JP3388564B2 - District heat supply system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a district heat supply system, and more particularly to improving the efficiency of operation of heat source equipment, improving the heat supply capacity of district heat supply pipes, and expanding the selectivity of customer side equipment. About the district heat supply system that can.

[0002]

2. Description of the Related Art In recent years, with the integration of urban functions, new urban heating and cooling equipment has been sought. inside that,
The district heat supply system is attracting attention as an air-conditioning system that is excellent in energy saving by leveling and enlarging the energy. A typical district heat supply system
A facility that supplies cold water or hot water from a central heat source plant equipped with a cold water generator such as a refrigerator and a hot water generator such as a boiler to each building where customer facilities are installed through a long district heat supply pipe. is there.

As described above, the conventional district heat supply system requires a relatively long district heat supply pipe, which has been a factor of increasing the initial cost. Further, since the transportation power for supplying cold water or hot water to each customer facility is large, the running cost is inevitably high, which is a problem. In view of this problem, conventionally,
Various measures to reduce the cost of the district heat supply pipe and save energy have been proposed. For example, Japanese Patent Application No. 4-4533
Japanese Patent Laid-Open No. 2 (1994) proposes a system for reducing the initial cost by connecting the central heat source plant and the customer facility with two pipes.

[0004]

However, the conventional cost reduction or energy saving measures for the district heat supply piping only enlarges the temperature difference of the cold water return, which causes the following problems. .

First of all, the performance of the central heat source plant is
Almost determined by the water supply temperature, in the case of supplying cold water, there is a problem that the coefficient of performance, which is an index of energy use efficiency, decreases when the water supply temperature is shifted to the low temperature side.

Secondly, there is a problem that a mere expansion of the temperature difference results in an increase in heat exchange equipment on the customer equipment side. That is, in order to achieve the large temperature difference, the heat transfer area of the heat exchanger of the consumer facility had to be increased. Further, it is necessary to subdivide the system of the air conditioning equipment on the customer side according to the load characteristics and to control each.

Furthermore, in the conventional district heat supply system, since the type of heat source and the temperature level are determined for each district heat supply system, the selectivity (or designability) of the equipment on the customer side is limited. I had to become.

The present invention has been made in view of the above problems of the conventional district heat supply system.
In addition to improving the energy use efficiency of the heat source system of the central plant and reducing costs, the initial cost and running cost of the facility are reduced by expanding the heat transfer power of the district heat supply piping facility, and the facility on the customer side is further reduced. It is an object of the present invention to provide a new and improved district heat supply system capable of expanding the selection range of.

[0009]

In order to solve the above-mentioned problems, according to a first aspect of the present invention, a central heat source system (102) and a customer facility (104) are connected to one line of an outbound pipe (106). ) And one return pipe (108),
In the district heat supply system that supplies the heat source water produced by the central heat source system (102) to the customer facility (104), the customer facility (104) is provided with a plurality of customer facility groups (104A, 104B, ...). , And 104a, 1
04b, ..., And each of the customer equipment groups is cascade-connected through at least one system of return path piping (112), and the customer equipment group (104) on the downstream side of the cascade connection is connected.
a), 104b, ..., Is supplied with the heat source water returned from the consumer equipment group (104A, 104B, ...) On the upstream side of the cascade connection to the return route piping (112). District heating system is provided. In the present specification, the cascade connection means a pipe connection such that a return pipe from a certain customer facility group is connected to a forward pipe to another customer facility group via the return route pipe. I will say.

Further, according to the second aspect of the present invention, the central heat source system (202) and the customer facility (204) are connected to one line of the forward pipe (206) and one line of the return pipe (20).
8), in the district heat supply system for supplying the heat source water produced by the central heat source system (202) to the customer facility (204), the first is obtained by dividing the customer facility (204) into a plurality. Consumer equipment group (204A, 204
B, ...,) and the second consumer facility group (204a, 204)
control valve means (210) for controlling the flow rate of the heat source water supplied to b, ..., And the central heat source system (102, 20)
2, 302 (402)) to supply the heat source water to the first consumer equipment group (204A, 204B, ...), and the central heat source system (102, 202, 302)
Directly supplying the heat source water produced in (402)),
Is the first consumer equipment group (204A, 204B, ...)
Return line piping (212) for supplying return water from the; return route
Heat source water from the pipe (212), or the heat source water is supplied
Second consumer equipment group (204a, 204b,
...,) and return pipe (208) to which return water is supplied.
The central heat source system (10
2,202,302 (402)) heat source water
Flow rate or first consumer facility group (204A, 204B,
The flow rate of the return water from the control valve means (210)
Controlled by the degree, and return traffic in the return pipe (208)
Flow rate of heat source water from the conduit (212) or second consumer
Flow rate of return water from the equipment group (204a, 204b, ...)
Is controlled by the opening of the control valve means (210).
A district heat supply system is provided which is characterized in that

Furthermore, according to a third aspect of the present invention, a central heat source system (302) and a customer facility (30) are provided.
4) is connected to the forward heat pipe (306) of one system and the return pipe (308) of one system to connect the central heat source system (30).
In the district heat supply system for supplying the heat source water produced in 2) to the customer facility (304), control valve means (3)
N-1 (however, n) that can selectively communicate with the forward pipe (306) or the return pipe (308) by 10).
Is any positive integer greater than or equal to 2) system return path piping (312
(1), 312 (2), ..., 312 (n-1)) are provided, and the (n-1) th consumer facility group (304 (n) α, 304) is provided.
(N) β, ..., Are the (n−2) th return path piping (312).
(N-2)) is supplied with heat source water and returns the return water to the n-1th return passage pipe (312 (n-1)), but
Consumer equipment groups (304 (1) A, 304 (1) B,
,) Is supplied with heat source water from the outgoing pipe (306) and returns the return water to the first outgoing pipe (312 (1)), and the nth consumer facility group (304 (n)). α, 304
(N) β, ..., Is the (n-1) th return path pipe (31).
2 (n-1)) to supply the heat source water and return the return water to the return pipe (308), the district heat supply system is provided.

In addition, in the district heat supply system constructed from the above first to third aspects, the forward piping (106, 2)
06, 306 (406)) and the first return path pipe (1
12, 212, 312 (1) (412)) and a first pressure sensor (P1) for detecting a pressure difference between the first and second n-1 return path pipes (112, 212, 312 (n-1) (412)). )
And the return pipe (108, 208, 308 (408))
The central heat source system (102, 2) according to the detection values of the second pressure sensor (P2) that detects the differential pressure between the first pressure sensor (P1) and the second pressure sensor (P2).
02, 302 (402)) and / or control means (150, 250, 350, 450) for controlling the flow rate of the heat source water supplied to each of the consumer facility groups.

[0013]

DETAILED DESCRIPTION OF THE INVENTION Referring to the accompanying drawings,
Several preferred embodiments of the district heat supply system constructed according to the present invention will be described in detail.

1 and 2 show a district heat supply system 100 (200) according to a first embodiment of the present invention. In the following description, each component of the district heat supply system configured according to the present invention is 3
Although referred to by a digit number, in each embodiment,
Unless otherwise specified, the same reference numerals are used in the last two digits for components having substantially the same configurations and functions, and duplicate description will be omitted.

As shown in FIG. 1, in the district heat supply system 100 according to the first embodiment, a central heat source system 102 and a customer facility 104 are connected to one line of outbound piping 106.
And a return pipe 108 of one system. The central heat source system 102 is a chilled water generator 10 such as a refrigerator.
2a and a hot water generator 102b such as a boiler are provided, and a desired amount of hot water or cold water (heat source water) can be supplied to each connected customer facility 104 by a water supply pump 102c.

According to the present embodiment, as shown schematically in FIG. 1, a plurality of customer facilities 104 (in the illustrated example,
2 groups) customer equipment groups (104A, 104B,
, And 104a, 104b, ...), and each consumer facility group is cascade-connected via at least one system of return route piping 112. In addition, the return route piping 112 that cascade-connects each customer facility group, as described below, according to the group to which each customer facility group belongs,
It functions as an outflow piping for heat source water for a certain customer equipment group and as a return piping for another customer equipment group. Then, according to the present embodiment, the customer facility group (104a, 104) on the downstream side of the cascade connection.
b), ...) is heat source water (that is, relatively high temperature cold water or relatively low temperature hot water) returned to the return passage pipe 112 from the customer equipment group (104A, 104B, ...) On the upstream side of the cascade connection. ) Is supplied. In this way, the return passage pipe 112 is connected to the customer facility group (1
04A, 104B, ..., As return pipes, and cascade connection downstream customer equipment group (104
a, 104b, ... As described above, in the present specification, a pipe capable of switching the functions of the outgoing pipe and the return pipe according to the customer facility group is referred to as the outgoing pipe.

FIG. 2 shows details of the cascade connection by the round-trip piping 206 on the customer facility side 204 in the district heat supply system 100 (200) according to the first embodiment shown in FIG. . In the illustrated example, the customer facility 204 is divided into two groups. That is,
The all-consumer facilities 204 are supplied with heat source water directly from the outward route pipe 206, and return the return water after heat exchange to the outward route pipe 212, a first consumer facility group 204A, 204B, ...
The return water from the first consumer facility group 204A, 204B, ... Is supplied from the return passage pipe 212 to be used as heat source water, and the return water after heat exchange is returned to the return water pipe 208. The customer equipment group 204a, 204b, ... In addition, each customer facility 204 has a heat exchanger 220 (2
20A, 220B, ..., 220a, 220b,
,) And control valves 222 (222A, 222B, ..., And 222a, 222b, ...).

As described above, according to the present embodiment, since a plurality of groups of customer facilities are cascade-connected, the heat transfer capacity of the district heat supply pipe is significantly increased (by a simple calculation about twice). Initial costs (pipe installation costs, etc.) and running costs (transportation power costs, etc.) are reduced. For example,
The incoming water of about 6 ° C. is supplied to the first consumer equipment group 204A, 204B, ...
After heat exchange with 20A, 220B, ..., Return water of about 12 ° C. is returned to the return passage pipe 212, and from this return passage pipe 212 to the second consumer facility group 204a, 204b ,. If the return water of about 18 ° C is returned to the return passage pipe 208 after supplying the incoming water of ℃, the heat transfer capacity is merely about 6 ° C as in the conventional system. It is about twice as much as the case of supplying the water and returning the returned water at about 12 ° C.

According to the present embodiment, since the inlet / outlet temperature difference of the central heat source system 202 is large as described above, in the case of producing cold water, for example, a plurality of refrigerating devices are arranged in series and the cold water is gradually provided. It becomes possible to cool. As a result, the coefficient of performance of the refrigeration system on the upstream side of the central heat source system 202 is improved, and the central heat source system 202 as a whole.
The energy use efficiency of can be improved.

Further, when the same amount of heat is conveyed, according to the present embodiment, the number of pipes is increased by the number of the return passage pipes, but it is possible to lay a small diameter pipe as compared with the conventional method. The piping system is determined by the arrangement of the first consumer groups 204A, 204B, ... And the second consumer groups 204a, 204b, ... And their heat load patterns, but according to the present embodiment. A pipe having a cross-sectional area of several tens% of the pipe diameter of the outward passage pipe 206 may be used as the outward passage pipe 212.

Further, the first consumer group 204 which directly receives the heat source water from the outgoing route pipe 206 and returns the returned water to the outgoing route pipe 212.
For A, 204B, ..., It is possible to use the conventional air conditioning system as it is. Further, as the second consumer groups 204a, 204b, ..., Which receive the heat source water (therefore, relatively high temperature cold water or relatively low temperature warm water) from the return passage pipe 212 and return the return water to the return passage pipe 208. For example, it is possible to use an energy-saving air conditioning system such as disclosed in Japanese Patent Application No. 7-286654 of the same applicant, in which a sensible heat load and a latent heat load are processed by different air conditioners. it can. Since the heat source water (relatively high temperature cold water or relatively low temperature hot water) from the return passage pipe 212 is sufficient to handle the sensible heat load that occupies most of the indoor load and the outside air load, the above air conditioning system The heat source water is used in the sensible heat treatment air conditioner. The residual load (latent heat load) is processed by a separately provided latent heat load processing air conditioner.

The customer equipment is the first customer equipment group 2
04A, 204B, ... Or the second consumer facility group 204a, 204b, ... Is preferably determined based on the heat load characteristics of the consumer. For example, when a meeting place facility has a high latent heat load, it is preferable to belong to the first consumer facility group 204A, 204B, .... On the other hand, in the case of an office facility with a high sensible heat load, the second customer facility group 204
It is preferable to belong to a, 204b, .... As described above, according to the present embodiment, it becomes possible for the customer side to select the quality of the temperature level of the heat source water, the range of facility planning is widened, and the customer side can efficiently use energy. It is possible to select equipment. In the actual operation of the system, the first customer equipment group 204A, 204B, ..., And the second customer equipment group 204
It is preferable to design the system so that the heat utilization with a, 204b, ...

Further, when the central heat source system 202 uses a heat storage system for storing ice heat or cold water (or hot water) in the heat storage tank by using inexpensive electric power at night, the present embodiment is used. According to the above, with the same heat storage tank volume, the amount of heat storage is increased by about two times by simple calculation. Therefore, in a system that requires the same heat load on the consumer side, a more economical system can be constructed by reducing the heat source unit capacity or the heat storage tank volume.

FIG. 3 shows still another embodiment of the district heat supply system according to the present invention. In the district heat supply system 100 (200) shown in FIG. 1 and FIG. 2, one system of the return route pipe 11 is provided for each system of the outward route pipe 106 (206) and the return route pipe 108 (208).
2 (212) was installed, in the district heat supply system 300 shown in FIG.
12 (1) and 312 (2)) are arranged. Furthermore, in this district heat supply system 300, the customer facilities 3
Reference numeral 04 denotes a first customer facility group (304 (1) A, 304 (1) B) that receives heat source water directly from the outward route pipe 306 and returns the return water to the first outward route pipe 312 (1) after heat exchange. ,
,), And the second customer facility group (304 (2) α, 304 (2) that receives the heat source water of the first return path pipe 312 and returns it to the second return path pipe 312 (2) after heat exchange. ) Β, ...,)
And a third consumer facility group (3) that receives the heat source water of the second return path pipe 312 (2) and returns it to the return path pipe 308 after heat exchange.
04 (3) a, 304 (3) b, ...

In this embodiment, in principle, n
-1 (where n is an arbitrary positive integer) return passage pipe 31
2 is applicable to the customer facility group 304 divided into n, and therefore, in FIG. 3, each customer facility 304 and each return route pipe 3 are used by using any positive integer n.
12 shows the configuration. However, actually, in the illustrated system, n = 3, and the two return path pipes 312
(1) Using 312 (2), the customer equipment group 304 divided into three, that is, the first customer equipment group 304
(1) A, 304 (1) B, ..., Second customer facility group 3
04 (2) α, 304 (2) β, ... And third consumer facility groups 304 (3) a, 304 (3) b ,. .

As described above, in the district heat supply system shown in FIG. 3, the three consumer facility groups are cascade-connected to efficiently use the heat energy, that is, to expand the heat transfer capacity of the piping system and the central heat source system. The efficiency of energy use is being improved. In addition, according to the present embodiment, it is possible to supply heat from the central heat source system to the customer facilities grouped into an arbitrary number, but in reality, the number of divisible groups is It is limited according to the operating capacity of the central heat source system and the air conditioning system installed in each customer facility.

Next, an embodiment of the operation control method for the district heat supply system according to the present invention will be described with reference to FIGS. 4 and 5. FIG. 4 shows a district heat supply system 400 according to this embodiment. The basic configuration of the district heat supply system 400 is substantially the same as the district heat supply system 200 shown in connection with FIG. 2, that is, a configuration including two groups of customer facilities and one system of return path piping. Since they are the same, detailed description thereof will be omitted. However, in this district heat supply system 400, as a control system of the system, the first pressure sensor P1 that detects the differential pressure between the outward passage pipe 406 and the forward return passage pipe 412, and the differential pressure between the forward return passage pipe 412 and the return passage pipe 408. Pressure sensor P for detecting
2, and these first and second pressure sensors P1, P
Central heat source equipment 402 according to the differential pressure detected by 2
Capacity of the water pump 402c of the
A control device 45 for controlling the opening of control valves 410a and 410b inserted near the inlet and the outlet of the valve 12, respectively.
It has 0.

FIG. 5 shows a flow of operation control of the district heat supply system 400 shown in FIG. Note that in this operation control, the state in which the control valve 410a installed near the entrance of the return passage pipe 412 is fully closed is set as the optimum operating condition of the system, and the return passage pipe 406 and the return passage pipe 41 are provided.
2 differential pressure DP1 and return path piping 412 and return path piping 4
08 and the differential pressure DP2 are set values P1S and P2S, respectively.
The control device 450 controls the operating capacity of the water pump of the central heat source system 402 and each control valve 4 so that
It is assumed that the opening degrees of 10a and 410b are controlled. In addition,
It is preferable that the set values P1S and P2S have a predetermined allowable range.

When the control sequence is started, first, in step S510, the outward route pipe 406 and the forward route pipe 4 are connected.
Control of the differential pressure DP1 with respect to 12 is performed by operating the control valve 412a. After adjusting the differential pressure DP1, step S51
Below 2, the control of the differential pressure DP2 between the return passage pipe 412 and the return passage pipe 408 is started.

First, in step S512, the differential pressure D
If it is determined that P2 is within the set value P1S, step S514 is entered. First, when the control valve 410a and the control valve 410b are both open, the control device 450 causes the control device 450 to approach the optimum operating conditions of the system.
The operation control is performed so that the control valve 410a is closed by one step. In other cases, that is, the control valve 410a
If at least one of the control valve 410b and the control valve 410b is in the fully closed state, the current operating state is maintained.

On the other hand, if it is determined in step S512 that the differential pressure DP2 is higher than the set value P1S, then step S516 is entered. Step S516
In the case where the control valves 410a and 410b are both in the open state in FIG.
The water supply capacity of c is controlled to be reduced by one step.
When the control valve 410a is closed and 410b is open,
When the control valve 410a is open and 410b is closed,
When the control valve 410a and the control valve 410b are both closed, the control device 450 operates and controls the opening degree of the control valve of 410b.

In step S512, the differential pressure D
If it is determined that P2 is lower than the set value P1S,
Enter into step S518. In step S518,
When both the control valves 410a and 410b are in the open state, and when the control valve 410a is in the closed state and 410b is in the open state, the control device 450 operates and controls the opening degree of the control valve of the control valve 410b. When the control valve 410a is in the open state and 410b is in the closed state, and when both the control valve 410a and the control valve 410b are in the closed state, the control device 45
By 0, the water supply capacity of the water supply pump 402c is controlled to be increased by one stage.

As described above, according to the present embodiment, by optimizing the differential pressure DP1 between the outgoing line 406 and the outgoing line 412 and the differential pressure DP2 between the outgoing line 412 and the incoming line 408. The necessary and sufficient heat can be efficiently supplied to each of the customer facilities 404, and the energy saving operation of the system can be performed.

Although some preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to the above embodiments. It is obvious to those skilled in the art that many modifications and variations are conceivable within the scope of the technical idea described in the claims, and of course, regarding these,
It is understood that it belongs to the technical scope of the present invention.

[0035]

As described above, according to the present invention,
Central heat source system (102) to return passage piping (112)
A plurality of consumer equipment groups (10
Since the heat source water is supplied to 4), it is possible to significantly improve the heat transfer capacity and reduce the initial cost and running cost of the piping system. Further, it is possible to make the temperature of the central heat source system (102) have a wide range of temperature at the inlet and outlet, and it is possible to effectively use the energy of the central heat source system (102). Furthermore, since it is possible to supply heat according to the energy needs of each customer equipment group (104), the range of equipment choices on the customer side expands, and energy saving corresponding to the energy needs of each customer is achieved. It becomes possible to provide a district heat supply system.

[Brief description of drawings]

FIG. 1 is a system configuration diagram showing a schematic configuration of a district heat supply system according to a first embodiment of the present invention.

FIG. 2 is a system configuration diagram showing in detail the state of the cascade connection of the district heat supply system according to the first embodiment of the present invention, in particular, customer facilities.

FIG. 3 is a system configuration diagram showing a schematic configuration of a district heat supply system according to a second embodiment of the present invention.

FIG. 4 is a system configuration diagram showing a schematic configuration of a district heat supply system according to a third embodiment of the present invention.

FIG. 5 is a flowchart showing the sequence of operation control of the district heat supply system according to the third embodiment of the present invention.

[Explanation of symbols]

100 district heat supply system 102 Central heat source system 104 Consumer equipment 104A, 104B, ..., The first customer facility group 104a, 104b, ..., Second customer facility group 106 Outward piping 108 Return piping 110 control valve 112 Return road piping

Claims (2)

(57) [Claims] 1. The central heat source system (202) and the customer's equipment (204) are connected to each other by a forward pipe (206) of one system and a return pipe (208) of one system, and the central heat source system (202) is connected. The produced heat source water is supplied to the customer facility (20
4) in the district heat supply system, the first customer equipment group (204A, 204B, ...) And the second customer equipment group (204a, 204b) obtained by dividing the customer equipment (204) into a plurality of parts. Control valve means (210) for controlling the flow rate of the heat source water supplied to the central heat source system (102, 202, 302 (40).
2)), the outward piping for supplying the heat source water produced in 2)) to the first consumer equipment group (204A, 204B, ...); and the central heat source system (102, 202, 302 (40)
2)) The heat source water produced in) is directly supplied, or
From the first consumer equipment group (204A, 204B, ...)
Return passage pipe (212) for supplying return water of the heat source water; or heat source water from the return passage pipe (212) or the heat
Second consumer facility group (204a, 20a) to which source water is supplied
4b, ...,) The return pipe (2) supplied with return water from
08) and; and in the return passage pipe (212), the central heat source system
System (102, 202, 302 (402))
Flow rate of the heat source water or the first customer facility group (204
The flow rate of the return water from A, 204B, ...
It is controlled by the opening degree of the means (210), and in the return pipe (208), the forward return pipe (2
12) Flow rate of heat source water from the second consumer equipment group
The flow rate of return water from (204a, 204b, ...)
The district heat supply system characterized by being controlled by the opening degree of the control valve means (210) . 2. The outward piping (206 (40
6)) and the return passage pipe (212 (412)) for detecting a pressure difference between the first pressure sensor (P1), the return passage pipe (212 (412)) and the return passage pipe (208 (40).
8)) a second pressure sensor (P2) for detecting a pressure difference from
The first pressure sensor (P1) and the second pressure sensor (P
2) The central heat source system (20
2 (402)) and / or the control means (2) for controlling the opening of the control valve means (210 (410)).
50 (450)) is provided, The district heat supply system of Claim 1 characterized by the above-mentioned.