JP4720538B2 - Cooling and heating system - Google Patents

Description

  The present invention relates to a cooling and heating system that does not enter a dangerous state even when a cooling / temperature switching valve fails.

  In recent years, cooling and heating systems used for various devices have been demanded to reduce power consumption from the viewpoint of environmental protection, and in order to reduce power consumption, heating is performed using a heat pump system instead of a heater. Has been proposed (see Patent Document 1).

  The conventional cooling and heating system will be described below with reference to the drawings.

  FIG. 7 is a system diagram when the conventional cooling and heating system is cooled. FIG. 8 is a system diagram when the conventional cooling and heating system is heated. As shown in FIGS. 7 and 8, the cooling and heating system 1 includes a compressor 2, a high pressure side cooling switching valve 3, a high pressure side heating switching valve 4, an outdoor heat exchanger 5, an indoor heat exchanger 6, The cooling pressure reducing means 7, the heating pressure reducing means 8, the cooling check valve 9, the heating check valve 10, the low pressure side cooling switching valve 11, and the low pressure side heating switching valve 12 are connected in an annular shape. It is configured. In addition, the four switching valves use electromagnetic valves that are closed when not energized.

  The operation of the cooling and heating system configured as described above will be described below.

  When the cooling and heating system 1 is cooled, the high-pressure side cooling switching valve 3 and the low-pressure side cooling switching valve 11 are opened, and the high-pressure side heating switching valve 4 and the low-pressure side heating switching valve 12 are closed. As a result, the high-temperature and high-pressure working fluid compressed by the compressor 2 flows through the high-pressure side cooling switching valve 3, is cooled by the outdoor heat exchanger 5 to be condensed and liquefied, flows through the cooling check valve 9, and is cooled. The pressure is reduced by the pressure reducing means 7 to form a low-pressure gas-liquid two-layer flow, evaporated in the indoor heat exchanger 6 due to a temperature difference from the surroundings, cooled by the evaporation vaporization heat, and then flows through the low-pressure side cooling switching valve 11 again. Sucked into the compressor 2.

  When the cooling and heating system 1 is heated, the high-pressure side heating switching valve 4 and the low-pressure side heating switching valve 12 are opened, and the high-pressure side cooling switching valve 3 and the low-pressure side cooling switching valve 11 are closed. As a result, the high-temperature and high-pressure working fluid compressed by the compressor 2 flows through the high-pressure side heating switching valve 4, condenses and liquefies while heating the surroundings by the indoor heat exchanger 6, and the heating decompression means 8. Is reduced to a low-pressure gas-liquid two-layer flow, flows through the heating check valve 10, evaporates due to the temperature difference from the surroundings in the outdoor heat exchanger 5, flows through the low-pressure heating switch valve 12, and is compressed again It is sucked into machine 2.

  Normally, when the cooling heating system 1 is heated, the efficiency is about twice as high as the heating by the heater.

  Therefore, an efficient cooling and heating system could be obtained.

In addition, switching between cooling and heating is generally performed using a four-way valve, but by using four switching valves, the working fluid inlet and outlet of the two heat exchangers can be freely selected. For example, by flowing the working fluid from the top to the bottom of the heat exchanger during cooling and warming, it is possible to prevent stagnation of the compressor lubricating oil in the heat exchanger. Oil reduction can be prevented and compressor reliability can be increased.
JP 2002-174478 A

  However, in the above-described conventional configuration, when the high pressure side cooling switching valve 3 fails and is closed during cooling of the cooling and heating system 1 due to a wiring mistake or a coil failure, or when the high pressure side heating is performed during heating. When the switching valve 4 is broken and closed, the working fluid compressed by the compressor 2 is discharged from the compressor 2, but the high-pressure side cooling switching valve 3 and the high-pressure side heating switching valve 4 are discharged. Since the low pressure side cooling switching valve 11 or the low pressure side warming switching valve 12 is opened, all the working fluid in the cooling and heating system 1 is switched to the compressor 2 and the high pressure side cooling. It is confined between the valve 3 and the switching valve 4 for high pressure side heating.

  At this time, the working fluid condenses in the piping to become liquid, the pressure increases, and when the ambient temperature changes suddenly, the liquid vaporizes, the volume expands rapidly, the pressure becomes extremely high, and the pressure limit of the piping As a result, the piping is broken and the working fluid may leak out of the cooling and heating system 1.

  If the working fluid leaks out of the cooling and heating system 1, the ability to cool and warm may be lost. If the working fluid leaks out of the cooling and heating system 1, it takes a lot of trouble such as re-filling the working fluid and pipe welding when repairing.

  Some recent cooling and heating systems use hydrocarbon gases that do not destroy the ozone layer and have a low global warming potential as the working fluid. This hydrocarbon gas is a flammable gas, and if it leaks out of the cooling and heating system, there is a risk of combustion or explosion if there is an ignition source nearby.

  The present invention solves the above-described conventional problems. When the cooling / heating system 1 is cooled, the high pressure side cooling switching valve 3 breaks down and becomes closed, or when heated, the high pressure side heating is used. When the switching valve 4 breaks down and closes, the operation of the cooling and heating system is stopped immediately, and the working fluid is prevented from leaking out of the cooling and heating system. It is only necessary to replace the coil of the switching valve 3 for cooling or the switching valve 4 for heating on the high-pressure side and to improve the wiring, and even if a hydrocarbon-based gas is used as the working fluid, the working fluid will not burn or explode. The purpose is to provide a cooling and heating system with high serviceability and safety.

In order to solve the above conventional problems, the cooling and heating system of the present invention includes a compressor, a high-pressure side cooling switching valve, a high-pressure side heating switching valve, an outdoor heat exchanger, and a cooling check. A valve, a pressure reducing means for cooling, a check valve for heating, a pressure reducing means for heating, an indoor heat exchanger, a switching valve for low pressure side cooling, and a switching valve for low pressure side heating are connected in a ring shape When cooling, flow the working fluid in the following order: compressor, high pressure side cooling switching valve, outdoor heat exchanger, cooling check valve, cooling pressure reducing means, indoor heat exchanger, low pressure side cooling switching valve. sometimes the compressor, the high pressure side heating switching valve for the indoor heat exchanger, flowing heating decompression means, for heating the check valve, an outdoor heat exchanger, the working fluid in the order of the low-pressure side heating switching valve for the Suction temperature detection means abutting on the compressor suction pipe is provided, and the temperature detected by the suction temperature detection means is a cooling and heating system from the start of the compressor In subsequent predetermined time to stabilize, the high pressure side cooling switching Ben'a
Alternatively, when the high-pressure side heating switching valve breaks down and the flow of the working fluid is obstructed and the heat conduction from the compressor exceeds a predetermined temperature, the compressor is stopped and at least during cooling, the high-pressure side heating is stopped. When the heating switching valve is heated, the high pressure side cooling switching valve is forcibly opened so that the narrow space between the compressor and the high pressure side cooling switching valve and the high pressure side heating switching valve is Control means for releasing an unsafe state caused by sealing the working fluid is provided.

As a result, even when the high-pressure side cooling switching valve fails and closes during cooling of the cooling and heating system, or when the high-pressure side heating switching valve fails and closes during heating, By detecting the failure reliably and without false detection and stopping the cooling and heating system, it is possible to prevent leakage of the working fluid, and all the working fluid is sealed between the compressor and the high-pressure side switching valve. Serviceability and safety can be improved without any problems.

  The cooling and heating system of the present invention can quickly detect a system failure, and can improve serviceability and safety.

The invention described in claim 1 includes a compressor, a high-pressure side cooling switching valve, a high-pressure side heating switching valve, an outdoor heat exchanger, a cooling check valve, a cooling pressure reducing means, A check valve for heating, a pressure reducing means for heating, an indoor heat exchanger, a switching valve for cooling on the low pressure side, and a switching valve for cooling on the low pressure side are connected in a ring shape. Switching valve, outdoor heat exchanger, cooling check valve, cooling pressure reducing means, indoor heat exchanger, low pressure side cooling switching valve in order, and when heating, compressor, high pressure side heating switching Suction temperature at which the working fluid flows in the order of the valve, the indoor heat exchanger, the pressure reducing means for heating, the check valve for heating, the outdoor heat exchanger, and the switching valve for low pressure side heating, in contact with the compressor suction pipe a detection means, in the temperature detected by the suction temperature detecting means, cooling and warming system from starting the compressor after a predetermined time to stabilize, high pressure When the switching valve for cooling or the switching valve for heating on the high pressure side breaks down and the flow of the working fluid is obstructed and the heat conduction from the compressor exceeds a predetermined temperature, the compressor is stopped, and at least during cooling, the high pressure When the warming switching valve is warmed, the high pressure side cooling switching valve is forcibly opened to narrow the space between the compressor and the high pressure side cooling switching valve and the high pressure side warming switching valve. By providing a control means for releasing the unsafe state due to the working fluid being sealed in the space, when the high-pressure side cooling switching valve breaks down while the cooling and heating system is cooling, or the cooling and heating system When the high-pressure side heating switching valve fails during heating, the failure detected by the temperature detected by the suction temperature detection means that does not become high during operation increases due to heat conduction from the shell temperature, Cooling and heating Since the stem can be stopped, can be prevented reliably and the erroneous detection without working fluid leakage at one temperature sensing means, and high service and safety in a simpler configuration cooling and heating system be able to.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments.

  In addition, the operation and action of the same configuration as the conventional one is the same, and the description is omitted.

(Embodiment 1)
FIG. 1 is a system diagram when the cooling and heating system according to Embodiment 1 of the present invention is cooled. FIG. 2 is a system diagram when the cooling and heating system of the embodiment is heated.

  1 and 2, the cooling and heating system 13 constitutes a cooling and heating cycle capable of cooling or heating the same room, and the outlet pipe temperature is set to the outlet pipe 14 of the high pressure side cooling switching valve 3 and the discharge gas temperature. As a substitute for the cooling discharge gas temperature detection means 15 and the outlet pipe 16 of the high pressure side warming switching valve 4, a heating discharge gas temperature detection means 17 for substitution as a discharge gas temperature is provided. Control means 18 for stopping the compressor 2 according to the temperature detected by the warm discharge gas temperature detection means 17 is provided.

  The high pressure side cooling switching valve 3 and the high pressure side heating switching valve 4 are provided in the vicinity of the compressor 2. Specifically, a high pressure side cooling switching valve 3 and a high pressure side heating switching valve 4 are connected to a discharge pipe connected to the compressor 2 between the compressor 2 and the outdoor heat exchanger 5 or the indoor heat exchanger 6. Is connected.

  The operation of the cooling and heating system configured as described above will be described below.

  While the cooling and heating system 13 is cooling, the high-temperature and high-pressure gas discharged from the compressor 2 first flows through the high-pressure side cooling switching valve 3 and maintains a high temperature also in the outlet pipe 14.

  In this state, if the high pressure side cooling switching valve 3 is closed due to a failure of the high pressure side cooling switching valve 3 or the like, the flow of the working fluid is hindered, so that the temperature of the outlet pipe 14 decreases.

  At this time, the temperature detected by the cooling discharge gas temperature detection means 15 becomes equal to or lower than the reference temperature T1 (for example, 40 ° C.) after the reference time t1 (for example, 5 minutes) from the start of the compressor 2 where the system is stabilized. Since the compressor 2 is stopped by the control means 18, all the working fluid in the cooling and heating system 13 is placed between the compressor 2 and the high pressure side cooling switching valve 3 and the high pressure side heating switching valve 4. The cooling and heating system 13 can be stopped before being confined.

  Therefore, leakage of the working fluid can be prevented, and a cooling and heating system with high serviceability and safety can be obtained.

  Even when the cooling and heating system 13 is warming, when the temperature detected by the warming discharge gas temperature detecting means 17 becomes equal to or lower than a reference temperature T1 (for example, 40 ° C.) by the same operation, the control means 18 compresses the temperature. Since the machine 2 is stopped, the cooling / warming system before all the working fluid in the cooling / warming system 13 is confined between the compressor 2, the high-pressure side cooling switching valve 3 and the high-pressure side heating switching valve 4. 13 can be stopped.

  Therefore, leakage of the working fluid can be prevented, and a cooling and heating system with high serviceability and safety can be obtained.

  In addition to the cooling discharge gas temperature detection means 15 and the warming discharge gas temperature detection means 17, a means for detecting the outside air temperature is provided. When the outside air temperature is low, the reference temperature T1 is lower, and when the outside air temperature is high, it is higher. By doing so, the cooling and heating system 13 can be stopped more quickly.

  Further, when a failure of the high pressure side cooling switching valve 3 or the high pressure side heating switching valve 4 is detected, the failure can be dealt with more quickly by providing and displaying the failure display means.

  Further, when a failure of the high pressure side cooling switching valve 3 or the high pressure side warming switching valve 4 is detected, among the four switching valves, at least the cooling high pressure side warming switching valve 4 and the warming high pressure side By opening the cooling switching valve 3, preferably all four switching valves, the abnormal state can be quickly escaped.

(Embodiment 2)
FIG. 3 is a system diagram when the cooling and heating system according to the second embodiment of the present invention is cooled. FIG. 4 is a system diagram when the cooling and heating system of the embodiment is heated.

  3 and 4, the cooling and heating system 19 includes suction temperature detection means 21 in the suction pipe 20 of the compressor 2, and includes control means 22 that stops the compressor 2 according to the temperature detected by the suction temperature detection means 21. I have.

  The operation of the cooling and heating system configured as described above will be described below.

  While the cooling and heating system 19 is cooling, the working fluid that has flowed through the outdoor heat exchanger 5 does not exceed the outside air temperature + 10K even if it is high, flows through the suction side cooling switching valve 11, and the temperature in the suction pipe 20 also Keep.

  In this state, if the high pressure side cooling switching valve 3 is closed due to a failure of the high pressure side cooling switching valve 3 or the like, the flow of the working fluid is obstructed, so that there is no working fluid flowing in the suction pipe 20. The temperature gradually rises due to heat conduction from the compressor 2.

  At this time, when the temperature detected by the suction temperature detection means 21 becomes equal to or higher than the reference temperature T2 (for example, 60 ° C.) after the reference time t1 (for example, 5 minutes) from the start of the compressor 2, which stabilizes the system. Since the compressor 2 is stopped by the control means 22, all the working fluid in the cooling and heating system 13 is confined between the compressor 2, the high-pressure side cooling switching valve 3, and the high-pressure side heating switching valve 4. The cooling and heating system 13 can be stopped before.

  Accordingly, since the leakage of the working fluid can be prevented with only one temperature detection means, a cooling and heating system with a simpler configuration and higher serviceability and safety can be obtained.

  Further, even when the cooling and heating system 19 is heating, when the temperature detected by the suction temperature detecting means 21 becomes equal to or higher than the reference temperature T2 (for example, 60 ° C.) by the same operation, the compressor 2 is controlled by the control means 22. Since the operation is stopped, the cooling and heating system 13 is stopped before all the working fluid in the cooling and heating system 13 is confined between the compressor 2 and the high pressure side cooling switching valve 3 and the high pressure side heating switching valve 4. Can be made.

  When a failure of the high pressure side cooling switching valve 3 or the high pressure side warming switching valve 4 is detected, the failure can be dealt with more quickly by providing a means for displaying the failure.

  Further, when a failure of the high pressure side cooling switching valve 3 or the high pressure side warming switching valve 4 is detected, among the four switching valves, at least the cooling high pressure side warming switching valve 4 and the warming high pressure side By opening the cooling switching valve 3, preferably all four switching valves, the abnormal state can be quickly escaped.

(Embodiment 3)
FIG. 5 is a system diagram when the cooling and heating system according to the third embodiment of the present invention is cooled. FIG. 6 is a system diagram when the cooling and heating system of the embodiment is heated.

  5 and 6, the cooling and heating system 23 includes an outdoor heat exchanger inlet temperature detection means 25 for detecting the inlet fluid temperature of the outdoor heat exchanger 5 in the inlet pipe 24 of the outdoor heat exchanger 5, and the outdoor heat Control means 26 for stopping the compressor 2 in accordance with the temperature detected by the exchanger inlet temperature detection means 25 is provided.

  The operation of the cooling and heating system configured as described above will be described below.

  While the cooling and heating system 23 is cooling, the outdoor heat exchanger 5 operates as a condenser, and the high temperature and high pressure gas compressed by the compressor 2 flows through the inlet pipe 24, so that the temperature becomes high.

  In this state, if the high pressure side cooling switching valve 3 is closed due to a failure of the high pressure side cooling switching valve 3 or the like, the flow of the working fluid is hindered. It is cooled and lowered by.

  At this time, the temperature detected by the outdoor heat exchanger inlet temperature detection means 25 is equal to or lower than the reference temperature T3 (for example, 50 ° C.) after the reference time t1 (for example, 5 minutes) from the start of the compressor 2 where the system is stabilized. Since the compressor 2 is stopped by the control means 26 at this time, all the working fluid in the cooling and heating system 13 is exchanged between the compressor 2, the high pressure side cooling switching valve 3 and the high pressure side heating switching valve 4. The cooling and heating system 13 can be stopped before being trapped in between.

  Further, while the cooling and heating system 23 is warming, the outdoor heat exchanger 5 operates as an evaporator, and the gas-liquid two-layer fluid depressurized by the heating decompression means 8 flows through the inlet pipe 24 to reduce the temperature. Become.

  In this state, when the high pressure side warming switching valve 4 is closed due to a failure of the high pressure side warming switching valve 4 or the like, the flow of the working fluid is obstructed, so that there is no working fluid flowing through the inlet pipe 24, and the inlet pipe 24. Is heated by the outside air and gets higher.

  At this time, the temperature detected by the outdoor heat exchanger inlet temperature detecting means 25 is equal to or higher than the reference temperature T3 (for example, 20 ° C.) after the reference time t1 (for example, 5 minutes) from the start of the compressor 2 where the system is stabilized. Since the compressor 2 is stopped by the control means 26 at this time, all the working fluid in the cooling and heating system 13 is exchanged between the compressor 2, the high pressure side cooling switching valve 3 and the high pressure side heating switching valve 4. The cooling and heating system 13 can be stopped before being trapped in between.

  Further, the temperature of the inlet pipe 24 decreases or rises as soon as the high-pressure side cooling switching valve 3 or the high-pressure side heating switching valve 4 fails, so that the suction temperature detecting means 21 stops the compressor 2. The cooling and heating system 23 can be stopped more quickly and reliably.

  Therefore, it is possible to provide a cooling and heating system with high serviceability and high safety that can detect an abnormal state more quickly and reliably with a simpler configuration.

  In addition to the outdoor heat exchanger inlet temperature detection means 25, a means for detecting the outside air temperature is provided, and when the cooling and heating system 23 is cooled, the reference temperature T3 is lowered when the outside air temperature is low, and is raised when it is high. Thus, the cooling and heating system 13 can be stopped more quickly.

  Further, when a failure of the high pressure side cooling switching valve 3 or the high pressure side heating switching valve 4 is detected, the failure can be dealt with more quickly by providing and displaying the failure display means.

  Further, when a failure of the high pressure side cooling switching valve 3 or the high pressure side warming switching valve 4 is detected, among the four switching valves, at least the cooling high pressure side warming switching valve 4 and the warming high pressure side By opening the cooling switching valve 3, preferably all four switching valves, the abnormal state can be quickly escaped.

  As described above, since the cooling and heating system according to the present invention can detect the failure of the switching valve by detecting the piping temperature, there is no switching of cooling and heating, for example, a plurality of compressors with one compressor. The present invention can be applied to all systems having a switching valve such as a system that operates by switching the system and devices using the system.

System diagram when cooling and heating system according to Embodiment 1 of the present invention is cooled System diagram when the cooling and heating system of the embodiment is heated System diagram when cooling and heating system according to Embodiment 2 of the present invention is cooled System diagram when the cooling and heating system of the embodiment is heated System diagram when cooling and heating system according to Embodiment 3 of the present invention is cooled System diagram when the cooling and heating system of the embodiment is heated System diagram when the conventional cooling and heating system is cooling System diagram when the conventional cooling and heating system is heated

Explanation of symbols

2 Compressor 3 High-pressure side cooling switching valve 4 High-pressure side heating switching valve 5 Outdoor heat exchanger 6 Indoor heat exchanger 7 Cooling decompression means 8 Heating decompression means 9 Cooling check valve 10 Heating reverse Stop valve 11 Low pressure side cooling switching valve 12 Low pressure side warming switching valve 13 Cooling warming system 14 Outlet piping 15 Cooling discharge gas temperature detection means 16 Outlet piping 17 Heating discharge gas temperature detection means 18 Control means 19 Cooling heating System 20 Suction piping 21 Suction temperature detection means 22 Control means 23 Cooling and heating system 24 Inlet piping 25 Outdoor heat exchanger inlet temperature detection means 26 Control means

Claims (1)

Compressor, high pressure side cooling switching valve, high pressure side heating switching valve, outdoor heat exchanger, cooling check valve, cooling pressure reducing means, heating check valve, heating Pressure reducing means, an indoor heat exchanger, a low-pressure side cooling switching valve, and a low-pressure side heating switching valve are connected in an annular shape, and at the time of cooling, the compressor, the high-pressure side cooling switching valve, and the outdoor heat The working fluid flows in the order of the exchanger, the cooling check valve, the cooling pressure reducing means, the indoor heat exchanger, and the low-pressure side cooling switching valve, and when warming, the compressor, the high-pressure side heating switching A working fluid is flowed in the order of a valve, the indoor heat exchanger, the heating decompression means, the warming check valve, the outdoor heat exchanger, and the low pressure side warming switching valve, into the compressor suction pipe comprising a contact with the suction temperature detecting means, the temperature detected by the suction temperature detecting means, from the cooling and warming system from starting the compressor After a predetermined time for the compressor, when the high-pressure side cooling switching valve or the high-pressure side heating switching valve fails and the flow of the working fluid is obstructed, and the heat conduction from the compressor exceeds the predetermined temperature, the compressor The high pressure side heating switching valve at least during cooling, and the high pressure side cooling switching valve is forcibly opened during heating, so that the compressor, the high pressure side cooling switching valve, and the high pressure side are operated. A cooling and heating system comprising control means for releasing an unsafe state due to the working fluid being sealed in a narrow space between the heating switching valve .

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