JPH09243140A - Secondary side system for district cooling and heating system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently utilize the low-cost heating medium supplied from a district cooling and heating system in a demander's building. SOLUTION: In a building 5a in which heating medium such as chilled water or steam is supplied from a district cooling and heating plant 3, the mutual relation of various causes of utilizing the medium is clarified, demand control of first, second and third controls is automatically conducted by a DDC 31, the basic contract amount of the medium is reduced to utilize the efficient cost performance. For example, in the case of cooling, the first control raises the supply air temperature of a conditioned air supply unit and lowers the dehumidifying amount. Further, it reduces the quantity of outdoor air intake and further raises the cooling set temperature.

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 a district heating and cooling system that uses demand control to reduce costs.

[0002]

2. Description of the Related Art Generally, in a district heating / cooling (heat supply) system, a heat medium such as cold water, hot water or steam is produced in a heat supply plant and supplied to a heat demander building in a limited area through a regional pipe. . The supplied heat medium is mainly used for cooling cold water for cooling, hot water for heating or hot water supply, and steam for heating.

FIG. 8 shows a conventional district heating and cooling system 101.
It is a block diagram which shows the outline | summary. District heating and cooling plant 103
Supplies cold water and steam as heat medium to the buildings (customer buildings) 105a, 105b, ... Through the regional piping. In addition to the district heating and cooling plant 103, there is a plant (not shown) that supplies hot water instead of steam, and a plant (not shown) that supplies hot water in addition to steam.

The regional piping of the district heating / cooling plant 103 comprises a cold water pipe 107 and a steam pipe 109, each comprising a supply pipe (not shown) and a recovery pipe (not shown). Each building 105a, 105b, ...
a, 111b, ... Are provided to receive the heat medium supplied by the regional piping, supply it to the inside of each building, and use it.

In the building 105a, an air conditioner (air conditioner) 115 is provided in a room 113, and an external air conditioner 119 is provided in a room 117.
And an FCU (fan coil unit) 121 are provided. When the air conditioner is used, the cold water flows through the cold water pipe 123 to the air conditioner 115, the external conditioner 119 and the FCU1.
21. Also, when heating is used, the steam pipe 125
Through the steam through the air conditioner 115, the air conditioner 119 and F
It is supplied to the CU 121 and the like.

The air conditioner (air conditioner) 115 is installed in the room 11
3 is a device for adjusting conditions such as temperature, humidity, air flow, dust, odor, toxic gas, bacteria, etc., in addition to the outside air intake 127, compressor, electric motor, condenser, direct expansion coil, humidifier, air Consists of a filter, blower, heat exchanger, etc. The heat exchanger is used to pass cold water into the extended portion of the cold water pipe 123 during cooling and to pass steam through the extended portion of the steam pipe 125 during heating.

The outside air conditioner (outside air conditioner) 119 is installed in the room 11
7 is a device for adjusting conditions such as temperature, humidity, air flow, dust, odor, toxic gas, and bacteria of the outside air taken in through the outside air intake 129, and includes a compressor, an electric motor, a condenser, a direct expansion coil, a humidifier, Consists of an air filter, blower, heat exchanger, etc. The FCU (fan coil unit) 121 is a device for adjusting conditions such as temperature, air flow, dust, odor, toxic gas, and bacteria in the room 117.
It is a small air conditioner that incorporates a small blower, coil, and air filter.

FIG. 9 shows a conventional district heating and cooling system 101.
It is a figure which shows the example of trial calculation of the usage fee of. A building (customer building) that is a user for a district heating and cooling system operator 10
The usage fee paid from 5a is the sum of the basic charge based on the contract heat medium amount and the usage-based charge for the excess usage amount for each of cold water and steam.

The amount of heat medium used varies significantly depending on the season and time even in the same building 105a. FIG.
FIG. 4 is a diagram showing an example of summer cold water usage without demand control, where A is the contract cold water quantity which is the contract heat medium quantity for cold water, and B is the cold water peak load. In FIG.
From noon to evening in summer, the amount of cold water used greatly increases, and the peak load B of cold water is reached at the maximum demand.

[0010]

However, from the standpoint of the building (consumer building) 105a in the conventional district heating and cooling system 101, for example, when the contracted cooling water amount A is large, the district heating and cooling use is paid annually. There was a problem that the basic cold water charge was high.

From the standpoint of the district heating and cooling system, each building (consumer building) 105a, 105b, ...
If the amount of heat medium required for the ... increases, the amount of heat medium to be supplied as a whole increases, so the district heating and cooling plant 1
We must prepare a large 03 facility capacity,
In addition, in some cases, the total amount of heat medium required becomes too large and the supply amount becomes insufficient.

The present invention has been made in view of the above problems, and an object of the present invention is to reduce the amount of heat medium used while maintaining the living environment on the consumer building side to some extent, thereby saving resources and costs. It is to provide a secondary side system for a district heating and cooling system that is lean.

[0013]

In order to achieve the above-mentioned object, the present invention relates to a district heating and cooling system in which a heat medium is introduced from a heat source to a heating and cooling facility inside a building in a region for cooling and heating, and the load of the cooling and heating facility is 2 of the district heating and cooling system, characterized by comprising cooling and heating mitigating means for mitigating the peak load condition of the cooling and heating equipment.
It is the secondary system.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a configuration diagram schematically showing a district cooling / heating system 1 according to the present embodiment. The district heating / cooling plant 3 has a capability of supplying a heat medium into a predetermined area, and supplies cold water and steam as a heat medium to the buildings (customer buildings) 5a, 5b, ...

The regional piping of the district heating and cooling plant 3 comprises a cold water pipe 7 and a steam pipe 9, each comprising a supply pipe (not shown) and a recovery pipe (not shown). Each building 5a, 5
Reception facilities 11a, 11b, ... Are provided in b. The receiving equipments 11a, 11b, ... consist of cold water amount measuring devices, heat exchangers, pumps, etc., receive the heat medium supplied by the regional piping, process it if necessary, and supply it to each building, To use.

In a room 13 in the building 5a, for example, an air conditioner (air conditioner) 1 for processing the load of outside air temperature, humidity, dust, etc. and the load of room air temperature, humidity, dust, etc.
5 are provided. Further, for example, in the room 17, there are an outdoor air conditioner 19 (outdoor air conditioner) that processes loads such as the temperature, humidity, and dust of the outside air, and a small-sized function-limited air conditioner that processes the temperature of the room and loads such as the dust. An FCU (fan coil unit) 21 is provided.

When the air conditioner is used, cold water is supplied to the air conditioner 15, the external conditioner 19 and the FCU 21 through the cold water pipe 23. Further, when heating is used, steam is supplied to the air conditioner 15, the external conditioner 19, the FCU 21, etc. through the steam pipe 25.

The air conditioner 15, the external conditioner 19, and the FCU 21 include a heating / cooling combined type, a heating exclusive type, or a cooling exclusive type, but in the example of the present embodiment, all of them are the combined heating / cooling type. I shall. Therefore, the heat exchanger used for the air conditioner 15, the external air conditioner 19 and the FCU 21 passes cold water through the extended portion of the cold water pipe 23 during cooling, and passes steam through the extended portion of the steam pipe 25 during heating. is there.

The air conditioner (air conditioner) 15 includes a compressor, an electric motor, a condenser, a direct expansion coil, and an outside air intake 27.
It consists of a humidifier, air filter, blower, thermometer, hygrometer, heat exchanger, etc. Outside air conditioner (outside air conditioner) 19
In addition to the outside air inlet 29, is composed of a compressor, an electric motor, a condenser, a direct expansion coil, a humidifier, an air filter, a blower, a thermometer, a hygrometer, a heat exchanger, and the like. The FCU (fan coil unit) 21 is composed of a small blower, a coil, an air filter, and the like.

The DDC (direct digital controller) 31 according to the embodiment of the present invention is uniquely provided in the building 5a and controls the setting conditions such as temperature and humidity and dust of the room 13 and the room 17. However, the operation of the receiving facility 11a, the air conditioner 15, the external conditioner 19, the FCU 21, etc. is comprehensively controlled.

Next, the demand control method by the DDC 31 will be described by taking the case of using cold water as an example. In the demand control, in order to use the heating medium for district heating and cooling in a cost-effective manner, the mutual relationship of various factors relating to the use of the heating medium is clarified, and then the receiving facility 11a, the air conditioner 15,
It controls the external conditioner 19, FCU 21, etc.

FIG. 2 is a flow chart showing demand control using cold water. Reception facility 11 in building 5a
a measures the current amount of cold water (the amount of cold water used), and the air conditioner 15, the external conditioner 19, etc. measure the temperature and humidity of the outside air, and the DDC 31 is used at all times or at predetermined intervals.
Send the measured value to.

The DDC 31 indicates the measured values by season, time,
In consideration of data such as weather and past examples, future changes in the cold water amount are predicted (step 201), and it is determined whether or not the predicted cold water amount is less than or equal to the contract cold water amount ( Step 202). In step 202, if the predicted cold water amount is less than or equal to the contracted cold water amount, D
The DC 31 includes the receiving facility 11a, the air conditioner 15, and the external conditioner 1.
9. No instruction is given to the FCU 21, and the measurement and prediction as before are continued.

If it is predicted in step 202 that the amount of cold water will become excessive in the future, the DDC 31 first sets the temperature of the outside air blown into the building to be high and decreases the amount of dehumidification as the first control. So that the air conditioner 15,
The external conditioner 19 is instructed (step 203). DDC31
The air conditioner 15 and the external conditioner 19 can reduce the amount of cold water for cooling and dehumidifying the outside air according to the instruction from. By performing step 203, the cooling set temperature is maintained unchanged.

The upper limit value of the blast temperature and the lower limit value of the setting of the dehumidification amount are set in advance for each room by the facility manager of the building 5a in consideration of the purpose of each room. DDC
When the predicted amount of cold water is excessively large, 31 gradually increases the setting of the blast temperature until the upper limit value of the blast temperature is reached, and gradually decreases the dehumidification amount until the lower limit value of the dehumidification amount is reached. We will continue to measure and predict the amount of cold water while reducing the amount.

The DDC 31 executes the step 203.
It is judged whether or not the predicted chilled water amount has decreased sufficiently (step 204), and if the predicted chilled water amount falls within the contracted chilled water amount range, use chilled water up to the contracted chilled water amount limit. , A comfortable living environment is maintained by keeping the cooling set temperature, the blast temperature as low as possible, and the dehumidification amount as large as possible.

The DDC 31 performs the processing of step 204, sets the blast temperature to the upper limit value, and sets the dehumidification amount to the lower limit value, but when it is determined that the chilled water amount is still excessive, As the second control, the intake amount of outside air into the building is set small, and the air conditioner 15 and the external conditioner 19 are instructed (step 205). The air conditioner 15 reduces the amount of outside air taken in from the outside air intake 27, and the air conditioner 19 uses the outside air intake 29.
Reduce the intake of fresh air from.

By reducing the intake amount of outside air that is warmer than room temperature, the air conditioner 15 and the external controller 19 can reduce the amount of cold water for cooling the outside air. Even if Step 203 and Step 205 are performed, the cooling set temperature is maintained unchanged.

Next, the DDC 31 determines whether or not the predicted amount of cold water has sufficiently decreased (step 206). If it is determined that the amount of cold water has sufficiently decreased, the cold water is used up to the limit of the contracted cold water amount. The amount of outside air intake is maximized to maintain the quality of air and maintain a comfortable living environment.

When it is determined in step 206 that the amount of cold water predicted is still excessive, the DDC 31 raises the set cooling temperature inside the building according to the predicted amount of cold water as the third control. This is instructed to the air conditioner 15 and the external controller 19 (step 207).

By raising the set cooling temperature, the air conditioner 15, the external conditioner 19, and the FCU 21 can reduce the amount of cold water for cooling the room temperature. In addition, by using cold water up to the limit of the contracted cold water volume, the set cooling temperature is made as low as possible to maintain a comfortable living environment.

When the amount of cold water decreases due to a decrease in outside air temperature, the DDC 31 reverses the order of FIG. 2, that is, the adjustment of the third control (step 207), the second control.
Adjustment of control (step 205), first control (step 2)
Cancel the adjustment in the order of 03).

That is, first, the set cooling temperature is gradually decreased, and when the amount of cold water after reaching the optimum cooling temperature is equal to or less than the contracted cold water amount, the outside air intake amount is gradually increased. . Next, when the amount of cold water after increasing the amount of outside air intake to a predetermined maximum is less than the contracted amount of cold water, the dehumidification amount is increased and the blast temperature is lowered.

In addition, the first control, the second control, and the third control
The order of adjusting the types shall be determined according to the intended use of the building. That is, the example of FIG. 2 is a case where importance is attached to the temperature maintenance, but when importance is attached to the maintenance of the air quality rather than the temperature maintenance, the air conditioning conditions are set in the order of the first control, the third control and the second control. May be adjusted.

FIG. 3 is a diagram showing an example of trial calculation of demand control at the peak of cooling. In FIG. 3, it can be seen that the period from 9:00 to 19:00 is a time zone in which the amount of cold water is large. Especially 11
Since the amount of chilled water is very large between 17:00 and 17:00, a comparison will be made in this time period between the case where demand control is not performed and the case where various demand controls are performed. The solid line 301 shows the case where the demand control is not performed, and it can be seen that the peak cold water amount becomes about 3,100 Mcal / h at about 15:00.

The broken line 303 shows the case where the outside air is cut by the second control. The outside air amount is gradually reduced between 11:00 and 12:00, and the outside air is cut to the maximum from 12:00 to 16:00, and after 16:00. The outside air volume is gradually increased to 11 between 17:00.
It returns to the amount before time. The dotted line 305 shows the case where the cooling set temperature is increased by 1 ° C. for 24 hours, and it can be seen that the effect of saving the amount of cold water is great especially between 9 o'clock and 19 o'clock when the outside air temperature is high.

The alternate long and short dash line 307 shows the case where the third control and the second control are carried out. The outside air amount is gradually increased from 11:00 to 12:00 with the cooling set temperature raised by 1 ° C. for 24 hours. The outside air is cut to the maximum from 12:00 to 16:00, and the outside air volume is gradually reduced from 16:00 to 17:00.
This is the case when the amount is returned to that before 1:00. Comparing the amount of cold water at 15:00, when demand control is not performed, it is about 3,1.
It can be seen that what was 00 Mcal / h was about 2,250 Mcal / h when the third control and the second control were performed, and the amount of cold water was significantly reduced.

Similarly, the case of using steam for heating will be briefly described with reference to the diagram of FIG. 4 showing an example of trial calculation of demand control during peak heating. The solid line 401 shows the case where the demand control is not performed, and the dotted line 403 shows the case where the set heating temperature is lowered by 1 ° C. for 24 hours by the third control.

The broken line 405 shows the effect of reducing the amount of steam when the outside air intake amount is limited by the second control. From 0 o'clock to 9 o'clock, the outside air volume is kept slightly reduced. The room temperature must be raised to start the activity time. From 9:00 to 11:00, the outside air volume is cut to the maximum, and from 11:00 to 12:00, the outside air volume is gradually increased to warm the outside air. From 12:00 to 16:00, the outside air is taken in to the maximum.

From 16:00 to 17:00 when the outside air temperature gradually decreases, the amount of steam is reduced by limiting the amount of outside air. In addition, the amount of outside air is maximally cut from 17:00 to 20:00, and the amount of outside air is slightly reduced after 20:00.

The alternate long and short dash line 407 indicates the third control and the second control.
Both the control and the control are performed, the set heating temperature is lowered by 1 ° C. over 24 hours, and the outside air amount is limited in the same manner as the case of the broken line.

Therefore, in order to perform demand control when heating is used, when it is predicted that the steam amount exceeds the contract steam amount, first, the second control is performed to reduce the intake amount of outside air into the building 5a. If the amount of steam is still excessive, the set heating temperature inside the building 5a is lowered by the third control.

FIG. 5 is a diagram showing an example of trial calculation of basic charge reduction when demand control is performed. When the basic charge for district heating and cooling that takes one year without demand control is 157,300,000 yen / year, as shown in FIG. 5, the first control, the second control, and the third control are executed. If done, the basic charge reduction rates are 4.0% and 8.6, respectively.
% And 15.7%.

The reduction rate of the basic charge when both the second control and the third control are performed is 23.0%. That is, the reduction rate of the basic charge when both the second control and the third control are performed is the reduction rate of only the second control and the third rate.
It is different from the total reduction rate due to control only.

FIG. 6 is a diagram showing the effect of performing demand control with respect to FIG. Actual load curve 5 shown by the broken line
1 shows the case where the demand control is not performed, and the effect of the demand control is shown with the cold water amount of the peak load in this case being 100%.

The one-dot chain line indicates 1 from 13:15
It is the 1st control execution curve 53 which shows the amount of cold water when the 1st control is performed by 9:00. The two-dot chain line is the second control execution curve 55 showing the amount of cold water when both the first control and the second control are performed in the same time zone. Further, the solid line is the third control execution curve 57 showing the amount of cold water when the first control, the second control, and the third control are all performed in the same time zone.

In FIG. 6, the contracted cold water amount line 59 shows an example of the contracted cold water amount. Compared with the actual load curve 51, the cold water amount indicates the contracted cold water amount from 12:00 to after 19:00. You can see that it is over. However, when the demand control is performed, the time for the first control execution curve 53 to exceed the contracted cold water flow rate curve 59 is greatly shortened, and the second control execution curve 53 and the third control execution curve always follow the contracted cold water flow rate curve 59. It is below.

Therefore, when the demand control is performed up to the second control or the third control, the peak load does not exceed the contracted cold water amount even if the contracted cold water amount is smaller than the amount indicated by the contracted cold water amount line 59. It is possible to The contracted chilled water amount can be determined by the operator of the building 5a in consideration of conditions such as a budget, an air conditioning standard to be maintained, and an expected temperature.

Further, in one building, it is possible to control the air conditioning control condition for each room or block in consideration of the purpose of each room. FIG. 7: is a block diagram which shows the outline of the hotel 71 which is an example of a consumer building. Guest rooms 73a, 73b, ... each having an air conditioner (not shown) on the floor where the hotel 71 is located, the warehouse 7
5, kitchen 77, restaurant 79, passage 81, machine room 83
It is assumed that there is. The machine room 83 is provided with a receiving facility 85 that supplies a heat medium to each air conditioner, and a DDC 87 that controls the receiving facility 85 and each air conditioner.

The person in charge of air conditioning of the hotel 71 performs the first control, the second control and the third control for the warehouse 75 and the machine room 83, and the first control and the first control for the kitchen 77 and the passage 81, for example. Guest room 73 with only 2 controls
a, 73b, ... and the restaurant 79,
The policy of demand control by the DDC 87 can be determined in advance such that neither control is performed.

As described in detail above, according to the present embodiment, the building of the district heating and cooling system 1 (customer building)
In 5a, by independently providing the DDC 31 to ease the peak load condition of the heating and cooling equipment, the heating medium supplied from the district heating and cooling plant 3 can be used efficiently, and the contracted heating medium amount related to the basic charge can be obtained. The building 5a
The district heating and cooling charges paid by can be reduced.

In this embodiment, the DDC 31
Although only one is provided in the building 5a to comprehensively control the receiving facility 11a, the air conditioner 15, the outdoor conditioner 19, and the FCU 21, in a larger and more complex building, each room is Or D for each predetermined block in the building
DC may be provided and controlled separately.

In the present embodiment, the outside air intake amount and the
Although the set temperature or the like is targeted, conditions such as the kitchen ventilation amount, the electric room cooling capacity, and the back area condition may be relaxed at the peak time.

In the present embodiment, the case where cold water is used for cooling and steam is used for heating has been described.
Also when hot water is used for heating or for heating and hot water supply, demand control similar to that when steam is supplied can be performed in order to reduce the cost for heating.

[0055]

As described above in detail, according to the present invention, it is possible to provide a district heating / cooling system which can efficiently use the heat medium supplied from the district heating / cooling system at low cost.

[Brief description of drawings]

FIG. 1 is a configuration diagram schematically showing a district cooling / heating system 1.

FIG. 2 is a flowchart showing demand control for using cold water.

FIG. 3 is a diagram showing an example of trial calculation of demand control during a peak cooling period.

FIG. 4 is a diagram showing an example of trial calculation of demand control during a heating peak time.

FIG. 5 is a diagram showing an example of trial calculation of basic charge reduction when demand control is performed.

6 is a diagram showing the effect of performing demand control on FIG.

FIG. 7 is a block diagram showing the outline of a hotel 71.

FIG. 8 is a configuration diagram showing an outline of a conventional district heating and cooling system 101.

FIG. 9 is a diagram showing an example of trial calculation of a conventional usage charge of the district heating and cooling system 101.

FIG. 10 is a diagram showing an example of the amount of cold water used in summer without demand control.

[Explanation of symbols]

 1 ... District heating / cooling system 3 ... District heating / cooling plant 5a, 5b ... Building 7 ... Cooling water pipe 9 ... Steam pipe 11a, 11b, ... Receiving facility 13 ... Room 15 ... …… Air conditioner (air conditioner) 17 …… Room 19 ………… Outside air conditioner 21 ………… FCU (fan coil unit) 23 ………… Cold water pipe 25 ………… Steam pipe 27 ………… Outside air intake 29 ………… Outside air intake 31 ………… DDC (direct digital controller) 51 ………… Actual load curve 53 ………… First control execution curve 55 ………… Second control execution curve 57 ………… Third control Implementation curve 59 ………… Contracted cold water flow line 71 ………… Hotel

Claims (5)

[Claims] 1. In a district heating / cooling system that conducts heating / cooling by introducing a heat medium from a heat source to a heating / cooling facility inside a building in a region, the load of the cooling / heating facility is predicted, and the peak load condition of the cooling / heating facility is relaxed. A secondary side system of a district heating and cooling system, characterized by comprising mitigation means. 2. The secondary side system of the district heating and cooling system according to claim 1, wherein the cooling and heating equipment is an air conditioner, or an air conditioner and a fan coil unit. 3. The mitigation means comprises means for predicting the usage amount of cold water, which is the heat medium, based on the outside air condition, and when the predicted usage amount of cold water is larger than a predetermined value, (a) ) Means for lowering the dehumidification amount by raising the temperature of the air blown into the building; (b) means for reducing the amount of outside air taken into the building; and (c) means for lowering the set cooling temperature inside the building. Among the above, (a) to (c) are appropriately combined and used, and the secondary side system of the district heating and cooling system according to claim 1 or 2. 4. The relaxing means comprises means for predicting the usage amount of the hot water or steam as the heat medium based on the outside air condition, and the predicted usage amount of the hot water or steam is larger than a predetermined value. In this case, among (d) means for reducing the amount of intake of outside air into the building and (e) means for raising the set heating temperature inside the building, (d) and (e) are appropriately combined and used. The secondary side system of the district heating and cooling system according to claim 1 or 2, characterized in that. 5. The secondary side system of the district heating and cooling system according to claim 1, wherein the mitigating means mitigates kitchen ventilation, cabin cooling capacity, and back area conditions.