JP5786645B2 - Refrigeration air conditioner - Google Patents

Description

The present invention relates to a refrigerating and air-conditioning apparatus that cools and heats buildings such as buildings and hospitals.

In operation control in a conventional refrigeration air conditioner, room temperature adjustment is performed by flow control for pumps and valves, capacity control for heat source devices, or air volume control for air conditioning fans. In addition, an air conditioning operation has been proposed in which an overall control target device such as a pump, a valve, a heat source device, and an air conditioning fan is controlled using an inverter to minimize energy consumption and save energy (for example, Patent Documents). 1).

Japanese Patent Laid-Open No. 2003-214685 (page 4-5, FIG. 1)

An air conditioning system for heating in a conventional refrigeration air conditioner includes a primary cycle that transports hot hot water generated by a heat source device to an air conditioner, and an indoor air that is fed to the air conditioner to supply hot air to the room. In general, it is constituted by a secondary cycle, and heat exchange by an air conditioner is performed between the primary cycle and the secondary cycle. There are other configurations in which the outside air is taken in and transferred to the air conditioner in the secondary side cycle, but the primary side cycle configuration and operating procedure are applicable regardless of whether the air intake in the secondary side cycle is indoor or outdoor. Is the same.

The temperature of the hot water transported from the heat source unit to the air conditioner in the primary side cycle is lowered by heat exchange with the air transported by the secondary side cycle. The hot water discharged from the air conditioner is supplied again to the heat source device by the pump, and after the temperature rises, the primary cycle is recirculated.

The heat exchange process in the air conditioner affects the change in hot water temperature of the entire primary side cycle. In order to warm the cold air of the secondary side cycle with the hot water of the primary side cycle, the larger the temperature difference between the air and the hot water, the larger the heat exchange amount, and the lower the temperature of the hot water discharged from the air conditioner. On the other hand, when the amount of heat exchange performed by the air conditioner is reduced, the hot water is discharged from the air conditioner while maintaining a high water temperature, and the water temperature of the entire primary cycle rises. The temperature difference between the air and hot water at this time, the heat exchange amount, etc. are collectively referred to as “load” in the air conditioner.
It should be noted that there is a difference in load fluctuation depending on the air intake system of the secondary side cycle. In a configuration where indoor air is used, the temperature difference between the room temperature and the set temperature is the main factor of the load. The load at the start of operation is the largest, and decreases as the room temperature approaches the set temperature due to heating operation.
On the other hand, in the configuration that takes in the outside air, the temperature difference between the outside air and the set temperature becomes the main factor of the load. The higher the outside air is, the smaller the load is. However, even if the room temperature rises due to the heating operation, the load is not changed.

Next, the conventional control accompanying the temperature change of warm water is demonstrated. The hot water generated by the heat source machine (for example, 55 ° C) is reduced by about 5 ° C after heat exchange with the air conditioner, discharged from the air conditioner, and re-supplied to the heat source machine by the pump. If the temperature difference is small, or if the load decreases as the indoor temperature rises as the heating operation continues, the temperature drop due to heat exchange will be less than 5 ° C, and the hot water temperature of the entire primary cycle will rise. When it rises, the operation of the heat source machine is stopped. The stop process at this time is referred to as “thermo stop” and is routinely performed to adjust the water temperature of the primary cycle.
When the heat source machine stops operating, the water temperature of the primary side cycle gradually decreases. Therefore, when the heat source machine falls below a certain temperature, the operation of the heat source machine is resumed.

Normally, the water temperature decreases due to the thermo stop, but when there is almost no load, the water temperature may increase due to heat generated by the pump even after the operation of the heat source machine is stopped. Under normal load conditions, the temperature that decreases due to heat exchange is greater than the temperature that increases due to heat generation by the pump, but when there is almost no load, the temperature decreases gradually due to heat generation by the pump because there is little temperature decrease due to heat exchange. It rises. In the air conditioning system, an upper limit temperature (for example, 65 ° C) is set to prevent damage to equipment due to a rise in hot water temperature. If a water temperature that exceeds the upper limit temperature is detected, a “temperature abnormal” alarm is generated. Let the pump stop emergency.

Recovery after an emergency stop of the pump is performed by manually canceling the alarm on the control panel. However, to cancel the alarm, it is necessary that the water temperature of the primary cycle is sufficiently lowered from the system upper limit reference temperature (for example, 55 ° C. or less). Although the water temperature drop time varies depending on the system, in this example, it takes about 3 hours for the primary cycle water temperature to drop by 10 ° C from 65 ° C to 55 ° C.

In addition, it is thought that it is possible to avoid the temperature rise of the primary side cycle by stopping the pump together when the thermo is stopped, but the pump during the thermo stop is generally operated at all times, and at the same time as the heat source machine Do not stop the pump.
The reason why the pump is always operated is that the secondary cycle for supplying hot air into the room continues to operate, so it is necessary to generate a water flow and continue supplying hot water to the air conditioner, and the hot water temperature. This is because it is necessary to restart the operation of the heat source unit when the temperature decreases, and to generate a water flow in order to detect the water temperature of the entire primary side cycle.

The control according to the prior art is as described above. When the hot water temperature reaches the system upper limit reference temperature of 65 ° C., the pump is urgently stopped and the water flow in the primary side cycle is stopped.
Stopping the pump is an action that accompanies the occurrence of an alarm, so it is necessary to manually cancel the alarm on the control panel and restart the pump operation. However, if the water temperature has not dropped to a level at which operation can be restarted, the alarm is released. It is not possible to measure the water temperature regularly. In addition, while the pump is stopped, the operation of the heat source machine cannot be resumed, so there is a problem that the heating operation cannot be resumed for about 3 hours (the estimated time in this example) until the water temperature decreases.

The present invention has been made in order to solve the above-described problems. The pump and the heat source apparatus are provided by avoiding an emergency stop alarm without increasing the hot water temperature of the primary cycle to the upper limit temperature of the system. The refrigerating and air-conditioning apparatus that enables the automatic restart of the above and the shortening of the waiting time until the heating operation is restarted is obtained.

In the refrigerating and air-conditioning apparatus according to the present invention, the operation of the heat source unit is controlled, and the heat source unit control unit that stops the heat source unit when the temperature exceeds the hot water temperature set as the stop reference temperature of the heat source unit, and the operation of the pump is controlled. The pump is stopped when the hot water temperature is higher than the reference temperature for stopping the system, and is lower than the reference temperature for stopping the pump, and the temperature is lower than the reference temperature for stopping the heat source. A controller having a pump control unit for resuming the operation of the pump.

This invention stops the pump at a pump stop reference temperature that is higher than the heat source machine stop reference temperature and lower than the system stop reference temperature, and resumes the pump operation when the temperature is lower than the heat source machine stop reference temperature. By doing so, it is possible to adjust the hot water temperature of the primary side cycle and to avoid the occurrence of an emergency stop alarm. In addition, the automatic operation of the pump and the heat source machine can be resumed by stopping the pump with normal control. Furthermore, since the pump is controlled at a temperature lower than the upper limit temperature of the facility, it is possible to shorten the waiting time until the heating operation is restarted by shortening the stop time of the pump.

It is a block diagram which shows the whole structure of the refrigerating air conditioner by Embodiment 1 of this invention. It is a figure which shows the fluctuation | variation of the water temperature of each installation in the normal driving | operation of the refrigeration air conditioner which concerns on this invention. It is a figure which shows the water temperature range in the pump control of Embodiment 1 which concerns on this invention. It is a block diagram which shows the principal part structure of the refrigeration air-conditioning control apparatus by Embodiment 1 of this invention. It is a flowchart which shows the process sequence of Embodiment 1 which concerns on this invention. It is a block diagram which shows the principal part structure of the refrigerating air-conditioning control apparatus by Embodiment 2 of this invention. It is a flowchart which shows the process sequence of Embodiment 2 which concerns on this invention. It is a block diagram which shows the principal part structure of the refrigerating air-conditioning control apparatus by Embodiment 3 of this invention. It is a flowchart which shows the process sequence of Embodiment 3 which concerns on this invention.

Embodiment 1 FIG.
FIG. 1 is a block diagram of the entire refrigerating and air-conditioning apparatus according to Embodiment 1 of the present invention. In FIG. 1, a primary cycle 1 is configured by connecting a heat source unit 11, a pump 12, and an air conditioner 3, and hot water is circulated. The secondary cycle 2 is configured by connecting an air conditioning fan 21, a room 22, and an air conditioner 3, and supplies air to the room 22. Further, the water temperature detection means 13 is installed to measure the hot water temperature, and the indoor detection means 23 is installed to measure the room temperature. Both the water temperature detection means 13 and the room temperature detection means 23 are connected to the controller 4, and the controller 4 controls the heat source device 11, the pump 12, and the air conditioning fan 21 based on the measured water temperature and room temperature.

Next, the operation will be described. In the primary cycle 1, hot water is generated by the heat source device 11, and then hot water is supplied to the air conditioner 3. After the heat of the hot water is exchanged with the air of the secondary side cycle 2 by the air conditioner 3, the hot water whose temperature has decreased is supplied to the heat source device 11 by the pump 12 to become hot water again and circulates in the primary side cycle 1. . In the secondary side cycle 2, the air heated by the heat exchange of the air conditioner 3 is supplied to the room 22 by the air conditioning fan 21, and is taken into the room 22 and then supplied to the air conditioner 3 again. In addition, in the secondary side cycle 2, there is also a configuration for taking in outside air. In this case, the outdoor unit 24 is provided and the outside air is taken in from the outdoor unit 24, but the configuration and operation of the primary cycle 1 are the same.

FIG. 2 shows the fluctuation of the water temperature of each facility in the normal operation of the primary side cycle 1. In FIG. 2, the hot water is heated to about 55 ° C. by the heat source unit 11 and supplied to the air conditioner 3. As a result of heat exchange in the air conditioner 3, the water temperature drops by about 5 ° C. and is discharged, and is re-supplied to the heat source unit 11 by the pump 12 and circulates in the primary cycle 1. The hot water rises by about 1 ° C. due to heat generated by the pump 12 when passing through the pump 12, but does not affect the operation because it has dropped by about 5 ° C. due to heat exchange in the air conditioner 3.
In addition, the hot water temperature which rises per hour by pump heat_generation | fever can be calculated | required with the following calculation formulas.
Rise temperature Delta T = (Pump input (kW) × 860) / Retained water volume (kl))
For example, when a pump 12 having an input capacity of 15 kW is operated in a system having a water volume of 1.0 t, a rising temperature of about 12.9 ° C. can be assumed theoretically in 1 hour, and the circulation time of the primary side cycle 1 is reduced. Assuming about 5 minutes, the temperature rises by about 1 ° C in one cycle (however, the rising temperature is somewhat lower than the calculated value due to motor power factor and heat dissipation into the air).

FIG. 3 shows a water temperature range in the pump control according to the first embodiment of the present invention. As shown in FIG. 2, normal operation is performed when the hot water temperature is 55 ° C. or lower, but depending on the load condition of the air conditioner 3, the hot water temperature may exceed 55 ° C., It is necessary to stop the heat source device 11 and the pump 12.
In the control of the heat source unit 11, a stop reference temperature (for example, 56.5 ° C.) when the water temperature exceeds 55 ° C. is set, and when the temperature is detected, the heat source unit 11 is stopped (thermo stop), and the temperature 5 When the temperature drops below ℃ (for example, 51.5 ℃), the operation is resumed (thermo return). On the other hand, when the water temperature control for the pump 12 is not performed, when the water temperature rises and reaches the system stop reference temperature of 65 ° C., an alarm is generated and the pump 12 is urgently stopped.

In the first embodiment of the present invention, pump control is added when the water temperature rises above the stop reference temperature (56.5 ° C.) of the heat source unit 11 after the thermo stop. A pump stop reference temperature (for example, 60 ° C.) is set to a temperature lower than the system stop reference temperature (65 ° C.), and the pump 12 is stopped when the temperature reaches that temperature. In the pump control, the water temperature measurement by the water temperature detecting means 13 is continued even after the pump 12 is stopped. For example, when 55 ° C. lower than the stop reference temperature (56.5 ° C.) of the heat source device 11 is set as the pump operation restart temperature, the water temperature is 55 ° C. If it drops below, normal operation of the pump 12 is resumed.

FIG. 4 is a block diagram of the controller 4 of the refrigerating and air-conditioning apparatus according to Embodiment 1 of the present invention. The heat source unit control unit 5 that controls the heat source unit 11 and the pump control unit 6 that controls the pump 12, the heat source unit control unit 5 includes a thermo stop determination unit 51 and an operation restart determination unit 52, The pump control unit 6 includes a stop determination unit 61 and an operation restart determination unit 62.
The operation of each function will be described. Normally, the heat source device control unit 5 is functioning, the stop reference temperature (56.5 ° C.) of the heat source device 11 is set by the thermo stop determination unit 51, and the water temperature value measured by the water temperature measuring means 13 is 56.5 ° C. or more. In this case, the operation of the heat source device 11 is stopped (thermo stop). The operation restart determination unit 52 continuously takes in the water temperature value even after the thermo stop, and restarts the operation of the heat source unit 11 when the temperature of the heat source unit 11 becomes lower than the operation restart temperature (51.5 ° C.) (thermo return). On the other hand, when the water temperature rises and exceeds the pump stop reference temperature (60 ° C.), the pump control unit 6 functions.
In the pump control unit 6, the pump 12 is stopped by the stop determination unit 61 when the water temperature becomes equal to or higher than the pump stop reference temperature (60 ° C.). The operation resumption determining unit 62 continuously takes in the water temperature value even after the pump 12 is stopped, and resumes the normal operation of the pump 12 when the operation temperature is lower than the operation resumption temperature (55 ° C.) of the pump 12.
Since the water flow in the primary cycle is stopped after the pump 12 is stopped, the water temperature is measured only around the water temperature measuring means 13, but the operation of both the heat source unit 11 and the pump 12 is stopped, and the entire primary cycle 1 is almost the same. Since the temperature change is uniform, measurement without water flow is sufficient.

FIG. 5 is a flowchart showing a control processing procedure of the heat source unit 11 and the pump 12 in the controller 4 of the refrigerating and air-conditioning apparatus according to Embodiment 1 of the present invention. ST11 to ST15 are flows related to heat source machine control, and ST21 and ST22 are flows related to pump control.
In the flow chart of FIG. 5, the rising state of the hot water temperature is normally confirmed in ST11 and ST12. In ST12, it is determined whether or not the hot water temperature has reached the stop reference temperature (56.5 ° C) of the heat source unit 11, and if it reaches 56.5 ° C or higher, the process proceeds to ST13 and the operation of the heat source unit 11 is stopped (thermo). Stop).
After the heat source unit 11 has stopped thermostating in ST13, the process proceeds to ST14, where it is determined whether the hot water temperature has dropped below the operation restart temperature (51.5 ° C) of the heat source unit 11. To do. On the other hand, if the temperature exceeds 51.5 ° C, the process proceeds to ST15, and it is determined whether the pump 12 has risen above the stop reference temperature (60 ° C). When it becomes 60 degreeC or more, it transfers to ST21, the driving | operation of the pump 12 is stopped, and it is determined whether it has fallen below the operation resumption temperature (55 degreeC) of the pump 12 by ST22. When the temperature becomes 55 ° C. or lower, normal operation of the pump 12 is resumed.
Each set temperature is variable, and a value corresponding to the system status is set.

According to the first embodiment, the pump 12 is stopped before the hot water temperature reaches the system stop reference temperature (65 ° C.), so that an emergency stop alarm can be avoided, and the pump 12 is provided as soon as the water temperature becomes 55 ° C. or lower. In order to resume the normal operation, the heat source machine 11 can automatically resume operation. Further, in order to suppress the rise in the temperature of the hot water to around 60 ° C., it is possible to reduce the waiting time until the pump 12 is restarted from the current about 3 hours.
The operation restart temperature of the pump is not limited to 55 ° C., and efficient operation is possible by setting the optimum temperature according to the system operation status.

Embodiment 2. FIG.
As Embodiment 2 of the present invention, an example will be described in which the pump 12 is intermittently operated at a constant period before the normal operation of the pump 12 is resumed. After the pump 12 is stopped, when the water temperature value measured by the water temperature detecting means 13 becomes equal to or lower than the stop reference temperature (60 ° C.) of the pump 12, the pump 12 is operated for a short time (for example, 5 minutes), and the primary cycle 1 Add a function to generate a water flow throughout. FIG. 6 is a block diagram of the controller 4 of the refrigerating and air-conditioning apparatus according to Embodiment 2 of the present invention, and FIG. 7 is a control process for the heat source unit 11 and the pump 12 in the controller 4 of the refrigerating and air-conditioning apparatus according to Embodiment 2 of the present invention. It is a flowchart which shows a procedure. 7, the same reference numerals as those in FIG. 5 denote the same or corresponding parts as those in FIG.

In FIG. 6, an intermittent operation determination unit 63 is added to the pump control unit 6, and the intermittent operation determination unit 63 takes in time data from the timer 7 and controls the intermittent operation of the pump 12.

In FIG. 7, after the operation of the pump 12 is stopped, the intermittent operation of the pump 12 is started in ST24 when the water temperature around the water temperature measuring means 13 becomes equal to or lower than the stop reference temperature (60 ° C.) of the pump 12 in ST23.
After starting the intermittent operation of the pump in ST24, if the intermittent operation time has elapsed 5 minutes or exceeds 60 ° C in ST25, the process proceeds to ST26 and the pump 12 is stopped. After stopping the intermittent operation of the pump 12, after waiting for a certain time (for example, 10 minutes) in ST29, if the water temperature is 60 ° C. or lower, the intermittent operation is performed again. At the same time, it is determined whether or not the operation restart temperature (55 ° C.) or lower of the pump 12 is lower than the temperature at ST 27 during intermittent operation and at ST 28 during operation stop. Normal operation is resumed regardless of the driving situation.
Each set temperature and intermittent operation time are variable, and values are set according to the system status.

According to the second embodiment, the pump 12 is temporarily operated to generate a water flow so that the water temperature of the entire primary side cycle 1 can be detected, the hot water temperature is detected more accurately, and the heating operation is resumed. Stability can be improved. Along with intermittent operation of the pump 12, for example, a temperature rise of about 1 ° C. may occur for 5 minutes, but it is possible to avoid an increase in the water temperature of the entire primary side cycle 1 by ensuring a sufficient operation interval. is there. Regardless of the operation status of the pump 12, the normal operation of the pump 12 is resumed when the water temperature becomes 55 ° C. or less, so that the heating operation can be resumed in the shortest time.
Note that the operation time during intermittent operation (5 minutes in this example) and the operation interval time (10 minutes in this example) are not limited, and efficiency can be improved by setting the optimal time according to the system scale. It is possible to implement general control.

Embodiment 3 FIG.
As Embodiment 3 of the present invention, an example in which a certain waiting time is provided until the normal operation of the pump 12 is resumed will be described. Normally, it takes about 3 hours (assumed time in this example) to lower the system stop reference temperature (65 ° C.) to the operation restart temperature (55 ° C.) of the pump 12. For this reason, after the pump 12 is stopped, a function of waiting for a certain period of time for the pump controller 6 to start processing is added before normal operation of the pump. FIG. 8 is a block diagram of the controller 4 of the refrigerating and air-conditioning apparatus according to Embodiment 2 of the present invention, and FIG. 9 is a control process for the heat source unit 11 and the pump 12 in the controller 4 of the refrigerating and air-conditioning apparatus according to Embodiment 3 of the present invention. It is a flowchart which shows a procedure. 9, the same reference numerals as those in FIG. 7 denote the same or corresponding parts as those in FIG.

In FIG. 8, a function for taking in time from the timer 7 is added to the operation resumption determining unit 62 of the pump control unit 6. After the pump 12 is stopped, a waiting time of a certain time (for example, 3 hours) is provided until the normal operation is restarted, and the water temperature is clearly assumed to exceed the stop reference temperature (60 ° C.) of the pump 12. Avoid restart judgment and intermittent operation.

In FIG. 9, after stopping the operation of the pump 12, when the water temperature is equal to or lower than the stop reference temperature (60 ° C.) of the pump 12 and the time after the pump 12 stops exceeds a set time (for example, 3 hours) in ST30. Implement intermittent operation.
However, in parallel, in ST31, it is continuously determined whether or not the operation restart temperature of the pump 12 (55 ° C.) or less is reached. If the temperature becomes 55 ° C. or less regardless of the passage of time, the normal operation of the pump 12 is performed. To resume.
After the intermittent operation of the pump 12, the process returns to ST30 again. However, the time setting of ST30 is variable, and the standby time (3 hours) after stopping the pump 12 is switched to the intermittent operation time interval (for example, 10 minutes). The intermittent operation of the pump 12 is performed.
The process of providing a certain waiting time until the normal operation of the pump 12 is resumed is effective even when the intermittent operation of the pump 12 is not performed.
Each set temperature and each set time are variable, and values are set according to the system status.

According to the third embodiment, the restart determination process is started when the water temperature is 60 ° C. or lower and 3 hours have elapsed after the pump is stopped. With the pump 12 shutting down, it takes about 3 hours (estimated time in this example) to reduce the water temperature from 65 ° C to 55 ° C. It is possible to avoid performing unnecessary processing. However, regardless of the standby time, the normal operation of the pump 12 is resumed when the water temperature is 55 ° C. or lower, so that the heating operation can be resumed in the shortest time.
Note that the standby time is not limited to 3 hours, and efficient control can be performed by setting an optimal time for lowering the water temperature according to the system scale.

1: Primary side cycle 11: Heat source machine 12: Pump 13: Water temperature detection means 2: Secondary side cycle 21: Air conditioning fan 22: Indoor 3: Air conditioner 4: Controller 5: Heat source machine control part 6: Pump control part

Claims (4)

In a refrigeration air conditioner that circulates hot water generated by a heat source machine to an air conditioner with a pump, and exchanges heat supplied to the room with the hot water by the air conditioner,
Water temperature measuring means for detecting the temperature of the circulating hot water;
A heat source unit control unit that controls the operation of the heat source unit and stops the heat source unit when the hot water temperature detected by the water temperature measuring unit is equal to or higher than a first hot water temperature set as a stop reference of the heat source unit;
And controlling the operation of the pump, and the hot water temperature detected by the water temperature measuring means is higher than the first hot water temperature and is lower than the hot water temperature as a system stop reference, as a stop reference for the pump. When the temperature is higher than the second hot water temperature, the normal operation of the pump is stopped,
And a controller having a pump control unit for resuming normal operation of the pump when the hot water temperature detected by the water temperature measuring means after the pump is stopped is lower than the first hot water temperature. Refrigeration air conditioner. 2. The refrigerating and air-conditioning apparatus according to claim 1, wherein the pump control unit causes the stopped pump to intermittently operate at a constant cycle. 3. The refrigerating and air-conditioning apparatus according to claim 1, wherein the pump control unit operates after the stopped pump waits for a certain period of time after the pump is stopped and before the normal operation of the pump is resumed. . 4. The refrigerating and air-conditioning apparatus according to claim 1, wherein a water temperature measuring means is installed at a hot water outlet of the heat source device.

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