JPH0816541B2 - Refrigeration system control method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a refrigeration system having a refrigerator, a heat storage tank, and a load-side heat exchanger, and more particularly to a control system thereof.

(B) Conventional technology Generally, the conventional technology of the refrigeration system using the heat storage tank is “Air Conditioning and Refrigeration” VOL /
26 No./9 There were some as described on P.44 to P.60 and P.91 to P.99. The former one uses ice stored in a heat storage tank by using night power to compensate for the lack of capacity of the refrigerator at the peak of cooling load or at the start of cooling operation by using during the time period when cooling operation is required. Met. Further, in the latter, the operation of the refrigerator was controlled while the microcomputer made a final comparison between the predicted load and the remaining amount of ice so that all the ice could be used during the daytime air conditioning period.

(C) Problems to be Solved by the Invention In the conventional technique thus configured, the heat storage tank is mainly used to compensate for the lack of the capacity of the refrigerator. These systems control the operation of the refrigerator by cooling and releasing the heat from the heat storage tank during the daytime air conditioning time and measuring and predicting the magnitude of the load at relatively short predetermined cycle intervals. In some cases, the number of times the machine started and stopped increased, the number of equipment failures increased, and the reliability of the system deteriorated. In addition, in the case of air-conditioning load, even if the entire load does not fluctuate rapidly throughout the day, if the refrigerating machine start-up cycle is shortened, the load side heat exchanger will be The cycle of temperature fluctuations of the brine circulating through is shortened. That is, the temperature variation of the air conditioning load (room temperature) becomes fast, and the user may feel uncomfortable. Furthermore, in such a system, about 50% of the total amount of heat for cooling the ice making amount at night during the air conditioning time
It is designed to correspond to about 60%, and when the refrigerator is operating for a long time during the air conditioning period, that is, when the heat storage tank usage rate is low, all ice in the heat storage tank can be used during the air conditioning time zone. However, there was a case that some of them remained in the heat storage tank. By leaving the ice like this, this ice grows every day,
There is a problem that the flow of brine in the heat storage tank is obstructed and the heat storage efficiency of the heat storage tank is deteriorated.

In view of such a problem, the present invention provides a control system that reduces the number of times of starting and stopping the refrigerator to suppress the failure of the refrigerator and also to prevent ice from remaining in the heat storage tank.

(D) Means for Solving the Problems The present invention comprises a refrigerator, a heat storage tank, and a load-side heat exchanger that are connected by piping so that the flow path of brine flowing to the load-side heat exchanger can be changed. In the control method of the refrigeration system that controls the operation of the refrigerator, the heat storage tank, the load side heat exchanger, and the flow path of the brine based on each operation mode for each time zone divided by the time indicated by the clock, refrigeration The first mode of driving the cooling machine to generate ice in the heat storage tank, and the operation of driving the refrigerator to cool the brine flowing to the load side heat exchanger, and / or
Alternatively, when the operation of cooling the load by circulating the brine between the heat storage tank and the load side heat exchanger is selected based on the size of the load, and when the amount of cold storage in the heat storage tank is equal to or greater than a predetermined amount. A third mode in which the operation of circulating the brine between the heat storage tank and the load side heat exchanger to cool the load is prioritized, and the first mode and the second mode are sequentially performed according to the time instructed by the timepiece.
The mode and the third mode are set, and the cooling operation in the third mode is preferentially performed during the work ending time period instructed by the timepiece.

(E) Action When such a refrigeration system control method is used, the cooling operation in the third mode in which brine is circulated between the heat storage tank and the load-side heat exchanger is preferentially performed during the work end time. , At the end of work, the ice in the heat storage tank is completely melted.

(F) Example An example of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram of a refrigeration system. In the figure, reference numeral 1 denotes a chiller unit (refrigerator), which cools brine flowing from the pipe port P and then discharges it from the pipe port S. As this unit, a unit using a compressor, a unit using an absorption refrigerator, or the like can be used. Reference numeral 2 denotes a heat storage tank, which circulates the brine cooled by the chiller unit 1 to make ice therein for cold storage. Reference numeral 3 is a load side heat exchanger, and a fan coil unit or the like can be used. 4 is a brine water heat exchanger, and the load side heat exchanger 3
It is intended to cool the water returning from. Chiller unit 1,
The temperature of the brine circulating through the heat storage tank 2 and the brine water heat exchanger 4 is set to about -6 ° C. The temperature of the brine circulating from the heat storage tank 2 to the load side heat exchanger 3 and the brine water heat exchanger 4 is set to about 7 ° C, and cold water is used for this brine. The chiller unit 1, the heat storage tank 2, the brine water heat exchanger 4, the brine pump 5, the electromagnetic opening / closing valves 6 and 7, the check valve 8
And a brine pipe, and when the electromagnetic on-off valve 6 is in the open state and the electromagnetic on-off valve 7 is in the closed state, the brine flows in the direction of the solid line arrow by driving the brine pump 5, and the inside of the heat storage tank 2 Brine pump 5 is used when ice is made on the solenoid valve 6 and the solenoid valve 6 is closed and the solenoid valve 7 is open.
Is driven, the brine flows in the direction of the dotted line arrow, and the brine water heat exchanger 4 cools the water returning from the load side heat exchanger 3. The heat storage tank 2, the load side heat exchanger 3, and the brine water heat exchanger 4 are connected by a temperature control valve 9, a water pump 10 and a water pipe. The temperature control valve 9 mixes cold water having different temperatures supplied to the piping ports A and B and maintains the temperature of the cold water discharged from the piping port C at a substantially constant value (about 7 ° C.). That is, by driving the water pump 10, the cold water flows as shown by the alternate long and short dash line and circulates through the load side heat exchanger 3.

FIG. 2 is an explanatory diagram showing a daily operating state of the present system. In the figure, I to VI are time zones separated by predetermined times. Time zone I is a cold storage mode (ice making operation), and after the electromagnetic on-off valve 6 shown in FIG. 1 is opened and the electromagnetic on-off valve 7 is closed, the chiller unit 1 and the brine pump 5 are operated to store the heat in the heat storage tank. Make ice on 2. The amount of ice made is equivalent to about 50 to 60% of the total cooling heat during the daytime (when the load needs to be cooled). When the amount of ice made in the heat storage tank 2 reaches this amount, the ice making operation is started. Stop. The amount of ice making can be detected by using a rise in water level in the heat storage tank 2 or an ice sensor.

Time zones II to V are the load cooling operation in the daytime, and in the time zone II, the operation of the chiller unit 1 and the brine pump 5 is stopped and only the water pump 10 is operated. Thereby, the cooling operation using the ice in the heat storage tank 2 is performed from the load side heat exchanger 3. That is, the cooling operation by the heat storage tank 2 is performed.

In time zones III to V, the outside air temperature T ₀ is detected, and at the beginning of time zone III, three states of T ₀ ≦ 22, 22 <T ₀ <29, T ₀ ≧ 29 are determined. First, when T ₀ ≧ 29, the chiller unit 1 and the brine pump 5 shown in FIG. 1 are operated, the electromagnetic opening / closing valves 6 and 7 are set to a predetermined state, and the brine is caused to flow in the direction of the dotted arrow, that is, the cooling operation of water, that is, Performing additional cooling operation and time zone II
Perform cooling operation in the same manner as in. Ie chiller unit 1
The load is cooled from both the heat storage tank 2 and the heat storage tank 2. This time zone III is maintained until 12:00.

When 22 <T ₀ <29, the cooling operation is maintained until the time reaches 15:00, and if the amount of ice in the heat storage tank 2 becomes 20% or less during this time, the cooling operation is also used to increase the load. A cooling operation is performed.

When T ₀ ≦ 22, or when the time has passed 15:00, only the cooling operation is performed and this operation is maintained until the time reaches 18:00. During this period, when the temperature of the cold water on the outlet side of the heat storage tank 2 becomes 10 ° C. or higher (it is judged that all the ice in the heat storage tank 2 has melted), the above-mentioned additional cooling operation is performed.

The time zone VI is a time zone in which the extended operation is performed, and the above-mentioned additional cooling operation is performed as necessary until the time of 22:00.

The operation of such time zones II to V is as shown in the flowchart of FIG. Therefore, the control unit includes a program or electronic circuit that performs such an operation.

In the refrigeration system configured as described above, the operation in which the cooling operation in the third mode is prioritized is performed during the time zone (working end time zone) from 15:00 to 18:00, and the ice in the heat storage tank 2 is cooled. It is possible to melt all of the above, and to prevent ice residue in the heat storage tank after 18:00.

(G) Effect of the Invention The present invention is configured by connecting a refrigerator, a heat storage tank, and a load-side heat exchanger so that the flow path of brine flowing to the load-side heat exchanger can be changed. The refrigerator, the heat storage tank, based on each operation mode for each partitioned time zone,
In the control method of the refrigeration system that controls the operation of the load side heat exchanger and the flow path of the brine, the first mode in which the refrigerator is driven to generate ice in the heat storage tank, and the load side heat exchange in which the refrigerator is driven Mode for cooling the brine flowing to the reactor and / or selecting an operation for cooling the load by circulating the brine between the heat storage tank and the load side heat exchanger, and the heat storage tank When the amount of cold storage in the inside is equal to or more than a predetermined amount, the third mode is provided in which the operation of circulating the brine between the heat storage tank and the load to cool the load is prioritized The first mode, the second mode, and the third mode are set, and the cooling operation in the third mode is preferentially performed during the work ending time zone instructed by the clock, so that the ice in the heat storage tank is finished working. Sometimes it finishes melting, so in the first mode the heat storage tank The cold energy stored in the case so as not exhausted by combining the refrigerator, for example, time 15
During the so-called end-of-work period between 18:00 and 18:00, the operation that gives priority to the cooling operation in the third mode can be performed to use up the cold heat stored in the heat storage tank, and efficient cold storage and cooling operation can be performed. It can be done.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an embodiment of a refrigeration system using the control method of the present invention, FIG. 2 is an explanatory diagram showing operation modes with respect to time of the refrigeration system shown in FIG. 1, and FIG.
It is a flowchart showing the operation mode of the figure. 1 ... Chiller unit, 2 ... Heat storage tank, 3 ... Load side heat exchanger, 4 ... Brine water heat exchanger.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hironori Sonoda 2-18, Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Co., Ltd. (56) Reference JP 62-206337 (JP, A) -35457 (JP, U) Japanese Patent Publication 7-72641 (JP, B2)

Claims (1)

[Claims] 1. A refrigeration machine, a heat storage tank, and a load-side heat exchanger, which are connected by piping so that the flow path of brine flowing to the load-side heat exchanger can be changed, and the time divided by the time indicated by the clock. In the control method of the refrigeration system that controls the operation of the refrigerator, the heat storage tank, the load side heat exchanger and the flow path of the brine based on each operation mode for each band, the refrigerator is driven to apply ice to the heat storage tank. The first mode to generate and the operation of driving the refrigerator to cool the brine flowing to the load side heat exchanger, and / or
Or, the second mode in which the operation of cooling the load by circulating the brine between the heat storage tank and the load side heat exchanger is selected based on the size of the load, and the amount of heat storage in the heat storage tank is equal to or greater than a predetermined amount. A third mode is provided in which the operation of circulating the brine between the heat storage tank and the load-side heat exchanger to cool the load is prioritized, and the first mode and the second mode are sequentially performed according to the time indicated by the clock. The third mode is set, and the cooling operation of the third mode is preferentially performed during the work end time zone instructed by the timepiece, and the ice in the heat storage tank is completely melted at the end of work. Refrigeration system control method.