JPH07172148A - Hot water circulating-type heating device - Google Patents

Abstract

PURPOSE:To enable the temperature unevenness of a radiator to be decreased even when the flow rate of hot water to be fed into the radiator is small by a simple device not costly. CONSTITUTION:In a hot water circulating-type heating device wherein a radiator 3 is connected on the way of lines 4, 5 through which hot water is circulated, and the heating capacity is controlled by changing the flow rate of hot water to pass the radiator 3, heat exchanging is performed between a water feeding line 4 for feeding hot water into the radiator 3 and return line 5 for feeding out water from the radiator 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water circulation type heating device, such as a heating device for automobiles, in which a radiator is connected in the middle of a conduit for circulating hot water.

[0002]

2. Description of the Related Art In recent years, a so-called air mix system is used in a heating system for an automobile, in which the heating capacity is controlled by controlling the flow rate of air flowing through the radiator without controlling the flow rate of hot water flowing through the radiator. It is the mainstream.

However, in this method, the flow of air flowing through the radiator and the flow of air bypassing the radiator are controlled by a large mix door, so that it is necessary to secure a space necessary for the mix door to rotate. The disadvantage is that the device takes up a large space.

On the other hand, if the method of controlling the heating capacity by controlling the flow rate of hot water passing through the radiator is adopted, the apparatus can be made much smaller than the air mix method.

In such a hot water circulation type heating device,
When the flow rate of hot water is reduced to reduce the heating capacity, only the hot water inlet part of the radiator has a high temperature, and when it goes a little inside, the water temperature drops sharply.

[0006] Such temperature unevenness becomes extreme as the heat exchanging performance of the radiator becomes better. However, in a heating system for an automobile or the like, air is blown out into a vehicle compartment from a plurality of outlets at the same time. If there is uneven temperature on the surface of the radiator, there will be a difference in the temperature of the air discharged from each outlet.

Therefore, conventionally, for example, Japanese Patent Laid-Open No. 5-2212 is used.
As shown in No. 34, a forced circulation pipe line was provided in which a part of the water discharged from the hot water outlet of the radiator was directly returned to the hot water inlet of the radiator and fed again into the radiator.

By forcibly circulating a part of the water in such a manner, even when the flow rate of the hot water sent from the engine side to the radiator is small, a certain amount or more of hot water flows in the radiator, and It is possible to suppress the occurrence of uneven temperature.

[0009]

However, in order to provide such a forced circulation line, a pump for forced circulation is indispensable, and a check valve or the like is also attached. Therefore, the manufacturing cost is considerably increased, and there is a problem that practical application is difficult in terms of cost.

Therefore, an object of the present invention is to provide a hot water circulation type heating device capable of reducing the temperature unevenness of the radiator even when the flow rate of the hot water sent to the radiator is small, by means of a simple and inexpensive device. And

[0011]

In order to achieve the above object, the hot water circulation type heating device of the present invention has a radiator connected in the middle of a pipe for circulating the hot water, and the hot water passing through the radiator is connected. In a hot water circulation type heating device in which the heating capacity is controlled by changing the flow rate, heat is exchanged between a water supply pipe for sending hot water to the radiator and a return pipe for sending water from the radiator. It is characterized by having done.

[0012]

By exchanging heat between the water supply pipe and the return pipe, the hot water in the water supply pipe is cooled and the temperature at the time of entering the radiator is lowered. On the other hand, the minimum temperature of the radiator is almost the same as the ambient temperature, and it hardly fluctuates. Therefore,
The temperature unevenness of the radiator becomes smaller as the inlet temperature decreases.

[0013]

Embodiments will be described with reference to the drawings. In FIG. 1, 1 is an automobile engine. 2 is a radiator. 3 is a radiator. Engine cooling water (hereinafter, also referred to as “hot water” or “water”) from the engine 1 to the radiator 2 and the radiator 3 is sent from a cooling water outlet 1a of the engine through a water supply conduit 4 and a return conduit. The water is returned to the engine 1 through the engine cooling water inlet 1b.

Reference numeral 6 denotes a circulation pump for circulating the engine cooling water in this way, which is driven by the engine 1. 7 is a thermostat. With such a configuration, hot water (generally, about 82 degrees Celsius) warmed by cooling the engine 1 can be caused to flow through the radiator 3 and the fan 8 can be rotated to radiate heat into the passenger compartment for heating. By passing through the radiator 3, the temperature of the hot water is lowered to become water.

A flow rate adjusting valve 20 for adjusting the flow rate of hot water flowing from the engine 1 into the radiator 3 is connected in the middle of the water supply pipe 4 extending from the engine 1 to the radiator 3. By adjusting the flow rate, the heat radiation amount (heating capacity) of the radiator 3 is controlled.

At a position closer to the engine 1 than the radiator 3 and the flow rate adjusting valve 20, a constant differential pressure valve (return flow rate adjusting valve) 12 is provided between the water supply line 4 and the return line 5. The pressure difference between the water supply pipe 4 and the return pipe 5 is constant (for example, 1
60 mmHg) or more, the constant differential pressure valve 12 is opened, and a part of the hot water does not pass through the flow rate adjusting valve 20, but returns directly from the water supply pipe line 4 to the return pipe line 5 to the cooling water inlet 1b of the engine 1. Will be returned.

A heat exchanger 15 is provided at a position closer to the radiator 3 than the flow rate adjusting valve 20 for exchanging heat between the hot water in the water supply conduit 4 and the water in the return conduit 5. The heat of the hot water in the water supply conduit 4 is given to the water in the return conduit 5.

FIG. 2 shows the water temperatures in the water supply conduit 4, the return conduit 5 and the radiator 3 with the position on the horizontal axis. As shown in FIG. 2, heat exchange between the hot water in the water supply conduit 4 and the water in the return conduit 5 cools the hot water in the water supply conduit 4 and causes the radiator 3 to cool. The temperature when entering is greatly reduced. On the other hand, the minimum temperature of the radiator 3 is almost the same as the ambient temperature and hardly changes.

As a result, as shown in FIG. 2, if the heat exchanger 15 is not provided, a large temperature unevenness occurs in the radiator 3 as shown by A. As shown, the temperature becomes small. The broken line shows the case without a heat exchanger.

By providing the heat exchanger 15,
Since the temperature of the hot water entering the radiator 3 is lowered in this way, in order to obtain the same heating capacity, it is necessary to increase the hot water flow rate as compared with the case where the heat exchanger 15 is not provided.

However, when the heating capacity is large, that is, when the hot water flow rate is very large, the inside of the radiator 3 and the heat exchanger 1 are
The flow velocity in 5 is high, the temperature drop of the hot water is small, and the temperature of the return water at the inlet of the heat exchanger 15 is high (for example, 70 degrees Celsius).
The heat exchange amount in the heat exchanger 15 is small.

Therefore, when the flow rate of hot water is large, the temperature drop of the hot water entering the radiator 3 through the heat exchanger 15 is small, and sufficient heating capacity can be obtained without further increasing the flow rate.

As a result, in the present invention, the flow rate when the heating capacity is maximized is almost the same as that when the heat exchanger 15 is not provided, and when the heating capacity is small, the flow rate is smaller than when the heat exchanger 15 is not provided. It is necessary to increase the flow rate. This means that the heating capacity can be controlled with a small flow rate change as a whole, and the device cost can be reduced.

When the flow rate is high, the temperature unevenness of the radiator 3 is small originally, and it does not matter as much when the flow rate is low.
It can be said that the property of the present invention that the temperature of the hot water flowing into the air cools is very well suited to such a heating control system.

As the heat exchanger 15, as shown in FIG. 3, a simple one may be used in which the water supply pipe 4 and the return pipe 5 are made of metal pipes and closely adhered to each other. As shown in FIG. 4, a plastic cylindrical flow path 5 a arranged so as to surround the outside of the water supply pipe line 4 formed of a metal pipe may be connected in the middle of the return pipe line 5. Alternatively, other types may be used.

Further, the present invention can be applied not only to a heating device for automobiles but also to various hot water circulating heating devices.

[0027]

According to the present invention, due to heat exchange in the hot water circulation pipe, the temperature of the hot water entering the radiator from the water supply pipe is lowered as the flow rate of the hot water is smaller, and the temperature unevenness in the radiator is reduced. can do. Moreover, since the heat taken there is given to the return conduit side of the circulation conduit, there is almost no heat loss.

Since the structure required for that purpose is only the piping for heat exchange between the water supply pipe and the return pipe, the device can be constructed at a very low manufacturing cost.

[Brief description of drawings]

FIG. 1 is an overall schematic view of a hot water circulation type heating device according to an embodiment.

FIG. 2 is a temperature characteristic diagram of an example.

FIG. 3 is a sectional view of a specific example of a heat exchanger.

FIG. 4 is a cross-sectional view of another specific example of the heat exchanger.

[Explanation of symbols]

 3 Radiator 4 Water supply pipe 5 Return pipe 15 Heat exchanger

Claims (1)

[Claims] 1. A hot water circulation type heating device in which a radiator is connected in the middle of a pipe for circulating hot water to control the heating capacity by changing the flow rate of hot water passing through the radiator. A hot water circulation type heating device, characterized in that heat is exchanged between a water supply pipe for sending hot water to the container and a return pipe for sending water from the radiator.