JP7375128B2 - Frame heat storage air conditioning system - Google Patents

Description

The present invention relates to a framework heat storage air conditioning system that performs air conditioning by dissipating thermal energy stored in a framework that constitutes the ceiling surface of a building.

BACKGROUND ART Conventionally, as one type of heat storage air conditioning system, a framework heat storage air conditioning system is known that utilizes a concrete framework such as a floor, wall, pillar, etc., which has a large heat capacity, as a heat storage material. In the frame heat storage air conditioning system, there is no need to newly provide a heat storage tank, so space and cost can be saved.

For example, Patent Document 1 discloses a frame heat storage structure in which a pipe for circulating hot water is buried inside the frame and heat is stored in the frame through the pipe .

Japanese Patent Application Publication No. 2000-274711

However, since the frame heat storage structure described in Patent Document 1 requires the pipes to be embedded inside the frame, the maintainability of the pipes is poor, and there is a risk that the pipes may be deformed or damaged during construction.

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, it is an object of the present invention to provide a framework heat storage air conditioning system that can ensure ease of construction and maintainability of the system.

The present invention is intended to solve the above-mentioned problems, and the present invention provides a framework heat storage air conditioning system that performs air conditioning by dissipating thermal energy stored in a framework that constitutes the ceiling surface of a building. A state in which a heat medium pipe in which a heat medium serving as a medium for the thermal energy flows, and a state in which the heat medium pipe extends along the flow direction in which the heat medium flows inside the heat medium pipe, and holds the heat medium pipe. The heat exchanger is characterized by comprising a heat exchange member having a heat exchange member and an elastic member having a higher thermal conductivity than the frame between the heat exchange member and the frame .

Further, in the personal air conditioning system according to the present invention, a recess formed in the body is provided with a latent heat storage material having a larger specific heat capacity than the body, and the heat exchange member is provided with the latent heat storage material provided in the recess. It is characterized by being able to transfer heat to .

According to the framework heat storage air conditioning system according to the present invention, the heat exchange member holds the heat medium piping along the flow direction, so there is no need to embed each part of the framework heat storage air conditioning system inside the framework. Therefore, ease of construction and maintenance of the system can be ensured.

In addition, by sandwiching the elastic member between the heat exchange member and the frame, the gap (air layer) between the heat exchange member and the frame can be reduced, the influence of the air layer can be reduced, and the elastic Since the members are made of a material with higher thermal conductivity than the structure, it promotes heat conduction between the heat exchange members and the structure, which suppresses the decrease in heat transfer due to unevenness of the structure. can.

1 is a diagram showing an example of the overall configuration of an air conditioning system 100 according to an embodiment of the present invention. An example of a framework heat storage air conditioning system 2 according to an embodiment of the present invention is shown, in which (a) is a schematic configuration diagram and (b) is a layout diagram on a ceiling surface. An installation example of the frame heat storage air conditioning system 2 according to the embodiment of the present invention is shown, in which (a) is an installation example of the hot and cold water pipe 20 and the heat sink 23 on the ceiling surface 11a, and (b) is A in the first installation example. -A is an enlarged sectional view taken along line A, and (c) is a diagram showing an enlarged sectional view taken along line AA in the second installation example. FIG. 3 is a diagram showing the transition of heat flow during heat storage due to differences in heat transfer methods. FIG. 3 is a diagram showing changes in heat storage rate due to differences in heat transfer methods. FIG. 3 is a diagram showing changes in temperature distribution within the building structure due to differences in heat transfer methods. FIG. 3 is a diagram showing changes in the amount of heat stored in the building frame and the cumulative amount of cold heat of cold water during heat storage and heat dissipation.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings. FIG. 1 is a diagram showing an example of the overall configuration of an air conditioning system 100 according to an embodiment of the present invention. The building 1 is constituted by a concrete frame including an upper slab 11 and a lower slab 12, and a floor material 13 is laid above the lower slab 12.

The building 1 has a double floor structure, and an underfloor chamber 14 is formed between a lower slab 12 and a floor material 13. A living room 10 is formed between the ceiling surface 11a, which is the lower surface of the upper slab 11, and the floor material 13. A plurality of beams 11b are formed in a waffle shape on the ceiling surface 11a.

The air conditioning system 100 is a system that air-conditions a living room 10 by combining a building frame heat storage air conditioning system 2 and a floor outlet air conditioning system 3. The frame heat storage air conditioning system 2 is a system that performs air conditioning by storing thermal energy in the upper slab 11 that constitutes the ceiling surface 11a and dissipating the stored thermal energy. The floor air conditioning system 3 is a system that is formed in the floor material 13 and performs air conditioning by blowing out conditioned air from a plurality of air supply ports (not shown). Note that the air conditioning system 100 may be a stand-alone system of the building frame heat storage air conditioning system 2, or may be a combination of the building frame heat storage air conditioning system 2 and another air conditioning system other than the floor blowing air conditioning system 3.

The skeleton heat storage air conditioning system 2 includes a cold and hot water pipe 20 through which cold and hot water (thermal medium) serving as a medium for thermal energy flows, a heat source 22 that supplies cold or warm heat as thermal energy, and a thermal energy supplied from the heat source 22. It is provided with a heat exchanger 21 that transfers heat to the cold and hot water flowing through the cold and hot water pipe 20 by heat exchange. The heat source 22 uses, for example, underground heat or electricity at night or late at night when electricity rates are lower.

The floor air conditioning system 3 includes an air conditioning unit 30 having an air conditioning function, an air supply pipe 31 that communicates with the living room 10 via an underfloor chamber 14 and a plurality of air supply ports, and a return air port (not shown) that communicates with the living room 10. 10 is provided. The air conditioning unit 30 introduces outside air OA, adjusts the temperature of the introduced outside air OA, and supplies it to the living room 10 via the underfloor chamber 14 and a plurality of air supply ports as air supply SA through an air supply pipe 31 . Further, the air conditioning unit 30 takes in air in the living room 10 through the return air port as return air RA through the return air piping 32, and discharges it to the outside as exhaust air EA.

FIG. 2 shows an example of a framework heat storage air conditioning system 2 according to an embodiment of the present invention, in which (a) is a schematic configuration diagram and (b) is a layout diagram on a ceiling surface. The frame heat storage air conditioning system 2 includes a cold and hot water pipe 20 (heat medium pipe) through which cold and hot water flows along the flow direction (the front and back directions of the page in FIG. 2(a)), and a cold and hot water pipe 20 that is held along the flow direction. A heat sink 23 (heat exchange member) attached to the ceiling surface 11a in a state of The pump is equipped with a control device (not shown) that controls the operating state of the pump installed in the pump.

The heat sink 23 is made of a metal with high thermal conductivity, such as aluminum, and is manufactured as a long member by extrusion molding. The heat sink 23 is a heat exchange member that transmits the thermal energy of the cold and hot water flowing through the cold and hot water pipe 20 to the upper slab 11 by thermal conduction.

As shown in FIG. 2(b), a spot fan 24 is arranged near the center of the ceiling surface 11a surrounded by a beam 11b formed in a waffle shape, and a spot fan 24 is arranged around the spot fan 24. Cold and hot water pipes 20a to 20c and a heat sink 23 are arranged.

The cold and hot water pipe 20 circulates cold and hot water, and the cold and hot water pipe 20a in the upstream part is arranged so as to protrude from the ceiling surface 11a, and the cold and hot water pipe 20c in the downstream part is arranged so as to be buried in the ceiling surface 11a. has been done. The cold and hot water pipes 20b in the midstream portion are arranged on the ceiling surface 11a in a state in which they are alternately folded back in a zigzag pattern in each of the four directions around the spot fan 24.

The heat sink 23 is arranged along the flow direction of the cold/hot water pipe 20b with the longitudinal direction being the flow direction of the straight line portion of the midstream cold/hot water pipe 20b arranged in a zigzag shape.

The spot fan 24 is, for example, an axial blower fan, is installed in a suspended state from the ceiling surface 11a, and generates an airflow from below the ceiling surface 11a toward the ceiling surface 11a. In this embodiment, as shown in FIG. 2(a), the spot fan 24 is disposed below the ceiling surface 11a in a portion where the heat sink 23 is not attached. An upward airflow is generated toward the ceiling surface 11a. Further, the spot fan 24 is controlled by the control device, and is stopped when storing thermal energy in the upper slab 11, and is activated when radiating thermal energy from the upper slab 11.

As shown in FIG. 2(a), the upward airflow directed toward the ceiling surface 11a generated by the spot fan 24 is radially diffused by the ceiling surface 11a when it reaches the ceiling surface 11a, and becomes a lateral airflow. Then, when the horizontal airflow reaches the hot and cold water pipe 20 and the heat sink 23, and further reaches the beam 11b surrounding the spot fan 24, it becomes a downward airflow and descends along the beam 11b.

(Example of installation of building frame heat storage air conditioning system 2)
FIG. 3 shows an installation example of the frame heat storage air conditioning system 2 according to the embodiment of the present invention, in which (a) is an example of the installation of the cold and hot water pipe 20 and the heat sink 23 on the ceiling surface 11a, and (b) is the first installation example. FIG. 6(c) is an enlarged cross-sectional view taken along line AA in the installation example; FIG. The heat sink 23 includes a holding part 230 that holds both sides of the hot and cold water pipe 20 between them, and a ceiling fixing part 231 that is fixed to the ceiling surface 11a with a fixing bolt 28A.

As shown in FIGS. 3(b) and 3(c), the holding portion 230 has a C-shaped cross-section. Moreover, an insert or an anchor for fixing the ceiling fixing part 231 is installed on the ceiling surface 11a at a position where the ceiling fixing part 231 is fixed.

In the first installation example shown in FIG. 3(b), the frame heat storage air conditioning system 2 includes an elastic member 25 disposed between the heat sink 23 and the ceiling surface 11a. The elastic member 25 is made of an elastic material having a higher thermal conductivity than the upper slab 11, and has a sheet-like shape. The elastic member 25 is, for example, silicone rubber made of silicone.

If there is an unevenness on the ceiling surface 11a, an air layer will be created between the frame and the heat sink 23, which will reduce the amount of heat conduction to the frame. By being sandwiched between the upper slab 11 and the upper slab 11, the elastic member 25 has elasticity, thereby reducing the gap (air layer) between the heat sink 23A and the ceiling surface 11a. The heat conduction between the heat sink 23A and the ceiling surface 11a is promoted by the fact that the heat sink 23A is made of a large material, so it is possible to suppress a decrease in the amount of heat conduction due to unevenness of the ceiling surface 11a.

In the second installation example shown in FIG. 3(c), the frame heat storage air conditioning system 2 includes a latent heat storage material 26 arranged on the ceiling surface 11a in a portion where the heat sink 23 is attached. The latent heat storage material 26 is made of, for example, a material called PCM (Phase Change Material) that has a larger specific heat capacity than the upper slab 11, that is, concrete, and is embedded in a recess 11c formed in the ceiling surface 11a.

Since the latent heat storage material 26 is formed of a material having a larger specific heat capacity than the upper slab 11, when storing thermal energy in the upper slab 11, a larger amount of heat is transferred to a place closer to the living room 10 where the thermal energy is radiated. Since energy can be stored, it is possible to improve heat dissipation performance when dissipating thermal energy from the upper slab 11.

(Modified example)
By combining the first installation example and the second installation example, for example, the frame heat storage air conditioning system 2 can be configured such that the first installation example elastic member 25 in the first installation example and the latent heat in the second installation example It may also include a heat storage material 26.

The arrangement of the hot and cold water pipe 20, the heat sink 23, and the spot fan 24 with respect to the ceiling surface 11a is not limited to the arrangement shown in FIG. 2(b), and may be changed as appropriate. The size and shape of the heat sink 23 may be changed as appropriate. Further, the heat sink 23 may be divided into a plurality of pieces and arranged in a longitudinal direction, and in this case, pieces having different lengths in the longitudinal direction may be arranged.

Instead of generating an upward airflow toward the ceiling surface 11a, the spot fan 24 may generate an oblique upward airflow, or the upward airflow generated by the spot fan 24 may be converted into a horizontal airflow by the ceiling surface 11a. By doing so, instead of the airflow generated by the spot fan 24 indirectly reaching the cold and hot water pipe 20 and the heat sink 23, the airflow generated by the spot fan 24 directly reaches the cold and hot water pipe 20 and the heat sink 23. 23 may be reached.

(About experiments to verify the thermal performance of the building frame heat storage air conditioning system 2)
Next, an experiment was conducted to verify the thermal performance of the structural heat storage air conditioning system 2 of the present invention. The experimental apparatus, experimental conditions, and experimental results will be explained below.

(Experimental equipment and experimental conditions)
The experimental apparatus consisted of a concrete specimen A (1400 x 1180 x 250 mm) or a concrete specimen B (simulating the upper slab 11) placed inside a box made of expanded polystyrene plates (100 mm thick, 0.028 W/m/K). 1400 x 1180 x 150 mm), and was divided into a space below test specimens A and B (simulating living room 10) and above test specimens A and B (simulating living room 10 on the OA floor + upper floor). . In order to adjust the temperature of the internal space, heaters were installed above and below test specimens A and B, respectively.

A blower fan simulating the floor air conditioning system 3 was installed above the test specimens A and B, and a spot fan was installed below the test specimens A and B to blow upward airflow onto the surfaces of the test specimens A and B. 24 was installed at a position 0.3 m away from test specimens A and B.

The test specimen A has a heat transfer section (100 mm) installed under the slab (150 mm), and the cold/hot water pipe 20 is embedded in the heat transfer section of the test sample A as the "first heat transfer method". shall be. A cold/hot water pipe 20 was installed under the test specimen B via a heat sink 23 and an elastic member 25 (thickness 3 mm, thermal conductivity 2.1 W/m·K) as the "second heat transfer method". shall be.

The conditions during heat storage were as follows: cold water at a temperature of 21° C. and a flow rate of 1.5 L/min was supplied to the cold/hot water pipe 20, and the heat storage time was 10 hours. Furthermore, during heat storage, the heater was controlled so that the temperature in the upper and lower spaces was 26°C.

Three heat dissipation conditions are adopted for the heat dissipation conditions: the "first heat dissipation condition" is natural heat dissipation, the "second heat dissipation condition" is when the blower fan is operated, and the "third heat dissipation condition" is when the blower fan is operated. and the spot fan 24 was operated. The blower fan blows air in the OA floor so that the airflow temperature is 26°C and the air volume is 10m3/h, and the spot fan 24 blows upward airflow onto the surfaces of test specimens A and B at a blowing speed of 3m/s. I sprayed it. Furthermore, during heat dissipation, the heater was controlled so that the temperature in the upper and lower spaces was 26° C., similarly to during heat storage.

(Experimental result)
FIG. 4 is a diagram showing the transition of heat flow during heat storage due to differences in heat transfer methods. FIG. 4 shows the results of plotting the average value of heat flow every 30 minutes. "Heat flow to the skeleton" is the value obtained by dividing the difference in heat storage amount every 30 minutes by time. "Heat flow to the air + heat reradiation from the skeleton to the air" is the value (Equation (1)) obtained by subtracting "heat flow to the skeleton" from the average heat flow of cold water for 30 minutes (hereinafter referred to as cold water heat flow). Test specimens A and B are designed to ensure thermal insulation properties, but if heat flow occurs outside the experimental system, that value is included in "heat flow to the air + heat reradiation from the structure to the air". It will be.

It was found that the cold water heat flow was larger in the "first heat transfer method" than in the "second heat transfer method." This indicates that the rate of heat transfer into the building structure by conduction is higher than the rate of heat transfer to the air by convection.

On the other hand, in the "second heat transfer method," the cold water heat flow remains at about 60% to 80% of that in the "first heat transfer method," and the difference is large immediately after the start of the experiment, and the difference increases over time. has tended to become smaller. It is assumed that this trend occurred because the air temperature was controlled to be constant. In addition, the reason why the heat flow to the air becomes large immediately after the start of the experiment in the "second heat transfer method" is due to the fact that the air temperature near the structure becomes low immediately after the start of the experiment. It is also inferred that the cold water heat flow is overestimated.

Regarding the presence or absence of the elastic member 25 (thickness: 3 mm, thermal conductivity: 2.1 W/m·K), when the elastic member 25 is present, the cold water heat flow and the heat flow to the frame are larger than when the elastic member 25 is not present. Ta. This is because if there is an unevenness on the surface of the structure, an air layer will be created between the structure and the heat sink 23 due to the unevenness on the surface of the structure, which will reduce the amount of heat conduction to the structure, but the elastic member 25 This shows that the influence of the air layer between the frame and the heat sink 23 can be reduced, and a decrease in the amount of heat conduction due to unevenness on the surface of the frame can be suppressed.

FIG. 5 is a diagram showing changes in heat storage rate due to differences in heat transfer methods. Figure 5 shows the proportion of cold water heat flow used to change the temperature of the building structure. After a heat storage time of 10 hours, the results showed that the "first heat transfer method" had a heat storage rate of 95 to 50%, and the "second heat transfer method" had a change in heat storage rate of about 80 to 25%.

FIG. 6 is a diagram showing changes in temperature distribution within the building blocks due to differences in heat transfer methods. FIG. 6 shows the transition of the temperature distribution within the building blocks in the central vertical cross section of test specimens A and B. The black circles in the figure indicate temperature measurement points, and the spaces between the measurement points were interpolated by normal Kriging.

Regarding heat storage, in the "first heat transfer method", the building block is cooled from the vicinity of the buried part of the hot and cold water pipe 20 (at a height of 50 mm from the bottom surface of the test specimen A), and the lowest temperature part is located deep inside the building block. occured. On the other hand, in the "second heat transfer method", the lowest temperature portion occurred on the lower body surface.

Regarding heat dissipation, in the "first heat transfer method", a cold pool remains inside the building body even after 5 hours have passed since the water supply was stopped. It was found that it became difficult to extract heat energy efficiently. On the other hand, in the "second heat transfer method", since the lowest temperature part occurs on the lower surface of the structure, airflow is blown onto the surface of the structure, which increases the efficiency of dissipating thermal energy from the structure. It is presumed that heat dissipation performance can be improved.

FIG. 7 is a diagram showing changes in the amount of heat stored in the building frame and the cumulative amount of cold water during heat storage and heat dissipation. In Figure 7, the difference between the cumulative amount of cold water when the cold water supply is stopped (10 hours of heat storage) and the amount of heat stored in the building frame represents the amount of cold heat radiated to the upper and lower spaces, and this difference is small. The higher the temperature, the greater the proportion of the amount of cold heat stored in the structure. In both heat transfer methods, immediately after the start of the experiment, the proportion of cold heat stored in the building blocks was high, and as time passed, the proportion of heat dissipated into the air without being stored in the building blocks increased. In addition, the amount of heat stored in the building frame relative to the cumulative amount of cold heat of cold water during 10 hours of heat storage was approximately 70% in the "first heat transfer method" and approximately 50% in the "second heat transfer method."

There was almost no difference in the change in the amount of heat storage in the building frame after the cold water supply was stopped under the "second heat dissipation condition" compared to the "first heat dissipation condition." It is thought that the air volume of the floor outlet had little effect on heat dissipation. On the other hand, under the "third heat dissipation condition", the amount of heat dissipated from the structure is about 1.2 to 1.4 times larger than that under the "first heat dissipation condition", and the spot fan 24 directs the airflow to the surface of the structure. It was found that spraying promoted convection near the surface of the building structure. Therefore, by stopping the spot fan 24 during heat storage and operating the spot fan 24 during heat dissipation, the heat storage performance when storing thermal energy in the structure is not reduced, and the heat energy is radiated from the structure. Heat dissipation performance can be improved.

As described above, according to the structural heat storage air conditioning system 2 according to the embodiment of the present invention, the heat sink 23 is attached to the ceiling surface 11a while holding the cold/hot water pipe 20 along the flow direction. Since there is no need to embed each part of the building frame heat storage air conditioning system 2 in the upper slab 11, ease of construction and maintainability of the system can be ensured.

As described above, according to the frame heat storage air conditioning system 2 according to the embodiment of the present invention, the spot fan 24 generates airflow toward the ceiling surface 11a to which the heat sink 23 is attached. When the generated airflow reaches the ceiling surface 11a, convection near the ceiling surface 11a is promoted, so that the heat dissipation performance when dissipating thermal energy from the upper slab 11 that constitutes the ceiling surface 11a can be improved. Furthermore, when the airflow generated by the spot fan 24 reaches the heat sink 23, convection near the surface of the heat sink 23 is promoted, so that the heat dissipation performance when dissipating thermal energy from the heat sink 23 can be improved. , it is possible to improve responsiveness to heat load fluctuations within the living room 10.

1... Building 2... Frame heat storage air conditioning system 3... Floor air conditioning system 10... Living room 11... Upper slab 11a... Ceiling surface 11b... Beam 11c... Recess 12 ...Lower slab 13...Floor material 14...Underfloor chamber 20, 20a to 20c...Cold/hot water pipe 21...Heat exchanger 22...Heat source 23, 23A, 23B...Heat sink 24 ... Spot fan 25 ... Elastic member 26 ... Latent heat storage material 28A to 28C ... Fixing bolt 29 ... Hanging fitting 30 ... Air conditioning section 31 ... Air supply piping 32 ... Return Air piping 100...Air conditioning system 230...Holding part 231...Ceiling fixing part

Claims (2)

A framework thermal storage air conditioning system that performs air conditioning by dissipating thermal energy stored in a framework that makes up the ceiling of a building,
a heat medium pipe through which a heat medium serving as a medium for the thermal energy flows;
a heat exchange member that extends along the flow direction of the heat medium inside the heat medium pipe and holds the heat medium pipe ;
A frame heat storage air conditioning system comprising: an elastic member having a higher thermal conductivity than the frame between the heat exchange member and the frame . A recess formed in the body is provided with a latent heat storage material having a larger specific heat capacity than the body,
The heat exchange member is capable of transferring heat to the latent heat storage material provided in the recess.
The framework heat storage air conditioning system according to claim 1.

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