JPH11351690A - Air conditioner and method for operating it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To circulate a phase variable fluid in any of cooling and heating without excess and without insufficiency. SOLUTION: An outdoor unit 10 installed in a high place such as a rooftop of a building or the like has an absorption refrigerator 11 for selectively supplying a cold heat and a warm heat. A liquid feeding tube 21 is connected to a lowest part of a heat transfer tube 12 of an evaporator functioned as a heat source generator for an exterior, and a cooling and heating switching valve 13, a liquid reservoir 14, a cooling auxiliary pump 15, and a cooling and heating switching valve 16 are arranged serially from the refrigerator 11 side. Then, an overflowing tube 22 is connected to a height of the tube 12 for assuring a liquid level height necessary at the time of heating, and its other end is connected to a tube 21 between the valve 13 and the reservoir 14. A liquid input tube 23 and a bypass tube 24 are connected to the tube 12 of a high site from the connector of the tube 22. An opening/closing valve 17 is provided at the tube 24, and the other end is connected between the pump 15 of the tube 21 and the valve 16. Further, a gas tube 25 is provided at an uppermost part of the tube 12, and the tube 25 is connected to an upper part of the reservoir 14 via an equalizing tube 26.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioning technology, and more particularly, to an air conditioner between an outdoor unit and a plurality of indoor units, all or a majority of which are installed below the outdoor unit.
The present invention relates to an air conditioning technology configured to circulate a phase-changeable fluid so that each indoor unit can be cooled and heated.

[0002]

2. Description of the Related Art As this kind of technology, a fluid phase-changed by cold or hot heat generated by an absorption refrigerator installed as an outdoor unit on the roof of a building or the like is dispersed and arranged on each floor in any of the cooling and heating operations. For example, Japanese Patent Application Laid-Open No. 7-318189 proposes an air-conditioning system for a building configured to be naturally circulated and supplied to indoor units.

[0003]

However, in the air-conditioning system having the above-mentioned structure, for example, when the heating operation is performed by circulating and supplying the gas evaporated by the heat generated by the absorption refrigerator of the outdoor unit to the indoor unit. However, when the amount of liquid recirculated to the heat source generating section of the absorption refrigerator is not sufficient, the amount of heat generated in the heat source generating section cannot be sufficiently transmitted to the fluid. In addition to the inconvenience, the degree of superheat of the vaporized gas becomes too large, and the temperature of the heat source generating section of the absorption refrigerator as an outdoor unit becomes abnormally high and stops.

If the amount of liquid recirculated to the heat source generating portion of the absorption refrigerator is too large, the liquid enters the trachea and obstructs the flow of gas, or enters the indoor unit to lower the heating capacity. There were problems such as these, and solving these problems has been an issue.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems of the prior art, the present invention relates to an outdoor unit having a heat source generating part to which a liquid intake pipe, a liquid delivery pipe, an overflow pipe, a liquid bypass pipe, and a trachea are connected. The units are installed above all the indoor units or the majority of the indoor units, circulate and supply the phase-changed fluid to the indoor units in the heat source generating section of the outdoor units, and use the latent heat of the fluid in each indoor unit to cool and heat. In the air conditioner, the liquid delivery pipe is connected to the lowest part of the heat source generating section, the overflow pipe is connected to a position where the required liquid level can be secured during the heating operation, and the liquid intake pipe and liquid Is connected to the bypass pipe,
An air conditioner of a first configuration in which the trachea is connected to the highest part,

[0006] In the air conditioner having the first configuration, the outdoor unit has a first cooling / heating switching valve interposed in the liquid delivery pipe, a first receiver tank sequentially connected and installed downstream of the first cooling / heating switching valve, an auxiliary cooling pump, A second cooling / heating switching valve is provided, and an opening / closing valve interposed in the liquid side pipe is provided. The other end of the overflow pipe is provided between or directly between the first cooling / heating switching valve of the liquid delivery pipe and the first receiver tank. Connected to the first receiver tank,
The other end of the liquid side pipe is connected between the auxiliary cooling pump of the liquid delivery pipe and the second cooling / heating switching valve, the upper part of the first receiver tank is connected to the trachea, and the other end of the liquid intake pipe is connected. Is connected to the lowest part of the liquid delivery pipe connected to each indoor unit, and
A second receiver tank and a heating pump are installed at the lowest part of the liquid intake pipe with the second receiver tank positioned upstream, and the liquid intake pipe can only flow fluid toward the outdoor unit. An air conditioner having a second configuration in which a check valve is provided;

[0007] The cooling operation in the air conditioner of the first or second structure, in which the heat source generating section of the outdoor unit generates cold heat and circulates and supplies the liquid condensed by radiating the cold to the indoor unit, The first and second cooling / heating switching valves are opened, the opening / closing valve of the liquid side passage pipe is closed, and cold is generated in the heat source generating section of the outdoor unit, and the liquid accumulated in the first receiver tank is located. After confirming that the amount is larger than the fixed amount, an operation method of the first configuration in which the cooling auxiliary pump is started and started,

The heating operation in the air conditioner of the first or second configuration, in which heat is generated in a heat source generating section of the outdoor unit and the gas heated and evaporated by the heat is circulated and supplied to the indoor unit, Closing the first and second cooling / heating switching valves and the opening / closing valve of the liquid bypass pipe to start the heating pump, recovering the liquid in the heat source generating section of the outdoor unit and the first receiver tank,
After confirming that the amount of liquid collected in the first receiver tank is larger than a predetermined amount, an operation method of a second configuration in which the heat source generation unit of the outdoor unit generates heat and starts the operation,

The heating pump is operated with the first and second cooling / heating switching valves and the on-off valve of the liquid side pipe closed, and is heated and evaporated by the heat generated in the heat source generating section of the outdoor unit. During the heating operation in the air conditioner of the first or second configuration, in which the supplied gas is circulated and supplied to the indoor unit, if the liquid level of the fluid in the heat source generating unit of the outdoor unit becomes lower than a predetermined position, the liquid side pipe Opening and closing the opening / closing valve to start the auxiliary pump for cooling, and perform the liquid level control in the heat source generating unit of the outdoor unit that refluxes the liquid from the first receiver tank to the heat source generating unit of the outdoor unit. Operation method of the configuration of

[0010] The heating pump is operated with the first and second cooling / heating switching valves and the on-off valve of the liquid side pipe closed, and heated and evaporated by the heat generated in the heat source generating section of the outdoor unit. During the heating operation in the air conditioner of the first or second configuration, in which the supplied gas is circulated and supplied to the indoor unit, the degree of superheat of the fluid in the heat source generating unit of the outdoor unit is calculated, and the calculated degree of superheat is determined to be a predetermined value. When the value exceeds the above value, control is performed to open the on-off valve of the liquid side pipe, start the auxiliary cooling pump, and return the liquid from the first receiver tank to the heat source generating section of the outdoor unit to reduce the degree of superheat of the fluid. And a driving method having a fourth configuration to be performed.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG.
It will be described based on. The air conditioner of the present invention includes, for example, an outdoor unit 10 installed on the roof of a building, a number of indoor units 30 distributed and installed on each floor, and a heating pump unit installed in the lowest part such as a basement. 40 and a fluid capable of phase change by connecting them, for example, R-13 of refrigerant
4a for circulating 4a.

The outdoor unit 10 is operated by utilizing heat generated by a gas burner or the like, and is provided with an absorption refrigerator 11 capable of selectively supplying cold and warm heat, and functions as a heat source generating unit for the outside. A liquid delivery pipe 21 is connected to the lowest part of the heat transfer pipe 12 of the evaporator (not shown), and a cooling / heating switching valve 13, a receiver tank 14, a cooling auxiliary pump 15, and a cooling / heating switching valve 16 are connected to the absorption refrigerator 11. It is installed in series from.

[0013] It should be noted that examples of a device that can supply cold heat or heat from a heat transfer tube 12 provided inside an evaporator of an absorption refrigerator are disclosed in, for example, JP-A-7-318189. Can be used. Further, during the cooling operation, R-134a staying in a pipe or the like on the way due to a high outside air temperature evaporates to a gas. On the other hand, during the heating operation, R-13 stays in the pipes or the like due to the low outside air temperature.
4a condenses into a liquid. For this reason, since more R-134a is needed at the time of heating operation than at the time of cooling operation,
R-1 sealed to prevent excess or shortage during heating operation
The capacity of the receiver tank 14 is determined so that 34a does not become excessive during the cooling operation.

An overflow pipe 22 is connected to the height of the heat transfer pipe 12 that can secure a required liquid level during the heating operation, and the other end is connected between the cooling / heating switching valve 13 of the liquid delivery pipe 21 and the receiver tank 14. To the heat transfer tube 12 at a position higher than the connection portion of the overflow tube 22.
Is connected to the liquid-side pipe 24, and an opening / closing valve 17 is interposed in the liquid-side pipe 24, and the other end is connected between the auxiliary cooling pump 15 of the liquid delivery pipe 21 and the cooling / heating switching valve 16. ing.

Further, a trachea 25 is provided at the top of the heat transfer tube 12.
The trachea 25 and the upper part of the receiver tank 14 are connected by a pressure equalizing tube 26.

The outdoor unit 10 has a liquid level sensor 18 for detecting the liquid level of the liquid R-134a flowing in the heat transfer tube 12, and a liquid level sensor R-134a for the liquid stored in the receiver tank 14. A liquid level sensor 19 for detecting the liquid level of the air conditioner, and controls the opening and closing of the cooling / heating switching valves 13 and 16 and the opening / closing valve 17 based on the outputs of these liquid level sensors and the like, and the cooling auxiliary pump 15 and Heating pump 4 described later
A control device 20 for controlling the operation of No. 2 is also provided.

Each indoor unit 30 has a heat transfer tube 31, an expansion valve 32, and a blower 33, and one end of each heat transfer tube 31 is branched from the vertical tube 25a of the trachea 25 and extends in the horizontal direction. The other end is connected to a horizontal drawing pipe 25b, and the other end is connected via an expansion valve 32 to a horizontal drawing pipe 21b branched from the vertical pipe 21a of the liquid delivery pipe 21 and extended in the horizontal direction.

The starting end of the liquid intake pipe 23 is connected to the end of the vertical pipe 21a of the liquid delivery pipe 21, that is, the lowest part, and a U-shaped portion is provided at the starting end side of the liquid intake pipe 23, and a heating pump is provided there. Receiver tank 41 constituting unit 40
A heating pump 42 and a check valve 43 are interposed and installed in series as shown.

The control device 20 is also configured so that a cooling and heating operation can be instructed by a button switch or the like provided on a panel surface (not shown). For example, when a cooling operation is instructed, the cooling and heating switching valve 13. A required control signal for opening the valve 16 and a required control signal for closing the on-off valve 17 are output.

Further, in the absorption refrigerator 11, the refrigerant heated and evaporated by the regenerator is sent to the condenser to be radiated and condensed, and the condensed refrigerant liquid is sent to the evaporator and required valves for evaporating. It is also configured to give instructions such as control, and the gas R-134a is cooled through the tube wall of the heat transfer tube 12 and condensed by the heat of vaporization of the refrigerant evaporated in the evaporator of the absorption refrigerator 11. The liquid is discharged to the liquid delivery pipe 21 as a liquid at a predetermined low temperature, for example, 7 ° C., and flows into and accumulates in the receiver tank 14.

The control device 20 controls the receiver tank 1
When it is confirmed by the liquid level sensor 19 that the liquid level of the R-134a stored in the fuel tank 4 has become equal to or higher than a predetermined level (a state close to being full), the auxiliary pump 1 for cooling is used.
5 is also output.

When the auxiliary cooling pump 15 is started, the liquid R-1 stored in the receiver tank 14 of the outdoor unit 10 is discharged.
34a is supplied to the indoor units 30 distributed and installed on each floor via the vertical pipe 21a and the horizontal drawing pipe 21b of the liquid delivery pipe 21.

The low-temperature liquid R-134a supplied to the indoor unit 30 flows into the heat transfer tube 31 through the expansion valve 32, and is supplied from the high-temperature room air supplied by the blower 33 to the heat transfer tube 31. It takes heat through the pipe wall and evaporates to perform cooling. The gas R-134a evaporated by the cooling action is circulated through the air pipe 25 to the heat transfer pipe 12 of the absorption refrigerator 11 of the outdoor unit 10 where the R-134a is condensed and the pressure is low.

On the other hand, when the heating operation is instructed by operating the control device 20, the control device 20 firstly operates the cooling / heating switching valves 13 and 16.
And a control signal for closing the on-off valve 17 and a control signal for starting the heating pump 42.

When the heating pump 42 is started, the R-1 of the liquid staying at the starting end of the liquid intake pipe 23 is removed.
34 a is collected in the heat transfer tube 12 of the absorption refrigerator 11. When the amount flowing into the heat transfer tube 12 increases, the overflow tube 2
The liquid R-134a flows into the receiver tank 14 through the second tank 2. Then, when the liquid level of R-134a in the receiver tank 14 detected by the liquid level sensor 19 reaches a predetermined level set in advance, the control device 20 sends a signal to the absorption refrigerator 11.
A required control signal is output to the evaporator, and the refrigerant and the absorbing liquid heated and evaporated by the regenerator are directly sent to the evaporator.

Therefore, in the outdoor unit 10, the liquid R-134a is heated by the high-temperature refrigerant vapor or the absorbing liquid flowing into the evaporator from the regenerator of the absorption refrigerator 11 via the tube wall of the heat transfer tube 12. It evaporates and becomes a gas at a predetermined high temperature, for example, 55 ° C., is discharged to the trachea 25, and is supplied to the indoor unit 30.

It should be noted that the R-
It is confirmed by the liquid level sensor 19 that the liquid level of 134a has reached a predetermined level, and when heating by the absorption refrigerator 11 is started, the operation of the heating pump 42 is temporarily stopped, and the heating by the absorption refrigerator 11 R-1 in the heat transfer tube 12
The control of the control device 20 may be configured so that the operation of the heating pump 42 is restarted after the temperature or the pressure of 34a reaches a predetermined value. By performing this control, the indoor unit 30 can take out hot air more quickly.

In each indoor unit 30, gas R-134 is added to the low-temperature indoor air supplied by the blower 33.
a dissipates heat through the tube wall of the heat transfer tube 31 to condense and liquefy, performs a heating action during this condensation, and furthermore, the condensed liquid R-134a passes through the expansion valve 32 and passes through the receiver tank 41.
And the circulation of R-134a is returned to the outdoor unit 10 by the heating pump 42, and the heating operation is continued.

During operation, the pressure in the pipe fluctuates due to fluctuations in the load, start / stop of the absorption refrigerator 11 of the outdoor unit 10, etc., so that the circulation amount of R-134a also fluctuates, and the heat transfer pipe 1
The level of liquid R-134a within 2 also varies constantly. If the liquid level of the liquid R-134a in the heat transfer tube 12 is too low, the heat transfer area required to transfer the heat generated by the absorption refrigerator 11 to the liquid R-134a cannot be secured. Therefore, the amount required by the indoor unit 30 cannot be transported.

For this reason, when the liquid level of the liquid R-134a in the heat transfer tube 12 detected by the liquid level sensor 18 during the heating operation becomes lower than a predetermined recovery start level, the control device 20 sets a required level. Control signal to output the on-off valve 1
7, the auxiliary pump 15 for cooling is started, and the R-134 of the liquid stored in the receiver tank 14 is released.
a is transferred to the heat transfer pipe 12 of the absorption refrigerator 11 through the liquid side pipe 24.
To recover the liquid level of R-134a in the heat transfer tube 12.

By this operation, the liquid R-134a does not run short in the heat transfer tube 12, so that the R-13
4a is overheated, and it is not possible to generate gas R-134a corresponding to the amount of heat required by the indoor unit 30, despite the heating capacity of the absorption refrigerator 11 remaining.
The disadvantage of not being able to provide the necessary heating is avoided.

The closing operation of the opening / closing valve 17 and the stopping operation of the auxiliary cooling pump 15 are performed when the liquid level of R-134a detected by the liquid level sensor 18 reaches a recovery stop level higher than the recovery start level. At this time, the control is performed by outputting a required control signal from the control device 20.

When the amount of the liquid R-134a flowing into the heat transfer tube 12 via the liquid intake tube 23 increases, the surplus liquid R-134a enters the receiver tank 14 via the overflow tube 22. Therefore, it is possible to prevent the R-134a that has leaked from the heat transfer tube 12 into the trachea 25 and circulates and is prevented from circulating.

The heat transfer tube 12 is controlled by the liquid level sensor 18.
Instead of detecting the decrease in the liquid level of the liquid R-134a, the degree of superheat at that time is obtained from the temperature and pressure of the gas R-134a evaporated in the heat transfer tube 12, and the degree of superheat exceeds a predetermined value. At this time, the on-off valve 17 is opened to start the auxiliary cooling pump 15, and when the degree of superheat is completely or partially eliminated, the on-off valve 17 is closed to open the auxiliary cooling pump 1.
It is also possible to configure so that each device is controlled by the control device 20 so as to stop 5.

The phase changeable fluid circulated between the outdoor unit 10 and the indoor unit 30 may be R-407c, R-404A, R-410c, etc., in addition to R-134a. good.

[0036]

As described above, according to the present invention, the phase-changeable fluid can be circulated between the outdoor unit and the indoor unit without excess or deficiency in any of the cooling and heating operations. Thus, air conditioning is always performed in a normal state.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Outdoor unit 11 Absorption refrigerator 12 Heat transfer tube 13 Cooling / heating switching valve 14 Receiver tank 15 Auxiliary pump for cooling 16 Cooling / heating switching valve 17 Open / close valve 18/19 Liquid level sensor 20 Control device 21 Liquid delivery pipe 22 Overflow pipe 23 Liquid intake pipe 24 Liquid side pipe 25 Trachea 26 Equalizing pipe 30 Indoor unit 31 Heat transfer pipe 32 Expansion valve 33 Blower 40 Heating pump unit 41 Receiver tank 42 Heating pump 43 Check valve

Claims (6)

[Claims] An outdoor unit having a heat source generating unit to which a liquid intake pipe, a liquid delivery pipe, an overflow pipe, a liquid bypass pipe, and a trachea are connected is installed above all indoor units or a majority of indoor units, An air conditioner that circulates and supplies the phase-changed fluid to the indoor unit in the heat source generating unit of the outdoor unit and performs cooling and heating using the latent heat of the fluid in each indoor unit, wherein the liquid delivery pipe is the lowest in the heat source generating unit. Section, the overflow pipe is connected to a position where the required liquid level can be secured during heating operation, the liquid intake pipe and liquid side pipe are connected above this, and the trachea is connected to the highest part An air conditioner characterized by being performed. 2. The air conditioner according to claim 1, wherein an outdoor unit has a first cooling / heating switching valve interposed in the liquid delivery pipe, a first receiver tank sequentially connected and installed downstream thereof, and a cooling auxiliary pump. A second cooling / heating switching valve, and an opening / closing valve interposed in the liquid side pipe, and the other end of the overflow pipe is directly or directly connected between the first cooling / heating switching valve of the liquid delivery pipe and the first receiver tank. Connected to this first receiver tank,
The other end of the liquid side pipe is connected between the auxiliary cooling pump of the liquid delivery pipe and the second cooling / heating switching valve, the upper part of the first receiver tank is connected to the trachea, and the other end of the liquid intake pipe is connected. Is connected to the lowest part of the liquid delivery pipe connected to each indoor unit, and
A second receiver tank and a heating pump are installed at the lowest part of the liquid intake pipe with the second receiver tank located upstream, and only the flow of fluid in the direction of the outdoor unit is possible through the liquid intake pipe. The air conditioner according to claim 1, wherein a check valve is provided. 3. Generating cold heat in a heat source generating section of the outdoor unit,
The cooling operation in the air conditioner according to claim 1 or 2, wherein the cooling operation is performed by circulating and supplying the liquid condensed by radiating the cool heat to the indoor unit by opening the first and second cooling / heating switching valves. The on-off valve is closed, cold is generated in the heat source generating section of the outdoor unit, and after confirming that the liquid stored in the first receiver tank is larger than a predetermined amount, the cooling auxiliary pump is started. An operation method of an air conditioner, which is started. 4. Generating heat in a heat source generating section of the outdoor unit,
The heating operation in the air conditioner according to claim 1 or 2, wherein the gas heated and evaporated by the heat is circulated and supplied to the indoor unit. Is closed, the heating pump is started, the liquid is collected in the heat source generating section of the outdoor unit and the first receiver tank, and it is confirmed that the liquid collected in the first receiver tank is larger than a predetermined amount. After that, the method starts operating by generating heat in the heat source generating section of the outdoor unit. 5. A heating pump is operated with the first and second cooling / heating switching valves and the on-off valve of the liquid side pipe closed, and the heating pump is heated by the heat generated by the heat source generating section of the outdoor unit. 3. A liquid side pipe when the liquid level of the fluid in the heat source generating section of the outdoor unit becomes lower than a predetermined position during the heating operation in the air conditioner according to claim 1 or 2, wherein the gas is circulated and supplied to the indoor unit. Opening the on-off valve to start the auxiliary cooling pump, and performing liquid level control in the heat source generating unit of the outdoor unit that refluxes the liquid from the first receiver tank to the heat source generating unit of the outdoor unit. How to operate the air conditioner. 6. A heating pump is operated in a state where the first and second cooling / heating switching valves and the opening / closing valve of the liquid side passage pipe are closed, and the heating pump is heated by the heat generated by the heat source generating section of the outdoor unit. 3. A superheat degree of a fluid in a heat source generating section of the outdoor unit is calculated during a heating operation in the air conditioner according to claim 1 or 2, wherein the superheat degree is predetermined. When the value exceeds the above value, control is performed to open the on-off valve of the liquid side pipe, start the auxiliary cooling pump, and return the liquid from the first receiver tank to the heat source generating section of the outdoor unit to reduce the degree of superheat of the fluid. An operation method of an air conditioner, which is performed.