JPH0347177Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention relates to an automatic ice maker, and in particular to an automatic ice maker configured so that the amount of hot gas circulated during deicing operation can be adjusted according to the ambient temperature.

Prior Art FIG. 8 shows a schematic configuration of a conventionally known fountain type automatic ice maker. In the figure, reference numeral 1 indicates a downwardly opening ice-making chamber disposed in an ice-making section, and the interior of this ice-making chamber 1 is divided into a large number of ice-making compartments 2 by partition plates provided vertically and horizontally. An evaporator 3 connected to the illustrated refrigeration system is closely arranged in a meandering manner on the outer upper surface of the ice-making compartment 1, and a water tray 4 is tiltably disposed below the ice-making compartment 1. i.e. water dish 4
is pivotally supported at one end on the machine frame, and the other end is connected via a lever to the actuator motor AM shown in FIG. 1 is closed from below. During the deicing cycle, the actuator motor AM rotates and opens the ice making chamber 1 by tilting the water tray 4 diagonally downward. Also, the valve of the refrigeration system is switched, hot gas is supplied to the evaporator 3 to warm the ice making chamber 1, and the ice cubes produced in the small ice making chamber 2 are released and stored in an ice storage tank (not shown). It's becoming like that.

A water fountain hole 7 is bored in the water tray 4 at a position corresponding to each of the ice-making compartments 2, and this fountain hole 7 communicates with a distribution pipe 6 arranged on the back surface of the water tray. An ice-making water tank 5 is provided below the water tray 4.
The ice-making water sent from the pump motor PM to the pressure chamber via the water pipe 8 is fed under pressure to the distribution pipe 6, and is fed into the corresponding ice-making chamber 2 from a large number of water fountain holes 7, and then the ice-making water is fed into the corresponding ice-making chamber 2 from the evaporator 3. As a result, ice cubes are gradually formed in layers on the inner surface of the ice-making chamber 2 which has been cooled to below freezing point. The ice-making residual water that has not yet frozen is returned and collected into the water tank 5 through a return hole 9 formed in the water tray 4 corresponding to each ice-making compartment 2. The water tank 5 is supplied with the required amount of ice-making water necessary for the ice-making cycle from an external water supply system 10 through a water supply valve.
Supplied via WV.

The outlet side of the evaporator 3 is connected to the suction port of a compressor 20 via a suction pipe 17, and the discharge pipe 14 connected to the discharge port of the compressor 20 is connected to a condenser 11 equipped with a fan motor FM. ing. This condenser 11 is connected to a dryer 12 via a liquid pipe 15.
The outlet side of the dryer 12 is connected to a liquid pipe 16 and an expansion valve 1.
3 to the inlet side of the evaporator 3. The discharge pipe 14 is branched before the inlet of the condenser 11 and connected to a hot gas pipe 18 having a hot gas valve HV, and the inlet of the evaporator 3 is connected to the hot gas pipe 18 by bypass. Further, an ice-making detection thermometer Th ₁ is disposed at a suitable upper surface position of the ice-making chamber 1, and a de-icing detection thermometer Th ₂ is disposed at a side position of the ice-making chamber 1.

FIG. 9 shows a connection diagram of the electrical system in the automatic ice making machine described above. This changeover switch in Figure 9
SW is the actuator motor during the de-icing cycle.
It is provided to switch from the ice making side contact a to the deicing side contact b when the water tray 4 is tilted by a predetermined angle due to the rotation of the AM. In addition, S ₁ indicates a reset switch, ice making detection thermo Th ₁ detects the completion of ice making and switches its contact a to contact b, and deicing detection thermo Th ₂ detects the completion of ice making and closes the contact. It is starting to become a reality.

There is an ice-making detection thermometer at contact a of the changeover switch SW.
Th ₁ and reset switch S ₁ are connected in parallel, and a cooling fan motor FM and a pump motor PM are connected in parallel to contact a of ice-making detection thermo Th ₁ .
Furthermore, the contact b of the ice-making detection thermometer _Th1 is connected to the reset switch _S1 and the actuator motor AM. Contact b of the changeover switch SW has a de-icing detection thermometer connected to the actuator motor AM.
Th ₂ , hot gas valve HV, and water supply valve WV are connected in parallel.

The operation of the conventional fountain-type automatic ice maker having this configuration will be described next. The changeover switch SW provided on the water tray 4 is connected to the contact a side during the ice making cycle, and the ice making detection thermometer Th ₁ is connected to the contact a side to energize the compressor 20, cooling fan motor FM, and pump motor PM. are doing. The refrigerant compressed by the compressor 20 is discharged and supplied to the condenser 11 through the discharge pipe 14, cooled by a cooling fan to become a high-pressure liquid, passed through the dryer 12 to remove moisture, and after being depressurized by the expansion valve 13. , and is fed to the evaporator 3 where it evaporates to cool the ice making compartment 1. The refrigerant gas vaporized in the evaporator 3 returns to the compressor 20 again through the suction pipe 17 and repeats the previous cooling cycle.

When ice cubes are generated in the ice making compartment 2 and ice making is completed, the ice making detection thermo _Th1 detects this and switches its contact to the "b" side to enter the deicing cycle.
This allows the fan motor FM and pump motor PM to
While the current is cut off, the actuator motor AM is energized and the water tray 4 is tilted. And a changeover switch SW arranged on the support frame of the water tray 4
contacts the arm of the motor AM and switches to the contact b side, and the hot gas valve HV and water supply valve WV are energized and opened. As a result, the refrigerant compressed by the compressor 20 is directly introduced into the evaporator 3 via the pipe 18 as a high-temperature hot gas before being cooled by the condenser 11, heating the ice-making compartment 1 and increasing its temperature. Promote de-icing.

Problems to be Solved by the Invention In the conventional automatic ice maker mentioned above, the time required for the ice cubes to leave the ice maker 1 after entering the deicing cycle (deicing time) generally depends on the outside temperature, etc. of the ice maker. depends on the ambient temperature, e.g. becomes shorter in summer,
It has been confirmed that it takes longer in winter. In other words, the refrigerant pressure in the pipes of the refrigeration system increases when the ambient temperature is high, such as in the summer, and the amount of hot gas circulated increases, and conversely, when the ambient temperature is low, such as in the winter, the amount of hot gas circulated decreases. . Therefore, if the pressure on the low pressure side (suction side) of the compressor 20 is set according to the temperature conditions in the summer, the pressure on the low pressure side of the compressor will further decrease in the winter, and the amount of hot gas circulating through the evaporator 3 will decrease. becomes less. For this reason, there are problems in that the heating time of the ice making chamber 1 becomes longer, the time for deicing becomes longer, the ice making capacity is significantly reduced, and the power consumption increases.

Further, the amount of refrigerant circulated is greater during the deicing cycle than during the ice making cycle because the refrigerant does not go through the pressure reducing means 13, and the load on the compressor 20 increases during the deicing cycle. Even during the same deicing cycle, during high temperatures such as summer when the amount of hot gas circulating increases,
The load on the compressor 20 further increases. Therefore, if the low pressure side pressure of the compressor 20 is set according to the winter season,
In the summer, there is a problem in that the compressor becomes overloaded during the deicing cycle, leading to failures such as motor burnout. Moreover, if the ice maker is actually used for a long time, dust and the like will adhere to the surface of the condenser 11, impeding heat transfer and reducing heat exchange efficiency. This further causes an increase in the amount of refrigerant circulation, which promotes overloading of the compressor 20. Therefore, the amount of refrigerant circulation cannot be set in advance to be unnecessarily large.

However, when the amount of refrigerant circulation is reduced, the following problems are pointed out. In other words, the hot gas having a small amount of circulation cannot uniformly heat the tube from the inlet side to the outlet side of the evaporator 3 because its heat capacity is small. For this reason, even if the inlet side can be heated to a high temperature, the closer you get to the outlet side, the higher the temperature cannot be ensured, and the ice cubes cannot be removed from each ice making compartment 2 all at once, resulting in a longer deicing time. .

Therefore, in order to remove all the ice at once without any time delay, a gap is generally formed in advance between the lower end of the ice-making compartment 1 and the surface of the water tray 4, and each ice cube is connected to this gap. It is designed so that rib-shaped ice is generated. Therefore, if the deicing time is long, the amount of ice cubes melted in the ice making chamber 2 near the inlet of the evaporator 3 will be larger than the amount of ice cubes melting in the ice making chamber 2 near the outlet of the evaporator 3. When all the ice cubes are separated by their own weight, a large amount of ice cubes with non-uniform shapes are produced.

The above-mentioned problems with automatic ice makers can occur not only in fountain ice makers but also in other types of ice makers, such as falling ice makers. Such issues are discussed in Section 10.
As shown in the figure, this is due to the fact that the hot gas circulation rate cannot be adjusted depending on the ambient temperature because only one hot gas valve is installed during the deicing cycle, regardless of the ambient temperature. do.

Purpose of the Invention The object of the present invention is to provide an automatic ice maker that can adjust the hot gas circulation amount depending on the ambient temperature, in order to solve the above-mentioned problems inherent in the conventional automatic ice maker. shall be.

Means for Solving the Problems In order to suitably solve the above problems, the present invention has the following features:
It consists of an evaporator disposed in the ice making section, a condenser that supplies liquefied refrigerant to the evaporator via a pressure reducing means, and a compressor that compresses the vaporized refrigerant from the evaporator and sends it to the condenser. In an automatic ice making machine equipped with a refrigeration circuit, a first pipe that directly bypasses compressed vaporized refrigerant before flowing into the condenser to the inlet side of the evaporator, and a first hot gas valve that opens and closes the first pipe. and a second pipe that directly bypasses the refrigerant flowing out from the condenser to the inlet side of the evaporator.
A second hot gas valve for opening and closing the second pipe is provided, and during deicing operation, only the second hot gas valve is opened when the outside temperature is higher than a first predetermined temperature;
When the temperature is between the first predetermined temperature and a lower second predetermined temperature, only the first hot gas valve is opened, and when the temperature is below the second predetermined temperature, both the first and second hot gas valves are opened. It is designed to do so.

Function The automatic ice maker of the present invention having the above-mentioned configuration has the following features:
During deicing operation when the outside temperature is below a second predetermined temperature, the hot gas is circulated through the first pipe, and the second
By circulating hot gas through piping, the liquefied refrigerant stored in the condenser is vaporized and used as hot gas. In this way, the amount of hot gas circulation necessary for deicing in a short time is ensured. When the temperature is higher than the second predetermined temperature and lower than the first predetermined temperature, there is a sufficient amount of hot gas circulation even if the hot gas is circulated only through the first pipe. When the outside temperature exceeds the first predetermined temperature, the refrigerant pressure in the refrigeration circuit increases and the load on the compressor increases.In this case, the hot gas is circulated through the second pipe and the heat is radiated by the condenser. temperature and reduce the load on the compressor.

Embodiment Next, a preferred embodiment of the automatic ice making machine according to the present invention will be described with reference to FIGS. 1 to 7. FIG. 1 is a schematic diagram of the ice making section of a fountain-type automatic ice maker according to an embodiment of the present invention, and FIG. 2 is a refrigeration circuit diagram thereof. In addition, in Figure 1, the 8th
Components that are the same as those explained in the figures are given the same reference numerals and their explanations will be omitted.

In the refrigeration circuit of this embodiment, the conventional hot gas piping and hot gas valve are shown as a first piping 18 and a first hot gas valve _HV1 , respectively. In addition to this configuration, a second pipe 19 that directly bypasses the liquefied refrigerant flowing out of the condenser 11 to the inlet side of the evaporator 3 and a second hot gas valve HV ₂ that opens and closes this second pipe 19 are newly provided. is,
In addition, an outside temperature detection thermometer is used as a means to detect outside temperature.
Th ₃ is arranged near the condenser 11.

In the embodiment shown in FIGS. 1 and 2, the sides where the first pipe 18 and the second pipe 19 connect to the evaporator 3 are combined into one pipe body, but they are connected to the evaporator 3 separately. It may be configured to be connected to the entrance side.
In addition, as shown in FIGS. 3 and 4, the liquid receiver 3
In the case of a refrigeration circuit having 0, the second pipe 19 may be led out from either the front or rear side of the liquid receiver 30. Further, although the thermostat _Th3 is used as a means for detecting the outside temperature, other temperature sensing elements such as a thermistor or thermocouple may be used. Also condenser 1
Instead of detecting the temperature in the vicinity of 1, the outlet temperature of the condenser 11 may be directly detected, and the ice-making time can be adjusted by taking advantage of the fact that the ice-making time tends to be short at low temperatures and long at high temperatures. It may be counted and used as a parameter representing the outside temperature, or the high pressure side refrigerant pressure may be detected and this may be used as a parameter representing the outside temperature.

FIG. 5 shows an electrical system connection diagram of the automatic ice maker according to the first embodiment of the present invention. In this example, the ninth
In addition to the conventional connection configuration shown in the figure, it is equipped with two outside temperature detection thermometers Th ₃ and Th ₄ . That is, the first outside temperature detection thermometer _Th3 and the second hot gas valve _HV2 , which are connected in series, are connected in parallel to the first hot gas valve _HV1 . In addition, the second outside temperature detection thermometer Th ₄ has one side connected to the contact point b of the changeover switch SW.
is connected to the power supply bus through the
It is possible to switch between the first hot gas valve HV ₁ connected via the contact a of Th 4 and the second hot gas valve HV ₂ connected via the contact b of Th ₄ . Note that the first outside temperature detection thermometer _Th3 opens when the second predetermined temperature A or higher, and the second outside temperature detection thermometer _Th4 contacts when the outside temperature reaches the first predetermined temperature B, which is higher than the predetermined temperature A. It is set to switch from contact a to contact b.

Therefore, the first hot gas valve according to the first embodiment
As shown in FIG. 6, both hot gas valves HV _{1 and} HV ₂ open when the outside air temperature is below a predetermined temperature A, and when the outside air temperature _is below the predetermined temperature A, When the temperature is between B, only the first hot gas valve HV ₁ is opened, and when the outside air temperature is higher than B, only the second hot gas valve HV ₂ is opened.
This is because there is a high risk that the refrigerant pressure in the refrigeration circuit will become too high at high temperatures and the compressor 20 will be overloaded.
This is to reduce the load on the compressor 20 by circulating the heat through the condenser 11 and radiating heat through the condenser 11. Here, it is more preferable to set the valve diameter of _the second hot gas valve _HV2 to be smaller than the valve diameter of the first hot gas valve HV1.

The operation of the automatic ice maker according to this configuration will be explained next. Note that the operation during the ice making operation is the same as the operation in the conventional example described with reference to FIGS. 8 and 9, so only the example of the operation during the deicing operation will be described.

When the outside temperature is lower than the predetermined temperature A, such as in winter, the refrigerant pressure in the refrigeration circuit is also low.
At this time, the contact of the outside temperature detection thermometer _Th3 is closed. Therefore, when the ice-making completion detection thermo _Th1 detects the completion of ice-making and switches its contact from the "a" side to the "b" side to drive the actuator motor AM, the water tray 4 tilts and the changeover switch SW is switched to contact b. As a result, the first hot gas valve HV ₁ opens via the second outside temperature detection thermometer Th ₄ which has already been switched to the contact a side, and
The second hot gas valve HV ₂ is also opened via the contact of the first outside temperature detection thermometer Th ₃ which is in the closed state.
That is, when the deicing operation is started, the first hot gas valve HV ₁ and the second hot gas valve HV ₂ switch to the sixth hot gas valve HV 2.
Both valves open as shown in the figure.

Therefore, the high temperature hot gas discharged from the compressor 20 is branched and supplied to the first piping 18 and the condenser 11 in FIG.
The hot gas branched into the first pipe 18 via the HV ₁ flows into the evaporator 3. On the other hand, the liquefied refrigerant stored in the condenser 11 (conventionally, this liquefied refrigerant remained in the condenser during deicing operation and was not circulated in the refrigeration circuit) is transferred from the liquid pipe 15 to the second hot gas. flows into the second pipe 19 via the valve HV ₂ ,
It flows into the evaporator 3. Therefore, in the evaporator 3, hot gas (refrigerant in a gas phase) that arrives via the first hot gas valve HV ₁ and refrigerant in a liquid phase that arrives via the second hot gas valve HV ₂ are mixed. A gas-liquid multiphase refrigerant will be introduced. The temperature of such gas-liquid mixed-phase refrigerant is lower than the temperature of the hot gas when only the first hot gas valve HV ₁ is opened by the amount of liquid-phase refrigerant mixed in. is only at the beginning of the deicing cycle, and as the circulation is repeated, it gradually becomes a gaseous state and becomes a high-temperature hot gas (especially since the cooling fan of the condenser 11 is stopped, The refrigerant that passes through it is hardly liquefied). Therefore, the amount of refrigerant circulating within the refrigeration circuit increases and the refrigerant pressure rises, so a large amount of high-temperature hot gas circulates through the evaporator 3, melting the ice cubes in the ice making compartment 1 in a short time. Can be made to leave. Although a heat loss occurs due to the amount of heat radiated by the condenser 11, the amount of hot gas circulated increases and becomes an appropriate amount compared to when only the first hot gas valve _HV1 is opened at low temperatures.

Next, when the outside air temperature (ambient temperature) is higher than the predetermined temperature A but lower than the predetermined temperature B, the refrigerant pressure in the refrigeration circuit is high. Therefore, the outside temperature detection thermometer _Th3 is opened and the second hot gas valve _HV2 is closed. At this time, when the ice-making completion detection thermo _Th1 detects the completion of ice-making, the contact is switched from the "a" side to the "b" side, and the actuator motor AM is driven to tilt the water tray 4. As a result, the changeover switch SW switches to contact b, and the first hot gas valve HV ₁ is connected via the second outside temperature detection thermometer Th ₄ , which is switched to contact a.
The second hot gas valve opens, but as mentioned above, the second hot gas valve opens.
HV ₂ is kept closed. However, since the refrigerant pressure is high, the amount of hot gas circulating in the evaporator 3 only via the first hot gas valve HV ₁ is at a proper value, so that ice can be removed in a short time without overloading the compressor 20. be able to.

When the outside temperature (ambient temperature) reaches a predetermined temperature B or higher, a second outside temperature detection thermometer is activated.
Th ₄ has been switched to the contact b side. Therefore, even when the switch SW is switched to the contact b side when deicing operation starts, the first hot gas valve _HV1 remains open. Further, by switching the switch SW to the contact b side, the second hot gas valve _HV2 is opened even though the first outside temperature detection thermometer _Th3 is open. At these extremely high temperatures, the hot gas is therefore circulated through the evaporator 3 via the condenser 11, where the temperature of the hot gas is lowered. Therefore, ice can be removed without placing a large load on the compressor 20.

When this deicing is completed and the cooling load on the ice making compartment 2 is removed, the temperature of the ice making compartment 1 rises rapidly due to hot gas circulation, and the deicing detection thermo _Th2 detects this and closes its contact. As a result, the actuator motor AM is reversely energized, the water tray 4 is returned to its original horizontal position, the ice making chamber 1 is closed, and the changeover switch SW is switched to contact a to proceed to the next ice making operation.

Note that when dissipating heat in the condenser 11, if the cooling fan is driven to increase the cooling efficiency, the compressor 20
The load can be further reduced. An embodiment that operates in this manner is shown in FIG. In the second embodiment of the present invention shown in FIG. ₇ , _a relay At the same time, the cooling fan motor FM is connected to the power supply bus through the normally open contact Xa-2, and further connected to the contact a of the ice-making detection thermometer _Th1 through the normally closed contact Xb of the relay. With this connection configuration, when the deicing operation is started when the ambient temperature is above the predetermined temperature B and the changeover switch SW is switched to contact b, the outside temperature detection thermometer Th ₄ is placed on the contact b side. Therefore _{, relay} Electricity is supplied to the fan motor FM through the normally open contact Xa-2, and the cooling fan is driven.

In each of the above embodiments, a configuration in which the present invention is applied to a fountain-type automatic ice maker equipped with an ice maker that opens downward has been described. Whether it is a plate method that freezes sheet ice, an open cell method that has an independent ice-making chamber that opens downward, or a block method that freezes water in a water tank, hot gas is pumped into the evaporator during deicing. As long as it circulates to melt the ice formed between the ice making section and the ice produced, it can be suitably used in all ice making methods. Further, the condenser is not limited to an air-cooled type, but may be a water-cooled type.

Effects of the invention According to the invention, the amount of hot gas circulation can be controlled based on the ambient temperature of the ice maker, resulting in the following effects.

(1) Since the deicing time can be set short even at low temperatures, ice making capacity is improved.

(2) Reduces power consumption and saves energy.

(3) Compressor overload at high temperatures is prevented.

(4) Even at low temperatures, the amount of hot gas circulated is large and the heat capacity is large, so the heating of the ice making chamber during the deicing cycle is uniform, and therefore ice of good quality and stable shape can be obtained.

(5) Since the structure is simple, it can be manufactured at low cost and maintenance is easy.

[Brief explanation of drawings]

The drawings show an embodiment of the automatic ice maker according to the present invention, in which FIG. The refrigeration circuit diagram of the automatic ice maker shown in the figure, FIGS. 3 and 4 are refrigeration circuit diagrams according to different embodiments, respectively.
Fig. 5 is a connection diagram of the electrical system of the first embodiment, Fig. 6 is an operation explanatory diagram of the first embodiment, Fig. 7 is a connection diagram of the electrical system of the second embodiment, and Fig. 8 is a conventional fountain. FIG. 9 is a schematic diagram of a conventional fountain-type automatic ice maker, and FIG. 10 is a diagram illustrating the operation of a conventional hot gas valve. 1... Ice making room, 3... Evaporator, 11... Condenser, 13... Expansion valve, 18... First piping, 19...
...Second piping, 20...Compressor, _HV1 ...First hot gas valve, _HV2 ...Second hot gas valve.

Claims (1)

[Scope of utility model registration request] An evaporator 3 disposed in the ice making section 1 and this evaporator 3
An automatic ice maker equipped with a refrigeration circuit consisting of a condenser 11 that supplies liquefied refrigerant to the evaporator 3 through a pressure reducing means 13, and a compressor 20 that compresses the vaporized refrigerant from the evaporator 3 and sends it to the condenser 11. , a first pipe 1 that directly bypasses the compressed vaporized refrigerant before flowing into the condenser 11 to the inlet side of the evaporator 3;
8, a first hot gas valve HV 1 that opens the first piping 18 during deicing operation when the outside temperature is below a first predetermined temperature B, and a first hot gas valve HV ₁ that connects the refrigerant flowing out from the condenser 11 to the inlet of the evaporator 3. a second pipe 19 that directly bypasses the second pipe 1 to the side, and a second pipe 19 that bypasses the second pipe 1 during deicing operation when the outside temperature is below a second predetermined temperature A lower than the first predetermined temperature B or above the first predetermined temperature B.
9. An automatic ice making machine characterized by being provided with a second hot gas valve HV ₂ which opens the second hot gas valve HV 2.