JPS645732Y2 - - Google Patents

Description

[Detailed Description of the Invention] a. Field of Industrial Application This invention relates to an automatic ice maker that is equipped with an auxiliary refrigeration circuit and removes ice using hot gas.

b. Prior Art Conventionally, in an automatic ice maker that de-ices by flowing hot gas into an evaporator during deicing, the gas refrigerant discharged from the compressor is sent directly to the evaporator via the hot gas valve, and the gas refrigerant is The liquid refrigerant was de-icing using latent heat of condensation, and the liquid refrigerant condensed in the evaporator was directly sucked into the compressor. As a result, liquid compression occurs within the compressor, and damage to the compressor occurs due to poor lubrication. In addition, the liquid refrigerant sucked into the compressor stays in the compressor, resulting in a refrigerant shortage, which reduces the amount of refrigerant that circulates, and therefore requires a long time to remove ice.

C. Problems to be solved by the invention As mentioned above, conventional automatic ice making machines had problems such as damage to the compressor and long deicing times.

d Means for Solving the Problems The automatic ice maker of this invention includes a refrigeration circuit A that generates ice, a medium heating heat exchanger 10 that stores the latent heat of condensation of the refrigerant in a heat storage medium, and a heat exchanger 10 that stores the latent heat of condensation of the refrigerant in a heat storage medium, and makes ice using the latent heat of evaporation of the refrigerant. An auxiliary refrigeration circuit B is provided which incorporates an ice-making water cooling heat exchanger 13 that pre-cools water, and a refrigerant heating circuit that evaporates the refrigerant condensed in the evaporator 1 during deicing using heat from the heat storage medium. heat exchanger 16
is provided between the evaporator 1 and the first compressor 2.

e Effect When making ice, the evaporator 1 is cooled by the latent heat of vaporization of the refrigerant circulating in the refrigeration circuit A, and the ice-making water pre-cooled in the auxiliary refrigeration circuit B is frozen in the ice-making section to which the evaporator 1 is attached. . Further, during ice making, the latent heat of condensation of the refrigerant in the auxiliary refrigeration circuit B is absorbed and stored in the heat storage medium in the heat storage tank 11 by the medium heating heat exchanger 10 incorporated in the auxiliary refrigeration circuit B. During deicing, the refrigerant in refrigeration circuit A is
The ice is sent from the first compressor 2 to the evaporator 1 through the bypass pipe 8, and the ice generated in the ice making section is removed by the latent heat of condensation of the refrigerant. The refrigerant that has changed into a liquid state in the evaporator 1 is sent to the refrigerant heating heat exchanger 16, where it takes away the latent heat of vaporization from the heat storage medium and changes into a gaseous state again. In this state, the first compressor 2
will be returned to.

f. Example Hereinafter, an example of this invention will be described with reference to the drawings. The figure is a refrigeration circuit diagram showing an embodiment of this invention, and this automatic ice maker includes a refrigeration circuit A that supplies cold heat to the ice making section, and a refrigeration circuit A that precools ice making water supplied to the ice making section and heats a heat storage medium. It is equipped with an auxiliary refrigeration circuit B. The refrigeration circuit A includes an evaporator 1 attached to, for example, a cup-shaped ice making section (not shown). The evaporator 1 is connected via a three-way deicing valve 3 to a first compressor 2 that converts a low-pressure, low-temperature gas refrigerant into a high-pressure, high-temperature gas. The first compressor 2 is connected to a condenser 4 via refrigerant piping, and the condenser 4 releases the heat of the high-pressure, high-temperature gas refrigerant to the high-temperature heat source, and the refrigerant undergoes a phase change into a high-pressure, high-temperature liquid state. do. The condenser 4 is connected to a first expansion valve 6 that lowers the pressure and temperature of the refrigerant via a gas-liquid heat exchanger 5, which will be described later. This first expansion valve 6 is connected to the evaporator 1 via a refrigerant pipe, and the low-pressure, low-temperature refrigerant is heated under constant low pressure in the evaporator 1 from the ice-making section corresponding to the low-temperature heat source side. It absorbs water and turns into low-pressure, low-temperature gas. In addition, the first compressor 2 and the condenser 4
The refrigerant pipes between the first expansion valve 6 and the evaporator 1 are directly connected by a bypass pipe 8 equipped with a two-way hot gas valve 7.

The auxiliary refrigeration circuit B includes a second compressor 9 that has the same function as the first compressor 2. The second compressor 9 converts the refrigerant from high-pressure and high-temperature gas to high-pressure and high-temperature gas.
Heat exchanger 10 for heating a medium for phase change to high temperature liquid
(hereinafter abbreviated as medium heat exchanger). This medium heat exchanger 10 is provided inside a heat storage tank 11 containing a heat storage medium, such as water, which acts as a heat storage. The refrigerant is transferred to the medium heat exchanger 10
By passing through the medium, the latent heat of condensation is absorbed by the heat storage medium, and the phase changes to a liquid state. The function of this medium heat exchanger 10 is that the condenser 4
is the same as The medium heat exchanger 10 is connected to an ice making water cooling heat exchanger 13 (hereinafter abbreviated as ice making water heat exchanger) via a second expansion valve 12 which has the same function as the first expansion valve 6. There is. This ice-making water heat exchanger 13 is provided inside the ice-making water tank 14 and has the same function as the evaporator 1. The refrigerant evaporates when passing through the ice-making water heat exchanger 13, and the latent heat of vaporization at that time is taken away from the ice-making water, so that the ice-making water is cooled. This pre-cooled ice-making water is sent as ice-making water for the next cycle via an ice-making water pipe 15 to an ice-making section (not shown) where it is cooled by the evaporator 1. The ice-making water heat exchanger 13 is connected to the second compressor 9 via the gas-liquid heat exchanger 5.

The gas-liquid heat exchanger 5, which is provided across both the refrigeration circuit A and the auxiliary refrigeration circuit B, exchanges high-pressure and high-temperature liquid refrigerant in the refrigeration circuit A and low-pressure and high-temperature liquid refrigerant in the auxiliary refrigeration circuit B. It is designed to exchange heat with a low-temperature gas refrigerant. As a result of heat exchange, the enthalpy of the liquid refrigerant in refrigeration circuit A decreases, and the enthalpy of the liquid refrigerant in refrigeration circuit B decreases.
The enthalpy of the gas refrigerant inside increases.

One outlet of the three-way deicing valve 3 is connected to one end of a refrigerant heating heat exchanger 16 (hereinafter referred to as refrigerant heat exchanger). The refrigerant heat exchanger 16 is provided inside the heat storage tank 11, and when the refrigerant condensed and liquefied in the evaporator 1 passes through the refrigerant heat exchanger 16 during deicing, the refrigerant is transferred to the inside of the heat storage tank 11. The refrigerant absorbs heat from the heat storage medium and evaporates to become a gas refrigerant. The other end of the refrigerant heat exchanger 16 is connected to a refrigerant pipe following the first compressor 2 . In the figure, reference numeral 17 indicates a heat storage medium temperature sensor, and reference numeral 18 indicates an ice-making water temperature sensor, and their signals are sent to the second compressor 9. Abnormal overheating of the heat storage medium and freezing of the ice-making water are prevented by intermittent operation of the second compressor 9 controlled by these signals.

In the automatic ice maker configured as above,
During ice making, the refrigerant in the refrigeration circuit A flows through the first compressor 2, the condenser 4, the gas-liquid heat exchanger 5, the first expansion valve 6, the evaporator 1, and the first It circulates and flows in the order of compressor 2. Then, when the refrigerant flows through the evaporator 1, the refrigerant evaporates under low pressure,
The latent heat of vaporization at that time freezes the ice-making water that is circulated and distributed in the ice-making section. During ice making, the refrigerant in the auxiliary refrigeration circuit B flows through the second refrigerant as shown by arrow D.
compressor 9, medium heat exchanger 10, second expansion valve 1
2, ice-making water heat exchanger 13, gas-liquid heat exchanger 5, second
It circulates and flows through the compressor 9 in this order. This refrigerant is
The medium heat exchanger 10 causes a phase change from high-pressure, high-temperature gas to high-pressure, high-temperature liquid, and the latent heat of condensation at that time stores and heats the heat storage medium in the heat storage tank 11 . moreover,
When this refrigerant enters the ice-making water heat exchanger 13 through the second expansion valve 12, it evaporates under low pressure, and the latent heat of vaporization at that time pre-cools the ice-making water used in the next ice-making cycle. Ru. Subsequently, the refrigerant is sent to the gas-liquid heat exchanger 5, where it exchanges heat with the high-pressure, high-temperature liquid refrigerant in the refrigeration circuit A. As a result, the enthalpy of the gas refrigerant in the auxiliary refrigeration circuit B increases, which increases the heat dissipation ability of the refrigerant in the medium heat exchanger 10, contributing to an increase in the temperature of the heat storage medium. On the other hand, the enthalpy of the liquid refrigerant in the refrigeration circuit A will decrease, but this will increase the heat absorption capacity in the evaporator 1 and contribute to shortening the freezing time in the ice making section.

After ice is sufficiently generated in the ice making section by circulating the refrigerant in the refrigeration circuit A according to a well-known method, the hot gas two-way valve 7 is opened, and the three-way deicing valve 3 is connected to the refrigerant heat exchanger 16 side. By opening the ice making section, the ice in the ice making section is peeled off and removed. By opening the hot gas two-way valve 7, the refrigerant in the refrigeration circuit A is
As shown in the figure, the air circulates through the first compressor 2, the evaporator 1, the refrigerant heat exchanger 16, and the first compressor 2 in this order. During deicing, high pressure from the first compressor 2
The high-temperature gas refrigerant flows into the evaporator 1 as it is without changing its phase, releases latent heat of condensation within the evaporator 1, and changes its phase into a liquid state. The heat melts the contact surface of the ice forming in the ice making section. thus,
The liquefied refrigerant is then sent to the refrigerant heat exchanger 16 through the three-way deicing valve 3. Refrigerant heat exchanger 1
In the compressor 6 , the refrigerant is heated by the heat storage medium stored during ice making, evaporates and changes its phase into a gaseous state, and this gaseous refrigerant is returned to the first compressor 2 . The above-mentioned circulation of the refrigerant is continued until the ice is completely peeled off from the ice making section and falls into the ice storage section (not shown).

In the above embodiment, both the medium heat exchanger 10 and the ice-making water heat exchanger 13 are provided inside the tanks 11 and 14, but they may be provided outside the tanks 11 and 14. Further, although the case where water is used as the heat storage medium has been described, brine may be used, and there is no particular limitation as long as it can store heat.

g. Effects of the invention As explained above, according to this invention, by providing an auxiliary refrigeration circuit B for pre-cooling ice-making water to an automatic ice-making machine having a refrigeration circuit A, the freezing time can be shortened, and the ice-making capacity can be reduced. increases. In addition, the latent heat of condensation of the refrigerant in the auxiliary refrigeration circuit B is stored in the heat storage medium in the heat storage tank 11, and this heat is used as the latent heat of evaporation of the refrigerant condensed in the evaporator 1 during deicing. Liquid backflow to the first compressor 2 during ice conditions is prevented, and it is possible to prevent damage to the first compressor 2 and prolongation of deicing due to a decrease in the amount of circulating refrigerant. .

Further, as in the above embodiment, across both the refrigeration circuit A and the auxiliary refrigeration circuit B, the enthalpy of the liquid refrigerant in the refrigeration circuit A decreases, and the enthalpy of the gas refrigerant in the auxiliary refrigeration circuit B increases. By providing the gas-liquid heat exchanger 5 at this position, the heat absorption capacity of the evaporator 1 is increased, and the freezing time in the ice making section is further shortened. On the other hand, the heat dissipation capacity of the medium heating heat exchanger 10 also increases, and this amount of heat is effectively used for evaporating the refrigerant condensed in the evaporator 1 during deicing.

[Brief explanation of the drawing]

The figure is a refrigeration circuit diagram showing an embodiment of this invention. DESCRIPTION OF SYMBOLS 1... Evaporator, 2... First compressor, 3... Three-way valve for deicing, 4... Condenser, 5... Gas-liquid heat exchanger, 6... First expansion valve, 7... ... Hot gas two-way valve, 9 ... Second compressor, 10 ... Heat exchanger for heating medium, 11 ... Heat storage tank, 12 ... Second expansion valve, 13 ... Heat exchanger for cooling ice making water , 14...
Ice making water tank, 16... Heat exchanger for heating refrigerant.

Claims (1)

[Claims for Utility Model Registration] 1. First compressor 2, condenser 4, and first expansion valve 6
and an evaporator 1 are sequentially connected via refrigerant piping, a refrigeration circuit A configured with It is connected to the evaporator 1 via a valve 7, and is connected to a bypass pipe 8 through which high-pressure and high-temperature gas refrigerant flows during deicing, and the outlet of the evaporator 1 is connected via a three-way deicing valve 3. a heat exchanger 16 for heating a refrigerant, which is installed in a heat storage tank 11 containing a heat storage medium in which heat is stored, and evaporates the refrigerant condensed in the evaporator 1 during deicing; A medium heating heat exchanger 10 and a second expansion valve 1 are provided in
2 and the ice-making water tank 14, an ice-making water cooling heat exchanger 13 that cools the ice-making water using the latent heat of vaporization of the refrigerant, and a second compressor 9 are sequentially connected via refrigerant piping. An automatic ice maker characterized in that it is equipped with an auxiliary refrigeration circuit B. 2. In the refrigeration circuit A, the gas-liquid heat exchanger 5, which enables heat exchange between the high-pressure and high-temperature liquid refrigerant in the refrigeration circuit A and the low-pressure and low-temperature gas refrigerant in the auxiliary refrigeration circuit B, is connected to the condenser 4 and the first The automatic ice making device according to claim 1 of the utility model registration claim is provided between the expansion valve 6 and the ice making water cooling heat exchanger 13 and the second compressor 9 in the auxiliary refrigeration circuit B. Machine.