KR20220036142A - District heating system by using heat from return pipe for the zero-energy building - Google Patents

Abstract

The present invention provides a storage tank for storing hot water, a heat source supply unit for heating and circulating the water inside the storage tank, a first supply pipe for supplying water stored in the storage tank to the user, and a device for recovering water used by the user. A first water return pipe, a three-way valve installed in one area of the first water return pipe, a first branch pipe connecting the three-way valve and the storage tank, and a second branch connecting the three-way valve and the storage tank. An engine, a heat exchanger disposed in one area of the second branch pipe to exchange heat with return water from district heating to raise the temperature of water supplied through the second branch pipe and supply it to the storage tank, and opening and closing the three-way valve It provides a low-temperature district heating supply system for a zero-energy building, including a control unit, wherein the control unit controls the opening and closing of the three-way valve to control the movement path of water flowing in through the first water return pipe.

Description

Low-temperature district heating supply system for zero-energy buildings {District heating system by using heat from return pipe for the zero-energy building}

The embodiment relates to a low-temperature district heating supply system for a zero-energy building. More specifically, it is about a low-temperature district heating supply system for zero energy buildings that utilizes low-temperature heat through district heating return pipes, which are unused energy.

In general, district heating systems send high-temperature water (100-120℃) produced in large-scale district energy facilities to users through supply pipes, and low-temperature water (45-60℃) that has consumed heat is sent to district energy facilities through return pipes. It is refunded.

In user buildings or complexes, heat exchangers are connected to district heating supply pipes and return pipes. The hot water on the primary side supplies heat to the user through a heat exchanger, and the hot water on the secondary side is sent to each household or user through a pump. The secondary low-temperature water used in each household or place of use returns to the heat exchanger.

Recently, as the insulation of buildings has been strengthened and zero-energy construction has been mandated to reduce greenhouse gases and save building energy, heat consumption in buildings is continuously decreasing.

Therefore, in these passive buildings, the overall required temperature for heat use is low, so heating and hot water supply are possible with only low-temperature hot water (30-50℃).

In general, zero energy buildings have passive architectural structures and energy self-sufficient facilities, so they can be operated without receiving heat from the outside. Recently, hot water is produced through renewable energy heat sources such as geothermal heat and fuel cells, then stored in storage tanks, and when necessary, hot water is sent to each household or user to be used for heating and hot water.

However, there are cases where additional heat is required due to the fixation of the heat source, low hot water temperature, lack of heat, etc., and this is supported by using gas boilers, etc.

The purpose of the embodiment is to supply the heat source required for a zero-energy building by using return heat from district heating.

The problem to be solved by the present invention is not limited to the problems mentioned above, and other problems not mentioned here will be clearly understood by those skilled in the art from the description below.

An embodiment of the present invention includes a storage tank for storing hot water; A heat source supply unit that heats and circulates the water inside the storage tank; a first supply pipe that supplies water stored in the storage tank to a user; a first water return pipe that returns water used by the user; A three-way valve installed in one area of the first water return pipe; A first branch pipe connecting the three-way valve and the storage tank; A second branch pipe connecting the three-way valve and the storage tank; A heat exchanger disposed in one area of the second branch pipe to exchange heat with return water from district heating to raise the temperature of water supplied through the second branch pipe and supply it to the storage tank; and a control unit for opening and closing the three-way valve, wherein the control unit controls the opening and closing of the three-way valve to control the movement path of water flowing in through the first water return pipe.

Preferably, the control unit may control the opening and closing of the three-way valve using a detection value of a temperature sensor disposed in the first supply pipe.

Preferably, the controller controls opening and closing the three-way valve so that water moving through the second water return pipe moves to the second branch pipe when the temperature of the hot water supplied through the first supply pipe is less than 45°C. It can be characterized as:

Preferably, the control unit controls opening and closing of the three-way valve so that water moving through the water return pipe moves to the second branch pipe when the temperature of the water supplied from the heat source supply unit to the storage tank is less than 50 ° C. It can be characterized.

Preferably, the control unit may be configured to control opening and closing of the three-way valve so that water moving through the first water return pipe moves to the second branch pipe when a failure signal is transmitted from the heat source supply unit. there is.

Preferably, the heat exchanger may include a second supply pipe and a second water return pipe connected to a district heating water return pipe.

Preferably, at least one of the second supply pipe and the second return pipe may be equipped with a pump.

Preferably, a pressure gauge is disposed in each of the second supply pipe and the second return pipe, and may further include a pump controller that receives pressure information from the pressure gauge and controls whether the pump operates.

Preferably, the pump controller may control the rotation speed of the pump so that a pressure difference between the second supply pipe and the second return pipe is 1 kg/cm ² or more.

Preferably, the pump controller may receive information about the need to use a heat source from the control unit and operate the pump when the three-way valve is opened to the second branch pipe.

Preferably, a thermometer is disposed in each of the second supply pipe and the second water return pipe, and a flow meter is disposed in at least one of the second supply pipe and the second water return pipe, and the temperature information of the thermometer and the flow meter are provided. It may be characterized in that a calorimeter is arranged to calculate the amount of heat using the flow rate information.

According to the embodiment, there is an effect of increasing energy use efficiency by utilizing low-temperature heat through the water return pipe of district heating, which is unused energy.

The various and beneficial advantages and effects of the present invention are not limited to the above-described content, and may be more easily understood through description of specific embodiments of the present invention.

1 is a structural diagram of a low-temperature district heating supply system for a zero-energy building according to an embodiment of the present invention;
Figure 2 is a diagram showing the structure in which heat sources are circulated in the zero energy building itself in Figure 1;
FIG. 3 is a diagram showing a structure in which a heat source is supplied using water exchange heat in FIG. 1.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

However, the technical idea of the present invention is not limited to some of the described embodiments, but may be implemented in various different forms, and as long as it is within the scope of the technical idea of the present invention, one or more of the components may be optionally used between the embodiments. It can be used by combining and replacing.

In addition, terms (including technical and scientific terms) used in the embodiments of the present invention, unless explicitly specifically defined and described, are generally understood by those skilled in the art to which the present invention pertains. It can be interpreted as meaning, and the meaning of commonly used terms, such as terms defined in a dictionary, can be interpreted by considering the contextual meaning of the related technology.

Additionally, the terms used in the embodiments of the present invention are for describing the embodiments and are not intended to limit the present invention.

In this specification, the singular may also include the plural unless specifically stated in the phrase, and when described as “at least one (or more than one) of A and B and C”, it is combined with A, B, and C. It can contain one or more of all possible combinations.

Additionally, when describing the components of an embodiment of the present invention, terms such as first, second, A, B, (a), and (b) may be used.

These terms are only used to distinguish the component from other components, and are not limited to the essence, order, or order of the component.

And, when a component is described as being 'connected', 'coupled' or 'connected' to another component, the component is not only directly connected, coupled or connected to that other component, but also is connected to that component. It can also include cases where other components are 'connected', 'combined', or 'connected' due to another component between them.

Additionally, when described as being formed or disposed “above” or “below” each component, “above” or “below” refers not only to cases where two components are in direct contact with each other, but also to one This also includes cases where another component described above is formed or placed between two components. In addition, when expressed as “top (above) or bottom (bottom)”, it can include not only the upward direction but also the downward direction based on one component.

Hereinafter, embodiments will be described in detail with reference to the attached drawings, but identical or corresponding components will be assigned the same reference numbers regardless of reference numerals, and duplicate descriptions thereof will be omitted.

1 to 3 clearly show only the main features in order to clearly understand the present invention conceptually, and as a result, various modifications of the illustration are expected, and the scope of the present invention is limited by the specific shape shown in the drawings. It doesn't have to be.

Figure 1 is a structural diagram of a low-temperature district heating supply system for a zero energy building according to an embodiment of the present invention, Figure 2 is a diagram showing the structure in which heat sources are circulated in the zero energy building itself in Figure 1, and Figure 3 is a diagram showing the structure in Figure 1. This is a diagram showing a structure in which a heat source is supplied using water return heat.

Referring to Figures 1 to 3, the low-temperature district heating supply system for a zero energy building according to an embodiment of the present invention includes a storage tank 100, a heat source supply unit 200, a three-way valve 300, and a heat exchanger 400. and a control unit 500.

District heating supplies medium-temperature hot water through a supply pipe (20), and returns water used through heat exchange using a water return pipe (30). This reclaimed water is returned to the heat source facility, and the reclaimed water is not used as a heat source.

The low-temperature district heating supply system for zero-energy buildings according to an embodiment of the present invention aims to solve the problems of conventional zero-energy buildings by using the heat of return water recovered from district heating.

The storage tank 100 can store hot water and supply it to the user 10. Unlike a heat storage tank that utilizes a temperature boundary layer using the density difference between water, the storage tank 100 may be used to store hot water in a structure where warm water and cold water are freely mixed.

The storage tank 100 can supply the water stored in the storage tank 100 to the user 10 using the first supply pipe 110.

Additionally, the water used by the user can be returned through the first water return pipe 120.

The heat source supply unit 200 can heat and circulate the water inside the storage tank 100.

The heat source supply unit 200 can heat the water in the storage tank 100 through a circulation pipe and supply it back into the storage tank 100.

In one embodiment, the heat source supply unit 200 may supply heat using renewable energy sources such as geothermal heat, solar heat, sewage heat, fuel cells, etc. There is no limit to the type of the heat source supply unit 200, and known technologies used as renewable energy heat sources can be applied.

The three-way valve 300 is installed in one area of the first water return pipe 120, and water flowing in through the first water return pipe 120 flows into the first branch pipe and the second branch connected to the storage tank 100. It can be branched into organs.

The three-way valve 300 can be opened and closed through the control unit 500, and the control unit 500 can control the movement of water to the first branch pipe or the second branch pipe using information on the entire system.

The heat exchanger 400 is disposed in one area of the second branch pipe and can heat the water supplied through the second branch pipe through heat exchange with district heating return water and supply it to the storage tank 100. In one embodiment, the heat exchanger 400 may be of a plate-type or tube-type structure, but the heat exchanger 400 is not limited thereto, and various types of known heat exchangers 400 may be used.

The heat exchanger 400 may include a district heating water return pipe 30, a second supply pipe 410, and a second water return pipe 420.

A pump 421 may be provided in at least one of the second supply pipe 410 and the second return pipe 420 connected to the heat exchanger 400. In general district heating, hot water is supplied through a supply pipe (20) and hot water flows due to pressure differential with the water return pipe (30). However, in the present invention, hot water is directly extracted from the water return pipe (30) and a second supply pipe ( 410). Therefore, in the present invention, the pump 421 can be connected to at least one of the second supply pipe 410 and the second return pipe 420 to introduce return water flowing along the district heating return pipe 30.

In addition, a pressure gauge 411 is disposed in each of the second supply pipe 410 and the second return pipe 420, and a pump controller 430 that receives pressure information from the pressure gauge 411 and controls the operation of the pump 421. can be provided.

The pump controller 430 detects the differential pressure between the second supply pipe 410 and the second return pipe 420 connecting the water return pipe 30 and the heat exchanger 400 in real time and pressurizes the pump 421. Water that has undergone heat exchange in the heat exchanger (400) can be introduced back into the water exchange pipe (30). In one implementation, the pump controller 430 may control the rotation speed of the pump 421 so that the pressure difference between the second supply pipe 410 and the second return pipe 420 is 1 kg/cm ² or more. And, when heat use is not necessary, the operation of the pump 421 can be stopped.

In addition, a thermometer 412 is disposed in each of the second supply pipe 410 and the second return pipe 420, and a flow meter 413 is installed in at least one of the second supply pipe 410 and the second return pipe 420. is disposed, and a calorimeter 440 that calculates the amount of heat using the temperature information of the thermometer 412 and the flow rate information of the flow meter 413 may be disposed.

When using the heat source of the water return pipe 30 in a zero energy building, settlement of the fee is required. In the present invention, temperature and flow information can be detected using the thermometer 412 and flow meter 413 installed in the second supply pipe 410 and the second return pipe 420.

The calorimeter 440 can calculate the fee by measuring the amount of heat actually used by driving the pump 421 using the sensed information.

The control unit 500 can control the movement path of water flowing in through the first water return pipe 120 by controlling the opening and closing of the three-way valve 300. The control unit 500 may control the opening and closing of the three-way valve 300 using the detection value of the temperature sensor 111 disposed in the first supply pipe 110.

In one embodiment, when the temperature of the hot water supplied through the first supply pipe 110 is less than 45°C, the control unit 500 causes the water moving through the second water return pipe 420 to move through the second branch pipe. Through this, water additionally heated in the heat exchanger 400 can be supplied to the storage tank 100.

In addition, when a failure signal is received from the heat source supply unit 200, the control unit 500 controls the opening and closing of the three-way valve 300 so that the water moving through the first water return pipe 120 moves to the second branch pipe. can do.

This control unit 500 can be linked with the pump controller 430.

In one embodiment, the pump controller 430 receives information about the need to use a heat source, that is, information about the need to raise the temperature of water using the heat exchanger 400, from the control unit 500, and controls the control unit 500. When the three-way valve 300 is opened to the second branch pipe, the pump 421 can be operated.

With reference to FIGS. 2 and 3, the operation of the low-temperature district heating supply system for a zero energy building according to an embodiment of the present invention will be described.

Referring to FIG. 2, FIG. 2 explains the operation of the system when hot water supplied from the storage tank 100 satisfies the temperature required by the user 10.

Hot water supplied from the storage tank 100 is supplied to the user 10 through the first supply pipe 110. At this time, when the control unit 500 determines that the detection value of the temperature sensor disposed in the first supply pipe 110 satisfies the temperature required by the user 10, the control unit 500 operates the first water return pipe ( The opening and closing of the three-way valve 300 can be controlled so that water flowing in through 120) moves through the first branch pipe.

Water flowing into the storage tank 100 through the first branch pipe may be heated while circulating through the heat source supply unit 200 and then supplied to the storage tank 100 again.

Referring to FIG. 3, the operation of the system when hot water supplied from the storage tank 100 does not satisfy the temperature required by the user 10 will be described.

Hot water supplied from the storage tank 100 is supplied to the user 10 through the first supply pipe 110. At this time, if the control unit 500 determines that the detection value of the temperature sensor disposed in the first supply pipe 110 does not satisfy the temperature required by the user 10, the control unit 500 controls the first water return pipe 110. The opening and closing of the three-way valve 300 can be controlled so that the water flowing in through (120) moves through the second branch pipe.

The water moving through the second branch pipe can exchange heat with return water for district heating in the heat exchanger 400.

The pump controller 430 can receive a signal from the control unit 500 to operate the pump 421, and the return water is supplied to the heat exchanger 400 through the second supply pipe 410 through the pump 421. After flowing in and exchanging heat, it moves to the water exchange pipe (30) through the second water exchange pipe (420).

Water flowing into the heat exchanger 400 through the second branch pipe may be heated through heat exchange with return water and then flow into the storage tank 100.

Above, embodiments of the present invention have been examined in detail with reference to the attached drawings.

The above description is merely an illustrative explanation of the technical idea of the present invention, and various modifications, changes, and substitutions can be made by those skilled in the art without departing from the essential characteristics of the present invention. will be. Accordingly, the embodiments disclosed in the present invention and the attached drawings are not intended to limit the technical idea of the present invention, but are for illustrative purposes, and the scope of the technical idea of the present invention is not limited by these embodiments and the attached drawings. . The scope of protection of the present invention should be interpreted in accordance with the claims below, and all technical ideas within the equivalent scope should be construed as being included in the scope of rights of the present invention.

10: user
20: supply pipe
30: water return pipe
100: storage tank
110: first supply pipe
111: Temperature sensor
120: 1st water return pipe
200: Heat source supply unit
300: 3-way valve
400: heat exchanger
410: Second supply pipe
411: pressure gauge
412: thermometer
413: flow meter
420: Second water return pipe
421: pump
430: Pump controller
440: calorimeter
500: Control unit

Claims (11)

A storage tank for storing hot water;
A heat source supply unit that heats and circulates the water inside the storage tank;
a first supply pipe that supplies water stored in the storage tank to a user;
a first water return pipe that returns water used by the user;
a three-way valve installed in one area of the first water return pipe;
A first branch pipe connecting the three-way valve and the storage tank;
A second branch pipe connecting the three-way valve and the storage tank;
A heat exchanger disposed in one area of the second branch pipe to exchange heat with return water from district heating to raise the temperature of water supplied through the second branch pipe and supply it to the storage tank; and
A control unit for opening and closing the three-way valve;
Includes,
A low-temperature district heating supply system for a zero-energy building, wherein the control unit controls the opening and closing of the three-way valve to control the movement path of water flowing in through the first water return pipe. According to claim 1,
The control unit is a low-temperature district heating supply system for a zero-energy building, wherein the control unit controls opening and closing of the three-way valve using a detection value of a temperature sensor disposed in the first supply pipe. According to clause 2,
The control unit is characterized in that when the temperature of the hot water supplied through the first supply pipe is less than 45°C, it controls the opening and closing of the three-way valve so that the water moving through the second water return pipe moves to the second branch pipe. A low-temperature district heating supply system for zero-energy buildings. According to claim 1,
The control unit is characterized in that it controls the opening and closing of the three-way valve so that water moving through the water return pipe moves to the second branch pipe when the temperature of the water supplied from the heat source supply unit to the storage tank is less than 50 ° C. Low-temperature district heating supply system for energy buildings. According to claim 1,
The control unit controls the opening and closing of the three-way valve so that water moving through the first water return pipe moves to the second branch pipe when a failure signal is transmitted from the heat source supply unit. District heating supply system. According to claim 1,
The heat exchanger is a low-temperature district heating supply system for a zero energy building, characterized in that it includes a second supply pipe and a second return pipe connected to the district heating return pipe. According to clause 6,
A low-temperature district heating supply system for a zero-energy building, characterized in that at least one of the second supply pipe and the second return pipe is provided with a pump. According to clause 7,
A pressure gauge is disposed in each of the second supply pipe and the second return pipe,
A low-temperature district heating supply system for a zero-energy building, further comprising a pump controller that receives pressure information from the pressure gauge and controls whether the pump operates. According to clause 8,
The pump controller is a low-temperature district heating supply system for a zero-energy building, characterized in that it controls the rotation speed of the pump so that a pressure difference between the second supply pipe and the second return pipe is ¹ kg/cm 2 or more. According to clause 8,
The pump controller receives information about the need to use a heat source from the control unit, and operates the pump when the three-way valve is opened to the second branch pipe. A low-temperature district heating supply system for a zero energy building. . According to clause 6,
A thermometer is disposed in each of the second supply pipe and the second return pipe,
A flow meter is disposed in at least one of the second supply pipe and the second return pipe,
A low-temperature district heating supply system for a zero-energy building, characterized in that a calorimeter is arranged to calculate the amount of heat using the temperature information of the thermometer and the flow rate information of the flow meter.

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