Water heat storage system and operatiing method thereof

Abstract

A thermal storage system according to an embodiment of the present invention comprises a thermal storage tank, a load, a first on-off valve for controlling the flow of water between the top of the thermal storage tank and the top of the load, a second on-off valve for controlling the flow of water between the top of the thermal storage tank and the bottom of the load, an inverter pump connected to the bottom of the load to control the speed of the water, an opening control valve capable of controlling the flow and amount of water between the top and bottom of the load and the bottom of the thermal storage tank, a first temperature sensor for measuring the temperature of water discharged from the bottom of the load, a second temperature sensor for measuring the temperature of water at the bottom of the thermal storage tank, a third temperature sensor for measuring the temperature of water at the top of the thermal storage tank, and a control unit. The control unit can control the inverter control rate of the inverter pump and the opening control rate of the opening control valve using at least one of the temperatures measured using the first to third temperature sensors, and at least one of the set temperature of the top of the thermal storage tank and the set temperature of the top of the load.

Description

Technology Field

[0001] The present invention relates to a thermal storage system and a method of operating the same. Specifically, the thermal storage system comprises an opening control valve and an inverter pump, and the invention relates to a method of operating the thermal storage system using the same. Background Technology

[0002] Due to global warming, summers are becoming hotter and winters colder, leading to a continuous increase in electricity demand for heating and cooling. This not only poses a risk of power shortages but also results in significantly rising heating and cooling costs. To address these issues, there is a growing demand for thermal storage systems that can curb electricity demand during peak daytime hours and reduce operating costs.

[0003] A thermal storage system refers to a system that utilizes heat sources such as geothermal, hydrothermal, or solar energy, or low-cost off-peak electricity, to accumulate hot or cold water in a storage tank and uses this to store heat or cold energy during peak power hours. More specifically, a thermal storage system is designed to store water in a heated or cooled state using a heat pump and subsequently supply heating or cooling to load units. Generally, by utilizing off-peak electricity to store heat at night and supplying it to load units during the day, it is possible to reduce power peaks while simultaneously saving energy.

[0004] As the thermal storage system utilizes water stored in the storage tank as the thermal storage material, it is necessary to maintain stratification to minimize heat exchange within the tank in order to utilize the water's thermal storage more effectively. If the temperature of the water supplied to the load fluctuates, it can cause variations in the load's output, potentially shortening the lifespan of the load-side equipment and making control difficult. Furthermore, if the temperature of the water supplied to the load is higher or lower than the reference temperature, heat loss increases. Therefore, for the stratification of the storage tank, the return temperature of the water entering the tank and the temperature of the water supplied to the load are critical. Prior art literature

[65535] Republic of Korea Published Patent No. 10-2009-0080757 (Storage heat type heat pump device and energy-saving individual cooling and heating system using the same) The problem to be solved

[0005] The technical problem to be solved by the present invention is to provide a thermal storage system capable of controlling the return temperature to the thermal storage tank and the supply temperature to the load, and a method for operating the same.

[0006] The technical problem to be solved by the present invention is to provide a method in which a thermal storage system includes an inverter pump and / or an opening control valve, and controls the return temperature to the thermal storage tank and the supply temperature to the load. means of solving the problem

[0007] According to an embodiment of the present invention, a thermal storage system comprises a thermal storage tank, a load, a first on-off valve for controlling the flow of water between the top of the thermal storage tank and the top of the load, a second on-off valve for controlling the flow of water between the top of the thermal storage tank and the bottom of the load, an inverter pump connected to the bottom of the load to control the speed of the water, an opening control valve capable of controlling the flow and amount of water between the top and bottom of the load and the bottom of the thermal storage tank, a first temperature sensor for measuring the temperature of water discharged from the bottom of the load, a second temperature sensor for measuring the temperature of water at the bottom of the thermal storage tank, a third temperature sensor for measuring the temperature of water at the top of the thermal storage tank, and a control unit. The control unit can control the inverter control rate of the inverter pump and the opening control rate of the opening control valve using at least one of the temperatures measured using the first to third temperature sensors, and at least one of the set temperature of the top of the thermal storage tank and the set temperature of the top of the load.

[0008] The control unit according to an embodiment of the present invention can adjust the inverter control rate of the inverter pump and the opening control rate of the opening control valve differently depending on the heating period and the cooling period.

[0009] A control unit according to an embodiment of the present invention can determine the opening control rate of the opening control valve during a heating period based on the set temperature of the upper load, the temperature measured through the third temperature sensor, and the temperature measured through the first temperature sensor.

[0010] A control unit according to an embodiment of the present invention can control the opening control rate of the opening control valve during a heating period as (set temperature of the upper load - temperature measured through the third temperature sensor) / (temperature measured through the first temperature sensor - temperature measured through the third temperature sensor).

[0011] A control unit according to an embodiment of the present invention can determine the inverter control rate of the inverter pump during a heating period based on the set temperature at the top of the load, the temperature measured through the first temperature sensor, and the set temperature at the bottom of the thermal storage tank.

[0012] A control unit according to an embodiment of the present invention can control the inverter control rate of the inverter pump during a heating period as (set temperature of the upper load - temperature measured through the first temperature sensor) / (set temperature of the upper load - set temperature of the lower thermal storage tank).

[0013] A control unit according to an embodiment of the present invention can determine the opening control rate of the opening control valve during a cooling period based on the set temperature of the upper load, the temperature measured through the second temperature sensor, and the temperature measured through the first temperature sensor.

[0014] A control unit according to an embodiment of the present invention can control the opening control rate of the opening control valve during the cooling period as (set temperature of the upper load - temperature measured through the first temperature sensor) / (temperature measured through the second temperature sensor - temperature measured through the first temperature sensor).

[0015] A control unit according to an embodiment of the present invention can determine the inverter control rate of the inverter pump during the cooling period based on the set temperature of the upper load, the temperature measured through the first temperature sensor, and the set temperature of the upper thermal storage tank.

[0016] A control unit according to an embodiment of the present invention can control the inverter control rate of the inverter pump during the cooling period as (set temperature of the upper load - temperature measured through the first temperature sensor) / (set temperature of the upper load - set temperature of the upper thermal storage tank).

[0017] In the control unit according to an embodiment of the present invention, the heating period and the cooling period can be determined by external input.

[0018] In the control unit according to an embodiment of the present invention, the heating period and the cooling period may be determined by the date or the average temperature of the said date. Effects of the invention

[0019] According to an embodiment of the present invention, the temperature of the water returned to the thermal storage tank can be controlled by controlling the inverter control rate of the inverter pump.

[0020] According to an embodiment of the present invention, the temperature of the water returned to the thermal storage tank can be controlled by controlling the opening control rate of the opening control valve.

[0021] The supply and return temperatures can be controlled simultaneously through the control of the inverter pump and the opening control valve. Brief explanation of the drawing

[0022] Figure 1 is a diagram showing the configuration of a thermal storage system according to an embodiment of the present invention. FIG. 2 is an operating state diagram of the heating period of a thermal storage system according to an embodiment of the present invention. FIG. 3 is an operating state diagram of the cooling period of a thermal storage system according to an embodiment of the present invention. Specific details for implementing the invention

[0023] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[0024] However, the technical concept of the present invention is not limited to some of the described embodiments but can be implemented in various different forms, and within the scope of the technical concept of the present invention, one or more of the components among the embodiments may be selectively combined or substituted.

[0025] In addition, terms used in the embodiments of the present invention (including technical and scientific terms) may be interpreted in a sense that is generally understood by those skilled in the art to which the present invention belongs, unless explicitly and specifically defined otherwise. Terms that are commonly used, such as terms defined in advance, may be interpreted in consideration of their meaning in the context of the relevant technology.

[0026] Furthermore, the terms used in the embodiments of the present invention are for the purpose of describing the embodiments and are not intended to limit the present invention.

[0027] In this specification, the singular form may include the plural form unless specifically stated otherwise in the text, and when described as "at least one of A and B and C (or more than one)," it may include one or more of all combinations that can be formed from A, B, and C.

[0028] In addition, terms such as first, second, A, B, (a), (b), etc. may be used when describing the components of the embodiments of the present invention.

[0029] These terms are intended merely to distinguish a component from other components and are not limited by the nature, order, sequence, etc., of the said component.

[0030] And, where it is stated that a component is 'connected', 'combined', or 'joined' to another component, this may include not only cases where the component is directly connected, combined, or joined to the other component, but also cases where it is 'connected', 'combined', or 'joined' due to another component located between the component and the other component.

[0031] Furthermore, when described as being formed or placed "above or below" each component, "above" or "below" includes not only cases where two components are in direct contact with each other, but also cases where one or more other components are formed or placed between the two components. Additionally, when expressed as "above or below," it may include the meaning of a downward direction as well as an upward direction relative to a single component.

[0032] Figure 1 is a diagram showing the configuration of a thermal storage system according to an embodiment of the present invention.

[0033] Referring to FIG. 1, a thermal storage system (100) according to an embodiment of the present invention may include a thermal storage tank (110), a load (120), a first on-off valve (130), a second on-off valve (140), an inverter pump (150), an opening control valve (160), a first temperature sensor (171), a second temperature sensor (172), a third temperature sensor (173), and a control unit (not shown). Components through which water flows within the thermal storage system (100) may be connected by piping.

[0034] The thermal storage tank (110) is configured to store thermal energy, and in the present invention, water is stored as the thermal storage material. The water stored in the thermal storage tank (110) can be stratified so that high-temperature water is located at the top and low-temperature water is located at the bottom. In the present invention, water is described as an example of the thermal storage material, but other fluids can also be the thermal storage material and are not limited thereto. For the water stored in the thermal storage tank (110) to be stratified, the return temperature of the water entering the thermal storage tank (110) must be above a certain temperature during the cooling period and below a certain temperature during the heating period.

[0035] Pipes may be connected to the top and bottom of the thermal storage tank (110), respectively. Through the pipes, water stored in the thermal storage tank (110) may be discharged to the outside or returned to the thermal storage tank (110) from the outside. In the present invention, the top of the thermal storage tank (110) may be connected to one end of the first on-off valve (130) and the second port of the opening control valve (160) via pipes, and the bottom of the thermal storage tank (110) may be connected to the first port of the opening control valve (160) and one end of the second on-off valve (140) via pipes.

[0036] According to one embodiment, the water in the thermal storage tank (110) may be reduced by evaporation, etc., and may be supplied additionally if necessary.

[0037] The load (120) is a device requiring cooling or heating, for example, it may be a heating and cooling system. The load (120) may be a heating system during the heating period and a cooling system during the cooling period.

[0038] Pipes are connected to the upper and lower ends of the load (120) respectively so that water can be supplied or discharged from the outside. External water can be supplied to the load (120) from the upper end of the load (120) and discharged to the lower end of the load (120). The upper end of the load (120) can be connected to the other end of the first on-off valve (130) via pipes, and the lower end of the load (120) can be connected to the other end of the inverter pump (150) via pipes.

[0039] In the present invention, the flow rate of water supplied to the top of the load (120) can be predetermined. That is, the flow rate of water discharged from the thermal storage tank (110) may vary depending on the opening control rate of the opening control valve (160) and / or the inverter control rate of the inverter pump (170), but the flow rate of water supplied to the top of the load (120) may be constant.

[0040] A first on-off valve (130) (or, an opening / closing valve) may be installed between the top of the thermal storage tank (110) and the top of the load (120). More specifically, one end of the first on-off valve (130) may be connected to the top of the thermal storage tank (110) and the second port of the opening control valve (160) via piping, and the other end of the first on-off valve (130) may be connected to the top of the load and the other end of the second on-off valve (140) via piping so that water can flow. The control unit may control the flow of water using the first on-off valve (130).

[0041] The first on-off valve (130) can be controlled to be on (or open) or off (or closed). When the first on-off valve (130) is on, water can move between the top of the thermal storage tank (110) and the top of the load (120), and when it is off, water cannot move between the top of the thermal storage tank (110) and the top of the load (120).

[0042] A second on-off valve (140) (or, opening / closing valve) may be installed between the bottom of the thermal storage tank (110) and the top of the load (120). More specifically, one end of the second on-off valve (140) may be connected to the bottom of the thermal storage tank (110) and the first port of the opening control valve (160) via piping, and the other end of the second on-off valve (140) may be connected to the other end of the first on-off valve (130) and the top of the load (120) via piping. The control unit may control the flow of water using the second on-off valve (140) when necessary.

[0043] Similar to the first on-off valve (130), the second on-off valve (140) can also be controlled to be on or off. When the second on-off valve (140) is turned on, water can move from the bottom of the thermal storage tank (110) and the bottom of the load (120) to the top of the load (120), and when it is turned off, water cannot move from the bottom of the thermal storage tank (110) and the bottom of the load (120) to the top of the load (120). The water moving (or flowing) from the bottom of the load (120) to the top of the load (120) may be referred to as bypassed water.

[0044] The inverter pump (150) is connected to the bottom of the load and can control the speed of water discharged from the load. One end of the inverter pump (150) can be connected to the third port of the opening control valve (160) via piping, and the other end of the inverter pump (150) can be connected to the bottom of the load (120) via piping.

[0045] An inverter pump (150) is a type of pump that uses an inverter to control the speed and operation of the pump. By adjusting the frequency of the inverter, the speed of the flow rate circulating within the pipe can be controlled. For example, if the frequency of the inverter is lowered, the flow rate circulating through the pipe decreases, and if the frequency of the inverter is higher, the flow rate circulating through the pipe increases. To control the speed of the flow rate, the control unit can control the inverter control rate of the inverter pump (150).

[0046] By using the inverter pump (150), the temperature of the water returned to the thermal storage tank (110) can be controlled. Additionally, by using the inverter pump (150), the temperature of the water supplied to the load (120) can also be controlled.

[0047] The opening control valve (160) can control the opening of the pipe that bypasses water in the present invention. If the opening control rate of the opening control valve (160) is 100%, it means that all the water is bypassed, and if it is 0%, it means that no water is bypassed. That is, if the opening control rate of the opening control valve (160) is 100%, the water is not returned to the thermal storage tank (110) and is supplied back to the load (120), and if the opening control rate of the opening control valve (160) is 0%, it means that all the water is returned to the thermal storage tank (110).

[0048] In the present invention, the first port of the opening control valve (160) is connected to the bottom of the thermal storage tank (110) and one end of the second on-off valve (140) via piping, the second port of the opening control valve (160) is connected to the top of the thermal storage tank (110) and one end of the first on-off valve (130) via piping, and the third port of the opening control valve (160) is connected to one end of the inverter pump (150) via piping. When the opening control rate of the opening control valve (160) is 100, all water entering through the third port of the opening control valve (160) is discharged through the second port of the opening control valve (160), and when the opening control rate of the opening control valve (160) is 0, all water entering through the third port of the opening control valve (160) is discharged through the first port of the opening control valve (160).

[0049] According to one embodiment, a temperature sensor may be installed at the bottom of the load (120). The temperature sensor installed at the bottom of the load (120) may be referred to as a first temperature sensor, and the return temperature according to the amount of heat consumed by the load can be measured through the first temperature sensor.

[0050] According to one embodiment, a temperature sensor may also be installed at the top and / or bottom of the thermal storage tank (110). The temperature sensor installed at the bottom of the thermal storage tank (110) may be referred to as a second temperature sensor, and the temperature at the bottom of the thermal storage tank (110) can be measured through the second temperature sensor. The temperature at the bottom of the thermal storage tank (110) measured through the second temperature sensor may be the temperature of low-temperature water for stratification of the thermal storage tank. The temperature of low-temperature water for stratification of the thermal storage tank may be determined according to the heat production amount of the heat source equipment during the cooling period. The temperature sensor installed at the top of the thermal storage tank (110) may be referred to as a third temperature sensor, and the temperature at the top of the thermal storage tank (110) may be measured through the third temperature sensor. The temperature at the top of the thermal storage tank (110) measured through the third temperature sensor may be the temperature of high-temperature water for stratification of the thermal storage tank. The temperature of the high-temperature water for stratification of the thermal storage tank can be determined according to the heat production amount of the heat source equipment during the heating period.

[0051] The control unit can control the first on-off valve (130), the second on-off valve (140) of the thermal storage system (100), the inverter control rate of the inverter pump (150), and the opening control rate of the opening control valve (160). The control unit can control the first on-off valve (130), the second on-off valve (140), the inverter control rate of the inverter pump (150), and the opening control rate of the opening control valve (160) by distinguishing between the heating period and the cooling period. According to one embodiment, the control unit can control the first on-off valve (130), the second on-off valve (140), the inverter control rate of the inverter pump (150), and the opening control rate of the opening control valve (160) of the thermal storage system (100) using wired or wireless communication.

[0052] The control unit can distinguish between the heating period and the cooling period through external input. For example, the thermal storage system (100) includes a button or switch on the outside so that the heating period and the cooling period can be distinguished based on the input of the button or switch.

[0053] As another example, the control unit can distinguish between the heating period and the cooling period based on the date or the average temperature of the date. For instance, the period requiring heating can be pre-set as the heating period and the period requiring cooling as the cooling period, and the control unit can distinguish between the heating period and the cooling period based on this.

[0054] The control unit can maintain stratification of the thermal storage tank (110) by adjusting the opening control rate of the opening control valve (160) to maintain the temperature of the water returned to the thermal storage tank (110) at or below a certain temperature or above. However, if only the opening control rate of the opening control valve (160) is adjusted, the temperature of the water supplied to the upper load may vary depending on the temperature of the water returned from the lower load.

[0055] The control unit can maintain a constant temperature of the water returned to the thermal storage tank (110) by adjusting the inverter control rate of the inverter pump (150). However, if only the inverter control rate of the inverter pump (150) is adjusted, the temperature of the water supplied to the load may be higher or lower than a certain temperature.

[0056] The control unit can control both the opening control rate of the opening control valve (160) and the inverter control rate of the inverter pump (150) when necessary to keep the temperature of the water returned to the thermal storage tank and the temperature of the water supplied to the load constant.

[0057] Below, the operating conditions of the thermal storage system (100) during the heating and cooling periods are described in detail.

[0058] FIG. 2 is an operating state diagram of the heating period of a thermal storage system according to an embodiment of the present invention.

[0059] First, the temperature (T2) of the water returned to the thermal storage tank (110) during the heating period s The temperature (T4) of the water supplied to the load (120) and load s ) can be set. For example, the temperature (T2) of the water returned to the thermal storage tank (110). s ) can be set to 45℃, and the temperature (T4) of the water supplied to the load (120) s ) can be set to 50℃. Also, the flow rate (F1) flowing to the top of the load (120) s ) can also be set. For example, the flow rate (F1) flowing to the top of the load (120). s ) can be set to 600lpm.

[0060] During the heating period, water stored in the thermal storage tank (110) can be supplied to the load (120) through the top and returned through the bottom. To this end, the control unit can set the first on-off valve (130) to ON. Water stored in the thermal storage tank (110) can be supplied to the top of the load (120) through the top of the thermal storage tank (110), and some of the water discharged through the bottom of the load (120) can also be supplied to the top of the load (120). Some of the water discharged through the bottom of the load (120) is water bypassed through the opening control valve (160). Additionally, the control unit can set the second on-off valve (140) to OFF to prevent water that should flow into the bottom of the thermal storage tank (110) from flowing into the top of the load (120).

[0061] The water discharged from the bottom of the load (120) can be measured by the first temperature sensor (171). If the load (120) is small, the temperature (T1) measured by the first temperature sensor (171) may be relatively high, and if the load (120) is large, the temperature (T1) measured by the first temperature sensor (171) may be relatively low. The control unit can control the inverter control rate of the inverter pump (150) and the opening control rate of the opening control valve (160) based on the temperature (T1) measured using the first temperature sensor (171).

[0062] Specifically, the control unit can calculate and control the opening control rate (b) of the opening control valve (160) using the law of conservation of energy as follows. According to the law of conservation of energy, the total heat amount of water supplied to the load (120) may be equal to the sum of the heat amount of water bypassed through the opening control valve (160) and the heat amount of water discharged from the top of the thermal storage tank (110). Here, the total heat amount of water supplied to the top of the load (120) is the flow rate (F1) flowing in the piping at the top of the load (120). s The set temperature (T4) of the water supplied to the top of the load (120) and the load (120) s The heat amount of the water bypassed through the opening control valve (160) is the product of ), and the flow rate (F1) flowing in the pipe s It is the value obtained by multiplying the temperature (T1) measured using the first temperature sensor (171) by the product of the opening control rate (b) of the opening control valve (160). The heat amount of water discharged from the top of the thermal storage tank is the value obtained by multiplying the amount of water discharged from the top of the thermal storage tank by the temperature (T3) measured using the third temperature sensor (173). Since the amount of water supplied to the load is predetermined, the amount of water discharged from the top of the thermal storage tank may be equal to the amount of water not bypassed through the opening control valve. This can be expressed as [Equation 1].

[0063] [Mathematical Formula 1]

[0064]

[0065]

[0066]

[0067] That is, the opening control rate (b) of the opening control valve (160) is the set temperature (T4) at the top of the load (120). s ) - Temperature measured through the third temperature sensor (T3)) / (Temperature measured through the first temperature sensor (T1) - Temperature measured through the third temperature sensor (T3)) can be determined.

[0068] In addition, the inverter control rate of the inverter pump (150) can be calculated as follows.

[0069] According to the law of conservation of energy, the product of the temperature difference and the flow rate is constant. Therefore, the set temperature (T2) of the water returned to the thermal storage tank (110) s If ) is changed, the inverter control rate (h) must also be changed. That is, the temperature difference of the water before it is supplied to the other end of the inverter pump (150) is the set temperature (T4) of the water supplied to the top of the load (120). s The difference between the temperature (T1) measured using the first temperature sensor (171) and the flow rate may be the flow rate (F1) flowing in the pipe at the top of the load. s ) It may be. Also, the temperature difference of the water discharged from one end of the inverter pump (150) is the set temperature (T4) of the water supplied to the top of the load (120). s ) and the set temperature (T2) of the water returned to the thermal storage tank (110) s The difference may be ), and the flow rate is the flow rate (F1) flowing in the pipe at the top of the load (120). s It is the value obtained by multiplying ) by the inverter control rate (h). This can be expressed as a mathematical formula as [Equation 2].

[0070] [Mathematical Formula 2]

[0071]

[0072]

[0073] That is, the inverter control rate (h) of the inverter pump (150) is (set temperature (T4) at the top of the load s ) - Temperature measured by the first temperature sensor (T1)) / (Set temperature at the top of the load (T4 s ) - Set temperature at the bottom of the thermal storage tank (T2 s It can be determined as ))

[0074] According to one embodiment of the present invention, the opening control rate (b) of the opening control valve (160) and / or the inverter control rate (h) of the inverter pump (150) can be controlled to lower the temperature of the water returned to the thermal storage tank (110) to a certain temperature or lower, and the temperature of the water supplied to the load (120) can be set to a constant temperature.

[0075] FIG. 3 is an operating state diagram of the cooling period of a thermal storage system according to an embodiment of the present invention.

[0076] First, the temperature (T2) of the water returned to the thermal storage tank (110) during the cooling period s The temperature (T4) of the water supplied to the load (120) and load s ) can be set. For example, the temperature (T2) of the water returned to the thermal storage tank (110). s ) can be set to 15℃, and the temperature (T4) of the water supplied to the load (120) s ) can be set to 10℃. In addition, the flow rate (F1) flowing to the top of the load (120) s ) can also be set. For example, the flow rate (F1) flowing to the top of the load (120). s ) can be set to 600lpm.

[0077] During the cooling period, water stored in the thermal storage tank (110) can be supplied to the load (120) through the bottom and returned through the top. To this end, the control unit can set the first on-off valve (130) to off and the second on-off valve (140) to on. Accordingly, water stored in the thermal storage tank (110) can be supplied to the top of the load (120) through the bottom of the thermal storage tank (110), and some of the water discharged through the bottom of the load (120) can also be supplied to the top of the load (120). Some of the water discharged through the bottom of the load (120) is water that is not bypassed through the opening control valve (160). Additionally, the bypassed water among the water discharged from the bottom of the load (120) can flow into the top of the thermal storage tank (110). Meanwhile, the flow of water between the top of the thermal storage tank (110) and the top of the load (120) can be prevented through the first on-off valve (130) that is turned off.

[0078] The water discharged from the bottom of the load (120) can be measured by the first temperature sensor (171). If the load (120) is small, the temperature (T1) measured by the first temperature sensor (171) may be relatively low, and if the load (120) is large, the temperature (T1) measured by the first temperature sensor (171) may be relatively high. The control unit can control the inverter control rate of the inverter pump (150) and the opening control rate of the opening control valve (160) based on the temperature (T1) measured using the first temperature sensor (171).

[0079] Specifically, the control unit can calculate and control the opening control rate (b) of the opening control valve (160) using the law of conservation of energy as follows. According to the law of conservation of energy, the total heat amount of water supplied to the top of the load (120) may be equal to the sum of the heat amount of water discharged from the bottom of the thermal storage tank (110) and the heat amount of water not bypassed through the opening control valve (160). Here, the total heat amount of water supplied to the top of the load (120) is the flow rate (F1) flowing in the piping at the top of the load (120). s The set temperature (T4) of the water supplied to the top of the load (120) and the load (120) s The heat amount of water not bypassed through the opening control valve (160) is the product of ), and the flow rate (F1) flowing in the pipe s It is the value obtained by multiplying the ratio of the opening control rate of the opening control valve (160) that is not bypassed (1-b) by the temperature (T1) measured using the first temperature sensor (171). The amount of heat of the water discharged from the bottom of the thermal storage tank (110) is the value obtained by multiplying the amount of water discharged from the bottom of the thermal storage tank (110) by the temperature (T2) measured using the second temperature sensor (172). The amount of water discharged from the bottom of the thermal storage tank (110) may be equal to the amount of water bypassed through the opening control valve. This can be expressed as [Equation 3].

[0080] [Mathematical Formula 3]

[0081]

[0082]

[0083]

[0084] That is, the opening control rate (b) of the opening control valve (160) is the set temperature (T4) at the top of the load (120). s ) - Temperature measured through the first temperature sensor (T1)) / (Temperature measured through the second temperature sensor (T2) - Temperature measured through the first temperature sensor (T1)) can be determined.

[0085] In addition, the inverter control rate of the inverter pump (150) can be calculated as follows.

[0086] According to the law of conservation of energy, the product of the temperature difference and the flow rate is constant. Therefore, the set temperature (T2) of the water returned to the thermal storage tank (110) s If ) is changed, the inverter control rate (h) must also be changed. That is, the temperature difference of the water before it is supplied to the other end of the inverter pump (150) is the set temperature (T4) of the water supplied to the top of the load (120). s The difference between the temperature (T1) measured using the first temperature sensor (171) and the flow rate may be the flow rate (F1) flowing in the pipe at the top of the load. s ) It may be. Also, the temperature difference of the water discharged from one end of the inverter pump (150) is the set temperature (T4) of the water supplied to the top of the load (120). s ) and the set temperature (T3) of the water returned to the thermal storage tank (110). s ) is the difference, and the flow rate is the flow rate (F1) flowing in the pipe at the top of the load (120) s It is the value obtained by multiplying ) by the inverter control rate (h). This can be expressed mathematically as [Equation 4].

[0087] [Mathematical Formula 4]

[0088]

[0089]

[0090] That is, the inverter control rate (h) of the inverter pump (150) is (set temperature (T4) at the top of the load s ) - Temperature measured by the first temperature sensor (T1)) / (Set temperature at the top of the load (T4 s ) - Set temperature at the top of the thermal storage tank (T3 s It can be determined as ))

[0091] According to one embodiment of the present invention, the opening control rate (b) of the opening control valve (160) and / or the inverter control rate (h) of the inverter pump (150) can be controlled to lower the temperature of the water returned to the thermal storage tank (110) to a certain temperature or lower, and the temperature of the water supplied to the load (120) can be set to a constant temperature.

[0092] Although the invention has been described above with reference to embodiments, this is merely illustrative and does not limit the invention. Those skilled in the art will understand that various modifications and applications not exemplified above are possible within the scope of the essential characteristics of the embodiments. For example, each component specifically shown in the embodiments may be modified and implemented. Furthermore, differences related to such modifications and applications should be interpreted as being included within the scope of the invention as defined in the appended claims.

Claims

Claim 1 Thermal storage tank; load; a first on-off valve for controlling the flow of water between the top of the thermal storage tank and the top of the load; a second on-off valve for controlling the flow of water between the top of the thermal storage tank and the bottom of the load; an inverter pump connected to the bottom of the load to control the speed of the water; an opening control valve capable of controlling the flow and amount of water between the top and bottom of the load and the bottom of the thermal storage tank; a first temperature sensor for measuring the temperature of the water discharged from the bottom of the load; a second temperature sensor for measuring the temperature of the water at the bottom of the thermal storage tank; a third temperature sensor for measuring the temperature of the water at the top of the thermal storage tank; A thermal storage system comprising a control unit, wherein the control unit controls the inverter control rate of the inverter pump and the opening control rate of the opening control valve using at least one of the temperatures measured using the first to third temperature sensors, the set temperature of the upper part of the thermal storage tank, and at least one of the set temperature of the upper part of the load, and controls the first on-off valve and the second on-off valve, and controls the inverter control rate of the inverter pump and the opening control rate of the opening control valve differently according to the heating period and the cooling period. Claim 2 delete Claim 3 delete Claim 4 In claim 1, the control unit controls the opening control rate of the opening control valve during the heating period as (set temperature of the upper load - temperature measured through the third temperature sensor) / (temperature measured through the first temperature sensor - temperature measured through the third temperature sensor), a thermal storage system. Claim 5 A thermal storage system according to claim 1, wherein the control unit determines the inverter control rate of the inverter pump during the heating period using the set temperature at the top of the load, the temperature measured through the first temperature sensor, and the set temperature at the bottom of the thermal storage tank. Claim 6 In claim 5, the control unit controls the inverter control rate of the inverter pump during the heating period as (set temperature of the upper load - temperature measured through the first temperature sensor) / (set temperature of the upper load - set temperature of the lower thermal storage tank), a thermal storage system. Claim 7 A thermal storage system according to claim 1, wherein the control unit determines the opening control rate of the opening control valve during the cooling period using the set temperature of the upper load, the temperature measured through the second temperature sensor, and the temperature measured through the first temperature sensor. Claim 8 In claim 7, the control unit controls the opening control rate of the opening control valve during the cooling period as (set temperature of the upper load - temperature measured through the first temperature sensor) / (temperature measured through the second temperature sensor - temperature measured through the first temperature sensor), a thermal storage system. Claim 9 A thermal storage system according to claim 1, wherein the control unit determines the inverter control rate of the inverter pump during the cooling period using the set temperature at the top of the load, the temperature measured through the first temperature sensor, and the set temperature at the top of the thermal storage tank. Claim 10 In claim 9, the control unit controls the inverter control rate of the inverter pump during the cooling period as (set temperature of the upper load - temperature measured through the first temperature sensor) / (set temperature of the upper load - set temperature of the upper thermal storage tank), a thermal storage system. Claim 11 A thermal storage system according to claim 1, wherein the heating period and the cooling period are determined by external input. Claim 12 A thermal storage system in which, in paragraph 1, the heating period and the cooling period are determined by the date or the average temperature of the said date.

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