Method of operating heating system of large building for reducing heat loss

Abstract

A method for operating a heating system for a large building may include the steps of: providing a heating system comprising a heat source, a heat source piping section for supplying heat source water heated by the heat source, an air conditioner provided to a heating space of the building, a heating piping section for supplying heating water to the air conditioner, and a heat exchanger for transferring thermal energy between the heat source piping section and the heating piping section; providing a heating water supply temperature sensor for measuring the real-time temperature (HWST(t)) of the heating water supplied from the heating piping section to the air conditioner, and a control unit for controlling the operation of the heating system by referencing the heating water supply temperature sensor; the control unit receiving the real-time temperature (SAT(t)) of the heated supply air supplied by the air conditioner; and the control unit controlling the real-time temperature (HWST(t)) of the heating water by referencing the real-time temperature (SAT(t)).

Description

Technology Field

[0001] The present invention relates to a heating system for large buildings, and more specifically, to a method for efficiently operating a heating system for large buildings by reducing heat loss. Background Technology

[0003] Boilers or heat exchangers are operated to meet heating demands for office or residential spaces in a building, and heat energy is consumed through the boiler. At this time, the amount of energy consumed by the boiler may increase or decrease depending on the performance of the boiler itself, the length of the heating pipes in the supply system, the insulation condition, the temperature of the supplied water, and the temperature around the supply system.

[0004] The amount of energy consumed by a boiler is always higher than the same heating demand. This is because a transport network is required to deliver thermal energy to where heating is needed, and heat loss through this process is inevitable.

[0005] In addition, conventionally, the energy supplied to the space requiring heating demand is fixed at the maximum value, so the amount of energy in the boiler is always at its maximum, and heat loss is also always maintained at its highest level.

[0006] Korean Registered Patent No. 10-2537556 relates to a building heating and cooling load prediction simulation system and method, comprising: a collection unit that collects measurement data including energy consumption of a target building and management data for electrical, HVAC, security, and fire prevention facilities from a Building Energy Management System (BEMS); an identification unit that identifies indoor and outdoor temperatures, humidity, and solar radiation measured in the building in real time based on a Radiant Time Series (RTS method); a relationship derivation unit that derives a correlation between the heating and cooling load according to energy consumption and the indoor and outdoor temperatures, humidity, and solar radiation identified by the identification unit based on the BEMS measurement data collected by the collection unit; a simulation unit that simulates changes in heating and cooling loads according to changes in at least one of the measurement data based on the correlation derived by the relationship derivation unit; and an information provision unit that provides the simulation results from the simulation unit to a user terminal in a visible form.

[0007] Applying BEMS to existing building systems can be burdensome, given that it requires not only using BEMS for building energy conservation but also collecting radiation time-series data and monitoring indoor and outdoor temperatures, humidity, and solar radiation. The problem to be solved

[0009] The present invention provides a method for operating a heating system of a large building in real time, which maintains the elements for controlling the system to a minimum while expecting optimal efficiency.

[0010] The present invention provides a method for operating a heating system in a large building that enables smart control of heating system control elements with minimal installation in existing buildings, thereby allowing for easy application in the improvement of existing building heating systems. means of solving the problem

[0012] According to an exemplary embodiment of the present invention, a method for operating a heating system of a large building may include the steps of: providing a heating system comprising a heat source, a heat source piping section for supplying heat source water heated by the heat source, an air conditioner provided to a heating space of the building, a heating piping section for supplying heating water to the air conditioner, and a heat exchanger for transferring thermal energy between the heat source piping section and the heating piping section; providing a heating water supply temperature sensor for measuring the real-time temperature (HWST(t)) of the heating water supplied from the heating piping section to the air conditioner, and a control unit for controlling the operation of the heating system by referring to the heating water supply temperature sensor; the control unit receiving the real-time temperature (SAT(t)) of the heated supply air supplied by the air conditioner; and the control unit controlling the real-time temperature (HWST(t)) of the heating water by referring to the real-time temperature (SAT(t)).

[0013] The air conditioner may include a return section (RA) for drawing in indoor air, a supply section (SA) for supplying air into the room, an outside section (OA) for drawing in outside air, and an exhaust section (EA) for discharging indoor air to the outside, and the supply section may be provided with a cooling coil and a heating coil. In addition, a filter, a humidifier, a dehumidifier, a blower, etc., may be installed.

[0014] The control unit defines the temperature of the air flowing into the heating coil of the air conditioner as the intake real-time temperature (MAT(t)) and the temperature of the air flowing out from the heating coil of the air conditioner as the supply real-time temperature (SAT(t)), and can control the supply real-time temperature of the heating water (HWST(t)) using the difference between the supply real-time temperature (SAT(t)) and the intake real-time temperature (MAT(t)).

[0015] The real-time supply temperature of heating water (HWST(t)) can be calculated by the following equation, where HWRT lowθ is the lower limit temperature of the return of heating water recovered from the air conditioner, Q(t) is the heating demand of the air conditioner by time period (Kcal / hr), and DF may be the characteristic coefficient of the air conditioner.

[0016] HWST(t)=HWRT low + Q(t) / DF

[0017] The characteristic coefficient of an air conditioner can be calculated by the following equation, where Q dsg is the appropriate design capacity of the air conditioner, and HWST dsg is the appropriate design temperature for the supply of heating water to the air conditioner, and HWRT dsg This can be the appropriate design temperature for the return of heating water recovered from the air conditioner.

[0018] DF = Q dsg / (HWST dsg - HWRT dsg )

[0019] Lower return temperature of heating water recovered from the air conditioner (HWRT) low ) can be calculated by the following formula, where HWST max is the maximum supply temperature of the heating water supplied to the air conditioner, and Q max This can be the maximum capacity of the air conditioner.

[0020] HWRT low = HWST max - Q max / DF

[0021] There are various methods to save heating energy in buildings during the winter, but energy loss (Q loss Efforts are needed to reduce ). Energy loss in the heating system can be affected by the length of the heating pipe section, the thickness of the pipe insulation, the ambient temperature, and the temperature of the water passing through the heating pipe. Effects of the invention

[0023] The method for operating a heating system for a large building according to the present invention controls the building's heating system in real time, and while minimizing the elements for controlling it, optimal efficiency can be expected.

[0024] The method for operating a heating system for large buildings according to the present invention enables the elements for controlling the system to be implemented in existing buildings with minimal installation, and allows for smart control to be achieved even with minimal installation. Therefore, improvements to the heating system can be easily applied to existing buildings rather than new ones. Brief explanation of the drawing

[0026] FIG. 1 is a drawing for explaining a heating system for a large building according to one embodiment of the present invention. Figure 2 is a drawing for explaining an air conditioner installed in the heating space of Figure 1. FIG. 3 is a graph illustrating the changes in heating load, supply air temperature, ventilation temperature, and outside air temperature of an air conditioner during one week in winter before applying a heating system according to one embodiment of the present invention. FIG. 4 is a graph illustrating the changes in the 24-hour heating load, supply air temperature, ventilation temperature, and outside air temperature of an air conditioner during winter before applying a heating system according to one embodiment of the present invention. FIG. 5 is a graph illustrating the changes in the heating load, heating water supply temperature, and outside temperature of an air conditioner during the winter for one week after applying a heating system according to one embodiment of the present invention. FIG. 6 is a graph illustrating the changes in the 24-hour heating load, heating water supply temperature, and outside temperature of an air conditioner during winter after applying a heating system according to one embodiment of the present invention. FIG. 7 is a diagram for comparing the correlation between the heating load and the supply temperature of the heating water before and after applying a heating system according to one embodiment of the present invention. FIG. 8 is a drawing for comparing the heating load, the heat loss rate of the heating pipe section, and the heat consumption before and after applying a heating system according to one embodiment of the present invention. Specific details for implementing the invention

[0027] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings, but the present invention is not limited or restricted by the embodiments. For reference, in this description, the same number refers to substantially the same element, and under this rule, descriptions of other drawings may be cited, and details deemed obvious to those skilled in the art or repetitive may be omitted.

[0028] FIG. 1 is a drawing for explaining a heating system for a large building according to an embodiment of the present invention, FIG. 2 is a drawing for explaining an air conditioner installed in the heating space of FIG. 1, FIG. 3 is a graph for explaining the changes in heating load, supply air temperature, ventilation temperature, and outside air temperature of an air conditioner during one week in winter before applying the heating system according to an embodiment of the present invention, FIG. 4 is a graph for explaining the changes in heating load, supply air temperature, ventilation temperature, and outside air temperature during one day in winter of an air conditioner before applying the heating system according to an embodiment of the present invention.

[0029] Referring to FIGS. 1 and 2, a heating system in a large building according to the present embodiment may include a boiler (10) as a heat source, a heat source piping section (20) that supplies heat source water heated by the boiler (10), an air conditioner (50) provided to a heating space on each floor of the building, a heating piping section (40) that supplies heating water to the air conditioner (50), and a heat exchanger (30) that transfers thermal energy between the heat source piping section (20) and the heating piping section (40).

[0030] These boilers (10), heat exchangers (30), air conditioners (50), etc. can be operated according to the control of the control unit, and a heating water supply temperature sensor (42) is installed in the heating pipe section (40) through which heating water is supplied from the heat exchanger (30) so that the real-time temperature (HWST(t)) of the heating water supplied to the air conditioner (50) through the heating pipe section (40) can be measured in real time.

[0031] The control unit can control the supply temperature of the heating water using the real-time supply temperature (HWST(t)) of the heating water measured by the heating water supply temperature sensor (42), and to do this, it can control the flow rate of the heating water or heat source water supplied to the heat exchanger (30), the operation of the boiler, etc.

[0032] The air conditioner (50) may include a recovery unit (RA) for drawing in indoor air, a supply unit (SA) for supplying air into the room, an outside unit (OA) for drawing in outside air, and an exhaust unit (EA) for discharging indoor air to the outside, and the supply unit may be provided with a cooling coil and a heating coil (52). The control unit may receive the real-time supply air temperature (SAT(t)) and the real-time intake air temperature (MAT(t)) from the supply air temperature sensor (54) and the intake air temperature sensor (56) of the air conditioner (50), and may control the real-time supply temperature of the heating water (HWST(t)) by referring to these.

[0033] The control unit may not be able to receive the real-time supply air temperature (SAT(t)) from the target air conditioner (50). In this case, the control unit may refer to the real-time supply air temperature (SAT(t)) received from another air conditioner on the same floor or adjacent to the target air conditioner among the air conditioners in operation. If this is also not feasible, it is also possible to use the real-time supply air temperature (SAT(t)) received from an air conditioner in operation by expanding the range of air conditioners further.

[0034] Generally, heat loss increases if the length of the piping is long, if the thickness of the pipe insulation is relatively thin, and if the temperature around the pipe is low. Additionally, heat loss increases if the temperature of the heating water flowing inside the pipe is high.

[0035] In the case of buildings currently in operation, it is difficult to modify the length of the piping sections or the thickness of the pipe insulation, and the temperature around the pipes cannot be artificially altered. In particular, in existing buildings where the heating system has been completed, making these changes is nearly impossible.

[0036] The operating results of existing heating systems can be verified through conventional winter heating. Most commercial building heating systems are designed to operate the heating water supply temperature of the boiler or heat exchanger within the range of 70°C to 80°C. This is to maintain the required indoor temperature during the winter season or during periods or times when peak heating demand occurs.

[0037] According to data analysis, for commercial buildings, peak heating demand occurs during the two-hour period starting one hour before the morning commute. There is no heating demand after the evening commute, and this pattern repeats the following morning. Additionally, there is no heating demand on weekends or holidays, even during the morning hours.

[0038] As shown in Fig. 3, the heating demand pattern, the supply air temperature pattern, the indoor temperature pattern, and the outdoor temperature pattern for an air conditioner supporting heating on one floor of a large commercial building for five days (Monday to Friday) can be identified.

[0039] Although the outdoor temperature varies by day of the week, the heating demand pattern is similar across days. Heating demand reached its peak around the morning rush hour, and then dropped to about 20% or less of the peak level from the following hour. This continued for about 6 hours or more.

[0040] Overall, the indoor temperature is well maintained at the set temperature of about 25℃ during working hours, indicating that the optimal working environment is satisfied.

[0041] Figure 4 shows the 24-hour heating demand pattern, the supply air temperature pattern, the indoor temperature pattern, and the outdoor temperature pattern for an air conditioner supporting heating on one floor of a large commercial building. It can be seen that the heating demand is at its lowest point before approximately 5:00 AM, then surges around 6:00 AM, maintains a peak of about 100 Mcal / hr until 9:00 AM, and then drops to about 20% to 30% of that level thereafter.

[0042] The temperature of the supply air supplied into the room by the air conditioner rose to about 40℃ at 6 AM, then dropped to around 25℃ after 10 AM, and then fluctuated slightly up and down again.

[0043] This phenomenon means that when the indoor temperature reaches the required appropriate temperature of about 25℃, there is no need for heating, and when the indoor temperature drops below about 25℃, heating energy can be supplied in the amount needed to maintain the appropriate indoor temperature.

[0044] Even if the outside temperature drops below freezing after 10 a.m., the demand for indoor heating may be low. This is because, after 10 a.m., heat sources other than heating may be generated indoors; for example, it can be assumed that internal heat sources such as lighting, occupants, and computers may contribute to heating energy.

[0045] Except during peak heating demand hours, the heating water temperature required by the air conditioner (usually a design standard temperature of 80°C) can be set and operated lower than the design standard. This can lead to the possibility of lowering the set value of the heating water supply temperature of the boiler or heat exchanger.

[0046] In the case of apartment district heating systems, approximately 10% of the heat loss through the heating pipes from the apartment machine room to the entrance of each unit is applied, and charges are applied by adding the loss occurring in the pipes to the value recorded by the unit's heat meter. For apartment district heating systems, the heating supply water temperature is set and operated at around 50℃.

[0047] In the case of commercial and office buildings, the heating supply water temperature is set to around 80°C, which is much higher than the heating supply water temperature of apartments, so the heat loss exceeds 10%, and if the distance from the machine room to the demand is long, the heat loss increases further.

[0048] In large buildings, it is possible to regulate the temperature of the heating water passing through the pipes, thereby reducing current energy losses. If the heating demand of the building or the space requiring heating is known, there are ways to supply the appropriate energy while minimizing energy loss.

[0049] The method involves supplying heating water at a lower temperature to minimize heat loss in the piping while supplying heating energy to meet heating demand, thereby reducing heat loss and ultimately reducing the amount of energy supplied.

[0050] FIG. 5 is a graph for explaining the changes in heating load, heating water supply temperature, and outside temperature of an air conditioner during winter for one week after applying a heating system according to one embodiment of the present invention, and FIG. 6 is a graph for explaining the changes in heating load, heating water supply temperature, and outside temperature of an air conditioner during winter for one 24-hour period after applying a heating system according to one embodiment of the present invention.

[0051] Referring to FIGS. 5 and 6, in a situation similar to FIGS. 3 and 4, the control unit controlled the real-time temperature of the heating water supply (HWST(t)) according to the heating demand, that is, the heating load pattern of the air conditioner.

[0052] As a result, the heating demand pattern, heating water (supply water) supply temperature pattern, and outdoor temperature pattern for five days (Monday to Friday) for the air conditioner supporting heating on one floor of the same large commercial building can be confirmed. For reference, the heating water supply temperature pattern is displayed by comparing the before and after improvement.

[0053] The control unit measures the real-time supply temperature (HWST(t)) of the heating water received from the heating water supply temperature sensor (42) and controls the real-time supply temperature (HWST(t)) of the heating water according to the heating demand (Kcal / hr) (Q(t)) of the air conditioner by time period based on this. Here, the heating demand by time period used as a reference may use real-time or historically recorded data.

[0054] The control unit receives the real-time supply temperature of the heating water (HWST(t)) and can simultaneously calculate the appropriate real-time supply temperature according to the following equation. Here, HWRT low θ is the lower limit temperature of the return of heating water recovered from the air conditioner, Q(t) is the heating demand of the air conditioner by time period (Kcal / hr), and DF may be the characteristic coefficient of the air conditioner.

[0055] HWST(t)=HWRT low + Q(t) / DF

[0056] Lower return temperature of heating water recovered from the air conditioner (HWRT) low ) can be determined according to the design characteristics of the air conditioner, and the maximum capacity of the air conditioner and the maximum supply temperature of the heating water can be used.

[0057] HWRT low = HWST max - Q max / DF

[0058] Here, HWST max is the maximum supply temperature of the heating water supplied to the air conditioner, and Q max can be the maximum capacity of the air conditioner.

[0059] In addition, the characteristic coefficient of the air conditioner can utilize the appropriate design capacity of the air conditioner, the appropriate design temperature for the supply of heating water, the appropriate design temperature for the return of heating water, etc.

[0060] DF = Q dsg / (HWST dsg - HWRT dsg )

[0061] Here, Q dsg is the appropriate design capacity of the air conditioner, and HWST dsg is the appropriate design temperature for the supply of heating water to the air conditioner, and HWRT dsg This can be the appropriate design temperature for the return of heating water recovered from the air conditioner.

[0062] FIG. 7 is a diagram for comparing the correlation between the heating load and the supply temperature of the heating water before and after applying a heating system according to one embodiment of the present invention, and FIG. 8 is a diagram for comparing the heating load, the heat loss rate of the heating piping section, and the heat consumption amount before and after applying a heating system according to one embodiment of the present invention.

[0063] Referring to FIGS. 7 and 8, before the heating system according to the present invention was applied, the supply temperature of the heating water was maintained at a high level of about 71 to 72°C regardless of the heating load of the air conditioner. This means that the amount of energy required to maintain the temperature of the heating water at about 71 to 72°C was excessive, and that the amount of heat loss through the heating pipe section (40) was also high.

[0064] However, after applying the heating system according to the present invention, the real-time temperature of the supply of heating water (HWST(t)) can be varied in the range of about 62 to 72°C depending on the heating load, and the amount of heat loss through the heating pipe section (40) can also be reduced over a considerable period of time.

[0065] As a result, as shown in Fig. 8, after the improvement, while maintaining the same heating load, the heat loss rate over one week was reduced by about 6.7%, and the heat energy consumption was also reduced by about 6.0%.

[0066] Although there are various methods to save heating energy in buildings during the winter, energy loss (Q) is achieved through real-time temperature control of the heating water supply (HWST(t)). loss It was confirmed that reducing ) is effective.

[0067] As described above, although the present invention has been explained with reference to preferred embodiments, those skilled in the art will understand that various modifications and changes can be made to the present invention without departing from the spirit and scope of the invention as set forth in the following claims. Explanation of the symbols

[0069] 10 : Boiler 20 : Heat source piping section 30 : Heat exchanger 40 : Heating piping section 50 : Air conditioner

Claims

Claim 1 A method for operating a heating system for a large building comprises: providing a heating system including a heat source, a heat source piping section for supplying heat source water heated by the heat source, an air conditioner provided to a heating space of the building, a heating piping section for supplying heating water to the air conditioner, and a heat exchanger for transferring thermal energy between the heat source piping section and the heating piping section; providing a heating water supply temperature sensor for measuring the real-time temperature (HWST(t)) of the heating water supplied from the heating piping section to the air conditioner, and a control unit for controlling the operation of the heating system by referencing the heating water supply temperature sensor; and the control unit receiving the real-time temperature (SAT(t)) of the heated supply air supplied by the air conditioner. The method of operating a heating system for a large building includes the step of the control unit controlling the supply real-time temperature (HWST(t)) of the heating water by referring to the supply real-time temperature (SAT(t)); wherein, if the control unit does not receive the supply real-time temperature (SAT(t)) from the specified air conditioner, the control unit controls the supply real-time temperature (HWST(t)) of the heating water by referring to the supply real-time temperature (SAT(t)) received from another air conditioner on the same floor or an adjacent floor. Claim 2 A method for operating a heating system of a large building according to claim 1, wherein the control unit defines the temperature of the air flowing into the heating coil of the air conditioner as the intake real-time temperature (MAT(t)), defines the temperature of the air flowing out from the heating coil of the air conditioner as the supply real-time temperature (SAT(t)), and controls the supply real-time temperature (HWST(t)) of the heating water using the difference between the supply real-time temperature (SAT(t)) and the intake real-time temperature (MAT(t)). Claim 3 In paragraph 2, the supply real-time temperature (HWST(t)) of the heating water is calculated by the following formula, HWST(t) = HWRT low + Q(t) / DF where, HWRT low A method for operating a heating system for a large building, characterized in that is the lower limit temperature of the return of the heating water recovered from the air conditioner, Q(t) is the heating demand (Kcal / hr) of the air conditioner by time period, and DF is the characteristic coefficient of the air conditioner. Claim 4 In paragraph 3, the characteristic coefficient of the air conditioner is calculated by the following formula: DF = Q dsg / (HWST dsg - HWRT dsg Here, Q dsg is the appropriate design capacity of the above air conditioner, and HWST dsg is the appropriate design temperature for the supply of heating water supplied to the above air conditioner, and HWRT dsg A method for operating a heating system for a large building, characterized in that the return temperature of the heating water recovered from the above air conditioner is the appropriate design temperature. Claim 5 In paragraph 4, the lower return temperature (HWRT) of the heating water recovered from the air conditioner low ) is calculated by the following formula, and HWRT low = HWST max - Q max / DF Here, HWST max is the maximum supply temperature of the heating water supplied to the above air conditioner, and Q max A method for operating a heating system for a large building, characterized by the fact that the above air conditioner has a maximum capacity. Claim 6 delete

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