JPH03181727A - Air-conditioning system of refrigerant natural circulation type - Google Patents

Abstract

PURPOSE:To achieve comfortable air conditioning in each story separately on a simple constitution and also prevent a leak of refrigerant from developing into serious trouble by installing in the same story a heat exchanger on the heat source side and heat exchangers on the users side and by providing each of the individual conditioners with a capacity-controlling means with which to control the amount of air passing through the user side heat exchanger. CONSTITUTION:Each room or the like in each story is provided with an individual air conditioner 8 equipped with a blower 6 and a user side heat exchanger 7 which acts as an evaporator. Each of the user side heat exchangers 7,... is connected to a second heat source side heat exchanger 2 by means of a second liquid refrigerant piping 11 and a second vaporized refrigerant piping 12, and through a loop of the second heat source side heat exchanger 2, second liquid refrigerant piping 11, user side heat exchangers 7,... and second vaporized refrigerant piping 12 refrigerant is hermetically contained to undergo, as the user side heat exchangers 7,... perform their function, a change in phase from liquid to vapor and condensation from vapor to liquid at the second heat source side heat exchanger 2.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention supplies refrigerant through natural circulation from a heat source side heat exchanger to a user side heat exchanger of an individual air conditioner installed on each floor, thereby providing air conditioning and heating. In order to perform air conditioning, the heat source side heat exchanger and the user side heat exchanger of the individual air conditioner are connected in communication via refrigerant piping, and the heat source side heat exchanger, the user side heat exchanger, and the A refrigerant that changes phase into liquid and vapor during heat exchange in the heat exchanger on the heat source side and the heat exchanger on the user side is filled in a closed state so as to circulate and flow through the refrigerant piping, and the heat exchanger on the heat source side The present invention relates to a refrigerant natural circulation type air conditioning system having a head difference sufficient to naturally circulate refrigerant between an exchanger and the user-side heat exchanger.

<Conventional technology> In a refrigerant natural circulation air conditioning system that naturally circulates refrigerant to perform air conditioning such as cooling or heating, for example, in the case of air conditioning, the heat source side heat exchanger that acts as a condenser is installed on the roof of a building. In the case of heating, the heat source side heat exchanger that acts as an evaporator is installed in the basement of the building, and a predetermined head difference is provided with respect to the heat source side heat exchanger. A user-side heat exchanger is installed on each floor, and the heat source-side heat exchanger and the user-side heat exchanger are connected via refrigerant piping, and the heat source-side heat exchanger, the user-side heat exchanger, and the refrigerant piping are connected. The refrigerant is sealed and filled with a refrigerant that changes phase between liquid and gas as heat is exchanged in the heat exchanger on the heat source side and the heat exchanger on the user side.

In the case of cooling, a superheat degree detection means such as a thermosensor tube is installed at the outlet of the refrigerant vapor from the user side heat exchanger, and the refrigerant liquid to the user side heat exchanger is installed. A flow control valve is installed at the inlet of the system, and the opening of the flow control valve is automatically adjusted so that the degree of superheat detected by the superheat detection means is within the set range, and the indoor temperature is maintained within the set range. It is composed of

On the other hand, in the case of heating, an electromagnetic on-off valve is installed at the outlet of the refrigerant liquid from the heat exchanger on the user side, and the electromagnetic on-off valve is closed when the indoor temperature measured by the room temperature sensor exceeds a set range. Conversely, the electromagnetic on-off valve is configured to open when the indoor temperature falls below a set range.

<Problem to be solved by the invention> However, as buildings have become taller in recent years, the number of user-side heat exchangers installed in the entire building has become extremely large in air conditioning systems with conventional configurations. , the amount of refrigerant required to circulate between the user side heat exchanger and the heat source side heat exchanger also increases. Since this large amount of refrigerant is filled in one closed system, if a leak occurs in the refrigerant piping at a certain point, a large amount of refrigerant will concentrate at that leaking point and leak out, resulting in oxygen deficiency. This had the disadvantage of causing a major accident.

In addition, since the amount of refrigerant is large, in the case of air conditioning, the refrigerant piping connected to the user heat exchanger on the lower floor side,
In the case of heating, large pressure is applied to each refrigerant pipe connected to the heat exchanger on the heat source side, and refrigerant pipes that are strong enough to withstand that large pressure are required, and high precision is required at the connection point. This requires a sealing structure, which has the drawback of making the configuration complicated and expensive.

Furthermore, since there is a difference in the pressure applied to the heat exchanger on the user side for each floor, when controlling the amount of refrigerant supplied, the pressure difference for each floor must be taken into account, making the configuration complex and expensive. It had some drawbacks.

In addition, when controlling the supply amount of refrigerant liquid during cooling, superheat detection means such as temperature-sensing tubes have poor responsiveness due to heat transfer through the pipes. Because the refrigerant liquid is under a lot of pressure, there is a problem that it cannot respond when the flow control valve opens and the refrigerant liquid suddenly flows.On the other hand, even during heating, when the solenoid on-off valve opens, There is a problem of rapid inflow of refrigerant vapor, and both in cooling and heating, the indoor temperature tends to change significantly due to control, making it difficult to provide comfortable air conditioning.

In addition, in the conventional example, when performing individual air conditioning control for multiple individual air conditioners installed on the same floor,
Conventionally, an electromagnetic on-off valve is installed in the refrigerant piping for the user-side heat exchanger, and the opening and closing of the electromagnetic on-off valve is controlled to control the amount of refrigerant supplied. When the load is low and the heat exchanger on the user side does not require much capacity, such as during the intermediate period, the required amount of refrigerant is immediately supplied when the solenoid valve is opened, so the solenoid valve is opened immediately after that. The valve must be closed, and the time between opening and closing the electromagnetic valve is extremely short, resulting in overshoot, such as more refrigerant being supplied than necessary, and people in the vicinity of the blown air. In some cases, the temperature change caused by the opening and closing of the electromagnetic on-off valve becomes easily felt and becomes uncomfortable.

The present invention has been made in view of these circumstances, and the invention of claim (1) has a simple configuration, and
The purpose of the invention is to enable comfortable air conditioning on each floor and to prevent major accidents caused by refrigerant leakage.
The object of the invention described in item 2) is to provide a low-cost FL system for supplying heat to the heat source side heat exchanger installed on each floor.

Means for Solving the Problems> In order to achieve the above-mentioned object, the present invention, as the invention of claim (1), provides a refrigerant natural circulation air conditioning system as described at the beginning. The heat exchanger and the user-side heat exchanger are provided on the same floor, and each individual air conditioner is equipped with a capacity control means for adjusting the amount of air passing through the user-side heat exchanger.

Furthermore, as the invention of claim No. (2), the above-mentioned claim No.
The heat source side heat exchanger on each floor in section 1) and the main heat source side heat exchanger are connected via refrigerant piping, and the main heat source side heat exchanger and the heat source side heat exchanger on each floor are connected in communication. The heat source refrigerant, which changes phase into liquid and vapor as a result of heat exchange in the main heat source side heat exchanger and the heat source side heat exchangers on each floor, is circulated and flowed in a sealed state across the container and the refrigerant piping. The main heat source side heat exchanger and the heat source side heat exchangers on each floor are provided with a difference between the two sides, which is sufficient to naturally circulate the heat source refrigerant.

The above-mentioned capacity control means configures the route of air supplied by the blower fan provided in the individual air conditioner into a first route passing through the user-side heat exchanger and a second route separate from the first route passing through the user side heat exchanger. However, it is possible to adopt a configuration in which a damper is provided in the second path so that the degree of opening can be changed, or the number of rotations of a blower fan provided in the individual air conditioner is increased or decreased.

<Operation> According to the configuration of the refrigerant natural circulation air conditioning system according to the invention of claim No. By allowing the refrigerant to flow naturally with a small amount of water, and by controlling the amount of air passing through the heat exchanger on the user side, the capacity of individual air conditioners on each floor can be controlled individually to perform air conditioning such as cooling or heating. be able to.

Further, according to the configuration of the refrigerant natural circulation air conditioning system according to the invention of claim (2), the main heat source side heat exchanger is connected to the heat source side heat exchanger installed on each floor. Refrigerant can be supplied by natural circulation.

<Example> Next, an example of the present invention will be described in detail based on the drawings.

Fig. 1 is an overall system configuration diagram of a natural refrigerant circulation type air conditioning system showing an embodiment of the refrigerant natural circulation type air conditioning system. A first heat source side heat exchanger is shown as a side heat exchanger, and cold water or ice slurry from a heat source such as an ice storage tank is supplied to this first heat source side heat exchanger l.

A second heat source side heat exchanger 2 as a heat source side heat exchanger for each floor is installed on each floor of the building, and the second heat source side heat exchanger 2... and the first heat source side heat exchanger are installed on each floor of the building. The exchanger 1 is connected via a first refrigerant liquid pipe 4 and a first refrigerant vapor pipe 5 in which a liquid receiver 3 is interposed.
The heat exchanger 1 on the heat source side, the liquid receiver 3, the first refrigerant liquid pipe 4, and the first refrigerant vapor pipe 5 convert gas into liquid by heat exchange in the first heat source side heat exchanger 1. A heat source refrigerant that changes its phase from liquid to gas by heat exchange in the second heat source side heat exchanger 2 is filled in a sealed state, and the liquid receiver 3 and the second heat source side heat exchanger 32. Between...
A sufficient head difference is provided to transfer the heat source refrigerant liquid whose phase has changed from gas to liquid by heat exchange to the second heat source side heat exchanger 2. from the heat source side heat exchanger 1 to the second heat source side heat exchanger 2
...It is configured to be able to supply low-temperature energy to each of them.

Each room on each floor is provided with an individual air conditioner 8 that includes a blower fan 6 and a user-side heat exchanger 7 that functions as an evaporator.

The second heat source side heat exchanger 2 and the usage side heat exchanger 7...
are connected to each other via the second refrigerant liquid pipe 11 and the second refrigerant vapor pipe 12, and the second heat source side heat exchanger 2, the user side heat exchanger 7..., the second heat source side heat exchanger 7... 2, the liquid refrigerant liquid pipe 11 and the second refrigerant vapor pipe 12 undergo a phase change from liquid to vapor as a result of heat exchange in the user side heat exchanger 7..., and the second heat source side heat exchanger 2 A refrigerant that changes phase from vapor to liquid upon condensation is sealed in a sealed state.

The second heat source side heat exchanger 2 is a user side heat exchanger H1...
- Installed at a higher position than each, the refrigerant whose phase has been changed from vapor to liquid by condensation in the second heat source side heat exchanger 2 is supplied downstream to the user side heat exchanger 7, and is used. A sufficient head difference is provided so that the refrigerant whose phase has changed from liquid to vapor due to heat exchange in the side heat exchangers 7 rises and is returned to the second heat source side heat exchanger 2, and cooling operation is performed. At this time, the refrigerant is configured to naturally circulate and flow between the second heat source side heat exchanger 2 and the utilization side heat exchanger 7 due to the phase change between vapor and liquid.

Freon gas R-22 is used as the heat source refrigerant and the refrigerant, respectively. This has the advantage that it contains hydrogen and chlorine and decomposes in the troposphere, so there is no risk of destroying the ozone layer.

The second refrigerant liquid piping 11 has a 1tift at the inlet point to each of the user-side heat exchangers 7...to prevent the refrigerant liquid from flowing in.
An on-off valve 13 is provided.

In each of the individual air conditioners 8..., a second suction path R2 separate from the first suction path R1 for sucking air into the user-side heat exchanger 7 is formed in the casing 14 thereof. , a damper 15 is provided in the suction path R2 so as to be rotatable around the axis in the horizontal direction, and the opening degree of the second suction path R2 is adjusted by the rotation of the damper 15, and the heat in the user side heat exchanger 7 is adjusted. It is configured such that the amount of air passing through the first suction path R1 for replacement can be adjusted. The above-mentioned user-side heat exchanger 7
A second refrigerant liquid pipe 11...・The black circle attached to each indicates the level of the refrigerant liquid filled.

A pulse motor 16 is interlocked with the damper 15, as shown in the enlarged view of the main part in FIG. Air conditioners 8... A room temperature sensor 17 is provided to measure the temperature of the return air as the temperature of the room in which each of the air conditioners 8 is installed.

A room temperature sensor 17 is connected to a controller 18, and a motor driver 1 of a pulse motor 16 is connected to the controller 18.
6a, a valve drive circuit 13-a of the electromagnetic on-off valve 13, and a rotary encoder I9 for measuring the opening degree of the damper 15 are connected.

As shown in the block diagram of FIG. 3, the controller 18 is equipped with a first comparing means 20, a fully open determining means 21, a switching means 22, an opening control means 23, and a second comparing means 24. .

The first comparing means 20 compares the indoor temperature TR measured by the room temperature sensor 17 and the set room temperature TS set by the room temperature setter 25, and outputs a high temperature signal when the room temperature TR is higher than the set room temperature TS. On the other hand, when the indoor temperature TR is lower than the set room temperature TS, a low temperature signal is output.

In the fully open determining means 21, the rotary encoder 19
Based on the output from the damper 15, a switching signal is output when a fully open state in which the attitude of the damper 15 is parallel to the second suction path R2 is detected.

In response to the switching signal from the fully open determining means 21, the switching means 22 uses the high temperature signal or low temperature signal from the first comparing means 20 to drive the electromagnetic on-off valve 13 when the switching signal is output. At other times, the high temperature signal or low temperature signal from the first comparison means 20 is output to the opening degree control means 23.

The opening degree control means 23 responds to the high temperature signal or the low temperature signal from the first comparison means 20 by applying a positive (closing side) or negative (opening side) drive signal to the motor by a preset predetermined number of pulses. The output is output to the driver 16a, and the opening degree of the damper 15 is adjusted to increase or decrease the cross-sectional area of the second suction path R2, that is, to increase or decrease the amount of air passing through the user-side heat exchanger 7. There is.

The second comparison means 24 compares the time t manually input from the timer counter 26 and the set time US input from the setting device 27.
The timer counter 26 is activated in response to the high temperature signal from the first comparing means 20 and measures the time t during which the high temperature signal is continuously output. When the high temperature signal duration time is longer than the set time US, the switching means 2
2, a return signal is output.

Next, the operation of the controller 18 described above will be explained using the flowchart of FIG.

First, upon starting the operation, the blower fan 6 is driven (Sl), the electromagnetic on-off valve 13 is opened (S2), and the room temperature TR measured by the room temperature sensor 17 is input (S3).

Next, the first comparison means 20 determines whether the indoor temperature TR is higher than the set room temperature TS (S4), and if the indoor temperature TR is higher than the set room temperature TS, outputs a high temperature signal (S5), and then steps Proceeding to S6, it is determined whether the flag is set (F=1) based on the output of the switching signal.

When the flag is set, that is, when the damper 15 is fully open and capacity control is being performed by opening and closing the electromagnetic on-off valve 13, the first comparison means 2
The high temperature signal from 0 is output as an opening signal to the valve drive circuit 13a (S7) and the timer counter 26 is started (S8). Here, if the timer counter 26 is already in an operating state, that operating state is maintained.

Next, the process moves to step S9, and the timer counter 26
After inputting the high temperature signal duration time measured by the second comparing means 24, it is determined whether the high temperature signal duration time t has become longer than the set time ts (SIO
).

If the high temperature signal duration time t is longer than the set time ts, it is assumed that the capacity of the heat exchanger 7 on the user side has been lowered more than necessary, and a return signal is output and the flag is lowered F←0)
, a switching signal is output to the switching means 22, and the signal from the first comparison means 20 is output to the opening control means 23, that is, the capacity is controlled by the air volume (Sll).
, then reset the timer counter 26 (S12
) and returns to step S3.

In step S6, if the flag is not set (F=O), the process moves to step S13, and the opening control means 2
3 outputs a positive drive signal with a predetermined number of pulses to the motor driver 16a, and closes the damper 15 by a preset opening degree in order to increase the capacity of the heat exchanger 7 on the user side. Increase the amount of air passing through exchanger 7.

In step S4, the room temperature TR is set to the set room temperature T.
When it is lower than S, a low temperature signal is output and then (S1
4) Proceeding to step S15, the fully open determining means 21 determines whether the damper 15 is fully open.

When the damper 15 is fully open, the low temperature signal from the first comparison means 20 is output as a closing signal to the valve drive circuit 13a via the switching means 22 (516), and a flag is set in step SI7 (F4-■ ), then
The process moves to step S12 to reset the timer counter 26, and then returns to step S3.

On the other hand, when the damper 15 is not in the fully open state, the process moves to step 31B, in which the opening control means 23 outputs a negative drive signal of a predetermined number of pulses to the motor driver 16a to reduce the capacity of the heat exchanger 7 on the user side. , damper 15
is opened by a predetermined opening degree to reduce the amount of air passing through the user-side heat exchanger 7, and then step S3
Return to

With the above configuration, in each individual air conditioner 8, the damper 15
By adjusting the opening degree of the damper 15, the amount of air passing through the user-side heat exchanger 7 is changed and the temperature of the blown air is adjusted. The opening and closing valve 13 is controlled to control the amount of refrigerant liquid supplied to the user-side heat exchanger 7, and each individual air conditioner 8
Capacity control can be performed well.

In the above embodiment, in order to control the amount of air passing through the user-side heat exchanger 7, the second blowing path R2 is provided, and a damper 15 is provided there, so that the air blown out from the blowing fan 6 is Since this method does not change the amount of air flow or reduce the wind force itself, it has the advantage that the distance that the blown air reaches does not change and the entire room can be comfortably cooled. The rotation speed of
It may be configured so that it can be changed steplessly by changing the frequency, and the amount of air passing through the utilization side heat exchanger 7 may be controlled by controlling the rotation speed.

In the above embodiment, the first heat source side heat exchanger l as the main heat source side heat exchanger and the second heat source side heat exchanger 2 as the heat source side heat exchanger on each floor side... Although the refrigerant is configured to flow through natural circulation, claim No. (1)
The invention described in Section 1 may be configured to use a district heating and cooling system as the main heat source side heat exchanger, and to forcibly flow the cold water or hot water as a heat source refrigerant by a pump or the like.

In addition, the user-side heat exchanger 7 of the second refrigerant liquid pipe 11...
Even when the damper 15 is fully opened and the amount of air passing through the user-side heat exchanger 7 is minimized, the capacity of the user-side heat exchanger 7 is maintained. Although the present invention is configured to be able to cope with a case where the electromagnetic on-off valve 13 is expensive, the present invention may not include the electromagnetic on-off valve 13.

In the above embodiment, the case of air conditioning was explained, but in addition to installing the first heat source side heat exchanger as the main heat source side heat exchanger in the basement of the building etc., each floor side heat exchanger that acts as an evaporator is installed. A second heat source side heat exchanger is provided as a heat source side heat exchanger, and the second heat source side heat exchanger and a user side heat exchanger acting as a condenser are provided with a predetermined head difference. , it can also be used when configured to perform heating.

<Effects of the Invention> According to the refrigerant natural circulation air conditioning system according to the invention of claim (1), since the refrigerant is circulated and flowed within the closed systems formed on the same floor, each closed system is Even if the amount of refrigerant to be filled is small and a leak occurs in a part of the refrigerant liquid piping or refrigerant vapor piping, and the entire amount of refrigerant in the closed system leaks, it will not leak to other floors. This makes it possible to avoid major accidents such as oxygen deficiency.

In addition, since the heat source side heat exchanger and the user side heat exchanger are installed on the same floor, the head difference between the heat exchangers for natural circulation of the refrigerant can be small, and the user side heat exchanger The pressure applied to the refrigerant liquid piping and refrigerant vapor piping connected to the heat exchanger and the second heat source side heat exchanger is small, and there is no need for highly pressure-resistant piping or a high-precision seal structure, making the configuration simple and inexpensive. became.

Furthermore, even if the floors are different, there is no difference in the pressure applied to the heat exchanger on the user side, and there is no need to control the refrigerant supply amount in consideration of the pressure difference, and the vIr! Even a single configuration can now be made easily and inexpensively.

Moreover, as mentioned above, the capacity is controlled by adjusting the amount of air passing through the heat exchanger on the user side when the pressure difference is small, so the response is not dependent on the opening/closing operation of flow control valves or electromagnetic on-off valves. It is now possible to perform highly accurate control with high performance and smooth temperature changes, making it possible to provide comfortable air conditioning.

In addition, when installing user-side heat exchangers for multiple individual air conditioners on the same floor, the capacity of each individual air conditioner can be increased by adjusting the amount of air passing through the user-side heat exchangers. Not only can it be adjusted individually, but it can also be opened and closed at short intervals, such as when controlling the supply amount of refrigerant with an on-off valve when the load is low and high capacity is not required, such as during intermediate periods. This has the advantage that air conditioning can be controlled comfortably without overshooting.

Further, according to the refrigerant natural circulation type air conditioning system according to the invention of claim (2), the heat source refrigerant is naturally circulated and flows between the main heat source side heat exchanger and each remote heat source side heat exchanger. Therefore, it is not necessary to use a forced transfer means such as a pump to flow the heat source refrigerant, and the cost can be further reduced.

[Brief explanation of drawings]

The drawings show an embodiment of the refrigerant natural circulation type air conditioning system according to the present invention, FIG. 1 shows the overall system configuration of the refrigerant natural circulation type cooling system, and FIG. 2 shows a schematic sectional view of the main parts. FIG. 3 is a block diagram, and FIG. 4 is a flowchart explaining the operation of the controller. l...First heat source side heat exchanger 2 as a main heat source side heat exchanger...Second heat source side heat exchanger 4 as a heat source side heat exchanger for each remote measurement...As refrigerant piping First refrigerant liquid piping 5...First refrigerant vapor piping 6 as refrigerant piping...Blower fan 7...Using side heat exchanger 8...Individual air conditioner 11...Refrigerant liquid Second refrigerant liquid pipe 12 as a pipe
...Second refrigerant vapor pipe 15 as refrigerant vapor pipe...
・Damper R1...First suction route R2...Second suction route

Claims (4)

[Claims] (1) The heat source side heat exchanger and the user side heat exchanger of the individual air conditioner are connected via refrigerant piping, and the heat source side heat exchanger, the user side heat exchanger, and the refrigerant piping are connected. , a refrigerant that changes phase into liquid and vapor as heat is exchanged in each of the heat source side heat exchanger and the usage side heat exchanger is filled in a closed state so that the refrigerant circulates and flows, and the heat source side heat exchanger and the user side heat exchanger In a refrigerant natural circulation air conditioning system that has a head difference sufficient to naturally circulate the refrigerant between the heat exchanger on the user side and the heat exchanger on the user side, the heat source side heat exchanger and the user side heat exchanger are provided on the same floor. A refrigerant natural circulation air conditioning system characterized in that said individual air conditioner is equipped with a capacity control means for adjusting the amount of air passing through said user-side heat exchanger. (2) The heat source side heat exchanger on each floor according to the top of claim (1) and the main heat source side heat exchanger are connected in communication via refrigerant piping, and the main heat source side heat exchanger and the heat source side heat exchanger on each floor side and the refrigerant pipe, and undergoes a phase change into liquid and vapor as a result of heat exchange in the main heat source side heat exchanger and the heat source side heat exchanger on each floor side, respectively. The heat source refrigerant is filled in a closed state so as to circulate and flow, and a head difference sufficient to naturally circulate the heat source refrigerant is created between the main heat source side heat exchanger and the heat source side heat exchangers on each floor. Equipped with natural refrigerant circulation air conditioning system. (3) In the refrigerant natural circulation air conditioning system according to claim (1) or (2), the capacity control means controls the path of the air supplied by the blower fan provided in the individual air conditioner. , a first path passing through the user-side heat exchanger;
A refrigerant natural circulation air conditioning system comprising a second path separate from the first path, and a damper provided in the second path so that the degree of opening can be changed. (4) In the refrigerant natural circulation air conditioning system according to claim (1) or (2), the capacity control means:
A refrigerant natural circulation air conditioning system that increases or decreases the rotation speed of the blower fan installed in each individual air conditioner.