JPH0148459B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention particularly relates to a water supply temperature control device in an air conditioning facility, which is provided with a plurality of heat exchangers.

(Prior art) Air conditioning equipment involves circulating cold and hot water (chilled water or hot water) from a heat source generating device for cooling or heating, such as a cooler unit or boiler, to a heat storage tank.
From this heat storage tank, multiple air conditioning heat exchangers (hereinafter referred to as
There are types that send water to each heat exchanger (called a heat exchanger). FIG. 1 shows this type of air conditioning equipment with two heat exchangers: 1 is a heat source generating device, 2 is a water pump, and 3 and 4 are pipes. The pipe 3 forms a waterway on the side that sucks cold and hot water 6 inside the heat storage tank 5, and the pipe 4 forms a waterway on the side that discharges cold and hot water from the heat source generating device 1 to the heat storage tank 5.

7 and 8 are heat exchangers, and 2 of the rooms where air conditioning equipment is installed.
They are placed separately in different locations. These heat exchangers 7 and 8 have pipes 9 and 10 that open into the heat storage tank 5 at the sides that receive cold and hot water 6 from the heat storage tank 5, and water pumps 11 and 12 are connected to the middle. One pipe 13 is commonly connected to the cold and hot water discharge side. In this device, the heat source generating device 1 and the water pump 2 are operated to maintain the cold and hot water in the heat storage tank 5 at a predetermined temperature, and then the water pump 1 is operated.
1 and 12 are activated to send cold and hot water to heat exchangers 7 and 8 for heat exchange.

Air conditioning equipment having the same heat storage tank and heat source generating equipment as described above has the following problems. In other words, if there are a large number of heat exchangers, let's say there are two groups of 20 heat exchangers, for a total of 40 heat exchangers. It is also assumed that the design margins of the coils in the heat exchanger are largely different between the two groups. In this case, water is sent to many heat exchangers from one heat storage tank, so even though the water sent to the two groups has the same temperature, the actual heat exchange is different because the heat exchangers have different capacities. As the amount of air is different, there will be a difference in the temperature of the air being blown, and as a result, the indoor temperature will be different. The above is not a problem when the air conditioning load can be controlled individually, but it becomes a problem when the load exceeds the capacity and cannot be controlled. In addition to the problem of the indoor temperature varying, the temperature of the return water from the heat exchanger to the heat storage tank varies greatly, so there is
There is also the problem of so-called mixed water.

(Objective of the Invention) The present invention has been made to solve the problems of the prior art described above. By individually controlling the water supply temperature for each system according to the capacity of the container, the temperature in separate rooms can be controlled at a constant level, and
It is an object of the present invention to provide a device in which the temperature of water returned from a heat exchanger to a heat storage tank is kept almost constant, and the temperature stratification of the heat storage tank is not disturbed.

(Structure of the Invention) In order to achieve the above object, the present invention includes a plurality of heat exchangers that circulate cold and hot water from a heat source generating device to a heat storage tank and send water from the heat storage tank to each air conditioning heat exchanger. In the air conditioning equipment, a part of the pipe that sends water from the heat source generation device to the heat storage tank is connected to a pipe that connects any heat exchanger and the heat storage tank, and a flow rate is maintained between the communication part and the heat exchanger. The structure is equipped with a control valve. And this flow control valve is
It takes in the water supply temperature of each system and works to supply water at a constant temperature difference.

(Embodiment) Next, an embodiment of the present invention will be described with reference to FIG. 2, in which the same parts as in FIG. 1 are given the same reference numerals. First, like the one in FIG. 1, the heat storage tank 5 includes a cold/hot water generating device 1 such as a cooler unit or a boiler (these are referred to as primary systems), and heat exchangers 7 and 8 provided in each room. (these are called secondary systems) are connected. The number of heat exchangers is not limited to two, and may be multiple. And the water supply pump 2 is in the primary system.
However, water pumps 11 and 12 are also connected to the secondary system.

Similar to the one in FIG. 1, the pipe 4 connects the cold/hot water generating device 1 and the inside of the heat storage tank 5, but a part of it branches into pipes 4a and 4b at part A, and the pipe 4b is connected to the flow control valve 14. The heat exchanger 7 is connected to a midway portion of a pipe 9 extending from the heat storage tank 5 via the heat exchanger 7 to the heat storage tank 5. The flow rate control valve 14 takes in the temperatures T ₂ and T ₄ of the cold and hot water flowing through the pipes 9 and 10, and opens and closes so that the difference between the two becomes α (a constant value). 15 is a control device for this purpose.

Next, the operation of this device will be explained theoretically. Now, the water pump 2 is denoted by P ₁ and the water pump 11 is denoted by P ₂ , and their conveyance flow rates are respectively Q ₁ and
Q ₂ , the water supply temperature is T ₁ and T ₂ respectively, and the flow rate distribution at part A is x to the water supply pump P ₂ side, and the heat storage tank 5
(1-x) to the side. The amount pumped from the heat storage tank 5 by the water pump _P2 is defined as _Q20 . Also, the amount of cold and hot water that can be used for cooling and heating in the heat storage tank 5 is Q ₄
Let T ₃ be the temperature before mixing from the primary system, and T ₄ be the temperature after mixing. However, Q ₄ is Q ₁ ,
Since the flow rate is extremely high compared to the flow rates of Q ₂ and Q ₂₀ , there is no change in flow rate before and after mixing from the primary system, and it is assumed to be almost constant.

From the above, the following four equations are established.

Q ₁ x＋Q ₂₀ ……(1) T ₄ −T ₂ = α (constant value) ……(2) Q ₁ x×T ₁ +Q ₂₀ ×T ₄ /Q ₁ x＋Q ₂₀ =T ₂ ……(3) Q ₁ (1-x)×T ₁ +Q ₄ ×T ₃ /Q ₁ (1-x)+Q ₄ =T ₄ ...
(4) Here, the variables (unknowns) are x, Q ₂₀ , T ₂ , T ₃ ,
There are five constants, _{Q 1 ,} Q ₂ , Q ₄ , T ₁ , and α. Since four equations hold true for five variables, fixing any one variable determines the other four variables, and the circuit in Figure 2 is a system in which the water supply temperature is completely determined. becomes. Here x
When the value of is determined by the flow rate control valve 14 in Fig. 2,
Other variables Q ₂₀ , T ₂ , T ₃ , and T ₄ are determined, and water can be fed to each of the heat exchangers 7 and 8 (as described above, there may be a plurality of heat exchangers) at the water feeding temperature difference α.

(Effects of the Invention) Since the present invention is configured as described above, it has the following effects.

When the temperature of the air conditioning system cannot be controlled (when the load exceeds the capacity of the heat exchanger, or when the capacity of the heat source generating equipment is insufficient), air conditioning zones with different capacities can be air conditioned at the same temperature.

In the above case, since the temperature of the water returned from the heat exchanger to the heat storage tank becomes almost uniform, the temperature stratification of the heat storage tank is maintained, and losses due to mixed water and the like are eliminated.

Even if the temperature of the air conditioning system is controlled, the above two advantages can be taken advantage of and the system can be used as is without changing settings such as temperature differences.

As a result of the above, it is possible to control the water supply temperature in accordance with the consumption load of the heat exchanger as an air conditioning equipment.
Power savings can be achieved through the combined use of open and closed types. In short, water can be delivered at different temperatures from the same heat storage tank.

[Brief explanation of drawings]

FIG. 1 is a system diagram of a conventional air conditioning system, and FIG. 2 is a system diagram of an embodiment of the present invention. 1...Heat source generation equipment, 2, 11, 12...Water pump, 3, 4, 9, 10, 13...Pipe, 5
... Heat storage tank, 6 ... Cold and hot water, 7, 8 ... Heat exchanger, 14 ... Flow rate control valve.

Claims (1)

[Claims] 1. In air conditioning equipment that has multiple heat exchangers that circulate cold and hot water from a heat source generation device to a heat storage tank and send water from the heat storage tank to each air conditioning heat exchanger, any heat exchanger and heat storage tank may be connected to each other. Water supply in an air conditioner, characterized in that a part of the pipe for sending water from the heat source generation device to the heat storage tank is communicated with the connecting pipe, and a flow control valve is provided between the communication part and the heat exchanger. Temperature control device.