JPH0517441U - Fluid heating device - Google Patents

Abstract

(57) [Abstract] [Purpose] The present invention aims to be able to use the primary medium according to the secondary load condition. The fluid heating device of the present invention comprises a temperature sensor 17 for detecting the temperature of the secondary medium after heat exchange, and a proportional motorized valve 18 for adjusting the flow rate of the primary medium to the heat exchanger depending on the opening. And a control circuit 19 for controlling the opening of the proportional motor-operated valve 18 based on the temperature detected by the temperature sensor 17. The control circuit 19 uses the proportional equation when the temperature detected by the temperature sensor 17 is higher than a predetermined temperature. The opening degree of the motor-operated valve 18 is reduced, and the opening degree of the proportional motor-operated valve 18 is increased when the temperature detected by the temperature sensor 17 is lower than a predetermined temperature.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a fluid heating device that heats a secondary medium by exchanging heat between the primary medium and the secondary medium, and in particular, wasteful consumption of the primary medium is suppressed and running cost is reduced. The present invention relates to a fluid heating device.

[0002]

[Prior Art]

 FIG. 3 shows a conventional fluid heating device. This fluid heating device includes a heat exchanger 10 for exchanging heat between a primary medium such as high-temperature water and a secondary medium such as tap water, and a heat exchanger 10 for providing a primary medium and a secondary medium, respectively. The supply pipes 15 and 16 and the secondary-side medium after heat exchange are mixed with the secondary-side medium before heat exchange that is supplied via the bypass pipe 16a so that the secondary-side medium after heat exchange has a certain level. Temperature control valve 11 for controlling the temperature of the secondary side, a flow switch 12 for detecting the flow of the secondary side medium, an electric ON-OFF valve 13 for supplying and stopping the primary side medium, and a detection signal from the flow switch 12. In response, the control circuit 14 opens and closes the electric ON-OFF valve 13. In the above configuration, when the secondary medium flows in the direction of arrow B in the pipe 16, the flow switch 12 detects it. The flow switch 12 outputs a detection signal to the control circuit 14, and the control circuit 14 opens the electric ON-OFF valve 13 based on the input of the detection signal from the flow switch 12. When the electric ON / OFF valve 13 is opened, the primary medium flows in the direction of arrow A in the pipe 15, and the heat exchanger 10 exchanges heat between the primary medium and the secondary medium. The secondary medium having undergone the heat exchange is mixed with the secondary medium before the heat exchange in the temperature control valve 11, adjusted to a constant temperature, and supplied in the direction of arrow C. Further, when the use of the secondary medium is finished, the control circuit 14 closes the electric ON-OFF valve 13 and stops the supply of the primary medium.

[0003]

[Problems to be solved by the device]

 However, according to the conventional fluid heating device, the primary side medium always uses a constant amount regardless of the secondary side load state, so that in the secondary side low load state, that is, before the heat exchange. When the temperature of the secondary medium is high or the flow rate thereof is small, there is a disadvantage that the primary medium is consumed more than necessary.

Therefore, an object of the present invention is to provide a fluid heating device that can use a primary medium according to a secondary load condition.

[0008]

[Means for Solving the Problems]

 In view of the above problems, the present invention provides a temperature detecting means for detecting the temperature of the secondary medium after heat exchange and an opening degree in order to control the flow rate of the primary medium according to the secondary load state. To provide a fluid heating device equipped with a flow rate control valve for controlling the flow rate of the primary side medium to the heat exchanger by means of a heat exchanger and a control circuit for controlling the opening degree of the flow rate control valve based on the temperature detected by the temperature detection means. Is.

[0010]

[Action]

 In the present invention having the above-mentioned configuration, the temperature of the secondary medium after heat exchange is detected by the temperature detecting means. When the detected temperature is higher than the predetermined temperature (during secondary side low load), the control circuit reduces the opening of the flow rate control valve to reduce the flow rate of the primary side medium to the heat exchanger. When the detected temperature is lower than the predetermined temperature (during secondary side high load), the control circuit increases the opening of the flow rate control valve to increase the flow rate of the primary side medium to the heat exchanger. As described above, since the flow rate of the primary medium is adjusted according to the secondary load state, wasteful consumption of the primary medium can be suppressed, which reduces running costs. Can be made

[0011]

【Example】

 Hereinafter, the fluid heating device of the present invention will be described in detail.

FIG. 1 shows an embodiment of the present invention. This fluid heating device is applied to a water heater with a hot water outlet temperature of 60 ° C., using hot water of 85 ° C. as a primary medium and tap water as a secondary medium, for example. .. Here, the same parts as those in FIG. 3 are denoted by the same reference numerals and symbols, and thus a duplicate description will be omitted, but the temperature at which the temperature of tap water heat-exchanged by the heat exchanger 10 in the pipe 16 is detected is detected. The sensor 17 is also provided with a proportional motor operated valve 18 for adjusting the flow rate of the primary side medium, that is, the consumption amount of the primary side medium in the pipe 15, respectively, and the proportional sensor with the temperature sensor 17 and the flow switch 12 is provided. The electrically operated valve 18 is connected via a control circuit 19.

In the above configuration, when tap water (secondary medium) flows in the direction of arrow B in the pipe 16, the flow switch 12 detects it. The flow switch 12 outputs a detection signal to the control circuit 19, and the control circuit 19 opens the proportional motor-operated valve 18 by a predetermined opening based on the input of the detection signal from the flow switch 12. Due to this opening, high temperature water (primary medium) flows in the direction of arrow A in the pipe 15, and heat exchange is performed between the high temperature water and the tap water in the heat exchanger 10. Then, the tap water heated by heat exchange is supplied to the temperature control valve 11. At this time, the temperature sensor 17 detects the temperature of the tap water after heat exchange. As a result, when the temperature is in the range of 65 ° C to 75 ° C, the control circuit 19 controls so that the opening degree of the proportional motor-operated valve 18 is maintained as it is. The opening is controlled so as to be increased, and when the temperature exceeds 75 ° C., the opening of the proportional motor-operated valve 18 is controlled so as to be decreased. By such control, the consumption of high-temperature water is optimized, and the tap water after heat exchange can always maintain the range of 65 ° C to 75 ° C. Then, the tap water at 65 ° C to 75 ° C is mixed with the tap water before heat exchange supplied from the bypass pipe 16a in the temperature control valve 11, and the temperature is adjusted to 60 ° C to be supplied to the user. When the flow switch 12 does not detect the flow of tap water, the control circuit 19 completely closes the proportional motor-operated valve 13 and stops the supply of high temperature water.

As described above, by detecting the temperature of the secondary-side medium, the secondary-side load state is grasped, and the flow rate of the primary-side medium is determined accordingly. You can save money.

FIG. 2 shows a second embodiment of the present invention. This fluid heating device was applied to a heat source for heating, using, for example, high-temperature water of 85 ° C. as the primary side medium and heating water reduced from a warm water mat etc. as the secondary side medium. It is configured such that two types of heating water, high temperature heating water and low temperature heating water, can be obtained from the pipes 21 and 22. That is, the secondary side medium supply system is a secondary system before heat exchange with the first system for supplying the heat-exchanged secondary side medium as it is in the direction of arrow D through the pipe 21 and the temperature control valve 11. The second system is configured to be mixed with the side medium and then supplied in the direction of arrow C through the pipe 22.

In the above configuration, when heat exchange is performed between the primary side medium and the secondary side medium in the heat exchanger 10, the control circuit 19 performs the above-described control for optimizing the consumption amount of the primary side medium. Then, the temperature of the heating water (secondary medium) after heat exchange is adjusted to 75 ° C ± 2 ° C. The heating water at 75 ° C ± 2 ° C is branched into two systems, the pipe 21 and the pipe 22, the heating water flowing to the pipe 21 is directly supplied as high-temperature heating water, and the heating water flowing to the pipe 22 is heated by the temperature control valve 11. It is mixed with the heating water before replacement and supplied as low-temperature heating water.

In the embodiment described above, since the heating water is used as the secondary medium, the temperature thereof is higher than that of the secondary medium of the first embodiment, that is, the secondary low load. It is in a state. Therefore, the consumption amount of the primary side medium can be reduced by the control of the control circuit 19 as compared with the first embodiment.

[0018]

[Effect of the device]

 As described above, according to the fluid heating device of the present invention, the temperature detecting means for detecting the temperature of the secondary medium after heat exchange and the flow rate adjusting for adjusting the flow rate of the primary medium to the heat exchanger by the opening degree. Since it is equipped with a valve and a control circuit that controls the opening of the flow rate control valve based on the temperature detected by the temperature detection means, the flow rate of the primary side medium can be adjusted according to the load state on the secondary side. Useless consumption of the medium can be suppressed. Therefore, the running cost can be reduced because the pump power is reduced.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a first embodiment of the present invention.

FIG. 2 is an explanatory view showing a second embodiment of the present invention.

FIG. 3 is an explanatory view showing a conventional fluid heating device.

[Explanation of symbols]

10 heat exchanger 14
Control circuit 11 Temperature control valve 15,1
6 Piping 12 Flow switch 17
Temperature sensor 13 Electric ON-OFF valve 18
Proportional motorized valve

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Yuzo Shiraishi 3550, Kidayomachi, Tsuchiura City, Ibaraki Prefecture Hitachi Cable Ltd. Tsuchiura Plant

Claims (2)

[Scope of utility model registration request] 1. A fluid heating apparatus for heating a secondary medium by performing heat exchange between a primary medium and a secondary medium via a heat exchanger, the temperature of the secondary medium after the heat exchange. Temperature detection means for detecting the flow rate, a flow rate control valve for controlling the flow rate of the primary side medium to the heat exchanger by the opening degree, and the opening degree of the flow rate control valve based on the temperature detected by the temperature detection means. A control circuit for controlling, wherein the control circuit reduces the opening degree of the flow rate control valve when the detected temperature is higher than a predetermined temperature, and the opening degree of the flow rate control valve when the detected temperature is lower than a predetermined temperature. A fluid heating device having a structure for enlarging. 2. A first supply means for supplying the secondary side medium after the heat exchange as it is, and a secondary side medium before the heat exchange is mixed with the secondary side medium after the heat exchange at a predetermined ratio. The fluid heating apparatus further comprising a second supply unit for supplying the fluid.