JP3442037B2 - Secondary system for district cooling and heating - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a secondary side system for district cooling and heating that reduces the heating and cooling costs by demand control. The secondary system is an air conditioning system for facilities such as buildings that are consumers.

[0002]

2. Description of the Related Art District heating and cooling is a system in which heat medium such as hot and cold water or steam from a heat supply plant is supplied to users in the area through regional piping, and is used for heating and cooling of users' buildings. The heat medium is used.

By the way, the usage fee paid by the heat medium user to the district heating and cooling business is the total amount of the basic fee based on the contracted heat medium amount and the metered fee for the excess amount. Then, this basic charge is determined based on the demand value at the time of maximum load (peak time).

Therefore, some proposals have been made to reduce the demand value at the maximum load. Japanese Unexamined Patent Application Publication No. 9-243140 discloses a method of reducing the demand value at the maximum load of the heating and cooling equipment. (A) Raising the temperature of the air blown into the building to reduce the dehumidification amount, and (b) taking in outside air into the building. The amount is reduced, and (c) the set cooling temperature inside the building is lowered. Further, (d) the amount of outside air taken into the building is reduced, and (e) control is performed such as raising the set heating temperature inside the building.

Although such control reduces the demand value at the maximum load, there is a problem that the control involves the limitation of the cooling / heating capacity at the maximum load.

Further, Japanese Patent Application Laid-Open No. 10-54590 relates to hot water supply equipment using a heat medium from a heat source plant for district heating and cooling, not to air conditioning, but to increase the demand value before and after the maximum load. , Storing the thermal energy as hot water in a hot water storage tank.

[0007]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
The method of reducing the demand value at the time of maximum load by using the thermal energy storage means such as the hot water storage tank of No. 590 requires the installation of equipment such as the hot water storage tank, resulting in high space efficiency and high equipment cost. there were. Furthermore, it is not always appropriate to apply such a method to heating and cooling. Normally, at the maximum load of cooling and heating, immediately after the start of normal cooling and heating operation (for example, in the case of a general office building, around 8:00 am)
become. This is not because the temperature difference between the room temperature and the set temperature is the largest immediately after the start of the normal operation.

When the air conditioning is stopped (for example, in the case of a general office building, around 9 o'clock at night), the fan of the air conditioner is stopped and the agitation of room air is stopped. Therefore, the indoor air remains stagnant until the operation of the fan of the air conditioner starts the next morning, and the indoor air forms an air layer having a temperature difference due to a partial difference in temperature.

Further, in the room after the air-conditioning equipment is stopped, the interior zone (business area / center of the room) is affected by wall temperature changes (temperature increase in summer, temperature decrease in winter) and drafts from windows. Part) and a perimeter zone (a non-business area such as a wall surface periphery / a peripheral part of a room), an air layer having a large temperature difference is formed. Especially, the temperature around the inner wall on the back side of the outer wall and the temperature around the window are easily affected by the external environment.

Since it is practically impossible to provide the room temperature sensor in the interior zone located in the central area of the room, the room temperature sensor detects the temperature of the air layer in the vicinity of the perimeter zone having the most temperature difference from the set temperature. Therefore, the room temperature sensor excessively detects the temperature difference between the room temperature and the set temperature for about 1 to 2 hours after the start of the fan operation when the agitation of the room air by the fan of the air conditioner is completed. This is the main factor for increasing the temperature difference between the room temperature and the set temperature immediately after the start of cooling and heating.

Therefore, even though the temperature difference between the room temperature and the set temperature in the interior zone is small, the air conditioner can be operated with the maximum capacity, and as a result, the demand value at the maximum load can be increased to an unnecessary level. It will increase.
Even if the method of reducing the demand value at the time of maximum load by using the thermal energy storage means such as the hot water storage tank is used for heating and cooling, after all, the formation of the indoor air layer having this temperature difference is allowed. Cannot effectively reduce the demand value of.

The present invention attaches great importance to the temperature distribution of indoor air,
An object of the present invention is to provide a secondary side system for district heating and cooling that can reduce the demand value of the heat medium at the maximum load without limiting the heating and cooling capacity.

[0013]

A secondary side system for district heating and cooling according to the invention of claim 1 includes an air conditioning facility for independently cooling and heating a plurality of areas, and a control device for controlling the air conditioning facility. A secondary side system for district heating and cooling, which has a plurality of indoors having different temperature distributions.
Control function before normal operation of the system
However , in the pre-operation control before the normal operation, only the air circulation in the air-conditioning target area in the room is performed while the supply of the heat medium is stopped, and the temperature distribution in the air-conditioning target area has a predetermined time.
The air-conditioning for all areas, the agitation step where the room temperature change is stable within a predetermined range, the partial preheating (pre-cooling) step for supplying the heat medium only to the area where the heat load is large. It is characterized by sequentially performing all preheating (precooling) steps of supplying a heat medium. A secondary side system for district heating and cooling according to the invention of claim 2 has an air conditioning facility for independently heating and cooling a plurality of regions, and a secondary side system for district heating and cooling having a control device for controlling the air conditioning facility. However , the control device has different temperature distributions.
Control of the system for multiple rooms before normal operation
The pre-operation control before normal operation has a function to control the air circulation in the area to be air-conditioned in the room with the supply of heat medium stopped.
A stirring step of performing only performs supply of heat medium only air conditioner for large areas of the heat load, stirring stage at the end of the chamber
Stage at which a predetermined room temperature rise (fall) rate is reached from temperature data a
It is characterized by sequentially performing a partial preheating (pre-cooling) step that ends in step 1 and a full pre-heating (pre-cooling) step that supplies a heat medium to air conditioning for all areas.

Here, the area having a large heat load refers to, for example, an area around an entrance having a doorway of a building, a perimeter zone of each room, and the like. Also, during cooling,
The area located on the back surface of the south outer wall of the building, and the area located on the back surface of the north outer wall during heating. Another feature of the present invention is described in claims 3 to 10, more details are described in the column of the embodiment of the invention the foregoing.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION A secondary system for district heating and cooling according to an embodiment of the present invention will be described below with reference to the accompanying drawings. In the present embodiment, the perimeter zone is shown as a region with a large heat load, and the interior zone is shown as a region with a small heat load, but this is merely an example and not a limitation.

FIG. 1 is a plan view of one floor of a 9-story building that uses the system of the present embodiment for cooling and heating. The floor is divided into 10 rooms 3, each having a room central area 1 and a window area 2. The indoor central area 1 is supplied with cold or warm air from an outlet provided on the ceiling surface of each room, and the window area 2 is provided with an outlet provided on the top surface or ceiling surface of the counter at the window of each room. Cold or warm air is being supplied.

The interior central area 1 and the window area 2 are
This is an example in which the interior zone and the perimeter zone are the air-conditioning target areas, respectively, and there is no limitation. For example, in addition to the window, an outlet may be provided around the inner wall surface located on the back surface of the outer wall to supply cool air or warm air to the perimeter zone around the inner wall surface.

FIG. 2 is an overall configuration diagram of the system of this embodiment. The above-mentioned building cools and heats the first to third floors, the fourth to sixth floors, and the seventh to ninth floors by three independent air-conditioning facilities. That is, the air conditioning equipment for cooling and heating the first zone on the first to third floors includes the first air conditioner 10 and the first inside / outside air controller 1
1 and the first heat quantity controller 12, and the other second zones on the 4th to 6th floors and the third zone on the 7th to 9th floors also have the air conditioning equipment of the same configuration. These air conditioning facilities are controlled by the control device 40. The air conditioning equipment in the first zone will be described below.

The first inside / outside air controller 11 is the first air conditioner 1
The ratio of the outside air to the room air (inside air) in the air supplied to 0 is controlled between 0 and 100%. The first heat quantity controller 12 controls the heat quantity of the heat medium supplied to the first air conditioner 10. Specifically, the amount of heat is measured from the flow rate of the heat medium and the temperature difference between the heat medium before and after the inflow, and the amount of heat is fed back to the control device 40 described later.

The first air conditioner 10 is composed of a heat exchanger and a blower for sending cold air or warm air. In addition, the present device also adjusts the delivery amount of cold air or warm air to the outlet provided in the interior zone and the outlet provided in the perimeter zone.

The control unit 40 further includes first to third room temperature sensor groups 5 for measuring room temperatures in the first to third zones.
1, 52, 53, an outside air temperature sensor 61, a solar radiation amount measuring sensor 62, and a wind speed measuring device 63 are connected. The control device 40 is a computer provided with a storage means, and controls the air conditioning equipment based on the data of these sensor groups and the database stored in the storage means. further,
The control device 40 is provided with a time measuring means for measuring the time elapsed since the last stop of the normal operation, and the air conditioning equipment is also controlled based on the measurement result.

Next, the principle of this embodiment will be described with reference to FIGS. 3 and 4. The solid line shown in FIG. 3 shows the demand value in the first zone of the conventional secondary system during heating when the increase and decrease in demand value at maximum load is relatively large.

The change of the demand value has a peak immediately after the system starts operating at 8:00 am, and then the demand value gradually decreases toward noon. Here, paying attention to the reduction rate of the demand value, it can be seen that the reduction rate becomes gentler after 9:30 am. This occurs because the stirring of the air layer having a temperature difference and stagnating in the room is not completed for one and a half hours from 8:00 am to 9:30 am.

When the cold air layer remains in the perimeter zone of the room, the temperature sensor provided in the perimeter zone detects a temperature lower than the room temperature of the interior zone. Therefore, the control device of the system connected to the temperature sensor tries to increase the demand value so that the room temperature of the perimeter zone rises to the set temperature of the interior zone.

When the temperature sensor is experimentally provided in the interior zone, the demand value changes as indicated by the one-dot chain line. In this case, the effect of the cold air layer remaining in the perimeter zone on the temperature sensor can be ignored, so the peak value decreases from a to b, and from 8 am to 9:30 am It can be seen that the useless amount A can be reduced.

The solid line shown in FIG. 4 shows the demand value of the secondary system of the present embodiment when heating the first zone in the same building as in FIG.

The secondary side system of the present embodiment eliminates the temperature difference between the perimeter zone and the interior zone by gradually starting the system to reduce the above-mentioned useless amount A of use, and The peak immediately after system operation can be eliminated.

The principle of the present embodiment is that, before normal operation of the system (before full-scale start-up), three preparatory operations of a stirring stage, a partial preheating (precooling) stage, and a total preheating (precooling) stage are performed in order. By increasing the room temperature while eliminating the temperature difference between the perimeter zone and the interior zone.
Hereinafter, the preliminary operation of the first zone will be described.

In the first stirring stage, only the air circulation inside the building is carried out while the introduction of the heat medium is stopped. The duration T1 of this stirring phase is shown as 1 hour from 6 o'clock to 7 o'clock in FIG. At this agitation stage, the inside air having a relatively high temperature which is stagnant in the interior zone is sucked in through the first inside / outside air controller 11, and the inside air is blown out to the perimeter zone where the first air conditioner 10 is cooled. This destroys the cold air layer in the perimeter zone.

Further, at the stage where the temperature distribution in the interior zone and the perimeter zone is made uniform by the stirring step and the room temperature is stable, and the room temperature change per predetermined time is stable in the predetermined range, the first room temperature sensor 51 measures the room temperature. Then, the stirring stage room temperature data a1 is acquired, and the stirring stage is completed.

In the next partial preheating (precooling) stage, the air conditioner for the perimeter zone starts introducing the heat medium and blows warm air to the perimeter zone without introducing the outside air. Further, the air conditioner for the interior zone circulates air without introducing the outside air while the introduction of the heat medium is stopped. This partial preheating (precooling) stage is shown as T2 in FIG.

By this partial preheating (precooling) step, the temperature of the wall surface and the window glass around the perimeter zone is raised, and the cooling element in the perimeter zone is eliminated. By performing the elimination of the cooling element in the perimeter zone prior to the all preheating (precooling) step described later, the warm air blown into the perimeter zone is cooled and the formation of a new cold air layer can be prevented. This partial preheating (pre-cooling) step is performed when the predetermined room temperature increase rate is reached from the stirring step room temperature data a1.
Room temperature at this point is the partial preheating (pre-cooling) stage room temperature data b
It acquires as 1 and ends.

The predetermined room temperature increase rate is obtained when the room temperature increase rate measured by the first room temperature sensor 51 is 90% or more of the room temperature increase rate predicted based on the demand value. It is considered that the cooling element in the perimeter zone is eliminated.

In the next all preheating (precooling) stage, introduction of the heat medium to the air conditioners for the perimeter zone and the interior zone is started, and hot air is blown out into the room without introducing outside air. At this stage, the cooling element of the perimeter zone can be ignored to plan the rise of the room temperature. It is possible to control the demand value accurately. Incidentally, this all preheating (precooling) step is shown as T3 in FIG.

Next, the preliminary operation for each of the first to third zones will be described. The room temperature becomes higher in the order of the first zone, the second zone, and the third zone regardless of the time of cooling and heating. Therefore, during heating, the preliminary operation is started in the order of the first zone, the second zone, and the third zone. On the other hand, during cooling, the third zone, the second zone, and the first zone are sequentially started. The above preliminary operation is started.

By shifting the start time of the preliminary operation for each zone in this way, it becomes possible to efficiently allocate the heat medium to the zones that require more heat medium while maintaining the demand value of the entire building at a certain value or less. . Incidentally, it is not necessary to divide the zones into layers, and in the case of a large-scale building, one floor may be divided into a plurality of zones. It is also effective to divide the zone by focusing on the north, south, east, and west directions of the outer wall of the building.

Further, in the stirring stage, the inside air of the first to third inside / outside air controllers 11, 21, 31 is not introduced independently from the room air of each zone, but the inside air of the first to third sones is supplied. First to third inside / outside air controller 1 after mixing
1, 21, 31 to the first to third air conditioners 10, respectively
By supplying to 20 and 30, warm air or cold air of the entire building can be effectively utilized. For example, during cooling, the inside air cooled by the cool air remaining in the first zone can be blown into the room in the third zone having a relatively high temperature.

The system according to the present embodiment is provided with an outside air temperature sensor 61, a solar radiation amount measuring sensor 62, and a wind speed measuring device 63, and the temperature environment outside the building measured by a sensor or the like as these external environment measuring means. Can be reflected in the control of the preliminary operation.

That is, the control device 40 stores the temperature environment outside the building and the time required for each stage of the agitation stage, the partial preheating (precooling) stage, and the total preheating (precooling) stage of the preliminary operation on that day every day. To do. For example, if the demand value at the preheating (precooling) stage is 70% or less of the demand value during normal operation, it is determined that the preheating (precooling) time is unnecessarily long, and the temperature environment of the next day is set. Are almost the same,
The demand value at the preheating (precooling) stage is 8 for normal operation.
The start time of the stirring stage is delayed so that it is in the range of 0% to 90%. Such control is executed by the learning function of the control device, and it is possible to minimize thermal loss due to heat radiation of the entire building in the preliminary operation.

Further, from the data of the outside air temperature sensor 61,
It becomes possible to determine the case where the room temperature can be controlled more efficiently by introducing the outside air than by circulating the inside air in the stirring stage or the like. For example, in the preliminary operation during cooling, when the outside air temperature is lower than the room temperature inside the building, each inside / outside air controller can control to supply outside air to each air conditioner.

The control device 40 is also provided with a time measuring means for measuring the time elapsed since the last stop of the normal operation. For example, when the operation of the cooling and heating system is stopped on a holiday and the operation is started after the holiday, the heat load becomes large. In this case, a more accurate start time of the preliminary operation can be determined from the measurement result of the time measuring means by using the learning function based on the data of the day when the elapsed time from the stop is approximate.

[Brief description of drawings]

FIG. 1 is a floor plan view of a building in which a secondary side system for district heating and cooling according to an embodiment of the present invention is operated.

FIG. 2 is an overall configuration diagram of a secondary side system for district heating and cooling according to an embodiment of the present invention.

FIG. 3 is a graph showing a change in demand value during heating of a conventional secondary side system for district heating and cooling.

FIG. 4 is a graph diagram showing a change in demand value during heating of the secondary side system for district heating and cooling according to the embodiment of the present invention.

[Explanation of symbols]

1 indoor central area 2 window area 3 rooms 10 First air conditioner 11 First Inside / Outside Air Controller 12 First heat quantity controller 20 Second air conditioner 21 Second Inside / Outside Air Controller 22 Second heat quantity controller 30 Third air conditioner 31 Third Internal / External Air Controller 32 Third heat quantity controller 40 control device 51 First Room Temperature Sensor 52 Second room temperature sensor 53 Third Room Temperature Sensor 61 Outside air temperature sensor 62 Sensor for measuring solar radiation 63 Wind speed measuring instrument

Continuation of the front page (56) Reference JP-A-10-288380 (JP, A) JP-A-8-136036 (JP, A) JP-A-6-50565 (JP, A) JP-A-2-61448 (JP , A) JP 4-320751 (JP, A) JP 11-132490 (JP, A) JP 54-112539 (JP, A) JP 2-251041 (JP, A) JP 7-12384 (JP, A) JP 63-161338 (JP, A) JP 9-243140 (JP, A) JP 10-54590 (JP, A) JP 47-21061 (JP, B1) (58) Fields investigated (Int.Cl. ⁷ , DB name) F24F 11/02 F24F 11/02 102

Claims (8)

(57) [Claims] 1. A district cooling and heating secondary-side system having an air conditioner for independently heating and cooling a plurality of areas, and a controller for controlling the air conditioner, wherein the controller has a plurality of different temperature distributions. System communication to other rooms
It has a control function before normal operation, and the pre-operation control before normal operation is the air conditioning inside the room with the supply of heat medium stopped.
Only air circulation in the target area
Regarding the temperature distribution of the
The stirring stage ends at a stable stage, the partial preheating (pre-cooling) stage in which the heating medium is supplied only to the air conditioning for large heat loads, and the total preheating (pre-cooling) in which the heating medium is supplied to all regions. ) A secondary system for district heating and cooling, which is characterized by sequentially performing the steps. 2. A district cooling / heating secondary system having an air conditioner for independently heating and cooling a plurality of areas, and a controller for controlling the air conditioner, wherein the controller has a plurality of different temperature distributions. System communication to other rooms
It has a control function before normal operation, and the pre-operation control before normal operation is the air conditioning inside the room with the supply of heat medium stopped.
While supplying the heat medium only for air conditioning to the area where the heat load is large, and the stirring stage that only performs air circulation in the target area ,
From the room temperature data a at the end of the stirring stage, a predetermined room temperature rise (lower
Secondary cooling of district heating and cooling, characterized by sequentially performing a partial preheating (pre-cooling) stage that ends when the rate reaches the ( falling) rate, and a full pre-heating (pre-cooling) stage that supplies the heat medium to the air conditioning for all areas. Side system. 3. The full preheating step is partial preheating (precooling)
The temperature difference between the room temperature data b at the end of the stage and the normal operation set temperature c and the time from the end of the partial preheating stage to the normal operation are calculated and controlled to be a demand value of 80% or more of the normal operation. The secondary side system for district heating and cooling according to claim 1 or claim 2. 4. The secondary system for district heating and cooling further comprises an external environment measuring means including any one or more of an outside air temperature sensor, a solar radiation amount measuring sensor, and a wind speed measuring device, which are connected to the control device, The secondary system for district heating and cooling according to claim 1 or 2, wherein the control device determines a start time of the preliminary operation from a measurement result of the external environment measuring means using a learning function. 5. The secondary side system for district heating and cooling according to claim 1 or 2, wherein the control device determines internal air circulation or external air introduction in the preliminary operation based on a measurement result of the external environment measuring means. 6. The district cooling and heating secondary system further comprises time measuring means for measuring the time elapsed from the last stop of the normal operation, and the control device has a learning function from the measurement result of the time measuring means. The secondary side system for district heating and cooling according to claim 1 or 2, wherein the start time of the preliminary operation is determined by using. 7. A district cooling / heating secondary-side system having an air conditioning facility for independently heating and cooling a perimeter zone and an interior zone, and a control device for controlling the air conditioning facility, wherein the control device is the perimeter. Zone and
Normal operation of the system for temperature distribution in the interior zone
It has a control function before switching , and the pre-operation control before normal operation is the target of air conditioning in the room with the supply of heat medium stopped.
Only the air circulation in the area is performed and the temperature of the area to be air- conditioned
Regarding the temperature distribution, the change in room temperature per given time is within the given range.
A stirring stage that ends in a stable stage, a partial preheating (pre-cooling) stage in which the heating medium is supplied only to the air conditioning for large heat loads, and a total preheating (pre-cooling) stage in which the heating medium is supplied to all regions The secondary side system for district heating and cooling, which is characterized by sequentially performing and. 8. A secondary side system for district heating and cooling, comprising air conditioning equipment for independently heating and cooling air conditioning target areas in rooms on different floors, and a control device for controlling the air conditioning equipment. The control device is installed in multiple rooms with different temperature distributions.
Has a control function before normal operation of the system ,
In the pre-operation control before the normal operation, only the air circulation in the air-conditioning target area in the room is performed while the supply of the heat medium is stopped, and the temperature distribution in the air-conditioning target area per unit time is determined.
The agitation stage that ends when the room temperature change is stable within a predetermined range, the partial preheating (pre-cooling) stage in which only the air conditioner supplies the heat medium to a large heat load region, and the heat medium supply to the air conditioner in all regions The secondary side system for district heating and cooling, which is characterized by sequentially performing all preheating (precooling) steps.