JP2006071228A - Supercooled water dynamic type ice heat storage tank device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a means for stably preventing freezing in a return pipe and efficiently utilizing the cold in an ice heat storage tank device producing ice from the supercooled water in piping of a sealed system. <P>SOLUTION: A bypass circuit is formed on the way of the return pipe, a first heat exchanger and a second heat exchanger are arranged in series in the bypass circuit, a secondary side of the first heat exchanger is connected with an air conditioning system line for processing night cooling load, and a secondary side of the second heat exchanger is connected with a cooling water recooling circuit communicated with a refrigerating machine of an air conditioning system. A secondary side of the first heat exchanger is connected with a cooling device for building frame heat storage of a building. The first and second heat exchangers are formed as an internal circuit of an integrated heat exchanger. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an ice heat storage tank apparatus using supercooled water, and more particularly to a dynamic ice heat storage tank apparatus of a type that supercools running water instead of a stationary type.

  Dynamic ice heat storage tank devices that produce supercooled water in a heat exchanger (supercooler), generate ice from this supercooled water in closed piping, and apply it to air conditioning systems are already widely used. However, during this ice making operation, ice nuclei are present in the 0 ° C. cold water taken from the heat storage tank, which causes freezing when supercooled water is generated. Therefore, it is necessary to heat the cold water at 0 ° C. to a temperature exceeding 0 ° C. to completely melt the ice nuclei in the cold water. Until now, the return pipe from the vicinity of the bottom of the ice heat storage tank to the heat exchanger for producing supercooled water is heated with an electric heater or the like, or a heat exchanger for heating is inserted to obtain heat energy from other systems. A method of absorption has been proposed.

  In some conventional techniques, the cold heat is used for general cooling load or cold water heat storage through a heat exchanger used to heat cold water at 0 ° C. taken from an ice heat storage tank.

The following points are cited as problems of this type of prior art.
(1) Since the amount of heat generated by heating the cold water that was 0 ° C. inside the return pipe to a temperature exceeding 0 ° C. must be cooled on the freezer side, the ice making capacity of the freezer is about 20%, for example. Will be reduced. Even when trying to make up for the loss with a general cooling load, there are many late-night hours during ice making, so it is rarely useful as a cooling load at night. (2) When using it for cold water heat storage, In addition, a water heat storage tank is required, the space increases, the heat storage amount for the entire tank volume decreases, and the economic efficiency is impaired. (3) If the cooling water is heated only with a general cooling load, the cooling load is reduced. Due to fluctuations, it becomes difficult to control the set temperature of the chilled water. (4) When the chilled water temperature is controlled using the control valve, it is difficult to control the chilled water temperature on the secondary side depending on the state of the primary load of the heat exchanger for heating. There are cases.

Examples of conventional ice heat storage devices related to the present invention include the following.
In Japanese Patent Laid-Open No. 8-219503 “Ice Thermal Storage Device Using Supercooled Water”, it is proposed to use the cold heat of the heating side fluid used for preheating water flowing through the return pipe as a cold heat source for other air conditioners. Yes. However, as described above, when there is no air conditioning load or when the air conditioning load is small, the target heating amount cannot be obtained from the air conditioning system, and the return pipe temperature cannot be increased to the target temperature. The ice making operation may become unstable due to freezing. In Japanese Patent Laid-Open No. 5-322395, “ice heat storage device”, ice contained in cold water is obtained by exchanging heat between cold water extracted from the ice heat storage tank and a cold load in a cold water circuit connecting the ice heat storage tank and the supercooler. Ice melting means to melt the nucleus is provided. The ice nucleus melting means includes a heat exchanger, a cold water temperature detector, a flow rate adjustment valve, and an opening control device. JP-A-63-14063 “Supercooled ice heat storage device” releases supercooled water from the supercooling water production heat exchanger from the top of the ice storage tank, freezes it, and draws it from the bottom of the ice storage tank. A technology for using cold water in an air conditioning system is described.

The main object of the present invention is to provide means for preventing ice formation in a return pipe in a stable state and effectively utilizing the cold heat in an ice heat storage tank device that generates ice from supercooled water in a closed pipe. There is to do.
Another object of the present invention is to increase the efficiency of the entire system including the ice heat storage tank device.

  In order to solve the above-mentioned problems, in the present invention, a bypass circuit is provided in the middle of the return pipe in order to melt ice nuclei existing in 0 ° C. cold water taken from the ice heat storage tank in a stable state during ice making operation. A first heat exchanger and a second heat exchanger are arranged in series in the bypass circuit, and the secondary side of the first heat exchanger is connected to an air conditioning system for nighttime cooling load processing (air conditioning load / body heat storage). -Connect to water heat storage etc.) and connect the secondary side of the second heat exchanger to the cooling water re-cooling circuit leading to the refrigerator of the air conditioning system.

Based on this configuration, according to the present invention,
(1) During ice making operation, cooling water having a constant temperature is constantly circulated between the refrigerator and the cooling tower, so that a stable antifreezing effect can be obtained. In other words, unlike the conventional case, the amount of heating does not cause a shortage of heat and does not cause freezing. (2) By using two heat exchangers, the temperature of the return pipe can be adjusted even if the air conditioning load fluctuates. It becomes possible to control to a stable state (3) Even when the cooling load is small and not all the heating component can be used, the cooling water temperature is lowered and the efficiency of the refrigerator is increased because the cooling water is used. . In other words, by using the 0 ° C. cooling water taken from the heat storage tank in the cooling water circuit, the normal cooling water temperature can be lowered and the cooling energy can be used effectively, and the operating efficiency of the refrigerator can be improved. (4) The efficiency of the entire system can be increased by stable freeze prevention, stable control, increase in operating efficiency of the refrigerator, and the like.

  The secondary side of the first heat exchanger can be connected to various air conditioning systems for nighttime cooling load processing (air conditioning load, housing heat storage, water heat storage, etc.), but the amount of heat for heating the return pipe is Since it is extremely large, the amount of water held in the water heat storage tank increases, and an extremely large installation space is required. Therefore, it is preferable to connect to a building heat storage cooling device.

As an advantage of housing heat storage,
(1) Since there is no need to install a water heat storage tank, it is possible to save space. (2) Instead of consuming cold heat in real time by connecting to an air conditioning load, it is practical if it is used for housing heat storage. The amount of heat storage (ice heat storage + body heat storage) increases and can greatly contribute to reducing the amount of air conditioning power during the daytime. (3) Even if there is no body heat storage load, stable freezing prevention can be achieved with cooling water. It can be used as a reliable heat storage.

As a control method of the heat storage tank apparatus according to the present invention, when the housing heat storage is not performed during the ice making operation, the cooling water circuit of the refrigerator is used to heat the cold water to a temperature exceeding 0 ° C. and control it to a constant temperature.
In order to control the chilled water to a temperature exceeding 0 ° C., control the amount of chilled water on the secondary side of the first heating heat exchanger first, and if it does not reach the set temperature, the second heating heat exchange It can control to preset temperature with the amount of secondary side cooling water of a vessel.
By first heating the cold water at 0 ° C. with the first heat exchanger for heating, the cold heat can be preferentially sent to the housing heat storage. Further, when the temperature does not reach a certain temperature exceeding 0 ° C., the cooling water circuit is heated by the second heating heat exchanger, and the temperature can be controlled with high accuracy.

More preferably, the above-mentioned two heat exchangers can be housed in an integrated heat exchanger and combined into one unit as a three-circuit type heat exchanger.
More preferably, in order to control the secondary chilled water temperature of the first heating heat exchanger used for housing heat storage, it is possible to control the secondary chilled water temperature by controlling the number of revolutions of the chilled water pump. .

The supercooled water dynamic ice storage tank device according to the present invention is operated as follows as a preferred mode.
(1) During the ice heat storage operation, when the cold water taken from the heat storage tank is heated to a temperature exceeding 0 ° C., the cold heat obtained at that time is stored in the building structure (2) When the building heat storage is not performed, Recool the cooling water of the refrigerator and increase the operating efficiency of the refrigerator. (3) As a means of controlling the temperature to an arbitrary temperature exceeding 0 ° C., out of the two heat exchangers, the first one is used for housing heat storage. The secondary chilled water is controlled by the heat exchanger, and then the secondary chilled water is controlled by the heat exchanger for the cooling water circuit. (4) The rotational speed of the chilled water storage chilled water pump is controlled, and the heat exchanger The supply temperature of the secondary side cold water is controlled by changing the amount of the secondary side cold water.

  Thus, a means for preventing freezing in the return pipe and effectively utilizing the cold energy is provided, and an advantage can be obtained that the efficiency of the entire system including the ice heat storage device can be increased. Furthermore, the installation space can be reduced by using two heat exchangers as one unit. By controlling the temperature by changing the number of rotations of the chilled water pump, energy saving of the pump power can be achieved and the load-side chilled water temperature can be controlled with high accuracy. Hereinafter, the present invention will be further described with reference to embodiments of the accompanying drawings.

  FIG. 1 is a circuit diagram showing the whole of a dynamic ice heat storage tank device using supercooled water according to the present invention. Like the prior art, the supercooled water produced by the heat exchanger 10 for producing supercooled water is made into ice. Ice is made by the machine 12 and supplied to the ice heat storage tank 14. The cold water drawn out from the vicinity of the bottom of the ice heat storage tank 14 by the ice-making heat radiation pump (cold water pump) 16 passes through the return pipe 18, passes through the ice core removal filter 20, and goes to the heat exchanger 10 for producing supercooled water. Returned.

  A brine low-temperature circuit 26 is disposed on the other side of the heat exchanger 10 for producing supercooled water, and a cold liquid of −3.3 ° C. is supplied from the brine refrigerator 22 by the brine pump 24. The other side of the brine refrigerator 22 is connected to a cooling tower 46 for the air conditioning system.

  The cold water pipe 28 branched from the middle of the return pipe 18 passes through the heat exchanger 30 for heat dissipation and returns to the ice heat storage tank 14, and this heat exchanger 30 is supplied from the cooling load (air conditioner etc.) to the cold water pump 32. Used to exchange heat with cold water carried by the

  FIG. 2 is an enlarged view of the characteristic part of the present invention, omitting a part of the conventional part in FIG. 1. As a bypass circuit 50 in the middle of the return pipe 18, a first heating heat exchanger 51 and Each primary side circuit of the second heating heat exchanger 52 is inserted and arranged in series, and the secondary side of the first heat exchanger 51 is connected to the building heat storage circuit 34 leading to the building heat storage cooling device 60 of the building. The secondary side of the second heat exchanger 52 is connected to a cooling water recooling circuit 38 that leads to the refrigerator 22 of the air conditioning system. Cold water is sent to the primary side of the bypass circuit 50 by a heating pump 58. A chilled water pump 36 is disposed in the housing heat storage circuit 34, and chilled water pumps 40, 42 are disposed in the cooling water recooling circuit 38.

  The building body heat storage cooling device 60 includes a radiator (heat exchanger) installed in the vicinity of a slab (floor slab) adjacent to a wall surface, and discharges cold air to store cold in the slab.

  By the way, when heating is performed using an external load in this way, the external load fluctuates greatly, so the temperature in the circuit of the two heat exchangers is adjusted, for example, ice making operation while keeping the secondary cold water temperature constant Need to do. For this purpose, motor-operated valves 53 (MV1) and 54 (MV2) are arranged in the secondary circuits of the first and second heat exchangers 51 and 52, respectively, and each motor-operated valve is in the middle of the return pipe 18. A control signal for opening / closing or switching the motor-operated valve is sent based on information from the temperature sensors TE1 and TE2 arranged at. The motor operated valves 53 and 54 are provided with bypass circuits 55 and 56 (FIG. 2) for releasing heat storage and recooling, respectively.

  Further, based on another feature of the present invention, a temperature sensor TE3 is also arranged in the middle of the housing heat storage circuit 34, and a control signal (analog control) for changing the number of revolutions of the chilled water pump 36 based on the information. Is to be sent. That is, here, the secondary side cold water temperature of the first heating heat exchanger 51 is controlled to be kept constant by changing the number of rotations of the cold water pump 36, and energy saving of the pump power is achieved. The load-side chilled water temperature can be controlled with high accuracy.

In the present invention, the first and second heat exchangers 51 and 52 for heating are arranged, but it is not always necessary to operate both heat exchangers. For example, when the housing heat storage using the first heating heat exchanger 51 is not performed during the ice making operation, the cooling water recooling circuit 38 of the refrigerator is operated so that only the second heating heat exchanger 52 is operated. , The cold water in the return pipe 18 is heated to a temperature exceeding 0 ° C. and controlled to a constant temperature.
That is, in order to control the chilled water to a temperature exceeding 0 ° C., the second chilled water amount of the first heating heat exchanger 51 is controlled first, and when the set temperature is not reached, the second heating is performed. The set temperature is controlled by the amount of secondary side cooling water of the heat exchanger 52 for use.

  In the embodiment of FIG. 1, a freeze release circuit 68 including a freeze release heat exchanger 64 and a brine pump 66 is further inserted between the refrigerating machine coolant recooling circuit 38 and the brine low temperature circuit 26. ing. This circuit 68 is used to release the freezing when the piping is frozen by the operation of the brine refrigerator 22.

  As a more preferred embodiment, the two heat exchangers 51 and 52 for heating can be housed in an integrated heat exchanger 70 and combined into one unit as a three-circuit type heat exchanger. This saves space and simplifies piping, wiring, maintenance, etc., and can reduce costs.

  Furthermore, in the illustrated example, the circuit of the heat exchanger for heating is configured by a bypass circuit so as not to increase the pipe resistance, but the first and second heat exchangers 51 and 52 are not bypass circuits but return pipes. It can also be made switchable so that it can be inserted in series in the middle.

FIG. 3 is a flow chart of the temperature control process when the cold water in the return pipe is heated using the ice heat storage tank device according to the present invention.
Step 81: Starts ice making by operating the ice making pump 16 and the brine pump 24, etc. Step 82 ... Starts the operation of the heating pump 58 Step 83 ... Electric drive according to the temperature sensed by the temperature sensor TE1 Step 84: If the detected temperature TE1 is 0.5 ° C. or less, the electric control valve 53 is switched to close the bypass circuit 55. Water flows into the housing heat storage circuit 34 and housing heat storage is started. Step 85... If the detected temperature TE1 is 0.5 ° C. or higher, the electric control valve 53 is switched to open the bypass circuit 55. The water in the housing heat storage circuit 34 stops and the housing heat storage ends.

Step 86: Judgment of opening / closing of the bypass circuit 56 by the electric control valve 54 in accordance with the temperature sensed by the temperature sensor TE2 Step 87: If the sensed temperature TE2 is 0.5 ° C. or less, turn the electric control valve 54 The bypass circuit 56 is closed by switching. Water flows into the cooling water recooling circuit 38 and cooling water recooling is started. Step 88 .. If the sensed temperature TE1 is 0.5 ° C. or higher, the electric control valve 54 is switched to open the bypass circuit 56. Water in the cooling water re-cooling circuit 38 is stopped and the re-cooling of the cooling water is finished. Step 89... The ice making pump 16 and the brine pump 24 are stopped to finish the ice making operation. The operation of the pump 58 is stopped.

  As described above in detail, according to the present invention, when ice is generated from supercooled water in a closed pipe, there is a means for preventing freezing in the return pipe and effectively utilizing the cold. The technical effects of the system including the ice heat storage device can be improved, and the technical effect is extremely remarkable.

The circuit diagram showing the whole ice heat storage tank apparatus by this invention. The circuit diagram which expands and represents the characteristic part of the ice thermal storage tank apparatus by this invention. The flowchart showing an example of the temperature control method of the ice thermal storage tank apparatus by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Heat exchanger for supercooled water production 14 Ice storage tank 16 Ice making pump 18 Return pipe 34 Housing heat storage circuit 36 Chilled water pump 38 Cooling water recooling circuit 50 Bypass circuit 51, 52 Heat exchanger 53, 54 Electric control Valves 55 and 56 Bypass circuit 58 Heating pump 60 Cooling device for housing heat storage 70 Integrated heat exchanger

Claims (4)

A supercooled water production heat exchanger that turns water into supercooled water;
An ice storage tank for storing ice produced from supercooled water;
A return pipe for guiding cold water from near the bottom of the ice heat storage tank to the supercooled water production heat exchanger;
A water circulation pump arranged in the middle of the return pipe;
In an ice heat storage tank device comprising an air conditioning or other secondary system circuit for circulating cold water from the ice heat storage tank,
A bypass circuit is provided in the middle of the return pipe, and the first heat exchanger and the second heat exchanger are arranged in series in the bypass circuit, and the secondary side of the first heat exchanger is subjected to nighttime cooling load processing. A supercooled water dynamic ice heat storage tank device, which is connected to a cooling air recirculation circuit connected to a cooling air recirculation circuit that is connected to an air conditioning system system and that leads to a secondary side of the second heat exchanger to a refrigerator of the air conditioning system. The ice heat storage tank device according to claim 1, wherein a secondary side of the first heat exchanger is connected to a building heat storage cooling device of a building as the nighttime cooling load processing air conditioning system system. The ice heat storage tank device according to claim 1 or 2, wherein each of the first and second heat exchangers is formed as an internal circuit of an integrated heat exchanger. The ice heat storage tank device according to claim 1 or 2, wherein the temperature of the secondary side cold water of the first or second heat exchanger is adjusted by controlling the number of rotations of the cold water pump.

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