JPH09264547A - Anti-freezing device in forced circulating circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a power loss and frequent occurrence of noise caused by a unrequired repetition of an anti-freezing operation by a method wherein a rest time in consideration of a temperature of water staying in a forced circulating circuit is applied for performing an anti-freezing operation. SOLUTION: When an operation switch 331 is in its closed state, a temperature of surrounding atmosphere detected by a surrounding atmosphere temperature sensor 15 is decreased to a value less than 3 deg.C, resulting in that a controlling operation is performed and an operation of a pump P and a weak combustion of a gas burner 22 are continued for a set time and then entire accumulated water in the forced circulating circuit 23 is heated to increase its temperature. Then, a rest time is determined in response to a table in which a time required up to an occasion in which accumulated water in the forced circulating circuit 23 is frozen under a condition of specified accumulated water temperature and a specified surrounding atmosphere temperature is calculated in advance in an experimental manner. That is, a micro-computer performs a controlling operation such that as the surrounding atmosphere temperature detected by the surrounding atmosphere temperature sensor 15 is increased, the rest time is extended even if the temperature of the accumulated water to be detected by the water temperature sensor 24 is kept same and further the rest time is extended as the temperature of the accumulated water is increased even if the surrounding atmosphere temperature is kept at the same value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for preventing freezing of a forced circulation circuit such as a hot water circulation circuit for hot water supply and heating or a bath reheating circuit.

[0002]

2. Description of the Related Art As a floor heating apparatus for supplying hot water to a heat radiation mat laid on the floor of a room, there is one having a schematic structure shown in FIG. 1, for example. Circulation heating device (1) casing
Inside the (11), there is provided a heat exchanger (21) heated by a gas burner (22) which is a heat source.

The heat exchanger (21) and the heat dissipation mat (32) laid on the floor of the room (31) are a forced circulation circuit (23) in which hot water flows.
A pump (P) and a water temperature sensor (24) are provided near the heat exchanger (21) in the forced circulation circuit (23). Further, a gas valve (26) is provided in the gas circuit to the gas burner (22) that heats the heat exchanger (21), and an ignition device (25) is arranged near the gas burner (22). The ignition device (25) and the water temperature sensor (2
4) Furthermore, the outside air temperature sensor required for freeze prevention operation described later.
(15) and the like are connected to the control device (41).

In this case, when the operation switch (331) of the remote control device (33) arranged on the wall surface of the room (31) is operated, the gas valve (26) is opened and the ignition device (25) is opened. Is activated and the gas burner (22) burns, while the pump (P) is activated. As a result, the hot water generated in the heat exchanger (21) is heated by the heat exchanger (21) → the water temperature sensor (24) → the heat dissipation mat (32) of the room (31) → the pump (P) → the heat exchanger ( The heating operation proceeds by being forcedly circulated through the route of 21).

On the other hand, in this type of floor heating apparatus, there is a risk that the forced circulation circuit (23) in the heating stopped state may be frozen in the cold season of winter, particularly in the portion exposed to the outside air. Therefore, many of the floor heating systems of this type have a built-in anti-freezing function. Specifically, the circulation heating system (1) is activated every predetermined rest time (B) determined according to the ambient temperature. Things are known. That is, as shown in step (ST1) of FIG. 6, the outside air temperature detected by the outside air temperature sensor (15) is determined, and as the outside air temperature decreases, 30 minutes, 20 minutes, 1
Set the rest time (B) so that it becomes gradually shorter as 0 minutes (see step (ST1)).

Then, in step (ST2), the gas burner (22)
The low-pressure combustion (for example, a constant input of 2000 Kcal / h) and the operation of the pump (P) are continued for 3 minutes to warm the water in the forced circulation circuit (23), and then set according to the ambient temperature. After waiting for the rest time (B) (step (ST3)), the control operation is returned to the first step for detecting the outside temperature again.

In this system, the freeze prevention operation is intermittently executed at every rest time (B) determined in consideration of the outside temperature.
It is possible to avoid the inconvenience of wasteful consumption of gas and electricity such as the case where the operation of the gas burner (22) or the pump (P) is continued for a long time until the outside air temperature rises above the freezing temperature of water.

[0008]

However, in the above-mentioned conventional one, the temperature of water staying in the forced circulation circuit (23) is high because the rest time (B) is determined only based on the outside temperature. In this case, the freeze prevention operation is repeated more than necessary. That is, the total length of the forced circulation circuit (23) changes depending on the size of the heat dissipation mat (32), etc., and during the freeze prevention operation in which the operation of the pump (P) and the combustion of the gas burner (22) are continued for 3 minutes, the forced circulation is performed. The shorter the total length of the circuit (23), the more the accumulated water circulates in the forced circulation circuit (23) in the three minutes. Therefore, the shorter the total length of the forced circulation circuit (23), the larger the temperature rise amount of the accumulated water due to one antifreezing operation (burner combustion for 3 minutes, etc.) and the higher the temperature. The higher the temperature of the accumulated water, the longer the time required for the accumulated water to cool to the freezing temperature, and thus the longer the time until the next freeze prevention operation is required. However, in the above-mentioned conventional one, since the pause time (B) until the next antifreezing operation is executed is determined based on only the outside temperature, the temperature of the water staying in the forced circulation circuit (23) is determined. Is high (when it takes a long time to cool to the freezing temperature), the antifreezing operation is repeated more than necessary. If the anti-freezing operation is repeated more than necessary, power for operating the pump (P) is wasted, and noise due to the operation of the pump (P) is frequently generated.

A method of determining the rest time (B) based only on the water temperature detected by the water temperature sensor (24) is conceivable. In this case as well, the water temperature is low even though the outside temperature is high and there is no possibility of freezing. And the freeze time (B) of the anti-freezing operation is set to be short, and there are the same problems as above. In the above description, the problems relating to the floor heating device are described as an example.
Even in the bath reheating device in which (1) and the inside of the bathtub are connected by the forced circulation circuit (23), there is the same problem as above with respect to the prevention of freezing of the forced circulation circuit (23). Then, in the case of such a reheating device, since a relatively large amount of high-temperature water may be stored in the bathtub, the pump for circulation is used for the rest time while maintaining the gas burner for reheating in a fire extinguishing state.
Even if each (B) is operated intermittently, the anti-freezing effect in the forced circulation circuit (23) can be obtained.

The present application has been made in view of the above points.
The anti-freezing operation is performed by using the down time (B) that considers the temperature of the water that stays in the forced circulation circuit (23), thereby avoiding the disadvantage that the anti-freezing operation is repeated more than necessary. The task is to

[0011]

The technical means of the invention according to claim 1 for solving the above-mentioned problems is "a pump (P), a water temperature sensor (24), and a heat exchanger ( 21) The forced circulation circuit (23), the outside air temperature sensor (15) that detects the outside air temperature, and the detected temperature of the outside air temperature sensor (15) drops below the reference temperature at which water may freeze. Is a pump control circuit that repeats the freeze prevention operation that activates the pump (P) for each set time, every pause time (B), and further shortens as the temperature detected by the outside air temperature sensor (15) decreases. ,
In addition, the pause based on both the detection temperature of the outside air temperature sensor (15) and the detection temperature of the water temperature sensor (24) is set so that the temperature decreases as the detection temperature of the water temperature sensor (24) decreases after the freeze prevention operation. It has a pause time setting circuit for setting the time (B). "

According to the above means, when the temperature detected by the water temperature sensor (24) is high after the freeze prevention operation of operating the pump (P) for a predetermined time, the accumulated water in the forced circulation circuit (23) is frozen. Since a comparatively long time is required, in such a case, the quiescent time setting circuit sets a long quiescent time (B), whereby the antifreezing operation is repeated for each comparatively long quiescent time (B). On the other hand, when the temperature of the water staying in the forced circulation circuit (23) is low and there is a risk of freezing at an early stage, the pause time setting circuit sets a short pause time (B). The frequency of execution increases and the freezing is reliably prevented.

When the outside air temperature detected by the outside air temperature sensor (15) becomes low, the inside of the forced circulation circuit (23) is likely to freeze quickly. In such a case, the downtime is the same as the conventional one. (B) becomes shorter, and the antifreezing operation is repeated at relatively short time intervals. Further, when the outside air temperature rises, there is less concern about the freezing. Therefore, in this case as well, the frequency of the antifreezing operation is reduced as in the conventional case.

Particularly, as in the invention of claim 2, the "pump
(P) operates to heat the circulating water in the forced circulation circuit (23) with a heat source, the temperature of the water in the forced circulation circuit (23) will rise when the antifreezing operation is performed, The pause time (B) determined based on the output of the water temperature sensor (24) for detecting the water temperature, that is, the pause time (B) until the next antifreezing operation is executed becomes long.

[0015]

As described above, according to the invention of claim 1, the pause time (B) is determined based on both the temperature of the accumulated water in the forced circulation circuit (23) and the outside air temperature. The rest time is based only on the outside temperature or only the temperature of the accumulated water.
The inconvenience that the anti-freezing operation is repeated more than necessary is less than that in the case of determining (B). That is, it is possible to prevent wasteful consumption of electric power for operating the pump (P) and reduce the frequency of noise generation due to frequent operation of the pump (P).

Particularly, according to the invention of claim 2, the down time
Since (B) is lengthened, the frequency of noise generation due to the operation is further reduced.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The antifreezing device according to this embodiment is the one in which the invention is applied to a floor heating device as in the conventional device described above. Circulation heating device (1) and heat dissipation mat (3
2) and the forced circulation circuit (23) that connects these two are shown in Fig. 1 above.
It is constructed similar to that of.

A control device (41) for controlling the circulation heating device (1)
A microcomputer in which a control program having the contents shown in the flowchart of FIG. 2 is stored is incorporated therein, and further, the table shown in FIG. 3 is stored in the microcomputer. The table of FIG. 3 is based on the outside air temperature (A0) detected by the outside air temperature sensor (15) and the accumulated water temperature (A1) in the forced circulation circuit (23) detected by the water temperature sensor (24). ) Makes it possible to select. For example,
When the outside air temperature (A0) is less than -10 ℃, the accumulated water temperature (A
When 1) is 50 ° C or higher, 25 minutes (top row) is selected as the rest time (B).

Specific pause times shown in the table of FIG.
(B) is the accumulated water in the forced circulation circuit (23) under the conditions of the specific accumulated water temperature (A1) described in the left column and the specific outside air temperature (A0) further described in the left column. Is the time it takes for the ice to freeze, and has been experimentally determined. The rest time (B) may be set to be slightly shorter than the time shown in FIG. This is to be careful to prevent freezing in the forced circulation circuit (23).

Next, the actual operation of the floor heating system according to this embodiment will be described with reference to FIG. When it is confirmed in step (ST10) that the operation switch (331) of the remote control device (33) arranged in the room (31) is turned on, step (ST11)
The pump (P) is operated and the gas burner (22), which is a heat source, is maintained in a combustion state. The gas burner (2
The combustion of 2) is started by opening the gas valve (26) and spark discharge from the ignition device (25) to the gas burner (22). Also, a water temperature sensor that detects the temperature of the hot water flowing out from the heat exchanger (21).
The opening of the gas valve (26) is controlled so that the output of (24) becomes equal to the temperature set by the temperature setting knob (332).
The amount of combustion in (22) is controlled, and as a result, the heating operation continues.

Next, in step (ST12), the operation switch (331)
When the OFF operation of is confirmed, the gas burner (22) is extinguished and the pump (P) is stopped in step (ST13) to end the heating operation. Next, the freeze prevention operation will be described. When the outside air temperature detected by the outside air temperature sensor (15) falls below 3 ° C. (corresponding to the reference temperature of the invention of claim 1) when the operation switch (331) is in the OFF state, step (ST15)- The control operation shifts to step (ST18), the operation of the pump (P) and the low-burn combustion of the gas burner (22) (for example, 20
A fixed input of 00 Kcal / h) is the set time, eg 3
This is continued for a minute, whereby the entire accumulated water in the forced circulation circuit (23) is heated and heated. Next, step (ST19) is executed, and the rest time (B) is determined based on the table of FIG. That is, referring to FIG. 3, when the outside air temperature (A0) detected by the outside air temperature sensor (15) becomes high, the table shows that the water temperature sensor
Even if the accumulated water temperature (A1) detected by (24) is the same, the rest time (B) is extended, and the outside temperature (A
It can be understood that even if the value (0) is the same, the rest time (B) becomes longer as the accumulated water temperature (A1) becomes higher.

Therefore, when the accumulated water temperature (A1) detected by the water temperature sensor (24) is high after the combustion of the gas burner (22) and the freeze prevention operation of operating the pump (P) are performed, that is, the forced circulation circuit. If the time required to freeze the inside of (23) is long, even if the outside air temperature (A0) detected by the outside air temperature sensor (15) is the same, there is a relatively long down time (B) from the table in FIG. If the temperature detected by the water temperature sensor (24) is low, on the contrary, it may freeze early, so a relatively short down time
(B) is selected. Also, when the outside air temperature detected by the outside air temperature sensor (15) is high, it takes a long time for the forced circulation circuit (23) to freeze, so the accumulated water temperature (A1) detected by the water temperature sensor (24) A relatively long downtime, even if
(B) is selected. Conversely, when the outside air temperature (A0) detected by the outside air temperature sensor (15) is low, a relatively short down time (B) is selected.

Next, step (S) is executed until the rest time (B) determined based on the outside air temperature (A0) and the accumulated water temperature (A1) elapses.
After waiting at T20), the control operation is returned to the step (ST10) of monitoring the operation of the operation switch (331).
In this embodiment, in FIG. 2, the functional unit in the microcomputer that executes the instructions of step (ST16) to step (ST18) and step (ST20) for intermittently operating the pump (P) is claimed. The functional unit in the microcomputer, which corresponds to the pump control circuit described as the invention specifying matter of the first aspect of the invention and executes the step (ST19) as an instruction to select the pause time (B) from the table of FIG. The invention corresponds to a pause time setting circuit which is an item specifying the invention.

In the above embodiment, the gas burner (22) is burned with a low flame in synchronization with the operation of the pump (P) during the antifreezing operation, but the pump (P) is maintained with the gas burner (22) kept in the extinguished state. Only P) may be activated. The room (31) may be relatively warm, and in such a case the accumulated water in the heat dissipation mat (32) laid on the floor of the room (31) is relatively warm. This is because if it is circulated in (23), it can be prevented from freezing.

The embodiment shown in FIGS. 4 and 5 is one in which the invention of the present application is applied as an antifreezing device for a reheating circuit of a bath device, and is the same as each component constituting the floor heating device of FIG. Alternatively, corresponding parts are given the same reference numerals. FIG.
As shown in Fig. 5, the bath (51) and the circulation heating device (1) are connected by the forced circulation circuit (23), and the heat exchanger (21) inserted in the forced circulation circuit (23) is connected to the upstream side. Is equipped with a pump (P), a water temperature sensor (24), and a water flow switch (27). The gas valve (26) inserted in the gas circuit to the gas burner (22) for heating the heat exchanger (21), the water temperature sensor (24), and the like are connected to the control device (41). In addition, the control device (4
An outside temperature sensor (15) for detecting the outside temperature is connected to 1).

A control program having the contents shown in the flow chart of FIG. 5 is stored in the microcomputer incorporated in the control device (41). Hereinafter, the freeze prevention operation of the bath device according to the present embodiment will be described with reference to the flow chart. It will be described based on. When the outside air temperature detected by the outside air temperature sensor (15) falls below 3 ° C (step (ST21)), step (ST22)
Then, the pump (P) is started, and then the output of the water flow switch (27) is judged in step (ST23). If the water flow switch (27) outputs the ON signal, it remains in the bathtub (51). Since it can be seen that hot water is stored, in this case step
In (ST24), wait for the set time of 3 minutes. Then, during this waiting time, the remaining hot water in the bathtub (51) is replaced with the cold water staying in the forced circulation circuit (23), and the relatively high temperature remaining in the forced circulation circuit (23). The water is full. Next, in step (ST25), the pump (P) is stopped, and then the rest time (B) as the time during which the pump (P) should be maintained in the stopped state is calculated.

In the present embodiment, the rest time (B) is the rest time (B) = accumulated water temperature (A1) + K / (1 + | outside air temperature (A0) |) (outside air temperature (A0) <0 ° C. Applied when) is determined by the arithmetic expression. When the outside temperature is ≧ 0 ° C., for example, it is good to obtain “rest time (B) = accumulated water temperature (A1) + K × outside temperature (A0). Therefore, the freeze prevention operation for operating the pump (P) is performed. The accumulated water temperature (A
Outside temperature (A0) detected by the outside temperature sensor (15) when 1) is high
Is high, that is, when the time required for freezing of the forced circulation circuit (23) is long, the pause time (B) obtained by the above calculation becomes long. On the contrary, if the accumulated water temperature (A1) or the outside air temperature (A0) becomes low, the forced circulation circuit (23) may freeze early. (B) becomes shorter.

Next, the rest time obtained as a result of the above calculation
Wait until the time (B) has passed (step (ST27)),
After that, the control operation is returned to the step (ST21) of determining the outside air temperature. In the bath device shown in FIG. 4, when the freeze prevention operation is executed, the gas burner is synchronized with the operation of the pump (P).
You may burn (22).

In the bath apparatus shown in FIG. 4, when a reheating switch (not shown) is operated, the gas burner (22) burns and the pump (P) operates to forcibly reheat the bath (51). When the temperature detected by the water temperature sensor (24) reaches the temperature set in the hot water temperature setter (not shown), the pump (P) and gas burner
(22) stops. The reference temperature of the outside air temperature can be arbitrarily set as long as it is a temperature that may freeze water.
In order to reliably prevent freezing, a higher temperature is desirable with respect to the freezing temperature of water, which is 0 ° C. Further, the set time of the antifreezing operation is not limited to 3 minutes described in the above-mentioned embodiment, and the water at the outlet of the heat dissipation mat (32) or the bathtub (51) in the forced circulation circuit (23) is circulated by the circulation heating device ( 1) Pass through the heat dissipation mat again (32)
Alternatively, it may be longer than the time required to return to the bathtub (51).

[Brief description of drawings]

FIG. 1 is an overall schematic diagram showing an embodiment in which the invention of the present application is applied to a floor heating system.

FIG. 2 is a flowchart for explaining the operation of the floor heating system shown in FIG.

FIG. 3 is a table showing the relationship between the outside air temperature (A0), the accumulated water temperature (A1), and the rest time (B) stored in the microcomputer incorporated in the control device (41) of the floor heating system of FIG.

FIG. 4 is an overall schematic diagram showing an embodiment in which the invention of the present application is applied to a bath device.

5 is a flow chart for freeze prevention control in the bath apparatus of FIG.

FIG. 6 is an explanatory view of a conventional example.

[Explanation of symbols]

 (15) ・ ・ ・ Outside temperature sensor (21) ・ ・ ・ Heat exchanger (23) ・ ・ ・ Forced circulation circuit (24) ・ ・ ・ Water temperature sensor (P) ・ ・ ・ Pump

Claims (2)

[Claims] 1. A forced circulation circuit (2) comprising a pump (P), a water temperature sensor (24) and a heat exchanger (21) heated by a heat source.
3), the outside air temperature sensor (15) that detects the outside air temperature, and the outside air temperature sensor (1) below the reference temperature where water may freeze.
When the temperature detected in 5) drops, pump (P) for the set time.
The pump control circuit that repeats the anti-freezing operation that activates at every rest time (B), and further shortens as the temperature detected by the outside air temperature sensor (15) decreases, and Water temperature sensor (24)
A pause time setting circuit that sets the pause time (B) based on both the temperature detected by the outside air temperature sensor (15) and the temperature detected by the water temperature sensor (24) so that the temperature decreases as the detection temperature decreases. An anti-freezing device for the forced circulation circuit provided. 2. A forced circulation circuit (23) when the pump (P) is operating.
The anti-freezing device for a forced circulation circuit according to claim 1, wherein the circulating water is heated by a heat source.