WO2014017040A1

WO2014017040A1 - Heat exchanger element and heat recovery ventilation device using same

Info

Publication number: WO2014017040A1
Application number: PCT/JP2013/004230
Authority: WO
Inventors: 泰世杉本
Original assignee: パナソニック株式会社
Priority date: 2012-07-24
Filing date: 2013-07-09
Publication date: 2014-01-30
Also published as: JP6127264B2; JP2014040991A

Abstract

A heat exchanger element, wherein a plate heat exchanger (16) is provided with spacers (13a, 13b) and a plurality of air duct ribs (13c), and in which an air exhaust unit, forming a plurality of air exhaust ducts, and an air supply unit (13), forming a plurality of air supply ducts, are layered. Moreover, the air exhaust flow and the air supply flow (5) orthogonally intersect or obliquely intersect at both ends (30) of the air exhaust duct and the air supply duct (15), and face in the center portion (31). In addition, the air supply duct (15g), closest to the inlet side of the exhaust air flow of the plurality of air supply ducts (15), is an enclosed region.

Description

Heat exchange element and heat exchange type ventilation equipment using it

The present invention relates to a heat exchange element and a heat exchange type ventilation device using the heat exchange element.

The heat exchange type ventilator exchanges heat between an exhaust flow for exhausting indoor air to the outside and a supply air flow for supplying outdoor air to the room. Heat exchange type ventilation equipment used in cold districts, etc., in the flow path in the heat exchanger in which warm exhaust flow from the room flows when the outdoor temperature becomes low such as −10 ° C. or lower in winter. A cold airflow from the outside flows in the flow path of the adjacent air supply, and after dew condensation, it forms ice and clogs. In the conventional heat exchange type ventilator, this clogging was prevented by stopping the operation (for example, see Patent Document 1).

Hereinafter, the heat exchange type ventilator disclosed in Patent Document 1 will be described. FIG. 7 is a conceptual diagram showing a configuration of a conventional heat exchange type ventilation device.

The heat exchanger unit 101 performs heat exchange and ventilation between indoor air and outdoor air. As shown in FIG. 7, the heat exchanger unit 101 includes a heat exchanger 102, an exhaust path 103, an air supply path 104, an exhaust fan 105, an air supply fan 106, a temperature sensor 107, and a control unit. I have. Here, the exhaust path 103 is a path through which indoor air is exhausted to the outside via the heat exchanger 102. The air supply path 104 is a path through which outdoor air is supplied indoors. The exhaust fan 105 is disposed in the exhaust path 103. The air supply fan 106 is disposed in the air supply path 104. The temperature sensor 107 detects the outside air temperature. The control unit controls the operation of the exhaust fan 105 and the supply fan 106 based on the outside air temperature detected by the temperature sensor 107.

Then, when the outside air temperature falls below −10 ° C., the control unit performs two freeze suppression controls according to the outside air temperature in order to prevent the heat exchanger 102 from freezing. These two freeze suppression controls are a first freeze suppression control and a second freeze suppression control.

The first freezing suppression control is an operation in which the exhaust fan 105 is always operated and the operation of the air supply fan 106 is stopped for the first 15 minutes out of 60 minutes.

The second freezing suppression control is freezing suppression control of the heat exchanger 102 that is stronger than the first freezing suppression control when the outside air temperature falls below −15 ° C. The second freezing suppression control is an intermittent operation in which the operation is resumed for 5 minutes after the exhaust fan 105 and the air supply fan 106 are suspended for 60 minutes.

As described above, in the conventional heat exchange type ventilator, the operation is stopped for a predetermined time with respect to the problem that the exhaust passage 103 is clogged. Therefore, for example, when only the supply air is stopped, the room becomes negative pressure, and the outdoor air flows from the gaps in the building. As a result, condensation occurs in the cold draft and the indoor space. In addition, when the supply air and the exhaust air are stopped, there is a problem that the necessary ventilation amount in the room cannot be secured.

JP 2003-148780 A

The heat exchange element of the present invention is provided with an exhaust unit in which a plurality of exhaust air passages are formed by providing interval holding portions and a plurality of air passage ribs for holding intervals on a heat transfer plate, and an air supply in which a plurality of air supply air passages are formed. Units are stacked. Further, in the heat exchange element, the exhaust air flowing through the exhaust air passage and the air supply air flowing through the air supply air passage are orthogonally or obliquely crossed at both ends of the exhaust air passage and the air supply air passage, and a central portion between both ends. Are facing each other. Of the plurality of supply air paths, the supply air path closest to the inlet side of the exhaust flow is closed.

The exhaust flow of such a heat exchange element is most likely to be frosted in the exhaust air passage, and does not exchange heat in the counterflow portion in the central portion of the air passage closest to the inlet side of the supply air flow, without causing a temperature drop. Can pass through. Therefore, frost formation in the exhaust air passage is suppressed. That is, the exhaust flow is suppressed from a total temperature decrease at the outlet of the exhaust flow even though the temperature is decreased in the cross-flow portion where heat exchange with the supply air flow occurs. As a result, after condensation occurs in the heat exchange element, it does not freeze and clog.

Also, the heat exchange type ventilation device using this heat exchange element is free from clogging due to icing of the heat exchange element by the method described above. Therefore, the heat exchange type ventilation device can be continuously operated, and condensation does not occur in the cold draft and the indoor space due to the intermittent operation. In addition, necessary ventilation can be secured.

FIG. 1 is a conceptual diagram showing a configuration of a house in which a heat exchange type ventilator according to an embodiment of the present invention is installed. FIG. 2 is a conceptual diagram showing a configuration of the heat exchange type ventilator. FIG. 3 is a perspective view showing a configuration of the heat exchange element. FIG. 4A is a plan view of an exhaust unit constituting an exhaust air passage when the heat exchange element is disassembled. FIG. 4B is a plan view of an air supply unit constituting an air supply air passage when the heat exchange element is disassembled. FIG. 5A is a conceptual diagram showing a normal state of a different configuration of the heat exchange type ventilator. Drawing 5B is a key map showing the state at the time of the airway closure of the different composition of the heat exchange type ventilation equipment. FIG. 6A is a plan view of a normal air supply unit that constitutes an air supply air path when different configurations of the heat exchange element are disassembled. FIG. 6B is a plan view of the air supply unit that constitutes the air supply air passage when the different configurations of the heat exchange element are disassembled when the air passage is closed. FIG. 7 is a conceptual diagram showing a configuration of a conventional heat exchange type ventilation device.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment)
FIG. 1 is a conceptual diagram showing a configuration of a house in which a heat exchange type ventilator according to an embodiment of the present invention is installed. As shown in FIG. 1, the house 1 includes a non-residential space that performs only exhaust and a residential space that supplies and exhausts air. Non-residential spaces are, for example, bathrooms, toilets, and toilets. The living space is, for example, a living room and a bedroom.

The exhaust and supply of air in each room is performed by connecting a duct to the heat exchange type ventilation device 2. The heat exchange type ventilator 2 has a built-in heat exchange element 3 for exchanging heat between the outdoor exhaust flow 4 and the outdoor air supply flow 5.

FIG. 2 is a conceptual diagram showing the configuration of the heat exchange type ventilator according to the embodiment of the present invention. As shown in FIG. 2, the heat exchange type ventilation device 2 includes an exhaust air blowing path 4 a, an air supply air blowing path 5 a, an exhaust air blowing part 6, an air supply air blowing part 7, and a heat exchange element 3. . Here, the exhaust flow 4 flows through the exhaust air blowing path 4a. The air supply air 5 flows through the air supply air passage 5a. The exhaust blower 6 blows the exhaust flow 4. The supply air blower 7 blows the supply airflow 5. In the heat exchange element 3, heat exchange between the exhaust flow 4 and the supply air flow 5 is performed.

The exhaust air blower 6 and the heat exchange element 3 are provided in the exhaust air passage 4a (solid line arrow in FIG. 2). An air supply air blowing section 7 and a heat exchange element 3 are provided in the air supply air flow path 5a (dotted arrow in FIG. 2). Here, the exhaust air blowing path 4a is from the inside air port 8 for introducing the inside air (RA) to the exhaust port 9 for exhausting (EA) to the outside. The supply air passage 5a extends from an outside air port 10 for introducing outside air (OA) to an air supply port 11 for blowing out air supply (SA) into the room. The exhaust air blowing unit 6 generates an exhaust flow 4 from the inside air port 8 toward the exhaust port 9 in the exhaust air blowing path 4a. The supply air blower 7 generates an air supply air flow 5 from the outside air port 10 toward the air supply port 11 in the air supply air passage 5a. The heat exchange element 3 is disposed at a position where the exhaust air blowing path 4 a and the supply air blowing path 5 a intersect, and performs heat exchange between the exhaust flow 4 and the supply air flow 5.

Here, the configuration of the heat exchange element 3 will be described with reference to FIGS. 3, 4A and 4B. FIG. 3 is a perspective view showing the configuration of the heat exchange element according to the embodiment of the present invention, FIG. 4A is a plan view of an exhaust unit constituting the exhaust air passage when the heat exchange element is disassembled, and FIG. 4B is the same heat exchange. It is a top view of the air supply unit which comprises the air supply air path when an element is decomposed | disassembled. In the following, the exhaust air passage 4a in the heat exchange element 3 is the exhaust air passage 14, the air supply air passage 5a is the air supply air passage 15, the inlet of the exhaust flow 4 of the heat exchange element 3 is the inner air outlet 8a, and the outlet is exhausted. The inlet 9a and the inlet of the supply airflow 5 are referred to as an outside air outlet 10a, and the outlet is referred to as an inlet 11a.

The heat exchange element 3 shown in FIG. 3 has a plurality of alternately stacked exhaust units 12 shown in FIG. 4A and air supply units 13 shown in FIG. 4B.

As shown in FIGS. 4A and 4B, the exhaust unit 12 and the air supply unit 13 have substantially hexagonal outer shapes. As shown in FIG. 4A, spacing

ribs

12 a and 12 b are provided on the outer periphery of the exhaust unit 12 other than the sides that form the inside air ports 8 a and the exhaust ports 9 a as spacing holding portions that hold the spacing. The exhaust unit 12 includes six air passage ribs 12c that divide air passages that are provided substantially in parallel and at substantially equal intervals. That is, the exhaust unit 12 is provided with

interval ribs

12a and 12b that maintain an interval between the heat transfer plate 16 and a plurality of air passage ribs 12c, and a plurality of

exhaust air passages

14a, 14b, 14c, 14d, 14e, and 14f. 14g are formed.

Similarly, as shown in FIG. 4B, on the outer periphery of the air supply unit 13 other than the sides forming the outside air port 10a and the air supply port 11a,

interval ribs

13a and 13b are provided as interval holding portions for holding intervals. Yes. In addition, the air supply unit 13 includes six air passage ribs 13c that divide the air passages provided substantially in parallel and at substantially equal intervals. That is, the air supply unit 13 is provided with

interval ribs

13a and 13b that hold an interval with the heat transfer plate 16, and a plurality of air passage ribs 13c, and a plurality of air

supply air passages

15a, 15b, 15c, 15d, and 15e, 15f and 15g are formed.

By stacking a plurality of such exhaust units 12 and air supply units 13 alternately, the heat exchange element 3 is configured such that the exhaust air passages 14 and the air supply air passages 15 are alternately arranged one by one. . The number of stacks of the exhaust unit 12 and the air supply unit 13 is determined by the size of the heat exchange type ventilation device 2 on which the heat exchange element 3 is mounted and the air volume.

Further, as shown in FIG. 4A, the exhaust air passage 14 is divided into seven exhaust air passages 14a to 14g by six air passage ribs 12c. Similarly, as shown in FIG. 4B, the supply air passage 15 is divided into seven supply air passages 15a to 15g by six air passage ribs 13c.

The heat transfer plate 16 performs heat exchange between the exhaust flow 4 and the supply air flow 5. In exchange only for sensible heat, a metal plate such as aluminum or a resin plate is used for the heat transfer plate 16. In the exchange of both sensible heat and latent heat, a moisture permeable film such as paper or resin is used for the heat transfer plate 16.

The

spacing ribs

12a, 12b, 13a, 13b are made of resin or metal. In particular, when the heat transfer plate 16 is a moisture permeable film, the

spacing ribs

12a, 12b, 13a, and 13b are preferably formed by integral molding by inserting the heat transfer plate 16 into a mold and insert injection molding with resin.

As shown in FIGS. 4A and 4B, the exhaust air flow 4 that flows through the exhaust air passage 14 and the air supply air flow 5 that flows through the air supply air passage 15 include both end portions 30 of the exhaust air passage 14 and the air supply air passage 15 (FIG. 4B). In the B part and the D part). And in the center part 31 (C section of FIG. 4B) between the both ends 30, the exhaust flow 4 and the supply airflow 5 oppose. Of the plurality of

supply air passages

15a, 15b, 15c, 15d, 15e, 15f, and 15g, the supply air passage 15g closest to the inlet side of the exhaust flow 4 is closed.

Note that both end portions 30 in the embodiment of the present invention indicate the B portion and the D portion in FIG. 4B, and the central portion 31 indicates the C portion in FIG. 4B. The exhaust air passage 14 and the supply air passage 15 in the central portion 31 are parallel and corrugated, and the corrugations are configured in opposite directions for each layer.

The heat exchanging element 3 shown in FIG. 3 is a plane of the exhaust unit 12 of FIG. 4A except for a portion constituting the exhaust air passage 14a of the air passage rib 12c and a portion constituting the supply air passage 15g of the air passage rib 13c. The drawing and the plan view of the air supply unit 13 in FIG. 4B are line symmetric with respect to the line AA in FIG. 4A.

The operation and effect of the heat exchange type ventilation device 2 and the heat exchange element 3 configured as described above will be described below.

When the ventilation operation is started in the heat exchange type ventilation device 2 installed in the house 1 shown in FIG. 1, the inside air (RA) is introduced from the inside air port 8 by the operation of the exhaust air blowing unit 6 as shown in FIG. The exhaust stream 4 passes through the exhaust air passage 4a. When the exhaust stream 4 shown in FIG. 4A passes through the exhaust air passage 14 of the heat exchange element 3, it exchanges heat with the supply air flow 5 passing through the supply air passage 15 of the heat exchange element 3 shown in FIG. Is discharged to the outdoors through the exhaust port 9 shown in FIG.

On the other hand, as shown in FIG. 2, the supply air flow 5 introduces outside air (OA) from the outside air port 10 by the operation of the supply air blowing section 7, and passes through the supply air blowing path 5a. 4B exchanges heat with the exhaust flow 4 passing through the exhaust air passage 14 of the heat exchange element 3 shown in FIG. 4A when passing through the supply air passage 15 of the heat exchange element 3, and then FIG. The air is supplied into the room through the air supply port 11 shown in FIG.

At this time, when the outdoor temperature becomes a low temperature such as −10 ° C. or less, for example, in the heat exchange element 3 through which the warm exhaust stream 4 flows from the room shown in FIGS. The cold supply airflow 5 which is ventilated from the air flows, and the vicinity of the exhaust port 9a of the exhaust air passage 14 is dewed and frozen and clogged.

Here, means for suppressing frost formation in the exhaust air passage 14 which is a feature of the present application will be described with reference to FIGS. 4A and 4B again.

When the outdoor temperature becomes a low temperature such as −10 ° C. or less, the temperature of the exhaust stream 4 flowing through the exhaust air passage 14g closest to the outside air port 10a becomes the lowest. That is, frosting starts from the vicinity of the exhaust port 9a of the exhaust air passage 14g.

In order to increase the temperature of the exhaust flow 4 flowing through the exhaust air passage 14g, the air supply air passage 15g is closed (shaded portion in the figure) as shown in FIG. 4B. For reference, a portion constituting a general normal supply air passage 15g of the air passage rib 13c is indicated by a broken line.

As described above, since the supply air passage 15g is closed, the supply air flow 5 does not flow through the supply air passage 15g. That is, the exhaust air flow 4 flowing through the exhaust air passage 14g does not cause heat exchange with the air supply air flow 5 because the air supply air flow 5 does not flow through the central portion 31 that theoretically has high heat exchange efficiency facing the air supply air flow 5. The temperature drop of the exhaust stream 4 is suppressed.

As a result of analysis of the heat exchange element 3 by thermal fluid analysis, when the supply air passage 15g is closed, the minimum temperature of the exhaust flow 4 flowing through the exhaust air passage 14g is increased by about 3K than the conventional heat exchange element. Was confirmed. This result corresponds to the fact that the outside air temperature at which frost formation occurs is reduced by about 3K.

In the present embodiment, the case where the heat transfer plate 16 is hexagonal as shown in FIGS. 4A and 4B has been described. At both end portions 30 of the exhaust air passage 14 and the supply air passage 15, the exhaust air flow 4 and the air supply air flow 5 are orthogonal or oblique to each other and face each other at the central portion 31 between the both end portions 30. Even a square has the same effect as described above.

As described above, in the present embodiment, in the supply air passage 15, the supply air passage 15g closest to the inside air port 8a of the exhaust flow 4 is closed. Thereby, in the counterflow part of the center part 31 of the exhaust air passage 14g, the exhaust air flow 4 and the supply air flow 5 do not exchange heat, and frost formation in the exhaust air passage 14g is suppressed.

That is, by not performing heat exchange in the counterflow portion of the central portion 31 closest to the outside air port 10a that is most likely to form frost in the exhaust air passage 14, the exhaust flow 4 passes through the counterflow portion without lowering the temperature. it can.

By eliminating the temperature drop in the counterflow portion, even if there is a temperature drop in the cross flow portion that exchanges heat with the supply airflow 5, the total temperature drop from the inside air port 8a to the exhaust port 9a of the exhaust flow 4 is reduced. It is suppressed. Therefore, frost formation in the exhaust air passage 14 is suppressed, and the outside air temperature at which frost formation occurs is reduced, so that the continuous operation time in which the necessary ventilation amount in the room can be secured is lengthened.

FIG. 5A is a conceptual diagram showing a normal state of a different configuration of the heat exchange type ventilator according to the embodiment of the present invention, and FIG. 5B is a concept showing a state of the heat exchange type ventilator with a different configuration when the air passage is closed. FIG. FIG. 6A is a plan view of a normal air supply unit that constitutes an air supply path when different configurations of the heat exchange element of the embodiment of the present invention are disassembled, and FIG. 6B is an exploded view of different configurations of the heat exchange element. It is a top view at the time of the air path closing of the air supply unit which comprises the air supply air path at the time.

The exhaust unit 12 of the heat exchange element 18 shown in FIGS. 5A and 5B has the same shape as the exhaust unit 12 shown in FIG. 4A. However, the air supply unit 13 of the heat exchange element 18 shown in FIGS. 6A and 6B has a shape symmetrical with the exhaust unit 12, unlike the air supply unit 13 shown in FIG. 4B.

As shown in FIGS. 5A and 5B, the heat exchange type ventilation device 17 includes a damper 19 as an air passage closing portion. Moreover, the wind speed sensor 20 as a frost formation judgment part which judges the presence or absence of frost formation, and the microcomputer 21 are provided. The damper 19 is installed on the outside air port 10 side of the heat exchange element 18. As shown in FIG. 5A, the damper 19 is normally held in a state where the air path of the heat exchange element 18 is not closed.

At this time, as shown in FIG. 6A, in the air supply unit 13 of the heat exchange element 18, the air supply air 5 flows through all of the air supply air passages 15a to 15g. For this reason, all of the heat transfer plate 16 excluding the portion of the air passage ribs 13c is used for heat exchange, resulting in high heat exchange efficiency.

As shown in FIGS. 5A and 5B, the wind speed sensor 20 is installed in the exhaust air passage 4a. The wind speed sensor 20 detects the wind speed of the exhaust stream 4 and the microcomputer 21 receives the measured value. When the wind speed of the exhaust flow 4 detected by the wind speed sensor 20 becomes slower than normal, the frosting determination unit determines that “there is frosting”, assuming that the air volume of the exhaust flow 4 has decreased. . Thus, when the wind speed sensor 20 detects a wind speed, it can be judged comparatively correctly whether frosting actually occurred.

In addition, the temperature sensor 22 and the microcomputer 21 may be used as the frost determination unit. In that case, the temperature sensor 22 is provided in the air supply air passage 5a close to the outside air port 10, and the temperature of the air supply air flow 5 close to the outside air is measured. When the value of the temperature sensor 22 is, for example, −10 ° C. or lower, the microcomputer 21 that has received the measurement value determines that “there is frost formation”. By measuring the temperature of the supply airflow 5 close to the outside air by the temperature sensor 22, it can be predicted to some extent whether or not frosting will occur at low cost.

When the frosting determination unit determines that “there is frosting”, the microcomputer 21 issues an instruction to the damper 19. As shown in FIGS. 5B and 6B, the damper 19 closes the inlet of the supply air passage 15 g closest to the inlet side of the exhaust flow 4 in the supply air passage 15 of the heat exchange element 18, that is, held in a closed space. To do. By closing the inlet of the supply air passage 15g, the supply air flow 5 does not flow into the supply air passage 15g. Therefore, the exhaust flow 4 and the supply air flow 5 do not exchange heat in the counterflow portion at the center of the exhaust air passage, and frost formation in the exhaust air passage is suppressed.

As described above, the heat exchange type ventilation device 17 can suppress frost formation in the exhaust air passage by closing the inlet of the supply air passage 15g during frost formation. Further, at normal times, the entire area of the heat transfer plate 16 is used for heat exchange, and high heat exchange efficiency can be realized. Since the heat exchange efficiency at the normal time is high, the air conditioning load due to ventilation of the house 1 is reduced.

The heat exchange element of the present invention and the heat exchange type ventilator using the heat exchange element are useful in cold regions.

DESCRIPTION OF SYMBOLS 1

House

2,17 Heat

exchange type ventilator

3,18 Heat exchange element 4 Exhaust flow 4a Exhaust air flow path 5 Supply air flow 5a Supply air air flow path 6 Exhaust air blower part 7 Supply

air blower part

8, 8a

Interior air hole

9,

9a Exhaust hole

10, 10a

Outside air port

11, 11a Air supply port 12

Exhaust unit

12a, 12b, 13a,

13b Spacing rib

12c, 13c Air passage rib 13

Air supply unit

14, 14a, 14b, 14c, 14d, 14e, 14f,

14g Exhaust air

15, 15 a, 15 b, 15 c, 15 d, 15 e, 15 f, 15 g Air supply air passage 16 Heat transfer plate 19 Damper 20 Wind speed sensor 21 Microcomputer 22 Temperature sensor 30 Both ends 31 Central portion

Claims

Laminating an exhaust unit that forms a plurality of exhaust air passages by providing an interval holding unit that holds a gap on the heat transfer plate and a plurality of air passage ribs, and an air supply unit that forms a plurality of air supply air passages,
The exhaust flow that flows through the exhaust air passage and the supply air flow that flows through the supply air passage intersect at right angles or obliquely at both ends of the exhaust air passage and the supply air passage, and at the central portion between the both ends. An opposing heat exchange element,
The heat exchange element characterized in that the supply air path closest to the inlet side of the exhaust flow among the plurality of supply air paths is a closed space.
A heat exchange type ventilator using the heat exchange element according to claim 1.
An exhaust blower,
An air supply section;
An air supply unit in which a plurality of air supply passages are formed by providing a plurality of air supply air passages by providing a plurality of air passage ribs provided in parallel and at equal intervals to a space holding portion for holding a space in the heat transfer plate. Laminating the unit,
The exhaust flow that flows through the exhaust air passage and the supply air flow that flows through the supply air passage intersect at right angles or obliquely at both ends of the exhaust air passage and the supply air passage, and at the central portion between the both ends. An opposing heat exchange element;
A frost determination unit for determining the presence or absence of frost;
When the frosting determination unit determines that there is frost, an airway closing unit that closes the supply airway closest to the inlet side of the exhaust flow among the plurality of supply airways is provided. Heat exchange type ventilation equipment characterized by