KR20200113439A - Low temperature district heating system to increase heating efficiency - Google Patents

Abstract

The present invention provides a low-temperature district heating system for increasing heating efficiency, which includes: a heat exchanger for exchanging heat between district heating medium hot water supplied through a first pipe line and heating water supplied to a user through a second pipe line; and an absorption type heat pump that is disposed on the first pipe line, receives the district heating medium hot water and an unused heat source to increase the temperature of the heating water recovered from the user, and supplies the medium hot water and the unused heat source to the second pipe line, wherein the district heating medium hot water supplied through the first pipe line is supplied to the heat exchanger in a state that the temperature is lowered while passing through the absorption type heat pump, and a temperature controller for adjusting the temperature in a preset range by mixing the heating water supplied from the absorption type heat pump to the second pipe line and the heating water supplied to the user through the heat exchanger is disposed in the second pipe line.

Description

Low temperature district heating system to increase heating efficiency

The embodiment relates to a district heating system that increases heating efficiency. In more detail, it relates to a district heating system that absorbs unused heat and excess heat of users by using medium-temperature water of district heating, and increases the heating efficiency produced by using a low-temperature power generation system for the electricity required in the system.

In general, a district heating system is a system in which a business that supplies collective energy supplies collective energy to a large number of individual users through pipes for heating and hot water supply, and is different from an individual heating system in which the user has individual heating facilities. .

In other words, district heating means that various buildings such as houses, shopping centers, offices, schools, hospitals, factories, etc. within a city or a certain area do not have individual heating facilities. It is one of the collective energy supply methods as a system that produces medium-temperature water (80-120℃) required for the facility and supplies it to each customer through a heat transfer pipe.

This district heating system is composed of a heat source facility that produces electricity and heat, a heat transport facility that transports the generated heat, and a heat user facility that supplies heat transported by the heat transport facility to users.

Heat source facilities include cogeneration facilities, heat-only boilers, waste incinerators, heat storage tanks, heat transport facilities, and heat user facilities.

The cogeneration facility is a comprehensive energy system that simultaneously produces heat and electricity by using the same fuel. In general, the high temperature part is used as power and the low temperature part is used as process heat. Compared to general power generation, energy saving and environmental improvement are greater. In the case of cogeneration, the amount of power generation is reduced by extracting some heat during the expansion process of the steam turbine, but the heat discarded from the condenser can be used for process or district heating.

Recently, technologies for increasing district heating efficiency by utilizing unused heat such as renewable heat energy have been developed.

However, the technology of additionally extending the recovery pipe to recover unused heat has a problem that an additional heat transport pipe installation cost is required.

In addition, when recovering the conventional unused heat, a lot of compression heat pumps using power were used, but there was a problem in that a large amount of power was used for recovery.

Korean Patent Registration No. 10-1434908.

The embodiment aims to provide a district heating system that absorbs unused heat and excess heat of users by using medium-temperature water of district heating, and increases the heating efficiency produced by using a low-temperature power generation system for the electricity required in the system. do.

In addition, it is an object to provide an optimal heating system by changing the supply temperature for heating according to the time or seasonal outdoor temperature.

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

An embodiment of the present invention includes a heat exchanger for exchanging heat between district heating medium hot water supplied through a first pipe line and heating water supplied to a user side through a second pipe line; And an absorption type heat pump disposed on the first piping line to receive the medium hot water of the district heating and an unused heat source to increase the temperature of the heating water recovered from the user and supply it to the second piping line, and the The district heating medium hot water supplied through the first piping line is supplied to the heat exchanger while the temperature is lowered while passing through the absorption heat pump, and the second piping line is supplied from the absorption heat pump to the second piping line. It provides a low-temperature district heating system for increasing heating efficiency, characterized in that a temperature controller is disposed to adjust the temperature in a predetermined range by mixing the heating water that is heated and the heating water supplied to the user through the heat exchanger.

Preferably, the temperature control unit may be characterized in that the temperature is controlled by adjusting the flow rate of the incoming heating water.

Preferably, the temperature control unit is connected to a control unit for controlling the temperature of the heating water, and the control unit controls the temperature of the heating water supplied to the user in consideration of the outside temperature and the amount of sunlight. .

Preferably, the control unit may be characterized in that it controls the temperature of the heating water at a temperature of 40 to 80 degrees.

Preferably, the unused heat source may be characterized in that a heat source is stored in a quarterly heat storage tank so that the supply amount varies depending on the season.

Preferably, it may further include an organic Rankine cycle generator for generating power using the district heating medium hot water supplied through the first pipe line and the low temperature heating water recovered from the user side.

Preferably, the district heating medium hot water passing through the organic Rankine cycle generator may be combined with the district heating medium hot water passing through the absorption heat pump and supplied to a heat exchanger.

Another embodiment of the present invention is an organic Rankine cycle generator for generating electric power using the district heating medium hot water supplied through the first piping line and the heating water recovered from the user side; And a heat exchanger for exchanging the heating water with the district heating medium hot water passing through the organic Rankine cycle generator, wherein the heating water passing through the heat exchanger is mixed with heating water produced in a heat production facility to have a predetermined temperature. It can be implemented as a low-temperature district heating system that increases heating efficiency, characterized in that the heating water is supplied to the user side.

Preferably, it may further include a temperature control unit for adjusting the temperature of the heating water supplied to the user by adjusting the flow rate of the incoming heating water.

According to the embodiment, there is an effect of optimally supplying heat using a system in which the supply temperature for heating is changed according to time or seasonal outdoor temperature.

In addition, power consumption can be reduced compared to using a compression heat pump to recover unused heat, and additional electricity can be used by using a district heating system and organic Rankine cycle power generation.

Various and beneficial advantages and effects of the present invention are not limited to the above-described contents, and may be more easily understood in the course of describing specific embodiments of the present invention.

1 is a structural diagram of a low-temperature district heating system that increases heating efficiency, which is an embodiment of the present invention,
2 is another embodiment of a structural diagram of a low-temperature district heating system that increases heating efficiency, which is an embodiment of the present invention.

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

However, the technical idea of the present invention is not limited to some embodiments to be described, but may be implemented in various different forms, and within the scope of the technical idea of the present invention, one or more of the constituent elements may be selectively selected between the embodiments. It can be combined with and substituted for use.

In addition, terms (including technical and scientific terms) used in the embodiments of the present invention are generally understood by those of ordinary skill in the art, unless explicitly defined and described. It can be interpreted as a meaning, and terms generally used, such as terms defined in a dictionary, may be interpreted in consideration of the meaning in the context of the related technology.

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

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

In addition, terms such as first, second, A, B, (a), and (b) may be used in describing the constituent elements of the embodiment of the present invention.

These terms are only for distinguishing the component from other components, and are not limited to the nature, order, or order of the component by the term.

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 the other component, but also the component and It may also include the case of being'connected','coupled' or'connected' due to another component between the other components.

In addition, when it is described as being formed or disposed on the “top (top) or bottom (bottom)” of each component, the top (top) or bottom (bottom) is one as well as when the two components are in direct contact with each other. It also includes a case in which the above other component is formed or disposed between the two components. In addition, when expressed as "upper (upper) or lower (lower)", the meaning of not only an upward direction but also a downward direction based on one component may be included.

Hereinafter, exemplary embodiments will be described in detail with reference to the accompanying drawings, but identical or corresponding components are denoted by the same reference numerals regardless of reference numerals, and redundant descriptions thereof will be omitted.

1 to 2, in order to clearly understand the present invention conceptually, only the main characteristic parts are clearly shown, 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.

1 is a structural diagram of a low-temperature district heating system that increases heating efficiency according to an embodiment of the present invention.

Referring to FIG. 1, a district heating system that increases heating efficiency according to an embodiment of the present invention includes a district heating heat supply unit 100, a heat exchanger 300, an absorption heat pump 200, and an organic Rankine cycle generator 400. can do.

The district heating heat supply unit 100 produces a heat source and supplies it to the user. In general, medium temperature water is used as the heat source.

District heating is necessary for heating and hot water supply by constructing a large-scale heat production facility, that is, a cogeneration plant, in which various buildings such as houses, shopping centers, offices, schools, hospitals, and factories within a city or a certain area do not have individual heating facilities. It is a system that produces medium-temperature water (110~120℃) and supplies it to each customer through a heat transfer pipe. It is one of the collective energy supply methods.

In such district heating, the structure of the heat supply unit can be variously modified.

The heat exchanger 300 may exchange heat between the district heating medium hot water supplied through the first pipe line 10 and the heating water supplied to the user through the second pipe line 20.

The district heating medium hot water supplied from the first piping line 10 undergoes heat exchange through the heat exchanger 300 and then is returned to the district heating heat supply unit 100, and the heated water heated through the heat exchanger 300 is on the user side. Is supplied as

In one embodiment, the heat exchanger 300 may be a plate heat exchanger 300 having good efficiency for heat exchange of fluids, but is not limited thereto and may be modified in various structures.

The absorption type heat pump 200 is disposed in the first piping line 10 to receive medium-temperature water from district heating and an unused heat source to increase the temperature of the heating water recovered from the user and supply it to the second piping line 20. I can.

Unlike a compression type driven by electric energy, the absorption type heat pump 200 pumps heat by using combustion heat of gas or heat of steam, and is mainly used for recovering large amounts of heat.

Heat from wastewater thrown into the sewer, heat from groundwater, heat from cooling water discharged during cooling, and the like may be used as a recovery heat source. If the temperature of the hot water used is low, even the heat of the river can be used.

The absorption type heat pump 200 can use 40% of the supplied heat as the recovery heat of waste heat, resulting in saving 40% of the energy cost, and increasing the temperature of the supplied hot water to 95°C, which is impossible in a compression type. It can be widely used for heating, hot water, and industrial processes.

There is no limitation on the structure of such a heat pump, and various known absorption heat pumps 200 may be used.

The district heating medium hot water supplied through the first piping line 10 may be supplied to the heat exchanger 300 in a state in which the temperature is lowered while passing through the absorption heat pump 200.

As the unused heat supplied to the absorption heat pump 200, new renewable energy (solar heat, geothermal heat, etc.), unused heat, user-side recovery heat, and the like may be used.

In addition, the unused heat source may be stored in the quarterly heat storage tank 700 and the amount supplied to the absorption heat pump 200 may vary depending on the season.

The quarterly heat storage tank 700 may store unused heat sources in various ways, such as a tank heat storage method, a pit heat storage method, a borehole heat storage method, and an aquifer heat storage method.

In one embodiment, the unused heat source stored in the quarterly heat storage tank 700 may vary in the amount supplied to the absorption heat pump 200 based on the spring and autumn seasons, summer seasons, and winter seasons. In the winter season when a large number of heat sources are required, the heating efficiency can be increased by utilizing the heat of the quarterly heat storage tank 700, and unused heat can be stored in the heat storage tank when heating heat is not required, such as in summer.

The temperature controller 500 is disposed on the second piping line 20 and supplied to the user through the heating water supplied from the absorption heat pump 200 to the second piping line 20 and the heat exchanger 300. The temperature can be adjusted within a preset range by mixing heating water.

In the conventional district heating system, water of about 115 degrees is supplied from the supply part of the heat source, and heating water of about 60 degrees is supplied to the user. However, supplying the heating water of such a constant temperature is difficult to absorb the unused heat existing at various temperatures in the surroundings, and there is a problem in that the heating efficiency is deteriorated.

The temperature controller 500 is connected to the controller 600 for controlling the temperature, and the controller 600 may determine the temperature of the heating water supplied to the user in consideration of various environmental conditions.

In one embodiment, the controller 600 may control the temperature of the heating water in consideration of various factors such as outside temperature, amount of sunlight, and standby state.

The outside temperature is a factor that varies depending on the season, and the amount of sunlight varies depending on the day and night. In addition, the atmospheric state corresponds to a factor that affects the amount of sunlight, and is a factor that affects the supply temperature of heating water.

The controller 600 may adjust the flow rate of the heating water by controlling the valve of the heating pipe supplied to the second piping line 20 in consideration of the outside temperature and the amount of sunlight, and the heating water supplied to the user by calculating the flow rate and temperature. You can adjust the temperature.

In one embodiment, the controller 600 may control the temperature of the heating water in the range of 40 to 80 degrees.

In addition, the present invention can generate power using the organic Rankine cycle generator 400.

The ORC (Organic Rankine Cycle) generator is a Rankine cycle that uses an organic medium as a working fluid. The working medium is boiled at high temperature and high pressure using relatively low temperature waste heat, and then expanded through a turbine to obtain torque. It produces power through The organic Rankine cycle has a basic configuration of an evaporator, a turbine, a condenser, and a pump.

The structure of the organic Rankine cycle generator 400 is not limited, and the organic Rankine cycle generator 400 of various known structures may be used.

The organic Rankine cycle generator 400 may generate power by using the district heating medium hot water branched from the first piping line 10 and the low temperature heating water recovered from the user side. In the organic Rankine cycle generator 400, as the temperature difference with the incoming heat source increases, the power generation efficiency increases, and the amount of power generation can be increased by using the district heating medium hot water supplied through the first piping line 10. have.

At this time, the district heating medium hot water passing through the organic Rankine cycle generator 400 may be combined with the district heating medium hot water passing through the absorption heat pump 200 and supplied to the heat exchanger 300.

Electric power produced by using the organic Rankine cycle generator 400 may be supplied to a place where electric power is needed in the district heating piping system.

Referring to Fig. 1, a specific embodiment will be described.

With the absorption heat pump 200, the district heating medium temperature water at around 115 degrees, the heating water at around 35 degrees that is recovered from the user, and the unused heat source at around 15 degrees stored in the quarterly heat storage tank 700 are moved to the absorption heat pump 200. Is done.

At this time, the district heating medium hot water whose temperature has been lowered to a temperature of around 95 degrees moves to the heat exchanger 300, and the unused heat source supplied from the quarterly heat storage tank 700 decreases to about 15 degrees, and the quarterly heat storage tank 700 Will move to within.

In addition, the district heating medium hot water branching from the first pipe and the heating water recovered from the user side are introduced into the organic Rankine cycle generator 400 to generate electric power.

The user-side heating water passing through the absorption heat pump 200 is supplied to the second piping line 20, and the heating water passing through the heat exchanger 300 is also supplied to the second piping line 20.

In this case, the temperature controller 500 may control the temperature of the heating water supplied to the second pipe line 20 in a range of 40 to 80 by receiving a command from the controller 600.

2 is another embodiment of a structural diagram of a district heating system that increases heating efficiency, which is an embodiment of the present invention.

In FIG. 2, the same reference numerals as in FIG. 1 denote the same members, and detailed descriptions thereof will be omitted.

Referring to FIG. 2, a district heating system that increases heating efficiency, which is another embodiment of the present invention, generates electric power by using hot water for district heating supplied through the first piping line 10 and heating water recovered from the user side. Heating water passing through the heat exchanger 300 including a heat exchanger 300 for heat exchange between the district heating medium hot water and the heating water passing through the organic Rankine cycle generator 400 and the organic Rankine cycle generator 400 The heating water produced by the heat production facility 800 may be mixed and the heating water having a preset temperature may be supplied to the user.

In another embodiment of the present invention, a heat source may be supplied from a heat using facility to provide variable temperature heating water.

The heat-using facility means various devices that produce a heat source, and various facilities such as a hydrogen fuel cell or a boiler may be used.

At this time, the temperature of the heating water transferred to the user can be adjusted through the temperature control unit 500, and the control unit 600 can control the temperature control of the temperature control unit 500 in consideration of the outside temperature and the amount of insolation. have.

In one embodiment, the temperature controller 500 may adjust the supply temperature by adjusting the flow rate of the incoming heating water.

Looking at a specific embodiment, the district heating medium temperature water of about 115 degrees Celsius and the user-side heating water recovered from about 35 degrees Celsius are introduced into the organic Rankine cycle generator 400 to generate electric power.

At this time, the district heating medium hot water and the user-side heating water whose temperature has decreased to around 95 degrees while passing through the organic Rankine cycle generator 400 passes through the heat exchanger 300 to perform heat exchange.

The heat-exchanged user-side heating water is mixed in the heat source supplied from the heat production facility 800 and the second piping line 20, and the temperature is adjusted through the temperature control unit 500 to be supplied to the user at a temperature of 40 to 80 degrees. .

As described above, with reference to the accompanying drawings with respect to an embodiment of the present invention was looked at in detail.

The above description is merely illustrative of the technical idea of the present invention, and those of ordinary skill in the technical field to which the present invention belongs can make various modifications, changes, and substitutions within the scope not departing from the essential characteristics of the present invention. will be. Accordingly, the embodiments disclosed in the present invention and the accompanying drawings are not intended to limit the technical idea of the present invention, but to explain, and the scope of the technical idea of the present invention is not limited by these embodiments and the accompanying drawings. . The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the present invention.

10: first piping line
20: second piping line
100: district heating heat supply unit
200: absorption heat pump
300: heat exchanger
400: Organic Rankine Cycle Generator
500: temperature control unit
600: control unit
700: quarterly heat storage tank
800: heat production facility

Claims (9)

A heat exchanger for exchanging heat between the district heating medium hot water supplied through the first pipe line and the heating water supplied to the user through the second pipe line;
An absorption type heat pump disposed on the first piping line to receive medium-temperature water from the district heating and an unused heat source to increase the temperature of the heating water recovered from the user and supply it to the second piping line;
Including,
The district heating medium hot water supplied through the first piping line is supplied to the heat exchanger in a state in which the temperature is lowered while passing through an absorption heat pump,
In the second piping line, a temperature controller is disposed to adjust the temperature in a predetermined range by mixing heating water supplied from the absorption heat pump to the second piping line and heating water supplied to the user through the heat exchanger A low-temperature district heating system that increases heating efficiency. The method of claim 1,
The temperature control unit is a low-temperature district heating system for increasing heating efficiency, characterized in that controlling the temperature by adjusting the flow rate of the incoming heating water. The method of claim 2,
The temperature control unit is connected to a control unit for adjusting the temperature of the heating water,
The control unit is a low-temperature district heating system for increasing heating efficiency, characterized in that controlling the temperature of the heating water supplied to the user in consideration of the outside temperature and the amount of sunlight. The method of claim 3,
The control unit is a low-temperature district heating system that increases the heating efficiency of controlling the temperature of the heating water at a temperature of 40 to 80 degrees. The method of claim 1,
The unused heat source is a low-temperature district heating system for increasing heating efficiency, characterized in that the supply amount is changed according to the season by storing the heat source in a quarterly heat storage tank. The method of claim 1,
An organic Rankine cycle generator for generating electric power using the district heating medium hot water supplied through the first pipe line and the low temperature heating water recovered from the user side;
Low-temperature district heating system to increase the heating efficiency further comprising a. The method of claim 6,
The district heating medium hot water passing through the organic Rankine cycle generator is combined with the district heating medium hot water passing through the absorption heat pump and supplied to a heat exchanger. An organic Rankine cycle generator that generates electric power using the district heating medium hot water supplied through the first piping line and the heating water recovered from the user side; And
A heat exchanger for exchanging heat between the district heating medium hot water and the heating water passing through the organic Rankine cycle generator;
Including,
The heating water passing through the heat exchanger is a low-temperature district heating system for increasing heating efficiency, characterized in that the heating water produced in a heat production facility is mixed and the heating water of a predetermined temperature is supplied to the user. The method of claim 8,
A low-temperature district heating system that increases heating efficiency, further comprising a temperature controller that adjusts the temperature of the heating water supplied to the user by adjusting the flow rate of the heating water introduced.

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