JPH0457943B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a regenerative refrigeration system having a cold heat storage device for storing cold heat cooled by a refrigerator.

[Conventional technology]

Recently, there has been a rapid increase in peak electricity consumption during the summer, and as a countermeasure to this, various electricity rate systems have been adopted to average electricity demand. Therefore, a heat storage system that operates a refrigerator at night and stores the cold energy in an ice heat storage device for use during the day is attracting attention. However, this system has the following major drawbacks.

First, a conventional ice heat storage system will be explained with reference to FIG. 1. During night heat storage operation, the refrigerator 1
Cold heat is stored in a heat storage tank 2 serving as a cold heat storage device. That is, brine is supplied as a cooling medium to the evaporator 4 of the refrigerator 1 by the brine pump 3,
This brine is cooled by a refrigerator 1. The cooled brine is sent to the tube 5 in the heat storage tank 2, cools the water in the heat storage tank 2 and turns it into ice, thereby storing cold heat. Conversely, the brine is heated and warmed, and then sent to the refrigerator 1 again to be cooled.

During the day, the load pump 6 is normally operated while the refrigerator 1 is operated. When the load is heavy, even if the refrigerator 1 is operating, the ice in the heat storage tank 2 will melt,
The cold energy stored during the night will be used.

[Problem to be solved by the invention]

In this conventional heat storage system, the return water from the return pipe 7 is cooled by ice in the heat storage tank 2, and then sent from the outlet pipe 8 by the pump 6 to a load such as a fan coil unit. In this operating state, the temperature inside the heat storage tank 2 is about 0°C, so the brine outlet temperature of the heat storage tank 2 is usually lower than this, for example, if it is -5°C, the evaporation temperature of the refrigerator 1 will be even lower than this. , approximately -15℃. Since the evaporation temperature of a normal chilled water cooling refrigerator is approximately 0°C, the evaporation temperature will be lowered by 15°C.

Therefore, as the evaporation temperature decreases, the power consumption of the refrigerator increases, so this heat storage system has the disadvantage that power consumption is large even during the daytime.

An object of the present invention is to eliminate this conventional drawback and provide a regenerative refrigeration system that consumes less power during daytime load operation.

[Means to solve the problem]

The present invention provides a refrigerator 1 having an evaporator, a cold heat storage tank 2 that stores cold heat cooled by the refrigerator 1, a load fluid flow path 7 that circulates between the cold heat storage tank 2 and a load, 8, a bypass path 1 is provided from the brine channels 17 and 18 circulating between the cold heat storage tank 2 and the evaporator 4.
9 is branched, and a heat exchanger 16 is provided in the bypass path 19, and the return side load fluid from the loads in the load fluid flow paths 7 and 8 to the cold heat storage tank 2 is introduced into the heat exchanger 16 and evaporated. When the heat exchanger 16 is operated, the valve 14 that shuts off the flow of the cold medium between the evaporator 4 and the cold heat storage tank 2 is bypassed. This is a heat storage type refrigeration device characterized in that it is provided in a road 19.

〔Example〕

Embodiments of the present invention will be explained with reference to FIGS. 2 to 4. Portions having the same reference numerals as those in FIG. 1 have the same configurations and functions. That is, during the night heat storage operation, cold heat is stored by the refrigerator 1 in the heat storage tank 2 as a cold heat storage device. In other words, the brine pump 3
Brine is supplied to the evaporator 4 as a cooling medium, and this brine is cooled by the refrigerator 1.
The cooled brine is sent to the tube 5 in the heat storage tank 2, cools the water in the heat storage tank 2 and turns it into ice, thereby storing cold heat. Return water from the return pipe 7 is cooled by ice in the heat storage tank 2, and is sent from an outlet pipe 8 to a load such as a fan coil unit by a pump 6.

A bypass path 19 is branched from the brine flow paths 17 and 18 that reciprocate between the evaporator 4 and the heat storage tank 2 serving as a cold heat storage device, and a heat exchanger 16 is provided along the way.
is provided.

In the heat exchanger 16, the evaporator 4 of the refrigerator 1
A cooling mechanism is formed that exchanges heat between the supplied brine cooled and supplied by the return side load fluid and cools the return side load fluid.

Reference numerals 14 and 15 are electrically operated valves, and when operated, the supply destination of brine from the evaporator tube 20 of the evaporator 4 is switched to either the heat storage tank 2 or the heat exchanger 16, and is cut off from the other. There is.

The inside of the heat storage tank 2 is divided by a partition wall 9, and the load fluid returned from the return pipe 12 is transported to the water surface 1.
A water passage 11 is always secured above 0.

Reference numeral 13 denotes a three-way valve, which bypasses the load fluid on the return side depending on the magnitude of the load.

[Effect]

To explain the operation, during the heat storage operation at night, cold heat is stored in the heat storage tank 2 by the refrigerator 1 as shown in FIG. That is, brine is supplied to the evaporator 4 of the refrigerator 1 by the brine pump 3, and this brine is cooled by the refrigerator 1.
The cooled brine is sent to the tube 5 in the heat storage tank 2, cools the water in the heat storage tank 2 and turns it into ice, thereby storing cold heat. Conversely, brine is heated and warmed;
It is sent to the refrigerator 1 again to be cooled.

During the day, the load pump 6 is usually operated while the refrigerator 1 is operated. A partition wall 9 is provided at the water outlet of the heat storage tank 2, and water in the heat storage tank 2 overflows at the upper end of the partition wall 9. Therefore, there is a space above the water surface 10, forming a water passage 11. Therefore, even if all the water in the heat storage tank 2 freezes at night, this water passage 11 can be secured.
When the pump 6 is started in the morning, water from the return pipe 12 passes through the water passage 11 and can be supplied to the load through the outlet pipe 8. Note that at this time, water flowing in from the return pipe 12 is cooled by ice in the heat storage tank 2.

Furthermore, when the load is small, the three-way control valve 13 operates to prevent the water supplied to the load from being too cold, and adjusts the temperature of the cold water so that it is always at a constant or appropriate temperature. Note that if there is no overflow partition wall 9, all the water in the heat storage tank 2 may freeze, making it impossible for the pump 6 to suck water.

Also, even during the day, the refrigerator 2 is normally operated as shown in FIG. At this time, the electric valves 14 and 15 are switched, and the brine flows as follows: evaporator 4 → pump 3 → electric valve 14 → heat exchanger 16 → evaporator 4.
In this heat exchanger 16, the brine is heated by return cold water from the load as load fluid. That is, the cold water that returns from the load via the return pipe 7 is cooled by the heat exchanger 16, and then sent to the heat storage tank 2.
It is further cooled and sent to a load such as a fan coil unit.

Note that the systems shown in Figures 2, 3, and 4 are indirect systems that use brine as the cooling medium.
Of course, a direct type that uses refrigerant directly may be used. In this case, the heat exchanger 16 becomes compact when incorporated into the refrigerator 1. That is, the return load fluid (chilled water) from the load may be introduced directly into the evaporator tube 20.

When the refrigerant extracted from the refrigerator is directly used without using brine, the following effects can be obtained.

Since there is no brine, the intermediate temperature cooling medium is omitted and the load fluid is directly cooled by the refrigerant, so the refrigerant evaporation temperature can be set high and the power consumption of the refrigerator can be suppressed.
Furthermore, since no brine, which does not necessarily have good thermal conductivity, is used, the refrigerant evaporation temperature can be set high, which also helps to reduce power consumption. Furthermore, unlike brine, which is generally an aqueous solution of salts, it can reduce corrosion of the refrigerant channels 17, 18, tube 5, etc., and the evaporator tube can be omitted, making the device compact and economical. Also excellent.

These effects are particularly noticeable in a regenerative refrigeration system that has a small overall capacity.

Note that the refrigerator is not operated as shown in FIG. 4 during peak power usage periods when a large amount of power is used.

〔Effect of the invention〕

In the present invention, a bypass path is branched from a brine flow path circulating between a cold heat storage tank and an evaporator, a heat exchanger is provided in the bypass path, and the load of the load fluid flow path is transferred from the load of the load fluid flow path to the cold heat storage tank. The return side load fluid is introduced into the heat exchanger and cooled by the cold medium guided from the evaporator, and when the heat exchanger is operated, the cold heat between the evaporator and the cold heat storage tank is By equipping the bypass path with a valve that shuts off the flow of the medium, when the refrigerator is operated during the daytime while using a load, the brine or refrigerant bypasses the heat storage tank and exchanges heat with the high-temperature cold water. It is possible to provide a thermal storage type refrigeration device that can be operated at a high brine or refrigerant temperature, and therefore can also increase the evaporation temperature, and can significantly reduce the power consumption of the refrigerator. ,
It can have extremely great practical effects.

[Brief explanation of drawings]

FIG. 1 is a flowchart of the conventional system, FIG. 2 is a flowchart of an embodiment of the present invention, and FIGS. 3 and 4 are flowcharts explaining the operation thereof. 1... Refrigerator, 2... Heat storage tank, 3... Brine pump, 4... Evaporator, 5... Tube, 6... Pump, 7
... return pipe, 8 ... outlet pipe, 9 ... partition wall, 10 ... water surface, 11 ... water passage, 12 ... return pipe, 13 ... three-way valve, 14, 15 ... electric valve, 16 ... heat exchanger, 1
7, 18... Refrigerant flow path, 19... Bypass path, 20...
Evaporator tube.

Claims (1)

[Claims] 1 A refrigerator 1 having an evaporator, a cold heat storage tank 2 that stores cold heat cooled by the refrigerator 1, and load fluid flow paths 7 and 8 that circulate between the cold heat storage tank 2 and a load. In the regenerative refrigeration system, a bypass path 19 is branched from the brine flow paths 17 and 18 that circulate between the cold heat storage tank 2 and the evaporator 4, and a heat exchanger 16 is provided in the bypass path 19. The return side load fluid from the loads in the load fluid flow paths 7 and 8 to the cold heat storage tank 2 is introduced into the heat exchanger 16 and cooled by the cold heat medium guided from the evaporator 4, and the heat exchanger 16, the valve 14 that shuts off the flow of the cold medium between the evaporator 4 and the cold heat storage tank 2 is connected to the bypass path 1.
A heat storage type refrigeration device characterized by being equipped with 9.