JPS6362664B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a natural circulation type heating machine, particularly a multi-connection type heating machine having a plurality of coils in use, and more specifically, in addition to the coils in operation, the number of coils in use that are currently stopped is increased. This invention relates to the structure of a natural circulation heater that allows smooth startup during operation.

In devices that perform heating mainly by condensation latent heat by sending high-temperature refrigerant gas to the utilization coil through natural circulation of the refrigerant, the activation of natural circulation occurs when the refrigerant that provides the heat source generates convection within the system. will be accomplished.

Therefore, especially at the start of heating, various measures have been taken to ensure that the refrigerant flows in a predetermined direction within the system, as previously proposed by the applicant.

However, such measures to improve startup have been made in response to a 1:1 combination of the heat source coil and the utilization coil, which is called a multi-connection type as schematically shown in FIG. If two or three or more utilization coils are connected in parallel to one heat source coil, an inconvenient problem will occur during startup.

That is, when one of the utilization coils 6a and 6b is in heating operation and the other utilization coil 6b is started from a stopped state, even if only a small amount of refrigerant is present in the stopped utilization coil 6b. However, since the refrigerant liquid has accumulated in a liquid state, even if the liquid electromagnetic valve 14b is opened to start up, the accumulated refrigerant liquid acts as a resistance to natural circulation, and as a result, normal startup will not be achieved forever. It is.

In this way, the present invention has been made to address the problem of lack of smoothness of subsequent startups, especially in multi-connection types, and to provide a new device that can eliminate this drawback, and in particular, to reduce the A refrigerant control means capable of reducing the amount of refrigerant sent to each of the two utilization coils, including zero flow rate, is provided corresponding to each of the utilization coils, and during heating operation of at least one utilization coil, The present invention is characterized by a configuration in which a control circuit is provided for temporarily operating the refrigerant control means corresponding to the operating coils in conjunction with the operation of increasing the number of operating coils that are stopped.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to embodiments shown in the accompanying drawings.

The present invention is applied to a multi-connection type device in which two or more utilization coils are connected in parallel to one heat source coil, and the device shown in the second figure is an outdoor unit 1 having a heat source coil 7. The second figure shows an example in which two outdoor units 2a and 2b each having coils 6a and 6b are connected in parallel, and the device shown in the second figure has a structure capable of cooling and heating. .

The outdoor unit 1 includes a compressor 3, a condenser 4, a cooling pressure reducing mechanism such as a capillary reach tube 5a,
5b, a refrigerant amount regulator 15, a heat source coil 7 equipped with a heating device 8, a dryer filter 23, and a refrigerant circuit switching device. It has electromagnetic valves 14a and 14b, respectively.

On the other hand, the indoor units 2a and 2b are provided with utilization coils 6a and 6b and fans 9a and 9b, respectively.

In the outdoor unit 1, the heat source coil 7 has a configuration in which there is a vertical level difference between both ends of the heat transfer tube, and a path is followed in the direction of gravity between the high position pipe end and the low position pipe end. It is also installed in conjunction with a heating device 8 consisting of a combustor using white kerosene, gas, etc. as fuel, and during heating operation, the combustion heat of the heating device 8 and the refrigerant in the heat source coil 7 generate heat. It is now possible to exchange.

Note that this heat exchange may be performed using, for example, a hot water boiler (not shown); in this case, the heating device 8
The structure may be such that the combustion heat acts on the refrigerant in the heat source coil 7 through the water in the hot water boiler to prevent the refrigerant from reaching an abnormally high temperature as much as possible.

On the other hand, the coils 6a and 6b used in the indoor units 2a and 2b are arranged so that there is a vertical level difference between the high-position tube end and the low-position tube end of the heat transfer tube, and the path between them follows the direction of gravity. The high end of the pipe is connected to the gas pipe 10, and the low end of the pipe is connected to the branch liquid pipes 11a and 11b, respectively.

Therefore, the outdoor unit 1 is installed outdoors at a low place such as on the ground or on the floor of a machine room where outside air can circulate, while the indoor units 2a and 2b are installed at a higher place than the outdoor unit 1, such as on the top of a wall inside the room. Place it in an appropriate position.

Next, the refrigerant circuit switching device can be of various forms including a combination of a solenoid valve and a check valve, but the illustrated example has a low-position pipe end and branch liquid pipes 11a and 11b at the heat source coil 7. Solenoid valve 1 in the connecting pipe
2 and check valves 24a, 24b are interposed, and when the solenoid valve 12 is closed, the compressor 3, condenser 4, dryer filter 23, capillary reach tubes 5a, 5b, and solenoid valve 14a are closed. ,14
b, branch liquid pipes 11a, 11b, utilization coil 6a,
6b, gas pipe 10, on-off valve 13, refrigerant amount regulator 1
This enables cooling operation using a compression refrigeration cycle in which refrigerant is forcedly circulated in a closed circuit consisting of the 5 accumulator 15b and the compressor 3.

On the other hand, the solenoid valve 12 is opened, and the heat source coil 7, the accumulator 15b, the on-off valve 13, the gas pipe 10, the utilization coils 6a and 6b, and the branch liquid pipe 11
a, 11b, check valves 24a, 24b, solenoid valve 1
2. Enables heating operation using a natural circulation heating cycle in which refrigerant is naturally circulated in a closed circuit consisting of the heat source coil 7.

Of course, in the case of cooling operation, compressor 3 and condenser 4
The outdoor fan 22 is operated, and in the case of heating operation, the heating device 8 is operated.

Next, the refrigerant amount regulator 15 arranges the vertically long cylindrical sealed container so that it can come into contact with the outside air.
divided into two chambers 15a and 15b, and both chambers 1
Heat exchange between 5a and 15b is performed via a partition cylinder 16, and the chamber 15a is formed as a liquid reservoir and the chamber 15b is formed as an accumulator.

The liquid storage container 15a is connected to a branch liquid pipe 11a through which low-pressure liquid refrigerant is sent to the utilization coils 6a, 6b during cooling operation, and condensed liquid refrigerant after heat exchange with utilization coils 6a, 6b during heating operation, respectively. ，
Capillary reach tubes 20a, 20b and check valve 21 are connected by a branch pipe 25 so as to be able to communicate with 11b.
The coils 6a and 6b are connected in a branch manner through the coils 6a and 21b, respectively, and the accumulator 15b is connected to the coils 6a and 6b used during cooling operation.
The low-pressure gas refrigerant that has undergone heat exchange is interposed in refrigerant pipes through which vaporized refrigerant is sent to the coils 6a and 6b during heating operation.

In addition, in order to have a structure in which the accumulator 15b has a gas-liquid separation function, the communication pipes 17 and 18 are set up in the vessel so that each open end opens in the upper part, and the communication pipe 17 is provided with a vessel. The connecting pipe 18 has a small hole for liquid inflow during heating which communicates with the lower part of the vessel, and a small hole for oil return during cooling which communicates with the lower part of the vessel. It is possible to adjust the amount of refrigerant liquid.

Further, this refrigerant amount regulator 15 is connected to the liquid reservoir container 15.
Since the refrigerant a and the accumulator 15b are in contact with each other via the partition cylinder 16, heat exchange can be performed between the refrigerants stored in the refrigerants 15a and 15b, respectively.

Accumulator 15b of the refrigerant amount regulator 15
is connected to a pipe connecting the inlet side of the heat source coil 7 and the outlet of the electromagnetic valve 12 via a high pressure control valve 19.

The high pressure control valve 19 forms an automatic pressure control valve whose opening degree changes in proportion to the pressure difference when the pressure within the valve body exceeds a predetermined pressure compared to atmospheric pressure.

The electrical control circuit of the air conditioner and heater formed in the refrigerant circuit described above is developed and shown in _{FIG .} It controls the solenoid 12s of the valve 12, the solenoid 14as of the solenoid valve 14a, the solenoid 14bs of the solenoid valve 14b, and the outdoor fan motor _22M . Relays 34 to 33, an operation switch 2as for the indoor unit 2a, and an operation switch 2bs for the indoor unit 2b are provided to perform the wiring connection procedure shown in the drawing.

With reference to this electric circuit and the refrigerant circuit shown in FIG. 2, the heating and cooling operations will be explained separately below.

◎Heating operation (a) Operation of one indoor unit 2a from all stops,
Set the cooling/heating switch 31 to the heating side,
When the operating switch 2as is closed, the electromagnetic relay 38 and timer 32a are energized.

As the electromagnetic relay 38 is energized, the contact 38
_-1 to 38 _-3 is closed, so indoor fan motor 9a _M and solenoid valve solenoid 14as are connected to contact 3.
8 _-1 , the timer 32b is energized via the time limit contact 32b _-1 , so the indoor fan 9a is energized, the solenoid valve 14a is opened, and this state is maintained.

At the same time, the solenoid 12s is energized by closing the contact _38-2 , so the solenoid valve 12 is opened.

At the same time, since the hot water thermostat 33 is closed without reaching a high temperature due to the closing of the contact 38 _-3 , the burner 8 _B is in combustion operation and the heat source coil 7 is closed.
starts heating operation.

On the other hand, when the timer 32a is energized, the contact 32a _-1 opens instantaneously and closes again after a predetermined period of time has passed, but as long as the operation switch 2bs is open, the indoor fan 9b and the solenoid valve 14
b is never energized.

In this manner, the refrigerant is heated by the heat source coil 7, and after being vaporized, it inevitably begins to flow toward the side of the gas pipe connected to the higher end of the pipe.

Therefore, the refrigerant convection at the start of the heating operation is regulated in a predetermined direction, flowing toward the gas pipe, and the vaporized refrigerant flows into the utilization coil 6a through the accumulator 15b and the on-off valve 13, and flows into the room where the indoor fan 9a is generated. It exchanges heat with the air, condenses and liquefies it, and heats the indoor air.

This liquefied refrigerant flows down from the utilization coil 6a, passes through the solenoid valve 14a, the check valve 24a, and the solenoid valve 12 in order, and reaches the heat source coil 7.
It is heated again and vaporized.

By performing the refrigerant circulation as described above, heating by the natural circulation heating cycle is performed smoothly under normal startup conditions.

(b) Increased operation of the second indoor unit 2b. This operation can be cited as a characteristic operation mode of the present invention. To start the heating operation, it is sufficient to close the operation switch 2bs, and thus the electromagnetic relay 37 and the timer 32b
is energized.

As the electromagnetic relay 37 is energized, the contact 37
_-1 to 37 _-3 are all closed, so the indoor fan motor _9bM and the solenoid valve solenoid 14bs are connected to the contact 37 _-1 and the time limit contact 32 of the timer 32a.
As a result of being energized through a _-1 , indoor fan 9b
is energized, and the solenoid valve 14a is opened.

On the other hand, the electromagnetic valve 12 is connected to the open state by closing the contacts 37 _-2 and 38 _-2 , and the burner 8 _B continues its combustion operation by closing the contacts 37 _-3 and 38 _-3 .

In this way, the coil 6b used in the outdoor unit 1
The refrigerant circuit communicates with the engine to start the engine.

At the same time as this activation is started, the timer 32b is energized, so that the time limit contact 32b _-1 is instantaneously opened, so that the energized indoor fan 9a is stopped, and the opened electromagnetic fan 9a is stopped. Valve 14a is closed.

As a result, indoor unit 2 is operated with additional units.
Simultaneously with the start of activation of unit b, the operation of the indoor unit 2a that is currently in operation is interrupted.

After this operation interruption continues for a predetermined time (about several minutes) set in the timer 32b, the time-limited contact 32b _-1 returns to close.
The indoor unit 2a is switched to operation again.

Indoor unit 2 operated in this way
By interrupting the operation of the indoor unit 2a that is already in operation for only a short time when the indoor unit 2b starts up, the entire amount of refrigerant gas generated in the heat source coil 7 can provide sufficient energy to the utilization coil 6b of the indoor unit 2b. Since the refrigerant gas flows forcefully in the maintained state, even if the refrigerant liquid is accumulated on the indoor unit 2b side and the flow resistance is large, the refrigerant gas stably flows in the normal direction, resulting in reliable startup. .

In this way, when the start-up is completed, the indoor unit 2a side resumes operation, and the start-up failure in the case of additional unit operation is resolved.

Contrary to what has been explained above, if the indoor unit 2a is already in operation and the indoor unit 2a
It is clear from the circuit shown in FIG. 3 that the operation of the indoor unit 2b that is already in operation is interrupted in exactly the same manner even when an additional unit is operated.

The operation control described above can be summarized as follows. That is, each of the utilization coils 6a and 6b is provided with a refrigerant control means for controlling the amount of refrigerant to be supplied. A control circuit for temporarily operating the refrigerant control means corresponding to the currently operating coil in conjunction with the operation of increasing the number of utilized coils is provided in common to each of the utilized coils 6a and 6b.

In the example shown in FIG. 2, the refrigerant control means stops the fan and closes the solenoid valve at the same time, thereby completely stopping the refrigerant, that is, reducing the flow rate to zero.

During heating operation after smooth startup as described above, the accumulator 15
Since inside b is a superheated gas region, it hardly exists in a liquid state, and the partition cylinder 16 is in contact with this superheated gas.

Therefore, the inside of the liquid storage container 15a communicating with the refrigerant pipe through which the condensed refrigerant flows is a partition cylinder 16.
heated by superheated gas through the

On the other hand, the inside of the liquid reservoir 15a is cooled by outside air via the peripheral wall.

As a result, the liquid reservoir 15a is adjusted to compensate for the difference between cooling by outside air and heating by superheated gas.
A refrigerant liquid is stored therein so that the amount of liquid can be adjusted.

For example, when there is too much refrigerant in the natural circulation system, the degree of superheating of the refrigerant decreases, and the liquid storage container 15a
The evaporation power for water decreases, and the amount accumulated in the container 15a increases.

When the amount of refrigerant in the natural circulation system decreases, the degree of superheating of the gas increases, and the amount of refrigerant accumulated in the liquid reservoir 15a tends to decrease.

As a result, a balance is finally reached with an appropriate accumulation amount, and in this way, the refrigerant in the natural circulation system is maintained at an appropriate amount.

During this heating operation or immediately after startup, the amount of circulating refrigerant may be large and the refrigerant temperature and pressure at the outlet of the heat source coil 7 may rise abnormally, and when the system pressure rises, the high pressure control valve 19
is opened by this pressure, and liquid refrigerant is sent into the accumulator 15b, reducing the amount of refrigerant in the system and adjusting the pressure so that it does not rise above the set pressure.

Since the refrigerant accumulated in the accumulator 15b flows out from the small hole provided in the communication pipe 17,
The inflow amount and the outflow amount are balanced when the liquid level in the accumulator 15b reaches a certain value, and thus the system pressure can be stably adjusted.

Needless to say, when the pressure in the system decreases, the refrigerant liquid in the accumulator 15b flows into the system through the small holes to prevent the pressure from decreasing.

As is clear from the pressure regulating function of the high pressure regulating valve 19, the refrigerant regulation during heating in the accumulator 15b is performed during a transient situation at startup or during heating overload; It will be fully understood from the above explanation that the refrigerant amount adjustment function in the liquid reservoir 15a is performed in accordance with the degree of superheating of the refrigerant in the heat source coil 7 under steady operating conditions.

◎Cooling operation Set the cooling/heating selector switch 31 to the cooling side, and turn the operation switch 2as and/or 2bs of the indoor unit 2a and/or 2b you want to operate.
Close.

For example, when operating the indoor unit 2a, when the operation switch 2as is closed, the electromagnetic relays 34 and 36 are energized.
When the contact 34 _-1 is closed, the indoor fan motor 9a _M and the solenoid valve solenoid 14as are energized, the indoor fan 9a is driven, and the solenoid valve 14a is opened.

At the same time, contacts 36 _-1 , 36 of electromagnetic relay 36
_-2 is closed, compressor motor 3 _M ,
The outdoor fan motor _22M energizes the compressor 3,
The outdoor fan 22 is driven.

On the other hand, the solenoid valve 12 is closed and the burner _8B is stopped.

The high-temperature, high-pressure refrigerant gas discharged from the compressor 3 thus reaches the condenser 4, where it is cooled by the outdoor fan 22 and condensed into a liquid.Then, it passes through the dryer filter 23 and is depressurized by the pressure reducer 5a, becoming a low-pressure liquid refrigerant. It reaches the usage coil 6a via the branch liquid pipe 11a and the electromagnetic valve 14a, where it exchanges heat with the indoor air to cool the room, while the refrigerant itself evaporates and flows through the gas pipe 10, on-off valve 13, and accumulator 15b. The air then reaches the suction side of the compressor 3.

At this time, the refrigerant flow is as indicated by the broken line arrow in the figure, and cooling operation is performed using a compression refrigerant cycle.

Since the inside of the accumulator 15b is a low-pressure superheated gas region, the liquid storage container 15a is
Cooled through. Further, the container 15a is heated by outside air through the peripheral wall, and the heating operation is reversed.

When the cooling load is high due to a rise in room temperature, the amount of heat exchanged by the utilization coil 6a is large, so the degree of superheating of the suction gas becomes large, and therefore a low pressure is created in the liquid reservoir 15a, which is in almost the same state as the outlet of the capillary reach tube 5a. When refrigerant liquid accumulates, this refrigerant is heated and evaporated, so that only gas refrigerant exists in the container 15a and does not become liquid and accumulate, and the required amount of refrigerant suitable for high loads is supplied to the refrigerant circuit. circulate within.

On the other hand, when the refrigerant load is due to a drop in room temperature, the amount of heat exchanged in the utilization coil 6a is small and the degree of superheating of the suction gas is reduced, and the capillary reach tube 5
Due to the pressure loss caused by the piping on the downstream side of a, the suction gas temperature is rather lower than the refrigerant temperature at the outlet of the capillary reach tube 5a. An amount of refrigerant liquid corresponding to the difference is stored, and thus a required amount of refrigerant corresponding to the low cooling load is circulated within the system.

Since the above-mentioned cooling operation is performed using a compression refrigeration cycle, there is no problem of startup failures like in natural circulation heating operation. Control such as temporary interruption is unnecessary.

Next, FIG. 4, FIG. 5, and FIG. 6 are electrical circuit diagrams relating to each example of the device of the present invention.
In the figure, the circuit shown in Figure 3 is a modification of the part surrounded by the two-dot chain line frame, and the time limit contacts 32a _-1 , 32 of each timer 32a, 32b
A circuit is formed in which the connection position of b _-1 is changed to one for fan motors 9a _M and 9b _M alone (solid line position) or for solenoid valve solenoids 14as and 14bs alone (dashed line position).

By doing this, instead of interrupting the operation of the one already in operation when increasing the number of units, it is possible to stop only the air blowing of the indoor fan to reduce the refrigerant flow rate, or close the solenoid valve to reduce the sluggishness indoors. Operation control is performed to maintain the condensing effect.In any case, it is possible to reduce the amount of refrigerant fed to the coils that are already in operation, and even with such control, it is possible to increase It is possible to reliably and smoothly start up the indoor unit to be put into initial operation.

In addition, in FIG. 5, the circuit shown in FIG. 3 is modified from the part surrounded by the two-dot chain line frame, and each timer 32a, 32b is provided with time-limiting contacts 32a _-1 , 32b _-1 . The normally closed contacts 38 _-4 and 37 _-4 of the electromagnetic relays 38 and 37 and the refrigerant temperature of each utilization coil 6a and 6b are detected at the positions where the time limit contacts 32a _-1 and 32b _-1 are installed without using them. Temperature detector that closes when the temperature reaches high temperature (e.g. 40℃)
This is a parallel circuit with Ta and Tb connected.

By doing so, in the case of an additional operation, the one already in operation can be temporarily stopped by the normally closed contact of the electromagnetic relay and the temperature sensor on the side of the coil to be used for the additional operation.

Moreover, it goes without saying that this arrangement can be applied to the circuit shown in FIG.

On the other hand, Figure 6 shows 3 heat source coils for 71 heat source coils.
It shows an electric circuit when more than one coil 6a, 6b...6n are connected in parallel,
By forming the illustrated circuit by combining an electromagnetic relay 37i and a timer 32i for each utilization coil 6i, where i=a, b...n, the amount of refrigerant sent to each utilization coil 6i is controlled to be reduced. a control circuit that temporarily operates a refrigerant control means corresponding to a currently operating coil in conjunction with an operation to increase the number of utilized coils that are currently in a heating operation and are currently stopped; Naturally, such a form is also included within the scope of the present invention.

In addition, the time limit contact 3 of the timer 32i in FIG.
Parallel circuits of the normally closed contact of the electromagnetic relay and the temperature sensor may be connected to the arrangement position 2i _-1 , respectively.

As clarified by the above explanation, the present invention provides a heating system in which at least two utilization coils 6a, 6b... are connected in parallel to the heat source coil 7 to form a natural circulation refrigerant circuit. A refrigerant control means capable of reducing the amount of refrigerant sent to the coils 6a, 6b, respectively, including zero flow rate, is provided corresponding to each of the coils 6a, 6b, etc., and during heating operation of at least one of the coils, It is equipped with a control circuit that temporarily operates the refrigerant control means corresponding to the operating coils in conjunction with the operation of increasing the number of stopped operating coils, and the control circuit temporarily operates the refrigerant control means corresponding to the operating coils that are already in operation. Temporarily stops the flow of refrigerant to the coil,
Alternatively, by reducing the amount, a large amount of refrigerant can be distributed to the coil to be operated, so that reliable startup can be performed in a short time.

Therefore, it would be a great invention to the world to be able to individually start the coils used in a multi-connection type natural circulation heater without any problems and to solve the problems of this type of equipment. It is.

[Brief explanation of drawings]

Fig. 1 is a basic circuit diagram of a multi-connection type heating machine, Fig. 2 is a piping system diagram according to one embodiment of the heating machine of the present invention, Fig. 3 is an electric circuit diagram of the heating machine shown in Fig. 2, and Fig. 4 figure,
FIGS. 5 and 6 are main part electric circuit diagrams and electric circuit diagrams of each example of the heater of the present invention. 6a, 6b... Utilization coil, 7... Heat source coil, 8... Heating device.

Claims (1)

[Claims] 1 For the heat source coil 7 having the heating device 8,
A natural circulation refrigerant circuit is formed by connecting in parallel at least two utilization coils 6a, 6b, etc., each disposed higher than the heat source coil 7, and the high-temperature refrigerant gas generated in the heat source coil 7 due to heating is Coil used 6
In a natural circulation type heater that performs heating by sending the refrigerant to at least one of the coils 6a, 6b... Each use coil 6
a, 6b..., and in conjunction with the operation of increasing the stopped usage coil during heating operation of at least one usage coil,
A natural circulation heating machine characterized by comprising a control circuit for temporarily operating the refrigerant control means corresponding to the utilized coil during operation.