temperature range is suitable. In addition, the load on the refrigeration mechanism 20 due to repeated opening and closing of the hot gas valve HV can be reduced in a normal temperature range where the stagnation phenomenon is unlikely to occur. Even when the ambient temperature of the automatic ice maker is in a low temperature range, the deicing time can be shortened, the deicing efficiency can be improved, and energy saving can be achieved.

(Change example)
The present invention is not limited to the configuration of the embodiment, and can be modified as follows.
(1) The ice making mechanism of the embodiment is a so-called closed cell type that opens and closes the ice making chamber with a water tray, but is not limited to this, and ice making that uses hot gas in an open cell type or a down flow type deicing operation. If it is a mechanism, the operation method mentioned above can be applied.
(2) The opening and closing of the hot gas valve in the low-temperature deicing step may be linked to the opening and closing of the water dish by the water dish opening and closing mechanism instead of the time measuring means.
(3) As the hot gas valve, an electromagnetic valve, a motor-operated valve or the like is preferably employed, but it is not particularly limited as long as it can be arbitrarily operated (opening and closing of the bypass pipe) under the control of the control means.
(4) In the embodiment, the mode in which the timing means counts the opening time once after the timing of the opening time has been described. However, even when the hot gas valve is opened, the timing is closed. A mode in which the time and the closing time are alternately measured a plurality of times may be employed.
(5) At the start of the deicing operation, the case of having a step of referring to the temperature detection result of the temperature detecting means every time has been described. However, the present invention is not limited to this. An aspect may be sufficient.
(6) In the low temperature start-up process, the hot gas valve opening control is linked to the downward tilt of the water pan. However, as in the low-temperature deicing process, The gas valve may be opened and closed.
(7) When the ambient temperature exceeds the set temperature, a temperature detection means is provided in the bypass circuit. When the temperature detected by the temperature detection means at the start of the deicing operation is higher than the set value, the hot gas valve is closed for a predetermined time. In addition, a refrigeration cycle may be performed in order to prevent the evaporator from overheating during the deicing process by driving the cooling fan.

It is the schematic which shows the principal part of the automatic ice making machine used for the operating method which concerns on the suitable Example of this invention. It is a control block diagram of the automatic ice making machine of an Example. It is a flowchart figure which shows the deicing operation at the time of starting in the automatic ice maker of an Example. It is a flowchart figure which shows the ice making operation | movement of the automatic ice maker of an Example. It is a flowchart figure which shows the deicing operation at the normal time in the automatic ice maker of an Example. It is a timing chart figure which shows the operation state of each apparatus in the automatic ice maker of an example, and is the case where ambient temperature is normal. It is a timing chart figure which shows the operation state of each apparatus in the automatic ice making machine of an Example, Comprising: It is a case where ambient temperature exists in a low temperature range. It is the schematic which shows the conventional automatic ice making machine.

Explanation of symbols

12 ice making room (ice making part), 14 evaporator, CM compressor, FM cooling fan, CD condenser,
EV expansion means, HV hot gas valve, TH temperature detection means

Claims (3)

During ice making operation, refrigerant is supplied from the compressor (CM) to the evaporator (14) via the condenser (CD) and expansion means (EV) cooled by the cooling fan (FM), and the evaporator (14). Ice-making water is supplied to the ice-making unit (12) cooled by this to produce ice blocks, and during deicing operation, hot gas is sent from the compressor (CM) to the evaporator (14) by opening the hot gas valve (HV). In the operation method of the automatic ice maker that is made to deicer from the ice making part (12) by heating the evaporator (14) by supplying directly,
During the deicing operation, if the ambient temperature detected by the temperature detecting means (TH) is below a preset temperature, the hot gas valve (HV) is closed for a predetermined time during the deicing process, An automatic is provided with a time zone for supplying hot gas to the evaporator (14) via the condenser (CD) and the expansion means (EV) with the cooling fan (FM) stopped. How to operate an ice machine.   When the ambient temperature detected by the temperature detecting means (TH) is equal to or lower than the set temperature, the hot gas valve (HV) is opened simultaneously with the start of the deicing operation, and then the hot gas valve (HV) is closed and 2. The method of operating an automatic ice making machine according to claim 1, wherein the opening step is set to be repeated a predetermined number of times.   In the deicing operation at the start of the compressor (CM), if the ambient temperature detected by the temperature detecting means (TH) is equal to or lower than a set temperature, the hot gas valve (HV) is delayed from the start of the deicing operation. The method of operating an automatic ice maker according to claim 1, wherein the automatic ice maker is set to open.

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