Icemaking system and a method of controlling evaporation temperature referred to by the icemaking system

Patent metadata

Field	Value
Publication number	US-11614264-B2
Application number	US-201916959621-A
Country	US
Kind code	B2
Filing date	Jan 11, 2019
Priority date	Jan 15, 2018
Publication date	Mar 28, 2023
Grant date	Mar 28, 2023

Abstract

An icemaking system includes: a refrigerant circuit that executes a vapor compression refrigeration cycle; a circulation circuit that circulates solution as a cooling target of the refrigerant circuit; and a control device that controls refrigerant evaporation temperature at the refrigerant circuit. The circulation circuit includes a solution flow path of: an ice generator; a solution tank that stores the solution; and a pump that pressure feeds the solution to the solution flow path. The refrigerant circuit includes: an evaporator of the ice generator; a compressor; a condenser; and an expansion valve. The control device includes a central processing unit (CPU) that adjusts to lower evaporation temperature at the evaporator as the solution has higher solute concentration.

First claim

The invention claimed is:

1. An icemaking system comprising:
a refrigerant circuit that executes a vapor compression refrigeration cycle;
a circulation circuit that circulates solution as a cooling target of the refrigerant circuit; and
a control device that controls refrigerant evaporation temperature at the refrigerant circuit, wherein
the circulation circuit comprises a solution flow path of:
an ice generator;
a solution tank that stores the solution; and
a pump that pressure feeds the solution to the solution flow path,

the refrigerant circuit comprises:
an evaporator of the ice generator;
a compressor;
a condenser; and
an expansion valve, and

the control device comprises a central processing unit that:
calculates target evaporation temperature based on a correlation between solute concentration of the solution and the refrigerant evaporation temperature, wherein the correlation is defined such that a temperature difference between freezing temperature of the solution and evaporation temperature at the evaporator increases as the solute concentration increases, and
adjusts the evaporation temperature at the evaporator to decrease as the solute concentration of the solution increases and to reach the target evaporation temperature thus calculated.

2. The icemaking system according to claim 1 , wherein
the ice generator is configured by a double pipe icemaker comprising an inner pipe and an outer pipe,
the correlation includes:
a first correlation for when the inner pipe has adjusted inner surface roughness; and
a second correlation for when the inner pipe has unadjusted inner surface roughness.

3. The icemaking system according to claim 2 , wherein
the central processing unit:
adjusts the evaporation temperature at the evaporator based on the first correlation when the ice generator has adjusted inner surface roughness; and
adjusts the evaporation temperature at the evaporator based on the second correlation when the ice generator has unadjusted inner surface roughness.

4. The icemaking system according to claim 1 , wherein the central processing unit outputs alarm information for warning a user that the solute concentration has a measurement value less than a first threshold.

5. The icemaking system according to claim 1 , wherein
the central processing unit:
executes a reliability priority mode of prioritizing freezing prevention rather than icemaking capacity when a measurement value of the solute concentration is less than a second threshold; and
executes a capacity priority mode of prioritizing icemaking capacity rather than freezing prevention when the measurement value of the solute concentration is equal to or more than the second threshold.

6. The icemaking system according to claim 1 , wherein the evaporation temperature at the evaporator is adjusted by:
adjusting a frequency of the compressor of an inverter type,
adjusting at least one of a full load or unload period and an unload percentage of the compressor of an unload type,
adjusting an opening degree of the expansion valve,
adjusting rotational speed of a fan,
adjusting output of a heater that heats a flow-in pipe of the evaporator, and
adjusting a flow rate of the solution.

7. A method of controlling evaporation temperature at an evaporator of an ice generator, where the evaporator in a refrigerant circuit executes a vapor compression refrigeration cycle having solution as a cooling target, the method comprising:
calculating target evaporation temperature based on a correlation between solute concentration and a refrigerant evaporation temperature, wherein the correlation is defined such that as the solution has higher concentration, an icemaking amount increases and a temperature difference between freezing temperature of the solution and the evaporation temperature at the evaporator increases; and
adjusting the evaporation temperature at the evaporator to reach the target evaporation temperature thus calculated.

Assignees

• Daikin Ind Ltd

Inventors

• Kondou Azuma
• Ueno Takeo
• Yasuda Shouhei
• Nakayama Takahito
• Sakae Satoru

Classifications

• F25C1/145

  from the inner walls of cooled bodies · CPC title

• F25C1/147 Primary

  by using augers · CPC title

• F25B2500/19

  Calculation of parameters · CPC title

• F25C1/00

  Producing ice (F25C3/00 takes precedence) · CPC title

• F25C2600/04

  Control means · CPC title