JPH10132337A - Cooler for cold transportation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a cooler capable of realizing an energy saving operation as well as an economical cold heat transportation by contorolling a program to have an ice water supply mode in a time zone having a small load. SOLUTION: Ice water is supplied to a main heat pipe 5 at 22 p.m. to 8 a.m. In a load side 1, ice water enters the bottom part 10 of a heat storage tank 4 from a branch pipe 9. A heat supply plant 2 is switched to an ice water supply mode. In this mode, while the temperature of a tank 26 is high, valves 31a and 31b are completely opened. When the temperature of the tank 26 falls, an ice making heat exchanger 25 repeats an ice making mode and a deicing mode. Since the number of operating loads 3 abruptly increases at 8 a.m., an ice water supply mode is switched to a cold water supply mode. Then, at the peak of power at 13 p.m., a cold water refrigerating machine 23 and a brine refrigerating machine 24 are both stopped. Accordingly, in this time zone, the cold water of ice water stored at midnight is substantially used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device with cold transport, and more particularly, to a cooling device with cold piping having a long piping distance such as district cooling. The ice water in the present invention is not limited to ice water composed of pure H ₂ O, and may be a mixture of other substances.

[0002]

_2. Description of the Related Art Recently, the Architectural Institute of Japan and the like have been actively studying the evaluation of buildings and equipment using LCCO ₂ (life cycle CO ₂ ) due to the problem of global warming. Research has also begun in the area of district heating and cooling (hereinafter abbreviated as DHC). That is, CO generated during construction of DHC
₂ generation amount, the amount of produced CO ₂ generated during operation, the CO ₂ generation amount generated at the time of disposal and a total of "life cycle" is the idea that should minimize the amount of produced CO _2. Recently, this idea has brought ice water transport DHC to the spotlight. The reason is that ice water transport DHC scheme even if somewhat CO ₂ emissions for the production of ice increases, reduces CO ₂ emissions for the pipe construction CO ₂ emissions and pump power per transport heat, Further, by performing the night heat storage operation, the amount of CO ₂ generated for the construction of the power plant can be reduced, and the total amount of LCCO ₂ can be reduced. However, many ice water transports D
Although the HC system has been proposed, it has not yet been put to practical use.

Among them, one of the ice water transport district cooling and heating systems described in Japanese Patent Application No. 5-347164 proposed by the present inventors is a heat storage system in which it is difficult to take a space for a heat storage tank on the heat supply plant side. The point of solving the biggest drawback of the regional district heating and cooling system is to provide an ice heat storage tank on the load side, and also to solve the problem of not being able to operate when the load is small, which is a problem when doing so. The system is easy to put into practical use in the future. However, since this system basically operates a refrigerator only at night, there is a drawback that annual costs are high in the current electricity rate system, and it is difficult to adopt this system in the current district cooling and heating system. In other words, in the current electricity tariff system, even if it is planned to operate only at midnight, the conventional heat storage tank plan "stops the refrigerator for the peak time from 13:00 to 16:00 and stops for 21 hours. Electricity rates are often rather expensive than "how to drive both daytime and nighttime." In addition, compared with the "method of operating both daytime and nighttime", the refrigerator is also large, and the annual cost is high in a small-scale district heating and cooling system with a short piping distance. In the future, the peak hours will be longer, and when driving only at midnight, the basic electricity tariff may be discounted and the tariff system may change, but at the present time practical application has been difficult.

[0004]

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to provide a cooling device which can be operated both in the daytime and at night, can be reduced in size, can be operated with energy saving, and can be economically transported with cold heat. As an issue.

[0005]

In order to solve the above-mentioned problems, the present invention comprises a cold heat supply device capable of supplying ice water, a cold heat supply main tube connected to the cold heat supply device, and a cold heat return main tube. A cold load that is cooled directly or indirectly by cold heat, a direct contact heat exchanger that also serves as a cold storage device that directly or indirectly heats ice water with load return water, and a flow control device that can control the cold flow rate, An ice water supply / cold water supply switch having a pipe, a valve, and a pump for sequentially connecting these, wherein the cold heat supply device can switch between an ice water supply mode for supplying ice water and a cold water supply mode for supplying cold water. In the cooling device constituted by the control device, the control device for switching between the supply of ice water and the supply of cold water is programmed so as to enter the ice water supply mode during a time period when the load is small. It is obtained by a cooling device, characterized in that it is configured to control.

Further, according to the present invention, there is provided a cold heat supply device capable of supplying ice water, a cold heat supply main tube and a cold heat return main tube connected to the cold heat supply device, and a cold heat load directly or indirectly cooled by the cold heat. And a direct contact heat exchanger that also serves as a regenerator that directly or indirectly heats ice water with load return water, a flow control device that can control the flow of cold heat, and pipes, valves, and pumps that sequentially connect these. A cooling device comprising an ice water supply / cool water supply switching control device, wherein the cold heat supply device can switch between an ice water supply mode for supplying ice water and a cold water supply mode for supplying cold water, The supply / chilled water supply switching control device detects the load-related physical quantity,
The cooling device is configured to be in the ice water supply mode when the load is small.

In the cooling device, the direct contact heat exchanger also serving as a cold storage device is an open type heat storage tank, which has a cold heat receiving amount control valve on a receiving side of the heat storage tank, and the heat storage device is in the ice water supply mode. In order to receive ice water in the tank, the control valve is preferably configured to be repeatedly opened and closed, and the flow rate of the cold water return side is preferably controlled by controlling the liquid level of the heat storage tank. As the quantity-related physical quantity, a cold water flow rate in the customer building or a total value of the heat usage in the heat supply system is preferably used.

[0008]

Next, the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory diagram of a district cooling system which is a cooling device of the present invention. In FIG. 1, reference numeral 1 denotes one of the buildings serving as a customer of a heat supply company, and reference numeral 2 denotes a heat supply plant. A cold heat supply device capable of supplying ice water or cold water is installed in this heat supply plant. There are many AHUs (Air Handling Units) and FCUs in Building 1.
(Fan coil unit). 4
Is a heat storage tank in which ice water or cold water is stored. 5 is a cold heat supply main pipe for sending cold heat from the heat supply plant 2 to the load side;
Is a cold heat return main pipe for returning cold water from the load side to the heat supply plant. Reference numerals 9 and 15 denote branch pipes connected to the main pipes 5 and 6, reference numeral 7 denotes a control panel for controlling the sluice valve 8, reference numeral 11 denotes a return pump, and reference numeral 13 denotes a bypass control valve controlled by a liquid level detector 12. , 17 are cooling heat supply pumps to the cooling load 3, and 18, 18a, 18b are control valves for controlling the flow of cooling heat to the cooling load. On the other hand, the cold heat supply device of the heat supply plant 2 includes a cold water / brine heat exchanger 22 and a cold water refrigerator 2.
3, brine refrigerator 24, ice making heat exchangers 25a, 25
b, a tank 26, an ice crusher 27, a cold heat supply pump 28, an ice fraction controller 29, and a control panel 30.

Next, referring to FIG.
The outline of the district cooling system of the present invention will be described separately at 3:00, 13:00 to 16:00, and 16 to 22:00. At 22 to 8 hours, ice water is sent to the cold main pipe 5. On the load side 1, a sluice valve 8 is provided by a signal from a control panel 7 incorporating a timer.
Is opened, and ice water flows into the bottom 10 of the heat storage tank 4 from the branch pipe 9. At this time, the sluice valve 8 is controlled to repeat the full closing and the full opening from time to time. By repeating the full closing and the full opening in this way, the size of the return pump 11 is reduced. That is, if this valve is left fully open, when the distance between the building 1 and the heat supply plant 2 is too short, the pressure of the main pipe 5 is too high and the heat storage tank must be increased unless the capacity of the return pump 11 is increased. 4 cannot control the water surface. Further, since the branch pipe 9 is made thicker in consideration of the total closing time, there is also an effect that ice is less likely to be blocked in the pipe. Even in the case where the width is reduced, the dynamic pressure during the flow is increased.

The heat storage tank 4 is controlled in liquid level. There are various methods for controlling the liquid level. In the case of the drawing, the flow rate of the bypass control valve 13 is controlled by the liquid level detector 12, so that the liquid level of the heat storage tank is kept substantially constant. .
In this time zone, a large amount of ice water flows from the sluice valve 8, so that the bypass control valve 13 is almost fully closed. Therefore,
The water of about 14 to 17 ° C. in the heat storage tank is
It returns from the pipe inlet 14 via the branch pipe 15 and joins the main pipe 6. In the case of July to August, almost all water at 14 to 17 ° C. in the heat storage tank is replaced with ice water at 8:00 in the morning. It should be noted that there is some load even in the late night time zone. For example,
Assuming that the fan coil unit 16 has a cooling load even at night, the pump 17 supplies cold water to the fan coil unit 16 even at night. However, the temperature of the supplied chilled water is as low as 0 ° C.
Therefore, the amount of supplied cold water is a small flow rate, and the temperature of the cold water exiting the fan coil unit 16 is about 18 ° C., which is close to the room temperature wet bulb temperature. Then, this cold water is sucked into the pump 11 via the pipe 19, the header 20, and the bypass pipe 21, and the branch pipe 15
And joins the main pipe 6. That is, the cold water having a high temperature of 18 ° C. is not mixed with the low-temperature water in the heat storage tank 4,
It is sent to the main pipe 6 while maintaining the high temperature.

On the other hand, the operation of the cold heat supply device of the heat supply plant 2 is as follows. At night, the mode is switched to the ice water supply mode by a signal from the control panel 30 in which a timer is incorporated. In this mode, while the temperature of the tank 26 is high, the valves 31 (31a and 31b are shown in the figure, but these are collectively referred to as 31 and the same applies to the others).
Are all open. The switching valves 32 and 33 are switched by a timer as described later. Return water from the load is chilled water / brine heat exchanger 22 → chilled water refrigerator 23 →
The cold water in the lower portion 34 of the tank 26 is sprinkled into the ice making heat exchanger 25 by a pump 35 through a sprinkling hole attached to a pipe 36, and is cooled by a brine flowing through the inside. Therefore, the temperature of the cold water in the tank gradually decreases.
, The ice making heat exchanger 25 repeats the ice making mode and the deicing mode. Although only two sets of ice making heat exchangers are shown in the figure, there are usually three to four sets, and the time of the deicing mode is controlled to be (1 / the number of ice making heat exchangers) of the entire time.

In the figure, an ice making heat exchanger 25a is in an ice making mode,
25b is a de-icing mode. Watering control valve 31a,
31b and three-way valves 32a, 32b, 33a, 33b
The ice making heat exchanger 25a is controlled to be in the ice making mode, and the ice making heat exchanger 25b is controlled to be in the de-ice mode. The brine is cooled by a brine refrigerator 24, 24 → header 38 → 32a → 2
5a → pump 39 → 33a → header 40 → 24, and the cold water flowing out of the water sprinkling pipe and flowing on the heat transfer surface of the ice making heat exchanger is cooled to make ice on the heat transfer surface. On the other hand, relatively high-temperature cold water is sent to the ice making heat exchanger 25b in the de-ice mode. That is, the brine heated by the cold water / brine heat exchanger 22 by the load return water is changed from 22 to the header 4.
1 → 32b → 25b → 42 → 33b → Header 43 → 2
Then, the heat transfer surface of the ice making heat exchanger to which the ice adheres is heated from the inside, and the attached ice is deiced. By repeating the ice making mode and the deicing mode in this manner, ice pieces are dropped into the tank 26 of the heat storage tank. The cold water cooled by the brine in the cold water / brine heat exchanger 22 is further cooled by a cold water refrigerator 23. That is, the return water in the return pipe 44 from the load is 18 to 14 ° C. in the ice water transport system.
Because of the high temperature, energy saving (at a high evaporation temperature) is pre-cooled by the cold water refrigerator 23 before ice making. This energy saving effect is greater as the ice fraction of the ice water to be transported is smaller.

The ice water stored in the tank 26 is adjusted to a predetermined ice fraction by an ice fraction controller 29 and sent to the load side by a pump 28 through the cold heat supply main pipe 5. Pump 2
8 is controlled by the controller 45 to control the rotation speed. When the ice in the tank 26 is large, the pump rotation speed is increased, and when the ice is small, the rotation speed is reduced.
Control is performed so that the amount of cold water flowing from the return pipe 9 through the return pipe 46 is not wasted. That is, although the ice fraction is controlled by the signal from the ice fraction meter 47 by the control valve 48, the flow rate is also controlled by the amount of ice, so that the amount of returned cold water passing through the pipe 46 is not excessive. . In some cases, depending on the type of the ice making heat exchanger 25, it may not be necessary.
Is equipped with an ice breaker 27 in the suction part of. The position of the ice crusher 27 may be below the ice maker 25, but the number of the ice crushers 27 can be reduced by placing the ice crusher 27 behind the tank. Reference numeral 49 denotes a bypass pipe for circulating a certain amount of ice water so as to stir the ice fraction in the tank 26 so as to keep the ice fraction constant.

At 8:00, the number of operating loads 3 increases rapidly, and the mode is switched from the ice water supply mode to the cold water supply mode by a signal from the control panel 30. That is, 18
a, 18b, etc. are opened and the flow through the tube 20 increases,
Most of the cold water sucked into the pump 11 is returned water from this load. Also, since the load increases, the pump 17
Since the amount of cold water sucked from the water increases, the bypass control valve 13 is adjusted by the liquid level control device, and the water is sprayed on the ice water in the direct contact heat storage tank by a number of water holes provided in the water sprinkling pipe 50, Dissolve. On the other hand, in the cold heat supply device in the heat supply plant 2, since the valves 31 are all open and the amount of cold water passing through the pipe 44 is large, the evaporation temperature of the brine refrigerator 24 gradually increases, and the cold heat supply main pipe 5 The temperature of the sent cold water rises and reaches about 7 ° C. around 13:00. However, the amount of cold water sent to the load by the pump 17 is
It is slightly larger than the amount of cold water sent from the pipe 9. This shortfall is compensated by the cold stored at night. In addition, the cold water sent by the pump 17 is about 7 ° C., and the flow rate is increased as compared with the case where cold water of about 0 ° C. is sent.

Next, at a power peak time of 13:00, a chilled water refrigerator 23, a brine refrigerator 24
Also stopped. Therefore, in this time zone, the cooling load is mostly covered by the cold heat of the ice water stored at midnight. That is, the amount of cold heat flowing from the electric sluice valve 8 becomes small, and the cold water sucked into the pump 17 is almost taken in from the heat storage tank 4 via the pipe 51. Therefore, due to the liquid level control of the heat storage tank 4, most of the return water from the load flows through the bypass adjustment valve 13 to melt the ice water. At 16:00, the ice fraction in the ice water in the heat storage tank 4 is almost zero. After 16:00, the sluice valve 8 is opened again, the refrigerator in the heat supply plant 2 is operated, and 7 ° C. cold water is supplied into the main pipe 5. Since the load is still large at 16:00, the cold water of 7 ° C. from the pipe 9 and the cold water of about 4 ° C. at the lower part of the heat storage tank 4 are mixed, for example, to 5.5 ° C., sucked into the pump 17, To be served. Then, the load gradually decreases, and the temperature of the cold water in the heat storage tank 4 also increases. When the time approaches 22 o'clock, the temperature becomes almost 18 to 15 ° C., except for a small portion at the lower part of the heat storage tank. Then, for example, the loads other than the fan coil unit 16 are stopped, that is, the temperature control valves 18a and 18b other than 18 are fully closed, and the amount of cold water flowing from the electric sluice valve 8 becomes small. Then, at 22:00, the sluice valve 8 is opened intermittently again despite the small load,
It becomes the ice water supply mode where ice water is made by the refrigerator.

[0016]

Since the cooling device of the present invention has the above-described configuration, it has the following excellent effects. (1) Since the method is operated during the daytime and at nighttime, the size of the refrigerator is reduced, the power equipment capacity is reduced, and the basic power rate is reduced. (2) Energy saving operation in the daytime when the evaporating temperature of the refrigerator is high. (3) Since the ice water is sent to the load side and stored at midnight, the pipe diameter can be reduced accordingly. (4) By making the load side heat storage tank an open type heat storage tank,
The heat storage tank can be inexpensive.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a district cooling system that is a cooling device of the present invention.

[Explanation of symbols]

1: Building, 2: Heat supply plant, 3: Cooling load, 4: Thermal storage tank, 5: Cold supply main pipe, 6: Cold return main pipe, 7: Control panel, 8: Sluice valve, 9, 15: Branch pipe 11, 17:
Pump, 18: control valve, 22: chilled water / brine heat exchanger, 23: chilled water refrigerator, 24: brine refrigerator, 25:
Ice making heat exchanger, 26: tank, 27: ice breaker, 28: cold heat supply pump, 29: ice fraction controller, 30: control panel

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Masao Murai 11-1 Haneda Asahimachi, Ota-ku, Tokyo Inside Ebara Works Co., Ltd. No. Sumitomo Metal Industries, Ltd. (72) Inventor Ken Hattori 1-4-28, Nagaoka-shi, Niigata Pref., Nagaoka 2-402 (72) Inventor Masataka Shiragashi 60-25, Nagamine-cho, Nagaoka, Niigata (72) Invention Takeshi Kawata 4-25 Kitazonocho, Nagaoka City, Niigata Prefecture

Claims (5)

[Claims] 1. A cold heat supply device capable of supplying ice water, a cold heat supply main tube and a cold heat return main tube connected to the cold heat supply device, a cold load directly or indirectly cooled by the cold heat, and a load return A direct contact heat exchanger that also serves as a cool storage device that directly or indirectly heats the ice water with water, a flow control device that can control a cold heat flow rate, and a pipe, a valve, and a pump that sequentially connect these, A chilled water supply / cooled water supply switching control device, wherein the chilled water supply device can switch between an ice water supply mode for supplying ice water and a chilled water supply mode for supplying chilled water; A cooling device, wherein the switching control device is configured to perform a program control so as to enter the ice water supply mode during a time period when the load is small. 2. A cold heat supply device capable of supplying ice water, a cold heat supply main tube and a cold heat return main tube connected to the cold heat supply device, and a cold load directly or indirectly cooled by the cold heat, and a load return. A direct contact heat exchanger that also serves as a cool storage device that directly or indirectly heats the ice water with water, a flow control device that can control a cold heat flow rate, and a pipe, a valve, and a pump that sequentially connect these, A chilled water supply / cooled water supply switching control device, wherein the chilled water supply device can switch between an ice water supply mode for supplying ice water and a chilled water supply mode for supplying chilled water; A switching control device configured to detect a physical quantity related to the load and to enter an ice water supply mode when the load is small. Place. 3. The cooling device according to claim 2, wherein the load-related physical quantity is a flow rate of chilled water in a customer building. 4. The direct-contact heat exchanger also serving as a cool storage device is an open-type heat storage tank, has a cold-heat receiving amount control valve on a receiving side of the heat storage tank, and is connected to the heat storage tank in an ice water supply mode. 3. The control valve according to claim 1, wherein the control valve is configured to be repeatedly opened and closed to receive ice water, and the flow rate of the cold water return side is controlled by controlling the liquid level of the heat storage tank. A cooling device as described. 5. The cooling device according to claim 2, wherein the physical quantity related to the load amount is a total value of a heat use amount in the heat supply system.