JP2004309032A - Central air conditioning and heating equipment and its operation control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide central air conditioning and heating equipment and its operation control method attaining energy saving as the whole equipment by minutely controlling the operation of a cold/hot water pump and a cooling water pump to lower the operation rate of a cold/hot water generator. <P>SOLUTION: This central air conditioning and heating equipment having the cold/hot water generator 9, a heat source control panel 17, the cold/hot water pump 10, the cooling water pump 13 and a fan coil unit 1 and performing the start and stop of the cold/hot water generator 9 by a cold/hot water supply temperature or a cooling water supply temperature, is provided with a programmable logical control device for controlling the operation of the cold/hot water pump 10 or the cold/hot water pump 10 and cooling water pump 13 by inverters 15, 16 based on the total load heating value which is the sum total on all rooms of load heat obtained by leading in a difference signal between an indoor set temperature and an actual temperature measured by each indoor temperature sensor 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a central heating / cooling facility using a hot / cold water generator (heat source) and an operation control method thereof.
[0002]
[Prior art]
Conventionally, in a large multi-room building, central cooling and heating equipment is provided.This central cooling and heating equipment is provided with a cooling and heat source device for the entire building at the center, and a plurality of air conditioners and terminal units are connected by a common pipe. The fan coil unit method is widely used among various methods. In this fan coil unit system, a large number of units (fan coil units) in which an air cooling / heating coil and a small electric fan are combined in a casing are arranged, and a cooling machine or a boiler in the central machine room is provided with the fan coil unit. Sends cold water and hot water for heating. Since the unit alone does not provide sufficient ventilation, freshly treated fresh air is sent to each room via ducts. This method has an advantage that the temperature can be adjusted for each room in a multi-room building such as a hospital.
[0003]
FIG. 3 is a schematic diagram of a fan coil type central cooling and heating facility using a conventional cold and hot water generator (heat source).
[0004]
31 is a cold / hot water generator (heat source), 32 is a heat source control panel, 33 is a cold / hot water pump, 34 is a cooling water pump, 35 is a cooling tower, 36 is an external controller for taking in outside air, 37 is a fan coil unit, 38 is a cold / hot water temperature sensor, 39 is a cooling water temperature sensor, and 40 is an indoor temperature sensor. The cold / hot water pump 33 and the cooling water pump 34 are provided on the return path, and the cold / hot water forward temperature sensor 38 and the cooling water forward temperature sensor 39 are provided on the forward path.
[0005]
The cold / hot water generator 31 is typically a boiler and a refrigerator. During heating, hot water is supplied by burning gas or oil in the boiler and exchanging heat with heated water. During cooling, the cooling water cooled by the refrigerator is sent to the cooling tower 35 by the cooling water pump 34. The start of the chilled / hot water generator 31 is stopped (on-off) by the signal of the chilled / hot water outgoing temperature sensor 38 by the heat source control panel 32 while the operation at the time of heating is permitted. That is, the boiler is ignited when the cold / hot water outgoing temperature falls below the lower limit value, and the combustion stops when it goes above the upper limit value. While the operation is permitted, the cold / hot water pump 33 continues to operate.
[0006]
Further, the cooling / heating water generator 31 is stopped by the heat source control panel 32 based on the signal of the cooling water upstream temperature sensor 39 while the cooling operation is permitted. That is, if the upstream temperature of the cooling water rises above the upper limit, freezing is performed, and if the temperature falls below the lower limit, freezing is stopped. While the operation is permitted, the cold / hot water pump 33 continues to operate. The cooling water pump 34 continues to operate, and the cooling tower fan operates when the cooling water rises above the upper limit, and stops when the cooling water falls below the lower limit.
[0007]
Usually, a plurality of fan coil units 37 and indoor temperature sensors 40 are installed, and the indoor temperature sensor 40 has a function of measuring the actual indoor temperature and setting the indoor temperature to a desired temperature. The start and stop of the fan of the fan coil unit 37 are controlled by the load determined by the signal indicating the difference between the actual temperature and the set temperature, and the operation of the fan is controlled.
[0008]
[Non-patent document 1]
Junhei Ohara, "Air Conditioning for One Million People," Ohmsha, December 10, 2002, p. 74-116
[0009]
[Problems to be solved by the invention]
Such central heating and cooling equipment is indispensable as a comfortable living environment, but generally consumes large amounts of energy, directly electricity and fuel, and also uses fossil fuels. The use emits a considerable amount of CO ₂ gas. On the other hand, emission control of CO ₂ gas to save resources and prevent global warming is attracting attention as a global issue, and measures are being sought. It is hoped that this will be realized in a targeted manner.
[0010]
In the conventional central air conditioning and heating, as shown in FIG. 3, the total energy amount E ₁ used in summer, indicating consumption power per unit time of each device in parentheses, expressed by the following equation.
[0011]
E ₁ = ｛(cooling water pump) + (cooling / heating water pump) + (cooling tower)
+ (Cold and hot water generator)} × 24h × operation dates Also, spring and autumn and winter of using the total amount of energy E ₂ is,
E ₂ = {(cold / hot water pump) + (cold / hot water generator)} × 24h × number of operating days However, although the operation of the fan coil unit 37 is controlled by the load, the chill / hot water pump 33 has a large capacity. The apparatus is operated all the time, and the cooling water pump is also operated all the time during cooling. The load on the fan coil unit 37 varies depending on the season, but is not monitored. Although the starting and stopping of the cold / hot water generator 31 is performed by the heat source control panel 32, the operation continues even when the fan coil unit 37 side is not loaded. In the building where the office is occupied, the energy consumption for cooling and heating throughout the year accounts for a large proportion of the energy consumption of other, for example, lighting, and the conventional technology has been improved in terms of energy saving. It can be said that there is room.
[0012]
Therefore, the present invention controls the operation of the chilled / hot water pump or the chilled / hot water pump and the chilled water pump with an inverter based on the total load heat amount based on the load of the fan coil unit, and finely controls the operation of the chilled / hot water pump or the cooling water pump. As a result, it is an object of the present invention to provide a central cooling and heating facility and a method for operating the same, which reduce the operation rate of the hot and cold water generator and realize energy saving as a whole facility.
[0013]
[Means for Solving the Problems]
In order to solve the above-described problems, the central cooling and heating equipment of the present invention has a cold / hot water generator, a heat source control panel, a cold / hot water pump, a cooling water pump, a fan coil unit, and has a cold / hot water outgoing temperature or a cooling water outgoing temperature. In the central cooling and heating equipment for stopping the start of the chilled / hot water generator, the sum of the load heat obtained by introducing the difference signal between the indoor set temperature and the actual temperature measured by the indoor temperature sensor for all the rooms is referred to as the total load calorie. And a programmable logic controller for controlling the operation of the cold / hot water pump or the cold / hot water pump and the cooling water pump by an inverter based on the total load calorific value.
[0014]
Further, the operating method of the central cooling / heating equipment of the present invention includes a cold / hot water generator, a heat source control panel, a cold / hot water pump, a cooling water pump, a fan coil unit, In the operation control method of the central air-conditioning system that stops the start and stop of the generator, the total load of all rooms obtained by introducing the difference signal between the indoor set temperature and the actual temperature measured by the indoor temperature sensor is calculated as the total load. The operation of the cold / hot water pump or the cold / hot water pump and the cooling water pump is controlled by an inverter based on the total load heat.
[0015]
With the above configuration, energy saving can be realized for the entire equipment.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
[0017]
FIG. 1 is a diagram illustrating a fan coil type central cooling and heating facility using a cold and hot water generator (heat source) according to an embodiment of the present invention.
[0018]
1 is a fan coil unit, 2 is an indoor temperature sensor, 3 is a fan coil control unit, 4 is an external controller, 5 is a motor valve, 6 is an external controller air temperature sensor, 7 is an external controller proportional controller, 8 is Exhaust fan, 9 is a cold / hot water generator, 10 is a cold / hot water pump, 11 is a cold / hot water upstream temperature sensor, 12 is a cooling tower, 13 is a cooling pump, 14 is a cooling water upstream temperature sensor, 15 and 16 are inverters, 17 is A heat source control board, 18 is a cold / hot water temperature sensor, 19 is a programmable logic controller (abbreviated PLC), and 20 is a CPU.
[0019]
The chilled / hot water generator 9 is turned off (on-off) by the heat source control panel 17 based on the signal of the chilled / hot water temperature sensor 11 during heating and based on the signal of the chilled water temperature sensor 14 during cooling. What is performed is the same as in the prior art. The indoor temperature sensor 2 measures the actual indoor temperature. The present invention further includes a PLC 19, inverters 15 and 16, and a CPU 20.
[0020]
The PLC 19 is a control device for performing a variable refrigerant flow rate (Variable Referent Volume, abbreviated to VRV) control system. The inverters 15 and 16 are for controlling the flow rates of the cold / hot water pump 10 and the cooling water pump 13, respectively. The CPU 20 manages data and changes the set temperature in the room, and is specifically a personal computer. The change of the set temperature in the room may be performed in each room similarly to the conventional technology. Also, the operation of the fan of the fan coil unit 1 in each room is controlled by the fan coil control unit 3 based on the load determined by the signal of the difference between the actual temperature and the set temperature. Same as technology.
[0021]
The signals input to the PLC 19 are the actual temperature signal measured by the indoor temperature sensor 2, the indoor set temperature signal set by the CPU 20 or the indoor, and the signal from the cold / hot water temperature sensor 18. Note that the cold / hot water outgoing temperature sensor 18 may be common to the existing cold / hot water outgoing temperature sensor 11.
[0022]
In the PLC 19, the total load calorie is calculated. The total load calorie is determined as follows. First, the difference between the set temperature in each room and the actual temperature (fan coil unit load) is introduced, and the load heat amount is calculated from the capacity of the fan coil in each room, the air volume, the absorbed heat amount, and the released heat amount. The heat load is also referred to as a heat load, and is described in a document in the technical field of air conditioning (for example, see Non-Patent Document 1), and a detailed description thereof will be omitted. Regarding the load calorific value, the total of each room is defined as the total load calorie. The value of the total heat load is input to the PLC 19, and the PLC 19 controls the flow rate of the chilled / hot water pump 10, specifically, the rotation speed of the pump, by the inverter 15. During cooling, the flow rate of the cooling water pump 13 is also controlled by the inverter 16.
[0023]
Here, the inverter is configured to obtain an alternating current from a direct current using a switching action of a transistor or a thyristor. It is already used in the power supply of home air conditioners, etc., and is converted from AC of commercial power to DC once by a rectifier circuit, converted to AC by an inverter, and the frequency of the motor is controlled, and the output is finely controlled. By controlling, power consumption can be reduced and indoor temperature fluctuation can be reduced.
[0024]
In the central cooling and heating equipment of the present invention, the energy saving rate R by the inverter control is expressed by the following equation when the consumption output per unit time of the cooling / heating water pump and the cooling water pump is shown in parentheses.
[0025]
R = {(cooling water pump) + (cold / hot water pump)} × {1- (control load factor / 100) ³ }
Moreover, energy saving value _{E R} by VRV control is expressed by the following equation.
[0026]
E _R = {(cooling water pump) + (cold / hot water pump)} × R × (operating rate)
In the present invention, the starting and stopping of the chilled / hot water generator is performed according to the chilled / hot water outgoing temperature or the chilled water outgoing temperature, and the operation of the chilled / hot water pump or the chilled / hot water pump and the cooling water pump is controlled by an inverter according to the total load heat quantity. The specific mode of the control is designed in consideration of the specifications of the apparatus. The following operating conditions are examples.
[0027]
FIG. 2 is a diagram showing an example of the operating state of the cold / hot water generator and the cold / hot water pump in the case of heating in the central cooling / heating facility of the present invention.
[0028]
At the time of (1), when the cold / hot water forward temperature starts to fall below the lower limit, the cold / hot water generator 9 is operated.
[0029]
At the same time as (1), the cold / hot water pump 10 is operated.
[0030]
At the time of (2), if the cold / hot water forward temperature starts to rise above the upper limit, the cold / hot water generator 9 is stopped.
[0031]
At the time point (3), the dilution time is finished in consideration of the dilution time of the cold / hot water pump 10 (cooling time of the heat source), and the cold / hot water pump 10 stops.
[0032]
In the periods (1) to (3), the flow rate of the cold / hot water pump 10 is continuously controlled by the inverter 15 according to the value of the total load calorific value. In the first half of the period (1) to (3), the flow rate is large, and in the second half, the flow rate is small. The specific flow rate (pump rotation speed) of the chilled / hot water pump 10 is controlled by, for example, considering the value of the current total load calorific value and the chilled / hot water incoming temperature signal from the chilled / hot water incoming temperature sensor 11 and the flow rate. Then, the increase / decrease tendency (differential value) of the total load calorie is predicted, and the smallest flow rate, that is, the flow rate (minimum) just before the total load calorie falls within the specified range in one control unit time is set.
[0033]
In the case of cooling, the start of the cold / hot water generator 9 is stopped according to the temperature of the cooling water as described above. The cold / hot water pump 10 operates at the same time as the cold / hot water generator 9 starts, and stops when the dilution time is over. The flow rate is controlled by the value of the total load calorific value during cooling. In addition, the cooling water pump 13 is controlled simultaneously with the cooling and heating water pump 10. That is, the cooling water pump 13 is operated simultaneously with the start of the cold / hot water generator 9, and stops when the dilution time is over. The flow rate is controlled by the value of the total load calorific value during cooling, but may be calculated in consideration of the outgoing water temperature and the outside air temperature.
[0034]
As described above, in the present invention, the operation of the cold / hot water pump or the cooling water pump can be finely controlled, and the power consumption of both pumps can be significantly reduced. In addition, the residual heat is sufficiently used, and as a result, the downtime of the cold / hot water generator becomes longer, and the operating rate can be reduced.
[0035]
The operation of the fan coil unit 1 is stopped while the cold / hot water pump 10 is stopped.
[0036]
By the way, also in the prior art, an external air conditioner and an exhaust fan are provided for the purpose of indoor ventilation, and these are usually operated without being controlled. In the present invention, the external controller and the exhaust fan may be operated as usual, but the operation may be controlled from the viewpoint of energy saving.
[0037]
That is, if the amount of heat consumed by the air conditioner 4 is large, although the ventilation frequency specified in advance is maintained, the fan of the air conditioner 4 is operated while the temperature of the outside air is equal to or lower than a certain temperature and the cold / hot water pump 10 is stopped. The operation of the exhaust fan 8 may be stopped. That is, the start and stop of the fan of the air conditioner 4 and the exhaust fan 8 are controlled based on the outside air temperature measured by the air temperature sensor 6 for the air conditioner.
[0038]
【The invention's effect】
As described above, according to the present invention, the operation of the cold / hot water pump or the cold / hot water pump and the cooling water pump is controlled by the inverter based on the total heat load based on the load of the fan coil unit, and the operation of the cold / hot water pump or the cooling water pump is operated. , The start and stop of the chilled / hot water generator is performed, and as a result, the operation rate of the chilled / hot water generator is reduced, and a central cooling / heating facility and an operation control method for the energy saving as a whole facility can be provided.
[Brief description of the drawings]
FIG. 1 is a diagram showing a fan coil type central cooling and heating system using a cold and hot water generator (heat source) according to an embodiment of the present invention. FIG. FIG. 3 shows an example of an operation state of a chilled / hot water pump. FIG. 3 is a schematic diagram of a fan coil type central cooling / heating facility using a conventional chilled / hot water generator (heat source).
DESCRIPTION OF SYMBOLS 1 Fan coil unit 2 Room temperature sensor 4 Outside air conditioner 6 Outside air temperature sensor 8 Exhaust fan 9 Cold / hot water generator (heat source)
Reference Signs List 10 cold / hot water pump 13 cooling water pump 15, 16 inverter 17 heat source control panel 18 cold / hot water upstream temperature sensor 19 programmable logic controller (PLC)
20 CPU

Claims (4)

In a central cooling / heating facility having a cold / hot water generator, a heat source control panel, a cold / hot water pump, a cooling water pump, a fan coil unit, and stopping the start of the cold / hot water generator according to a cold / hot water outgoing temperature or a cooling water outgoing temperature, The sum of the load heat obtained by introducing the difference signal between the set temperature and the actual temperature measured by the indoor temperature sensor for all the rooms is defined as the total load heat, and the cold / hot water pump or the cold / hot water pump is used according to the total load heat. And a programmable logic controller for controlling the operation of the cooling water pump by an inverter. The central cooling and heating system according to claim 1, wherein the programmable logic controller further stops the start of the fan and the exhaust fan of the external controller based on the temperature measured by the air temperature sensor of the external controller. The central heating and cooling equipment according to claim 1 or 2, wherein a CPU for performing data management and changing a set temperature is connected to the programmable logic controller. Operation control of central cooling and heating equipment that has a chilled / hot water generator, a heat source control panel, a chilled / hot water pump, a chilled water pump, and a fan coil unit, and that starts and stops the chilled / hot water generator based on the cold / hot water outgoing temperature and the cooling water outgoing temperature In the method, the total load calorie of the load heat obtained by introducing a difference signal between the indoor set temperature and the actual temperature measured by the indoor temperature sensor is taken as the total load calorie, and the cold / hot water pump or An operation control method for a central cooling / heating facility, wherein the operation of the cold / hot water pump and the cooling water pump is controlled by an inverter.

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