JPH08247508A - Ice heat storage equipment - Google Patents

Abstract

PURPOSE: To prevent excessive icing and the breakdown of an ice making heat exchanger which are consequent upon a repeated operation of making and melting ice, by providing a function of reversing the supply side and the takeout side of cold water of a cold water header at an arbitrary time cycle, in a system wherein the heat of melting of ice is used as a demanded cooling energy in the daytime. CONSTITUTION: At the time of an ice making operation of ice heat storage equipment 1, a brine circulation selector valve 7 is switched so that a brine may circulate between a refrigerating machine 1a and an ice making heat exchanger 3 and ice is made on the surface of a heat transfer tube of the ice making heat exchanger 3. At the time of an ice melting operation, on the other hand, the brine circulation selector valve 7 is switched so that the brine may flow to a brine/water heat exchanger 5 and cold water is made to flow to a cold water outlet temperature regulating valve 9a and cold water headers 4a and 4c in a heat storage tank 2 in a branching manner in the meantime. After a prescribed number of times of the operations of making and melting ice, cold water circulation selector valves 8a and 8c are switched so that a direction of flow of the cold water in the heat storage tank 2 may be reversed. Thereby the melting of ice is made to start from a region wherein the amount of icing is large and the breakdown of the ice making heat exchanger 3 due to excessive icing is prevented in this way.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ice heat storage device for making ice by using nighttime electric power or the like, converting the electric power into a form of cold heat, and storing the cold heat.

[0002]

2. Description of the Related Art It has previously been proposed to use night-time electric power to make ice and use the heat of ice melting during the daytime to use a part or all of the demand side cooling energy. In this case, if the supply port and outlet of the cold water that circulates in the heat storage tank are fixed, the direction of the flow of cold water that flows through the tank will be constant during melting, and the closer the supply port is, the faster the melting proceeds and the reverse The closer it is to the mouth, the slower the melting time. This means that if the load energy used on the demand side is smaller than the cooling energy supplied by the ice heat storage device, the ice will remain unmelted especially in the region near the cold water outlet in the heat storage tank. , In this state, if the cycle of heat storage at night and heat release at daytime is repeated, the amount of unmelted local ice will increase further, and eventually contact with ice generated around other adjacent heat transfer tubes (below , Called bridging). Due to the progress of this bridging, the area of water filled between adjacent ice pieces is confined by the area of ice, and the area of water is further expanded by ice-making and cooling, so that the heat transfer tubes are expanded by the expansion action. This increases the risk of stress and damage to the ice making heat exchanger. Also, this is
It becomes more remarkable when cooling energy is supplied to the demand side by circulating cold water at the same time as ice making at night. In order to prevent this, for example, when detecting the temperature inside the tank before the start of ice making operation, and when the ice making operation below the predetermined temperature is continuously performed a predetermined number of times, the next ice making operation is not performed and the next ice melting operation is performed. , A method of forcing the ice to melt is also proposed.

[0003]

In this case, when the demanded cooling energy is small, an excessive icing condition occurs before forcibly melting the ice, and the risk of damage increases, and conversely the melting is forced. If the required cooling energy is relatively large when iced, there is a problem that the supplied cooling energy becomes insufficient because the ice making operation before that is not performed. Also, if the heat storage tank becomes relatively large and the flow path from the cold water inlet to the outlet in the tank becomes long, even if the difference in cooling energy between supply and demand is small, residual ice will remain near the cold water outlet in the tank. There is a problem that the risk of breakage increases. The purpose of the present invention is to
Even if the cooling energy on the demand side is continuously low, continuous unmelting of ice that appears at a certain place is prevented, damage to the ice making heat exchanger is prevented, and the cooling energy on the demand side is kept at a predetermined level. It is to prevent the supply cooling energy from being insufficient even when the power supply suddenly increases within the limit.

Another object of the present invention is to reduce the risk of damage to the ice making heat exchanger even during the ice making operation while supplying the cooling energy which is considered to make the non-uniformity of the amount of ice generated and distributed significantly. To enable driving.

[0005]

In order to achieve the above-mentioned object, the ice heat storage device of the present invention is, as means corresponding to claims 1 and 2, a cold water supply port to a heat storage layer and a cold water from a heat storage tank. Both outlets have a header structure, a pair or a plurality of pairs of cold water headers are housed in the heat storage tank, and an electric valve and a brine /
A cold water pipe with a water heat exchanger is connected to the cold water header from outside the tank, and an ice making heat exchanger and a brine / water heat exchanger, a brine circulation switching valve, a brine pump, and a refrigerator housed in the heat storage tank are connected. The point is to connect with brine piping. As a means for claim 3, a temperature sensor is attached to a pipe on the downstream side or the upstream side of the cold water system adjacent to the brine / water heat exchanger, the detected temperature is taken into the control panel, and the refrigeration is performed on the basis of the predetermined detected temperature. The gist of the invention is to switch and control a brine circulation switching valve to a brine circulation circuit that connects a machine and a brine / water heat exchanger or a brine circulation circuit that connects a refrigerator and an ice making heat exchanger.

[0006]

By the operation of melting ice, the flow of cold water in the heat storage tank flows substantially evenly from the cold water supply header to the cold water extraction header. As a result, the ice distribution in the tank becomes larger on the cold water extraction header side, and when the cooling brine circulation path is switched from the brine / water heat exchanger to the ice making heat exchanger, the ice making operation is performed. There is a risk of damage to the ice-making heat exchanger due to excessive ice accretion in the area near. Therefore, if the chilled water circulation direction switching valve is switched at any operation cycle from half a day to several days between the latter half or end of the ice melting operation and the start of the next ice melting operation, the function of the previous cold water supply and extraction header will be By reversing, the region where the distribution of ice accretion is large becomes the cold water supply side, and this region can be melted quickly and local excessive ice accretion can be prevented.
In addition, if the cold water circulation direction switching timing is before or at the start of the ice making operation, when cooling energy is supplied during the ice making time zone, cold water is supplied from the demand side to a region with a large residual ice distribution amount, The speed of ice formation can be suppressed. In this case, the cold water temperature from the demand side is
Detect either upstream or downstream of the water heat exchanger,
If it is greater than or equal to a specified value or greater, the cooling brine from the refrigerator is circulated to the brine / water heat exchanger for efficient chilled water cooling, and if less than or equal to the specified value, brine is circulated to the ice making heat exchanger. Then, cooling energy is supplied through the heat exchanger and ice is made on the surface of the heat exchanger tubes.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a principle system system diagram of an ice heat storage device of the present invention. The ice heat storage device 1 includes a refrigerator 1a, a brine /
Water heat exchanger 5, ice-making heat exchanger 3 housed in heat storage tank 2
And a brine system including a brine pipe 11 connecting these components, a brine circulation switching valve 7 and a brine pump 6, and cold water headers 4a and 4c stored in the heat storage tank 2, a brine / water heat exchanger 5, and a cold water pipe 10 connecting these. , Cold water circulation switching valves 8a and 8c, cold water outlet temperature adjusting valve 9a,
A cold water system including a cold water outlet temperature sensor 9c and a control panel are provided, and both the cold water inlet fitting portion 10a and the cold water outlet fitting portion 10c are connected to the demand side cold water pipe 13. FIG. 2 shows an embodiment of the ice heat storage device of the present invention during the ice making operation. In this operation, the brine circulation switching valve 7 is switched so that the brine circulates between the refrigerator 1a and the ice making heat exchanger 3, and the brine sent out by the brine pump 6 is cooled by the refrigerator 1a. After passing through the brine circulation switching valve 7, it enters the heat transfer tube of the ice making heat exchanger 3, cools the water outside the heat transfer tube, and returns to the brine pump. This cycle is carried out continuously,
Ice is made on the surface of the heat transfer tube of the ice making heat exchanger 3. 3 and 4 show an embodiment of the ice heat storage device of the present invention during the ice melting operation. In the main operation, after the above-mentioned ice making operation is completed, the brine circulation switching valve is switched so that the brine flows to the brine water heat exchanger 5. Cold water from the demand side flows in from the cold water inlet coupling section 10a, is cooled when passing through the brine / water heat exchanger 5, and is partly diverted to the cold water temperature control valve, and the rest is the cold water in the heat storage tank 2. It is led to the header 4a or 4c. In FIG. 3, the chilled water that has passed through the brine / water heat exchanger 5 is chilled water circulation switching valve 8
a flows to the cold water header 4a in the heat storage tank 2 and melts the ice generated on the surface of the heat transfer tube of the ice making heat exchanger 3 while passing through the heat storage tank 2 from the outer peripheral surface, thereby cooling the cold water. Cold water circulation switching valve 8c taken from the header 4c
And it is supplied to the demand side through the cold water outlet temperature adjusting valve 9a. At that time, the distribution of the remaining amount of ice deposited on the ice making heat exchanger 3 increases near the cold water header 4c, and if ice making and melting are repeated as it is, a part of the ice making heat exchanger 3 near the cold water header 4c becomes excessively iced. Damages the ice making heat exchanger 3.
Therefore, after performing a predetermined number of ice making and melting operations, the flow directions of the cold water circulation switching valves 8a and 8c are switched as shown in FIG. 4, and the cold water flow direction in the heat storage tank 2 is reversed.
It is possible to prevent the damage to the ice making heat exchanger 3 due to excessive ice accretion by preferentially melting the ice in a region having a large amount of ice accretion. FIG. 5 shows an embodiment of the ice heat storage device of the present invention during simultaneous operation of ice making and melting. In this operation, the brine circulation switching valve 7 is switched to the ice making heat exchanger 3 side, and the brine cooled by the refrigerator 1a is circulated to the ice making heat exchanger 3 using the brine pump 6.
At the same time as cooling the cold water in the heat storage tank 2, the ice making heat exchanger 3
Make ice on the heat transfer tube surface. On the other hand, a part of the chilled water from the demand side is circulated to the chilled water outlet temperature adjusting valve 9a, the remaining chilled water is guided to the chilled water header 4a or 4c in the heat storage tank 2, and is passed through the ice making heat exchanger 3 in the heat storage tank 2. And then cools the cooled cold water from the cold water header 4c or 4a on the outlet side and supplies it to the demand side. This operation corresponds to the above-described ice making operation, and one ice making operation and the next ice melting operation are set as one set, and the cold water header 4a is set every one to several sets.
By switching the inflow side and the outflow side of 4c,
It is possible to simultaneously supply cold water to the demand side while making ice without damaging the ice making heat exchanger 3.

[0008]

According to the present invention, it is possible to reduce the risk of excessive ice accretion occurring in a fixed region such as the cold water removing side in a tank due to repeated ice making / melting operation and damage to the ice making heat exchanger accompanying it. it can. Further, it is possible to supply cooling energy to the demand side while making ice while reducing the risk of damage to the ice making heat exchanger.

[Brief description of drawings]

FIG. 1 is a principle system system diagram of an ice heat storage device of the present invention.

FIG. 2 is a system diagram of a system during an ice making operation of the ice heat storage device.

FIG. 3 is a systematic diagram of a system when the present heat storage device is in an ice melting operation.

FIG. 4 is a systematic diagram of a system during the ice melting operation of the heat storage device.

FIG. 5 is a system diagram of the present heat storage device during simultaneous operation of ice making and melting.

[Explanation of symbols]

1 ... Ice heat storage device, 1a ... Refrigerator, 2 ... Heat storage tank, 3 ... Ice heat exchanger, 4a, 4c ... Cold water header, 5 ... Brine / water heat exchanger, 6 ... Brine pump, 7 ... Brine circulation switching valve , 8a, 8c ... Cold water circulation switching valve, 9a ... Cold water outlet temperature adjusting valve.

Claims (1)

[Claims] 1. A refrigerating machine, a brine / water heat exchanger, a brine pump, an ice making heat exchanger, a heat storage tank for housing the ice making heat exchanger, a piping system connecting these, and a control panel,
In an ice heat storage device in which a demand-side cold water system is connected to at least these cold water systems, both the cold water supply port and the outflow port in the heat storage tank are housed as one or a plurality of pairs of header structures, and outside the heat storage tank. In the cold water system piping connected to
An ice heat storage device comprising a cold water switching valve for reversing a cold water circulation direction in the heat storage tank, and having a function of reversing a cold water supply side and a takeout side of a cold water header in an arbitrary time cycle.