JP2018004190A - Air conditioning system - Google Patents

Abstract

An air conditioning system capable of suppressing wasteful power consumption of a circulation pump and contributing to energy saving of a building is obtained. SOLUTION: The number of valves individually provided on the inlet side of a heat exchange tube in each location, the inverter output of an inverter that changes the number of revolutions of a circulation pump that circulates a heat medium, and ground heat exchange Select the table corresponding to the number of operating air conditioners from a plurality of preset tables that associate the heat exchange amount of the tube for each number of operated air conditioners, and calculate the calculated air conditioner from the selected table. Select the number of open valves and inverter output corresponding to the heat exchange amount of the underground heat exchange tube closest to the heat exchange amount, and control the opening and closing of each valve and the operation of the inverter according to the selection result Has been. [Selection] Figure 1

Description

  The present invention relates to an air conditioning system using geothermal heat.

  Conventionally, various things are proposed as an air-conditioning system using underground heat (for example, refer to patent documents 1-4). In addition, the air conditioner is configured to heat-exchange water as a heat medium used in a plurality of water-cooled PACs currently installed in a building or the like by a heat exchange tube embedded in the ground. In the system, if even one PAC is operating, a circulation pump for circulating water is operated.

JP-A-6-174333 JP 2002-054850 A JP 2003-130494 A JP 2011-247564 A

  Here, in the air conditioning system configured as described above, the circulation pump is an ON / OFF type, and is selected in anticipation of the maximum load, so that only one PAC is operating. Even so, it is necessary to operate the circulation pump at the maximum capacity of the pump. Thus, since the circulation pump is operated with the maximum capacity regardless of the number of operating PACs, there is a problem in that the power of the circulation pump is wasted.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain an air conditioning system that can suppress wasteful power consumption of a circulation pump and contribute to energy saving of a building. .

  An air conditioning system according to the present invention includes a plurality of air conditioners, a plurality of underground heat exchange tubes embedded in the ground, a circulation pump that circulates a heat medium, an inverter that changes the rotation speed of the circulation pump, Measures the upstream temperature of the heat medium flowing into the merging pipe, which is connected to the outlet side of the tube for heat exchange in each location on the inlet side, the main pipe connected to the outlet side of the merging pipe, and the merging pipe A temperature sensor, a branch pipe connected to the inlet side of the heat exchange tube in each region on the outlet side, a return side main pipe connected to the inlet side of the branch pipe, and return of the heat medium flowing into the branch pipe A return temperature sensor that measures the temperature, a flow meter that measures the flow rate of the heat medium circulated by the circulation pump, multiple valves individually installed on the inlet side of the heat exchange tubes in each location, and the opening and closing of each valve And the operation of the inverter A controller that controls the air conditioner by monitoring each air conditioner to obtain the number of operating air conditioners, the forward temperature measured by the forward temperature sensor, the return temperature measured by the return temperature sensor, Calculate the heat exchange amount of the air conditioner from the flow rate measured by the flow meter, and calculate the number of open valves, the inverter output of the inverter, and the heat exchange amount of the underground heat exchange tube for each number of operating air conditioners. Select a table corresponding to the number of operating air conditioner units acquired from a plurality of preset tables associated with, and use the selected table to replace the underground heat with the value closest to the calculated heat exchange amount of the air conditioner Select the number of open valves and inverter output that correspond to the heat exchange amount of the tube, control the opening and closing of each valve according to the selected number of open valves, and follow the selected inverter output. And it controls the operation of the inverter Te.

  ADVANTAGE OF THE INVENTION According to this invention, the useless power consumption of a circulation pump can be suppressed and the air conditioning system which can contribute to the energy saving of a building can be obtained.

It is a block diagram which shows the air conditioning system in Embodiment 1 of this invention. It is explanatory drawing which shows the some table for every driving | operation number of the air conditioner used by the controller of FIG.

  Hereinafter, an air-conditioning system according to the present invention will be described with reference to the drawings according to a preferred embodiment. In the description of the drawings, the same portions or corresponding portions are denoted by the same reference numerals, and redundant description is omitted. Moreover, this invention is applicable to the air conditioner currently installed in the building, for example.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram illustrating an air conditioning system according to Embodiment 1 of the present invention. The air conditioning system in FIG. 1 includes n (n is an integer of 2 or more) air conditioners 1, m (m is an integer of 2 or more) underground heat exchange tubes 2, a circulation pump 3, and an inverter 4. A merging pipe 5, an outgoing main pipe 6, a branch pipe 7, a return side main pipe 8, m valves 9, an outgoing temperature sensor 10, a return temperature sensor 11, a flow meter 12, And a controller 13.

  The air conditioner 1 is installed in a building, and is configured by a water-cooled PAC (Packaged Air Conditioner). When the air conditioner 1 functions as heating, the air conditioner 1 performs a heating operation using geothermal heat having a temperature higher than the outside air as a heat source. On the other hand, in the case of functioning as cooling, the air conditioner 1 performs cooling operation using ground heat at a temperature lower than the outside air as an exhaust heat source.

  The underground heat exchanging tube 2 is buried in the ground, and is constituted by a U tube inserted into a borehole dug in the ground. Moreover, the diameter and length of the tube 2 for heat exchange in various places embedded in the ground are adjusted to be the same.

  The circulation pump 3 circulates water as a heat medium in a system including the underground heat exchange tube 2, the junction pipe 5, the forward main pipe 6, the air conditioner 1, the return side main pipe 8, and the branch pipe 7. That is, water circulates between the air conditioner 1 and the underground heat exchange tube 2 by the operation of the circulation pump 3.

  The inverter 4 is connected to the circulation pump 3 and changes the rotational speed of the circulation pump 3 by changing the frequency of the power supply of the circulation pump 3 according to the control by the controller 13. When the rotation speed of the circulation pump 3 changes, the flow rate of the circulating water changes. The junction pipe 5 is connected to the outlet side of the heat exchange tube 2 in each region on the inlet side, and joins the water flowing in from the heat exchange tube 2 in each region.

  The outgoing main pipe 6 is connected to the outlet side of the merging pipe 5 and allows water to flow from the merging pipe 5 to the air conditioner 1 side. The branch pipe 7 is connected to the inlet side of the middle heat exchange tube 2 on the outlet side, and branches the water flowing from the return side main pipe 8. The return-side main pipe 8 is connected to the inlet side of the branch pipe 7 and allows water to flow from the air conditioner 1 side to the branch pipe 7.

  The valves 9 are individually provided on the inflow side of the heat exchange tubes 2 in various places, and perform opening and closing operations according to control by the controller 13. The valve 9 and the underground heat exchange tube 2 have a one-to-one correspondence. When the valve 9 is open, water flows from the branch pipe 7 to the underground heat exchange tube 2 corresponding to the opened valve 9. On the other hand, when the valve 9 is closed, water does not flow from the branch pipe 7 to the underground heat exchange tube 2 corresponding to the closed valve 9.

  The forward temperature sensor 10 is provided in the junction pipe 5, and the temperature of the water flowing into the junction pipe 5 from the heat exchange tube 2 in each location, that is, the temperature of the water after the heat exchange by the heat exchange tube 2 in each location. Is measured as the outgoing temperature, and the measured value is output to the controller 13.

  The return temperature sensor 11 is provided in the branch pipe 7 and returns the temperature of the water flowing into the branch pipe 7 from the return side main pipe 8, that is, the temperature of the water before heat exchange by the heat exchange tubes 2 in various places. The temperature is measured and the measured value is output to the controller 13.

  The flow meter 12 measures the flow rate of water circulated by the circulation pump 3 and outputs the measured value to the controller 13.

  The controller 13 is realized by, for example, a CPU that executes a program stored in a memory and a processing circuit such as a system LSI.

  The controller 13 acquires the number of operating air conditioners 1 by monitoring each air conditioner 1 of how many of the n air conditioners 1 are operating. The controller 13 controls the start and stop of the circulation pump 3.

  The controller 13 acquires the number of operating air conditioners 1, the forward temperature of water acquired from the forward temperature sensor 10, the return temperature of water acquired from the return temperature sensor 11, and the flow rate of water acquired from the flow meter 12. Thus, the opening and closing of each valve 9 is controlled and the operation of the inverter 4 is controlled.

  Next, the opening / closing control of each valve 9 and the control of the operation of the inverter 4 by the controller 13 will be further described with reference to FIG. FIG. 2 is an explanatory diagram showing a plurality of tables for each number of operating air conditioners 1 used by the controller 13 of FIG. The plurality of tables shown in FIG. 2 are set in advance.

  FIG. 2 shows a table in which the number of opened valves of the valve 9, the inverter output of the inverter 4, and the heat exchange amount of the underground heat exchange tube 2 are associated for each number of operating air conditioners 1.

  The number of opened valves 9 means the number of opened valves 9. The inverter output of the inverter 4 means the frequency of the power source converted by the inverter 4, and the maximum value of the frequency of the convertible power source is assumed to be 100%, and is shown as a percentage relative to the maximum value.

  The heat exchange amount of the underground heat exchange tube 2 means the amount of heat exchanged by the underground heat exchange tube 2 corresponding to the opened valve 9. For example, when the number of open valves is 2, the total amount of heat exchanged by the two underground heat exchange tubes 2 corresponding to the two open valves 9 is equal to that of the underground heat exchange tubes 2. This is the amount of heat exchange.

  Next, a method for setting a plurality of tables shown in FIG. 2 in advance will be described. First, as a premise of the control of the opening and closing of each valve 9 and the control of the operation of the inverter 4 by the controller 13, it is necessary to set in advance a table for each number of operating air conditioners 1 shown in FIG.

  In order to set a table for each number of operating air conditioners 1, it is necessary to determine the number of operating air conditioners 1, the number of open valves, and the heat exchange amount of the underground heat exchanging tube 2 corresponding to the inverter output. Specifically, after the air conditioning system is constructed, the air conditioning system is operated while changing the values of the number of operating air conditioners 1, the number of open valves, and the inverter output. Obtain the heat exchange amount.

  For example, as shown in FIG. 2, consider a case where the air conditioning system is operated under the condition that the number of operating air conditioners 1 is 1, the number of open valves is 1, and the inverter output is 10%. While the air conditioning system is operating under such conditions, the water temperature measured by the temperature sensor 10, the water return temperature measured by the return temperature sensor 11, and the flow meter 12 are measured. Get the flow rate of water. Subsequently, the amount of heat exchange is determined according to the following equation using the flow rate of the acquired water and the temperature difference between the acquired return temperature and the acquired forward temperature.

Q = ρ × qv × C × ΔT / 60
However, Q [J / s] is the amount of heat exchange, ρ [kg / dm ³ ] is the density of water, qv [dm ³ / min] is the flow rate of water, and C [J / (kg · K)] is the specific heat of water, and ΔT [° C.] is the temperature difference between the return temperature of water and the forward temperature of water.

  In this way, the air conditioning system is operated while changing the values of the number of operated air conditioners 1, the number of open valves, and the inverter output, and the water flow rate, the water return temperature, and the water forward temperature are actually measured. Thus, the heat exchange amount is obtained, and the table shown in FIG. 2 is set in advance.

  Subsequently, the control of the opening / closing of each valve 9 and the control of the operation of the inverter 4 by the controller 13 will be described. When the controller 13 controls the opening / closing of each valve 9 and the operation of the inverter 4, the controller 13 controls the forward temperature measured by the forward temperature sensor 10, the return temperature measured by the return temperature sensor 11, and the flow meter 12. From the measured flow rate, the heat exchange amount of the air conditioner 1 is calculated using the above equation. The heat exchange amount of the air conditioner 1 means the total heat exchange amount that is heat exchanged by all the air conditioners 1 that are operating.

  Subsequently, the controller 13 determines the table shown in FIG. 2, that is, the number of open valves of the valve 9, the inverter output of the inverter 4, and the heat exchange amount of the underground heat exchange tube 2 for each number of operating air conditioners 1. One table corresponding to the obtained number of operating air conditioners 1 is selected from a plurality of preset tables.

  Subsequently, the controller 13 selects the number of open valves and the inverter output corresponding to the heat exchange amount of the underground heat exchange tube 2 having a value closest to the calculated heat exchange amount of the air conditioner 1 from the selected table.

  Subsequently, the controller 13 controls the opening and closing of each valve 9 according to the selected number of opened valves. That is, the controller 13 opens the valves 9 by the number of selected open valves among all the valves 9 and closes the remaining valves 9.

  The controller 13 controls the operation of the inverter 4 according to the selected inverter output. That is, the controller 13 causes the selected inverter output and the output of the inverter 4 to match.

  In this way, the controller 13 acquired from the flow meter 12, the acquired number of operating air conditioners 1, the forward temperature of water acquired from the forward temperature sensor 10, the return temperature of water acquired from the return temperature sensor 11, and the flow meter 12. The opening and closing of each valve 9 is controlled from the flow rate of water, and the operation of the inverter 4 is controlled. In addition, by performing such control, the heat exchange amount of the air conditioner 1 and the underground heat exchange tube 2 can be reduced without always operating the circulation pump 3 with the maximum capacity regardless of the number of air conditioners 1 operated. The amount of heat exchange can be made almost the same.

  In addition, in this Embodiment 1, although the case where water is used as a heat medium is illustrated, it is not limited to this, What kind of thing may be used if it is a liquid which functions as a heat medium.

  The controller 13 updates a plurality of preset tables (FIG. 2) according to the operating status, and selects a table corresponding to the obtained number of operating air conditioners from the updated tables. It may be configured.

  As mentioned above, according to this Embodiment 1, the inverter of the inverter which changes the open valve number of the valve | bulb separately provided in the inflow port side of the heat exchange tube in each place, and the rotation speed of the circulation pump which circulates a heat carrier It is configured to select a table corresponding to the number of operating air conditioners from a plurality of preset tables in which the output and the heat exchange amount of the underground heat exchange tube are associated with each number of operated air conditioners. ing. Also, from the selected table, select the number of open valves and inverter output corresponding to the heat exchange amount of the underground heat exchange tube with the value closest to the calculated heat exchange amount of the air conditioner, and select each valve according to the selection result. Is configured to control the opening and closing of the inverter and the operation of the inverter.

  By configuring as described above, the open valve can realize a state in which the heat exchange amount of the air conditioner in the operating state and the heat exchange amount of the underground heat exchange tube corresponding to the open valve are substantially the same. The number and the inverter output can be appropriately adjusted according to the number of operating air conditioners.

  Therefore, it is not necessary to operate the circulation pump with the maximum capacity of the pump regardless of the number of operating air conditioners, so that wasteful power consumption of the circulation pump can be suppressed, and as a result, the building where the air conditioning system is constructed. Can contribute to energy saving.

  1 Air conditioner, 2 Ground heat exchange tube, 3 Circulation pump, 4 Inverter, 5 Junction piping, 6 Outward main piping, 7 Branch piping, 8 Returning main piping, 9 Valve, 10 Outward temperature sensor, 11 Return temperature Sensor, 12 Flow meter, 13 Controller.

Claims (2)

Multiple air conditioners,
A plurality of underground heat exchange tubes embedded in the ground;
A circulation pump for circulating the heat medium;
An inverter for changing the rotational speed of the circulation pump;
A merging pipe in which the outlet side of the tube for heat exchange in each region is connected to the inlet side;
An outward main pipe connected to the outlet side of the merging pipe;
A forward temperature sensor for measuring the forward temperature of the heat medium flowing into the junction pipe;
A branch pipe in which the inlet side of the tube for heat exchange in each region is connected to the outlet side;
A return-side main pipe connected to the inlet side of the branch pipe;
A return temperature sensor for measuring a return temperature of the heat medium flowing into the branch pipe;
A flow meter for measuring a flow rate of the heat medium circulated by the circulation pump;
A plurality of valves individually provided on the inlet side of the tube for heat exchange in each location;
A controller for controlling the opening and closing of each valve and the operation of the inverter;
With
The controller is
By monitoring each air conditioner, obtain the number of operating air conditioners,
From the forward temperature measured by the forward temperature sensor, the return temperature measured by the return temperature sensor, and the flow rate measured by the flow meter, the heat exchange amount of the air conditioner is calculated,
The number of open valves of the valve, the inverter output of the inverter, and the heat exchange amount of the underground heat exchange tubes are obtained from a plurality of preset tables that are associated with the number of operating units of the air conditioner. Select the table that corresponds to the number of air conditioner units in operation,
From the selected table, select the number of open valves and the inverter output corresponding to the heat exchange amount of the underground heat exchange tube of the value closest to the calculated heat exchange amount of the air conditioner,
An air conditioning system that controls the opening and closing of each valve according to the selected number of open valves, and controls the operation of the inverter according to the selected inverter output. The air conditioning system according to claim 1, wherein the controller updates the plurality of preset tables, and selects a table corresponding to the acquired number of operating air conditioners from the updated tables.

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