JPS6219634A - Freezing prevention device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] Equipment that uses outdoor air and indoor air, such as a ventilation system that supplies and exhausts indoor and outdoor air via a heat exchanger, etc. The present invention relates to an antifreeze device.

[Conventional technology]

Figures 8 to 1) show a conventional heat exchanger wedge-shaped ventilation system similar to that shown in, for example, Japanese Utility Model Publication No. 54-42125, with Figure 8 being a longitudinal sectional view and Figure 9 being a longitudinal sectional view. An enlarged perspective view of the end face of the heat exchanger, tigta is a configuration diagram.

Figure 1) is an explanatory diagram of ice formation.

In the figure, (1) is the main body of the ventilation system as a device that uses indoor air and outdoor air, and the outer box of the T2+Fi main body (1).

(2a) is an outside air inlet provided on the side of the outer box (2).

(2b) is the same air outlet, (2c) is the same indoor air suction port, (2a) is the same air outlet, and (3) is the heat exchanger housed inside the outer box (2), which is made of many corrugated plates. (3
a) and a large number of flat plates (3b) having moisture permeability and heat conductivity are alternately laminated, and the corrugated plates (3a) are formed into a prismatic shape by alternately interposing the corrugated plates (3a) with their waveform forming direction changed by 90 degrees. The outer box (21) is placed sideways in the center and 45
It is installed at an angle. (4) is an air filter 151ti provided on the supply air inflow side of the heat exchanger (3), and a companion air filter also provided on the exhaust air inflow side.

(6) is a supply air blower installed on the outflow side of the supply air of the heat exchanger (3), (7) is also an exhaust blower installed on the outflow side of exhaust air, A is the supply air flow, B is the exhaust flow.

A conventional heat exchange type ventilation system is constructed as described above, and outside air is sucked in through the suction port (2a) by the rotation of the air supply blower (6), as shown by airflow A, and passed through the air filter (4).
) and the heat exchanger (3), and is blown into the room through the air outlet (2b) fib. In addition, as shown by airflow B, indoor air is circulated through the suction port (2c) by the rotation of the exhaust blower (7).
), air filter (5) and heat exchanger (
3) It is blown out from the air outlet (2d) to the outside in t-way. In this way, heat exchange takes place between the supply air and the exhaust air.

[Problem that the invention seeks to solve]

In the heat exchange type ventilation system as described above, when the ventilation system is used in a cold region, the supply air flow A generally becomes a low temperature air flow, and the exhaust flow B becomes a high temperature air flow.

When the supply air flow A is at a low temperature (below -5C), the exhaust air flow B is transferred to the heat exchanger (31) at the part (3A) close to the inlet.

Due to the cooling caused by the supply air flow A, condensation, frost or ice formation occurs. Therefore, the heat exchanger (3) becomes clogged and the exhaust stream B no longer flows near it. As a result, 1 part (3
Since there is no heat exchange in the vicinity of A), the vicinity of the adjacent part (3B) is cooled the most by the air supply flow A in the primary order, and ice formation occurs. Therefore, if the operation continues in this state, the parts adjacent to part (3B) will begin to freeze.

Eventually, the entire area freezes, and exhaust air and heat exchange are no longer performed.

In order to prevent such ice formation and the resulting functional deterioration, if conditions occur where the heat exchanger (31) freezes, a temperature detector and timer are used to intermittently turn on the supply air blower (6).
) All operations are stopped and only the exhaust blower (7) is operated to melt any ice that has formed.

However, in this case, the following first-order problem occurs.

(7) If only exhaust operation is used, the balance of indoor air will be disrupted,
Cold air intrusion occurs because air is drawn in from elsewhere in the room.

ii) As a result of the above, the indoor pressure will become negative, so exhaust-type combustion appliances (pot-type kerosene stoves, gas furnaces, etc.)
There is a risk of abnormal combustion.

(b) 1st) If the area (3A) in the diagram is clogged with ice, indoor air will not be able to pass through it.

There is no heat and the ice is not sufficiently melted.

In addition, as another means, a heating element is installed on the low temperature air (outside air) side to preheat the low temperature air to a temperature (below OC) at which ice does not form on the heat exchanger (31). However, this requires a lot of energy.Se1) For example, indoor temperature 20C, outside temperature -15C - ventilation air volume 50C.
Assuming 0m/hour, to raise the temperature of -15C air to OC, the weight of the air is 1.2 kg 7m, and 1
5XQ, 24X500X1.2:2J 60 Kcal
7 o'clock heat is required, and to raise the temperature with a heating element, approximately 2.5 ff 7 o'clock electric power is required. In addition, when the temperature exchange efficiency of this equipment is 10%, the amount of heat exchanged with the air heated to Oc is 2.016 Kcal 7
The time error also becomes large, and the efficiency of energy saving becomes poor.

In this way, a lot of energy is required to prevent the heat exchanger (3) from being degraded or damaged due to freezing. Also,
The heat exchanger (
When melting the ice in item 31, it is difficult to completely melt it, and the room becomes negative pressure during defrosting operation, which causes problems such as cold air entering and abnormal combustion of indoor combustion appliances. There is.

This invention was made in order to solve the above-mentioned problems, and an object of the present invention is to provide an anti-freeze device that can melt ice with less energy even under low-temperature conditions where the heat exchanger is frozen. do.

However, another object of the present invention, in addition to the above object, is to provide an antifreeze device that can automatically perform an accurate thawing operation.

[Means for solving problems]

The anti-freeze device for a ventilation system according to the present invention has a low-temperature air inlet for introducing outside air, a high-temperature air inlet for introducing indoor air, and an antifreeze device for equipment that uses indoor air and outdoor air, on the wall of a single box. and an air outlet for supplying outdoor air, respectively, and an air flow path is provided in the two box bodies, and the air flow path is provided in the air flow path to selectively close the low temperature air inlet and the high temperature air inlet. It is equipped with a damper and a heating element that is provided near the air outlet of the air flow path and heats the air in the air flow path.

Further, the anti-freeze device for a ventilation system according to another invention of the present invention is provided in the vicinity of the low-temperature gust inlet, detects the temperature of the outside air, and operates when the temperature of the outside air is detected as a predetermined low temperature. A detector is provided, and a control device is provided which, when the @degree detector operates, gives a command to the damper to close the low-temperature air inlet at regular intervals, and also energizes the heating element at regular intervals. .

[Effect]

In this invention, the low-temperature air inlet is closed by the operation of the damper, and the high-temperature air inlet is opened to introduce high-temperature air, which is then heated by the heating element and supplied from the air outlet.

In another aspect of the present invention, when the outside air temperature reaches the freezing temperature, high temperature air is intermittently introduced, heated and supplied.

〔Example〕

Figures 1 to 5 rf! J is a diagram showing an example in which this invention is used to prevent freezing of a simultaneous air supply and exhaust type ventilation system.
Figure 1 is a block diagram of only the antifreeze device, Figure 2 is a diagram of the configuration when used in a ventilation system, Figure 3 is a diagram explaining the operation, Figure 40
and FIG. 5 is a characteristic curve diagram, showing fll to +21.
(2a) to (2d), [31-(3A), (3B)
, (61°(7)・A and B are the same as the above-mentioned conventional device.

In the figure, (9) is placed on the suction side of the main body (1), and has a nine-box shape with an air flow path formed inside the warehouse. (9a) is a box (
9) and opens to the outside air.
) is a high temperature air inlet opening on the indoor side, (9c
) is also the air outlet, and the air outlet (9C) is the main body (
1) is connected to the suction port (2a). αa is a box (
Air inlet ports (9a), (9b)'f pivotally connected to 9): dampers that open and close.

αυ is a heating element provided near the air outlet (9C) of the box (9). αη is a damper (IG drive mechanism).

In the anti-freezing device for the ventilation system configured as described above, as shown in Fig. 1, the t-damper (IQ is normally open with the low-temperature air inlet (9g) open and the high-temperature air inlet (9b)'
i It's blocked. Therefore, as shown by airflow A, low-temperature air enters the box body (9) from the low-temperature air inlet (9a), passes through the air outlet (9C) to the suction port (2a), and is supplied to the main body (1). be done. The subsequent operation is the same as the conventional one.

Next, the low-temperature air temperature is low and ice forms on the heat exchanger (3). Next, the damper (IQ) rotates, and the low-temperature air inlet (9a) is blocked as shown in Figure 3, and the high-temperature air The inlet port (9b) is opened.At the same time, the heating element (Iυ) is energized.The damper unit is driven by an electric motor (not shown), but may also be operated manually. If you stop the ventilation & (71?), you can prevent outside wind from entering.

The high temperature air is now flowing from the high temperature air inlet (9b) to the box body (
9), is heated by the heating element αυ, and then passes through the air outlet (9C
) is supplied to the low temperature side flow path of the main body (1). As a result, high-temperature air flows through the flow path in the heat exchanger (3) where low-temperature air normally flows.

The ice formed in the high temperature side flow path is melted.

After the ice melts, the damper (IG) rotates in the opposite direction to the state shown in Figures 1 and 2, and at the same time, the current to the heating element αυ is cut off.

FIG. 4 shows the outside air temperature -tsc in the apparatus of this embodiment.
The curve az represents the relationship between the indoor temperature and the time until freezing starts for case o, and the song [a3'! (Show. Also.

Figure 5 shows the time it takes to switch to thawing operation to completely thaw the ice when ice has formed until the airflow rate has decreased by approximately 30 cm, and the amount of time it takes to completely melt the ice by switching to thawing operation. Shows the relationship with air temperature.

As is clear from Figures 4 and 5, the indoor temperature does not have a large effect on the time it takes for ice to start forming or for the air volume to drop by 30 inches. This has a large effect on the melting time of the ice. Therefore, if the heating element αυ is modified to raise the temperature of the air supplied to the heat exchanger (3: 1200 or higher), the ice can be melted in a short time. .

As an example, consider a device with a room temperature of 10C9 treated air of 31,500 m/hour and a heat exchange efficiency of 70%.

Assume that thawing operation is started with an air flow rate of 30% or less.

It takes about 12 minutes to thaw, and during this time the exhaust blower is stopped and circulation operation is started, making ventilation impossible.

Or, ventilation is insufficient due to exhaust only. Here, 2
When a KW heating element αυ is installed and energized, the temperature of indoor air from 10C is raised to 122C and supplied to the heat exchanger (31), so thawing is possible within 4 minutes.The power consumption in this case is: If you turn on the power for 4 minutes once every 1 hour and 30 minutes, 0.
081 KW/hour, making it possible to operate with much less electricity than conventional preheating systems.

In addition, during thawing operation, the exhaust blower (7) is completely stopped in conjunction with the ventilation system, the damper αl) is switched, and the heating element Qυ
By energizing the system and reducing the amount of air in the supply air flow path by narrowing the high-temperature flow path, the thawing time will be shortened and the ventilation stop time will be shortened, assuming the capacity of the heating element aυ is the same as the conventional device. It becomes possible to do so.

The amount of air blown at this time may be controlled by changing the capacity of the blower motor or by changing the area of the air duct.

The 80th and seventh cause is a configuration diagram of a damper portion showing another embodiment in which this emission 8A is applied to a ventilation system in the same manner as the previous embodiment.

In FIG. 6, a temperature detector αS is installed in the low temperature air inlet (9a) to detect the temperature (preset) at which the heat exchanger (3) freezes. When this produces an output, the control device 00 operates, The drive mechanism αη moves the damper α (once), energizes the heating element aυ, maintains this state for a certain period of time, and then switches the damper ati′t- to normal operation and stops the energization of the heating element. This process is repeated intermittently at predetermined time intervals.This allows accurate defrosting operation to be performed automatically.

Figure 7 shows the temperature detector α for the 6th factor! 9 is placed on the upstream side of the heater (1)), and the damper (is placed in a position where the high temperature air temperature can be detected when the IG is activated, and the indoor temperature is detected the next time the thawing operation starts, and the indoor temperature is High enough (e.g. 20
0 or higher), when the temperature is such that it can be thawed in a short time,
The heating element αυ is not energized. This saves power when the indoor temperature is high, resulting in further energy savings.

In addition, although the damper GI was explained as one plate-like object,
Low temperature air inlet (9a) and high temperature air inlet (9b)t
- Other types of mechanisms (as long as they can be opened and closed)
(slide type, butterfly type) may be used.

In each of the above embodiments, a cross-flow type heat exchanger (3) is used, but a 9-turn type, a counter-flow type, etc. may also be used.
Similarly applicable.

Furthermore, in the embodiment, a ventilation device was explained.

It can also be applied to other equipment such as air conditioners that use indoor air and outdoor air.

〔Effect of the invention〕

As explained above, the heat exchanger wedge type ventilation system of the present invention has the effect of melting ice that occurs when equipment that uses outdoor air and indoor air is used at low temperatures in a short time.

In another invention of the present invention, a temperature detector is provided to detect the outside air temperature, and when the temperature detector detects a predetermined temperature, the damper is operated at regular intervals and the heating element is energized, so that accurate This has the effect of automatically performing a defrosting operation.

[Brief explanation of drawings]

1 to 5 are diagrams showing an embodiment of the antifreeze lid for a ventilation system according to the present invention, where FIG. 1 is a block diagram and FIG. 2 is a diagram of the construction when applied to a ventilation system. FIG. 3 is an operation explanatory diagram, FIG. 4 is a freezing time characteristic curve diagram, FIG. 5 is also a melting time characteristic curve diagram, and FIGS. 6 and 7 are configurations of damper portions showing other embodiments of the present invention. Figure, 8th
Fig. 1) shows a conventional heat exchanger wedge type ventilation system, Fig. 8 is a longitudinal sectional view, Fig. 9 is an enlarged end view of the heat exchanger, and Fig. 1
Figure 0 is a configuration diagram. Figure 1) is an explanatory diagram of ice formation. In the figure, (1) is the main body of the ventilation system, (2a) is the low temperature air inlet, (2c) is the high temperature air inlet, (3) is the heat exchanger, (9) is the box, (9a) is the low temperature Air inlet, (9b) is high temperature air inlet, (9c) is air outlet, aα is damper, α1JIfi heating element, α5 is temperature detector, (IeV'i control device. Note that the same reference numerals in Figure 1) indicates the same or equivalent part.

Claims (2)

[Claims] (1) A low-temperature air inlet that introduces outside air into the box wall,
A high-temperature air inlet that introduces indoor air and an air outlet that supplies outdoor air to equipment that uses outdoor air and indoor air are provided, and an air flow path is provided inside the box body. a damper provided therein to selectively close the low-temperature air inlet and the high-temperature air inlet, and a heater provided near the air outlet of the air flow path to heat the air in the air flow path. Freeze prevention device. (2) A low-temperature air inlet that introduces outside air into the box wall, a high-temperature air inlet that introduces indoor air, and an air outlet that supplies outdoor air to devices that use outdoor air and indoor air. an air flow path is provided in the box body, a damper is provided in the air flow path and selectively closes the low temperature air inlet and the high temperature air inlet, and an air guide for the air flow path is provided. a heating element provided near the outlet to heat the air in the air flow path; a temperature detector provided near the low-temperature air inlet to detect the temperature of the outside air and operate when it detects a predetermined low temperature; An anti-freeze device comprising: a control device that issues a command to the damper to close the low-temperature air inlet at regular intervals when a detector operates, and also causes the heating element to be energized at regular intervals.