KR100633238B1 - Heating storage system for several heat storage-tank in one network - Google Patents

Abstract

The present invention relates to a heat storage tank system for district heating that can directly connect and operate a plurality of heat storage tanks in one pipe network, and has an object of enabling one or more heat storage tanks to be directly installed in a pipe network in different regions without using a heat exchanger.

District heat storage tank system capable of directly connecting and operating a plurality of heat storage tank according to the present invention, the heat storage tank 10 is connected to the inlet pipe (1) and the outlet side pipe (2) of the district heating system; A flow rate control valve installed in the inlet-side pipe of the heat storage tank to adjust the opening degree of the pipe; A pump for discharging the amount of water introduced into the heat storage tank; And a controller for detecting the amount of water flowing into the heat storage tank through the outlet pipe and adjusting the opening of the valve and the rotation speed of the pump so that the amount of water flowing through the outlet pipe is the same. It is configured by. The controller calculates the fluid mass based on the flow rate and temperature respectively detected by the flow meters 21.31 and the thermometers 22.32 installed in the inlet / outlet pipes, respectively, to control the inflow and outflow during operation at all times.

District heating, heat storage, piping, overflow, PID, mass flow

Description

Heating system for district heating that can directly connect and operate multiple heat storage tanks in one pipe network {Heating storage system for several heat storage-tank in one network}

1 is a block diagram of a heat storage tank system for district heating that can be directly connected to and operate a plurality of heat storage tank according to the present invention one pipe network.

<Description of the symbols for the main parts of the drawings>

1,2: pipe, 10: heat storage tank

20-1 ~ 4: Inflow flow control valve, P-1: Minimum flow pump

P-2: Heavy Load Flow Control Pump, P-3: High Load Flow Control Pump

P-4: High load flow control pump, 21, 31: Flow meter

22,32: thermometer, 40: heat storage tank internal temperature detection thermometer

50: ultrasonic sensor

The present invention relates to a heat storage tank system for district heating capable of directly connecting and operating a plurality of heat storage tanks to one pipe network. More specifically, one or more heat storage tanks can be directly installed in different regions of one pipe network without a separate heat exchange means. The present invention relates to a district heating storage system that can directly connect and operate a plurality of heat storage tanks in a pipe network so that hot water stored in the heat storage tank can be continuously supplied to a user from a minimum flow rate to a maximum flow rate through a pump having different capacities.

In general, district heating system is a system in which a group energy supplying company supplies collective energy through a pipe for heating and hot water supply to a large number of individual users, which is different from individual heating systems in which users have individual heating facilities. .

In other words, district heating is not equipped with heating facilities in various buildings such as houses, shopping malls, offices, schools, hospitals and factories in a city or a certain area, but a large scale heat production facility, that is, a cogeneration plant, is heated and heated. It is one of the group energy supply system that produces the hot water (80-120 ℃) necessary for the production and supply to each customer through the heat transportation pipe.

The district heating system is composed of a heat source facility for producing electricity and heat, a heat transport facility for transporting the generated heat, and a heat user facility for supplying heat transported by the heat transport facility to the user.

The heat source facilities include cogeneration plants, thermal boilers, and waste incinerators. Heat storage tanks and the like.

A cogeneration plant is a comprehensive energy system that produces heat and electricity at the same time using the same fuel. In general, the high-temperature unit uses power and the low-temperature unit as process heat, and the energy saving and environmental improvement effect is greater than general energy generation. When using cogeneration, there is a reduction in the amount of power generated by extracting some heat during expansion of the steam turbine, but the heat discarded in the condenser can be used for process or district heating.

Thermal boilers are boilers that produce heat for district heating. Steam boilers and hot water boilers use low-sulfur wax oil (LSWR), B-C oil and LNG as fuels. In Europe, coal is also used.

Waste incinerators can incinerate waste and produce steam as a by-product to generate electricity or use it for cogeneration.However, depending on the quality of waste, the heat generated is not constant and the calorie itself is not high. It is used as a base load.

The heat storage tank performs three functions as follows. The first is to maintain the static pressure of the district heating pipe network so that the re-evaporation phenomenon of hot water below the saturation pressure does not occur under any operating conditions. The second is the increase of the specific volume as the district heating water temperature in the heat pipe increases. To maintain the optimum system by absorbing the amount of expansion generated or reducing the shortage of pipe water according to the temperature decrease. Third, by storing excess heat at the time of low heat load, It is responsible for the peak load or the heat storage tank absorbs the fluctuation of the daily load to store the surplus heat, thereby improving the operation rate of the facility to play a role in economical operation.

The heat transportation facility includes a main transport pipe system circulation water pump, a heat transport pipe, a pressurized field facility, a heat exchanger chamber (or a pressure reducing valve room), and a distribution pipe system circulation water pump.

The thermal user equipment consists of a user heat exchanger capable of receiving district heating, a differential pressure flow control valve for smooth flow control, an expansion tank for heating and hot water circulation, and an expansion tank for storing and replenishing piping water.

On the other hand, the heat storage tank system applied to the district heating piping system is operated by installing one or two heat storage tanks in the same place in one pipe network, but when another heat storage tank is installed in the same pipe network in different places, Problems such as excess flow out of hunting and heat storage tanks occur.

In order to solve this problem, the heat storage tank is installed and operated in an indirect manner in which the heat storage tank is not directly installed in the piping system but separated from the piping system through a plate heat exchanger.

However, the indirect heat storage system using the plate heat exchanger according to the prior art has the following problems.

The heat storage tank and piping system are installed through the plate heat exchanger, and the heat storage tank is heat-exchanged with the plate heat exchanger, so that the temperature is limited when heat storage and heat dissipation occur. Therefore, energy efficiency and energy loss are generated in terms of energy. When the heat stored in the heat storage tank is supplied to the area by the heat exchanger, the loss of supply temperature is about 4-5 ° C. due to the characteristics of the heat exchanger. This energy loss causes unnecessary boiler operation and wastes much energy. In addition, the recovery temperature through the heat storage tank heat exchanger is formed to be higher than the temperature used in the region to increase the vacuum degree of the turbine exhaust stage to reduce the power generation efficiency. In terms of cost, there is a problem that a lot of maintenance costs are required.

The present invention is to solve the above-described problems, so that the supply fluid is circulated through the pump according to the load while maintaining a constant balance in the piping system while preventing the hot water and cold water stored in the heat storage tank to flow out of the heat storage tank. The purpose is to provide a district heating storage system that can directly connect and operate a plurality of storage tanks to one pipe network.

In addition, another object of the present invention is to increase the utilization rate and operation rate of the heat storage tank by operating a pump having a capacity corresponding to the pressure in the piping system to free the load adjusting capability.

District heat storage tank system capable of directly connecting and operating a plurality of heat storage tank according to the present invention for achieving the object as described above, the heat storage tank is connected to the inlet pipe and the outlet pipe of the district heating system, respectively; A flow rate control valve installed at an inflow pipe of the heat storage tank to control an opening degree of the pipe; A pump for discharging water at a flow rate flowing into the heat storage tank; The controller may be configured to adjust the valve opening and the rotation speed of the pump such that the amount of water flowing into the heat storage tank through the inlet pipe is equal to the amount of water flowing out through the outlet pipe.

And, according to the present invention, the controller is characterized in that for controlling the flow control valve and the pump on the basis of the temperature and the water level of the water stored in the heat storage tank.

The features and advantages of the present invention will become more apparent from the following detailed description based on the accompanying drawings. Prior to this, the terms or words used in the present specification and claims are defined in the technical spirit of the present invention on the basis of the principle that the inventor can appropriately define the concept of the term in order to explain his invention in the best way. It must be interpreted to mean meanings and concepts.

The district heat storage tank system capable of directly connecting and operating a plurality of heat storage tanks according to the present invention includes: a heat storage tank 10 to which the inlet pipe 1 and the outlet pipe 2 of the district heating system are respectively connected; Flow control valves (20-1, 20-2, 20-3, 20-4) installed in the middle of the inlet side pipe (1) of the heat storage tank (10) and the opening of the heat storage tank (10) Pumps (P-1, P-2, P-3, P-4) capable of pumping outflow as much as the flow rate, and the inflow pipe (1) and the outflow pipe (2), respectively, 2) Thermometers 21 and 31 for detecting the flow rate passing through, and thermometers mounted on the inlet pipe 1 and the outlet pipe 2 to detect the temperature of water flowing along the pipes 1 and 2 ( The mass of water supplied to the heat storage tank 10 and discharged from the heat storage tank 10 are detected by detecting the mass of water through the flow rates and temperatures detected through the 22 and 32 and the flow meters 21 and 31 and the thermometers 22 and 32. The mass of water is equal And a controller (proportional calculus controller) (not shown) for controlling the operation of the pumps P-1, P-2, P-3, and P-4.

That is, by maintaining the same mass of the water flowing through the inflow pipe 1 and the outflow pipe 2 of the heat storage tank 10, no overflow occurs in the heat storage tank 10 and the same flow rate is maintained in the heat storage tank 10. ) As it flows into and out of the tank, the pressure in the entire piping system does not rise more than necessary and can continue to operate stably.

The flow control valves 20-1, 20-2, 20-3, and 20-4 have a plurality of openings having different opening adjustment capabilities (shown as four in the drawing, but not limited to four) for precise opening adjustment. It is configured and selectively operated under the control of the controller. That is, after the controller determines the inflow of water, the controller selects and operates the flow control valves 20-1, 20-2, 20-3, and 20-4 suitable for the inflow of water by the determined inflow.

Then, pumps of different capacities (P-1, P-2, P-3, P-4) (shown as four in the drawing, but the quantity is not limited to four) are installed in parallel to the outlet side pipe ( The pump (P-1, P-2, P-3, P-4) corresponding to the pressure and load of 2) is operated so that the minimum flow rate can be supplied while preventing the pump from burning out.

Since the supply pressure of the piping system varies depending on the operating conditions and seasons, a flow control valve on the discharge side of the pump P-1 (for convenience, the pump P-1 is called the minimum flow pump) to control the minimum flow rate and the minimum load. (V-1) is installed, and the fluid circulation pipe (3) and automatic relief valve (V-5) are installed respectively, so that the minimum flow rate can be supplied in response to the pressure change in the piping system. That is, a pressure sensor (not shown) for measuring the pressure of the outlet side pipe (2) is further included, and the controller is a pump (P-1, P-2, P- of capacity corresponding to the pressure detected through the pressure sensor) 3, P-4) is controlled to operate.

In addition, since the total mass flow rate of the fluid in the heat storage tank 10 must be constant at all times to maintain the fluid balance of the entire piping system and prevent the disturbance of the system, according to the present invention, the temperature of the water stored in the heat storage tank 10 is measured. In addition to the thermometer 40 for the installation and the ultrasonic sensor 50 for measuring the water level is installed, the controller is based on the data detected through the thermometer 40 and the ultrasonic sensor 50 flow control valve 20- 1,20-2,20-3,20-4) to adjust the opening degree to prevent overflow. The thermometer 40 is installed at both sides in multiple stages with a predetermined height (for example, 0.5 m to 1 m) so that the temperature for each height in the heat storage tank 10 can be measured, and the ultrasonic sensor 50 is the bottom of the heat storage tank 10. The distance to the part and the distance of the surface of the stored water are respectively calculated. The controller compares the total fluid mass of the heat storage tank 10 with the amount flowing in and out of the heat storage tank 10, and is introduced when the fluid mass inside the heat storage tank 10 increases. The opening degree is adjusted through the flow control valves 20-1, 20-2, 20-3, 20-4 of the inlet pipe 1 so as to reduce the amount of fluid, and the fluid mass inside the heat storage tank 10 is reduced. When the inlet side pipe (1) through the flow control valve (20-1, 20-2, 20-3, 20-4) to open the opening to increase the mass of the fluid.

In the drawings, reference numeral V6 denotes a mode switching valve for switching the heat storage mode and the heat dissipation mode, P-5 is a district heating circulation main pump, and 60 is a district heating heat exchanger.

The function of the district heating storage tank system capable of directly connecting and operating a plurality of heat storage tanks according to the present invention configured as described above is as follows.

The hot water generated by the heat source facility (cogeneration plant, heat boiler, etc.) is transferred to the user's heat exchanger through the pipe, and then recovered to the heat source facility. At this time, when the usage amount of the user-side heat exchanger is small, it is stored in the heat storage tank 10. That is, the heat storage tank 10 accumulates the excess heat when the load is small, and radiates heat when the load is high.

In district heating system, the fluid is circulated along the pipe by the pumping force of the pump. The fluid pressure flowing through the pipe depends on the operation status of the district heating system. In other words, the fluid pressure in the pipe gradually increases from the lowest at the beginning of operation. The controller receives the pressure of the outlet pipe (2) through the pressure sensor, the pump corresponding to the fluid pressure of the input pipe (2) of the pump (P-1, P-2, P-3, P-4) Select (P-1, P-2, P-3, P-4) to operate. That is, when the initial operation and the low flow rate are required, the minimum flow rate is supplied by operating the minimum flow rate pump P-1, and the pumps P-2 and P-3 increase as the fluid pressure of the outlet pipe 2 increases. Select and operate P-4). Since the flow rate is not discharged when the flow rate sent by the minimum flow pump is less than the head pressure of the pipe network, the pump is overheated by the fluid. Therefore, when the discharge pressure of the minimum flow rate is lower than the piping pressure of the system, the relief valve (V-5) ) Is operated so that the fluid is automatically circulated to prevent overheating of the pump, and when the minimum flow discharge pressure is higher than the system piping pressure, the system automatically closes the system of the relief valve (V-5) to allow the fluid to be discharged. In this case, the small flow rate pump (P-1) allows the small flow rate to axially freely radiate even at a low load state.

When hot water is supplied to the heat storage tank 10 through the inflow pipe 1 in the heat storage mode, the flow meter 21 and the thermometer 22 respectively detect the flow rate and temperature of the hot water flowing along the inflow pipe 1 and the controller. To transmit. The controller detects the mass through the temperature and the flow rate, and pumps P-1, P-2, P- of the outlet side pipe 2 so that water having the same mass as the fluid mass flowing through the inlet side pipe 1 flows out. 3, P-4) by selecting one pump to adjust the rotational speed to the load to maintain the fluid mass flowing into the heat storage tank 10 and the fluid mass flowing out. The controller maintains the outflow amount equal to the inflow amount by calculating the fluid mass flowing out through the outflow side pipe 2 through the flow meter 31 and the thermometer 32 of the outflow side pipe 2.

On the other hand, the thermometers 40 inside the heat storage tank 10 respectively detect the temperature of the water stored in the heat storage tank 10 and transmit it to the controller, the ultrasonic sensor 50 detects the water level of the water stored in the heat storage tank 10 to the controller To transmit. The controller calculates the total fluid mass inside the heat storage tank 10 based on the temperature and the water level detected by the thermometer 40 and the ultrasonic sensor 50, and when the calculated current fluid mass is higher than the set value, the amount of the fluid flowing in is set. Since it is necessary to reduce the flow rate control valves (20-1, 20-2, 20-3, 20-4) by reducing the opening degree of the inlet pipe (1) or by selecting a pump with a large rotational speed to operate the internal storage tank (10) Maintains the total fluid mass at the set point and, on the contrary, if the current fluid mass is lower than the set point, the inlet flows through the flow control valves 20-1, 20-2, 20-3, 20-4 to increase the flow rate of the fluid. The fluid mass inside the heat storage tank 10 is maintained at a set value by increasing the opening degree of the side pipe 1 or selecting a pump having a low rotation speed to operate.

Although only the heat storage mode has been described so far, a constant amount of fluid mass is always stored in the heat storage tank 10 based on the above-described method in the heat radiation mode as well, and no overflow occurs.

As described above, according to the axial heat dissipation system for district heating according to the present invention, the heat storage tank can be directly installed in the district heating pipe network to reduce heat loss while reducing the cost, thereby maximizing the efficiency of the system, and In the district heating cogeneration system, it is possible to produce the maximum electricity at the time of high power unit price and save the maximum heat at the same time, thereby reducing the heat production and supplying the stored heat during the low electric unit price period, thereby increasing the economic efficiency of the cogeneration plant have.

In addition, since a pump having a capacity corresponding to the pressure of the pipe network is selectively driven to supply a minimum flow rate, and the burnout of the pump can be prevented, maintenance cost of the facility can be reduced.

While the invention has been described and illustrated in connection with a preferred embodiment for illustrating the principles of the invention, the invention is not limited to the configuration and operation as such is shown and described. Rather, it will be apparent to those skilled in the art that many changes and modifications to the present invention are possible without departing from the spirit and scope of the appended claims. Accordingly, all such suitable changes and modifications and equivalents should be considered to be within the scope of the present invention.

Claims (5)

A heat storage tank 10 to which the inlet pipe 1 and the outlet pipe 2 of the district heating system are respectively connected; A flow rate control valve capable of adjusting an inflow amount of hot water or cold water into an inlet-side pipe of the heat storage tank; A pump for delivering water as much as the flow rate introduced into the heat storage tank; And, the controller for controlling the opening degree of the valve and the number of revolutions of the pump to detect the mass of the water flowing into the heat storage tank through the outflow side pipe to the same amount of water flowing through the outlet side pipe Axial heat radiation system for district heating, characterized in that configured to include. A flow meter (21, 31) mounted to said pipes (1, 2) for detecting a flow rate of water flowing along each pipe; And further equipped with thermometers 22 and 32 mounted on the pipes 1 and 2, respectively, for detecting the temperature of water flowing along the pipes. A heat storage tank system for district heating that can directly connect and operate a plurality of heat storage tanks in one pipe network, by detecting a mass and adjusting the opening degree of the valve and the rotation speed of the pump. The valve of claim 1 or 2, wherein the valve is connected to the outlet pipe in parallel and includes a plurality of valves 20-1, 20-2, 20-3, and 20-4 having different opening ranges. And the controller selects and operates the valve corresponding to the opening degree control of the outlet side pipe among the valves. The heat storage tank system for district heating for directly connecting and operating a plurality of heat storage tanks to one pipe network. 4. The pump according to claim 3, wherein the pump comprises pumps of different capacities (P-1, P-2, P-3, P-4) connected in parallel to the outlet pipe. A heat storage tank system for district heating that can directly connect and operate a plurality of heat storage tanks to one pipe network, wherein the pump corresponding to the pressure and load of the outflow pipe is operated. 5. The apparatus of claim 4, further comprising: thermometers (40) installed at a predetermined height in the heat storage tank and measuring temperature of water corresponding to each unit height; An ultrasonic sensor 50 for measuring the level of water stored in the heat storage tank is further included, and the controller detects the fluid mass through the thermometer and the ultrasonic sensor so that a predetermined amount of water is maintained in the heat storage tank so as to maintain the inflow side flow control valve. District heat storage tank system that can be directly connected to a plurality of heat storage tanks and operating in a pipe network, characterized in that to adjust the opening degree of.

Images