JPH11223413A - Refrigerating facility - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigerating facility with low initial cost and running cost. SOLUTION: A refrigerating facility is designed to cool a refrigerating storehouse 1 by two refrigerating machines 2. Both an absorption refrigerating machine 2A and a compression refrigerating machine 2B are used. Upon start of a cooling operation, the compression refrigerating machine 2B is used. Upon refrigerating temperature maintaining operation, the absorption refrigerating machine 2A is used. When refrigerating load reaches a set value or more during the refrigerating temperature maintaining operation, the compression refrigerating machine 2B is used together to perform the operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigeration system which can be operated most economically when refrigeration is performed using a plurality of refrigerators.

[0002]

2. Description of the Related Art Generally, a refrigeration warehouse requires refrigeration equipment having a considerable refrigeration capacity. That is, a plurality of chillers are provided in accordance with the capacity at the start of refrigeration operation, which requires the most refrigeration capacity. is set up. After the temperature in the warehouse reaches the set refrigeration temperature, during the refrigeration temperature maintenance operation for maintaining this temperature, the refrigeration capacity is as large as at the time of the refrigeration start operation.
Not required.

Conventionally, a compression type refrigerator is used as the above refrigerator.
In the case of refrigeration tons, two compression refrigerators of 50 refrigeration tons were installed.

[0004]

Incidentally, an absorption-type refrigerator has recently been used as a refrigerator, but the above-mentioned compression-type refrigerator has an initial cost (compared to the absorption-type refrigerator). (Installation cost) is low, but there is a problem that running cost is high. On the other hand, when an absorption refrigerator is installed, the running cost is low, but the initial cost is high.

[0005] Therefore, an object of the present invention is to provide a refrigeration facility that is low in both initial cost and running cost.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a refrigeration system of the present invention is a refrigeration system for cooling the inside of a warehouse by using a plurality of chillers. The refrigeration start operation uses a compression chiller and the refrigeration temperature maintenance operation uses an absorption chiller. At the time, when the refrigeration load becomes equal to or more than a set value, the operation is performed by using the compression chiller together.

[0007] According to the above configuration, when performing freezing in a freezing warehouse, when starting operation requiring a large refrigeration capacity,
Since a compression chiller with a large refrigeration capacity and low initial cost is used, and an absorption chiller with a low running cost is mainly used during the maintenance operation at a refrigeration temperature that does not require much refrigeration capacity. This is advantageous in terms of cost and running cost.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A refrigeration system according to an embodiment of the present invention will be described below with reference to FIGS.

As shown in FIG. 1, this refrigeration facility freezes, for example, a large refrigeration warehouse 1 at a predetermined refrigeration temperature (set temperature) or lower. is set up.

[0010] Of these refrigerators 2, one of the refrigerators 2A is of an absorption type, and the other refrigerator 2B is used.
Is a compression type, and these two refrigerators 2A,
Ammonia is used as the refrigerant (brine) in 2B, and the refrigerant (brine) is cooled by the evaporators 11 and 12, respectively.

That is, the evaporator 11 in the absorption refrigerator 2A and the evaporator 12 in the compression refrigerator 2B,
The heat exchangers 13 arranged on the freezer warehouse 1 side are connected in parallel by refrigerant circulation pipes 14, respectively. In FIG. 1, reference numeral 15 denotes a refrigerant pump provided in the refrigerant circulation pipe 14.

When the freezing warehouse is used by the above-mentioned refrigeration equipment, for example, when the temperature in the freezing warehouse 1 is set to the set temperature, that is, at the time of the freezing start operation, first, the compression type refrigerator 2B is operated to start the predetermined operation. After cooling to the temperature, the operation is switched to the operation of the absorption refrigerator 2A, and the predetermined refrigeration temperature is maintained.

After the inside of the freezing warehouse is brought to a predetermined freezing temperature, in the maintenance operation for maintaining the freezing temperature,
The absorption chiller 2A is mainly used, and the operation mode is different between daytime and nighttime.

That is, when the nighttime electricity rate is low during the late night hours, only the compression refrigerator 2B is mainly operated, but for the operation load exceeding 40%, the absorption refrigerator 2A is operated. Backup (Operation load is 20
%). On the other hand, when the refrigeration load is 60% or less of the full load of the refrigeration equipment in the daytime hours other than the late night time zone, the operation is performed only by the absorption chiller 2A, and the refrigeration is performed. When the load exceeds 60%, the absorption chiller 2A and the compression chiller 2B are operated in combination.

Here, a more specific operation method (control method) will be described with reference to FIG. FIG. 2 shows a case where the set temperature in the freezer warehouse is −37 ° C. to −40 ° C., where (a) shows the load ratio and (b) shows the control state.

That is, as shown in FIG. 2A, in the case of the absorption refrigerator 2A, during the daytime period from 8:00 to 22:00, it is activated when the temperature in the warehouse becomes -39 ° C. or higher. Also, in other late-night hours (time when electricity rates are low), the operation of the refrigerator is stopped when the temperature falls below −38 ° C.

On the other hand, in the case of the compression refrigerator 2B,
In the daytime period until 22:00, the temperature in the warehouse is -3.
The operation is stopped when the temperature is 8 ° C. or lower, and the operation of the refrigerator is performed when the temperature becomes −39 ° C. or higher in the nighttime period other than the above.

In the actual operation, the operation start time starts about 30 minutes before 8:00 in consideration of the rise time of the refrigeration cycle of the absorption refrigerator 2A. About 2B, it starts about 1 hour before 22:00.

As described above, when freezing a freezer warehouse,
At the start of operation that requires a large refrigeration capacity, use a compression chiller that has a large refrigeration capacity and low initial cost, and absorbs mainly low running costs when maintaining a refrigeration temperature that does not require much refrigeration capacity. Since the refrigeration system is used, an optimal refrigeration facility advantageous in terms of initial costs and running costs can be obtained.

[0020]

As described above, according to the structure of the present invention, when freezing a refrigerated warehouse, when starting operation requiring a large refrigeration capacity, a compression chiller having a large refrigeration capacity and a low initial cost is used. In addition, during maintenance operation at a refrigeration temperature that does not require much refrigeration capacity, an absorption chiller whose running cost is low is mainly used, so that optimal refrigeration equipment advantageous in terms of initial cost and running cost can be obtained. .

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic overall configuration of a refrigeration facility according to an embodiment of the present invention.

FIG. 2 is a graph showing an operation method of the refrigeration facility in the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Freezing warehouse 2A Absorption refrigerator 2B Compression refrigerator 11 Evaporator 12 Evaporator 13 Heat exchanger

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroo Iwamoto 1-7-89 Minami Kohoku, Suminoe-ku, Osaka-shi, Osaka Inside Hitachi Zosen Corporation (72) Inventor Kimio Ochi 1 Minami-Kohoku, Suminoe-ku, Osaka-shi, Osaka No. 7-89 Hitachi Zosen Corporation

Claims (2)

[Claims] 1. A refrigeration facility for cooling a warehouse by a plurality of chillers, wherein both chillers of an absorption type and a compression type are used.
A refrigeration facility that uses a compression chiller and uses an absorption chiller during a refrigeration temperature maintenance operation. 2. The refrigeration system according to claim 1, wherein during the refrigeration temperature maintenance operation, when the refrigeration load exceeds a set value, the operation is performed using a compression chiller in combination. Facility.