Siphon with safety locking device

Abstract

Device for moisture management in the housing of a heat pump or refrigeration system, in which a siphon connected to the housing is provided for the removal of liquid from the housing, which siphon has a pressure-operated sliding gate valve as a shut-off device to the interior of the housing.

Description

[0001] The invention mainly relates to the humidity management and condensate drainage from a heat pump casing of a heat pump installed inside a building and equipped with an encapsulated refrigeration circuit, but it is also applicable to similar machines with refrigeration circuits in which condensate may occur, for example in air conditioning systems and dehumidifiers.

[0002] An encapsulated refrigeration circuit is an internal housing that contains all or some of the refrigerant-carrying devices and has connections for aqueous heat transfer fluids such as heating circuit water, cooling brine, or similar heat transfer fluids. They are generally not subject to air flow—that is, neither to air to be cooled or dehumidified in the case of air conditioning systems, nor to air to be heated in the case of heat pumps, which directly heat the air in residential buildings and direct the heated air into interior spaces. The term "encapsulated refrigeration circuit" is not identical to "heat pump housing" or "air conditioning housing" and, in this case, refers only to the part that is installed and operated within a building. In the case of split systems, the entire refrigeration circuit can also comprise several housings, of which those operated within the building are encapsulated.In the case of combination units that, for example, generate hot water in addition to heating water and have a hot water storage tank, the encapsulation only applies to the refrigerant-carrying parts. Multiple housings and multiple encapsulated refrigerant circuits can also be interconnected and / or networked.

[0003] Within these encapsulated refrigeration circuits, the individual components such as compressors, expansion devices, and heat exchangers are connected to each other via refrigerant lines, which may be protected against overpressure by safety valves. Furthermore, the heat exchangers through which the refrigerant flows are usually connected to heat transfer fluid lines. These heat transfer fluid lines may be equipped with safety valves that release the heat transfer fluid or mixtures containing gas in the event of overpressure.

[0004] Even without an encapsulated housing, it can happen that a safety valve releases liquid or vapor, and condensate accumulates in the housing, which should or must be drained from the housing. Preferably, but not necessarily, such safety valves for heat transfer fluids are also installed in the encapsulated refrigeration circuit housing.

[0005] A further complication can be a leak in the refrigeration circuit. Such leaks can occur, for example, in heat exchangers. If the refrigerant is under higher pressure than the respective heat transfer fluid, this refrigerant can enter the heat transfer fluid and contribute to the pressure buildup. This can result in the refrigerant being blown out of the heat transfer fluid safety valve along with the heat transfer fluid. This can be particularly critical if the refrigerant is flammable. Leaks can also occur at the pipe connections.

[0006] It is already known from air conditioning systems to drain away accumulating condensate using a siphon. JP H07 41325 U describes a siphon system with an extraction system. It is typically used in multi-story buildings with an air conditioning system installed on each floor, for example a chilled water system that produces condensate from cooled room air. This condensate must be drained away, either as wastewater via the general sewer line or via a separate, but corrosion-protected system. For this purpose, every air conditioning system is provided with a collecting tray with a sieve filter at the outlet of the collecting tray of the air conditioning system housing, below which a float rests on a support. To the side of this is the access to a siphon, which the float usually seals tightly, with a vacuum being created at the siphon by a pump.Instead of a siphon, a solenoid valve can also be used.

[0007] However, if there is a risk that evaporated refrigerant could also be drawn in, such systems are not suitable, as there is no guarantee that flammable mixtures could form. Therefore, a standard solution cannot be used for potentially contaminated condensate.

[0008] When using a flammable refrigerant, such as R290, R32, R1270, R600a, or R454C, a housing must be used to ensure that no flammable refrigerant can escape into the installation room. Typically, such heat pump housings or refrigeration system housings are not pressure-tight, but rather breathe, meaning that air pressure fluctuations are compensated. In many cases, such air exchange takes place through a filter, for example, an adsorber that serves as a filter. This filter is permeable in both directions to ambient air, including humidity, and is designed to prevent flammable refrigerants from escaping into the installation room.

[0009] However, there are limitations to such adsorptive filtration, which is related to the fact that heat is generated during adsorption, which temporarily reduces the capacity of the adsorbent. If the adsorption process were designed to capture all conceivable leaks despite heating, a very large amount of adsorbent would be required. This is especially true since incoming moisture also reduces the capacity of the adsorbent.

[0010] Therefore, a pressure-tight inner casing is often provided within the casing of a heat pump or refrigeration system. A ventilation opening is connected from this pressure-tight inner casing to a sorption bed. The connection between the ventilation opening and the sorption bed can be made directly or via a pipe. The sorption bed can be provided either within the casing of a heat pump or refrigeration system, which surrounds the pressure-tight inner casing, or outside the casing of a heat pump or refrigeration system as a separate sorption bed. The connecting pipe, if provided, should be sealable and equipped with a pressure reducing valve.

[0011] It is also possible to run an exhaust air duct from the installation room and the installation building to the outside if this is permitted for the respective refrigerant.

[0012] One or more safety valves are provided within the pressure-tight inner casing, which respond in the event of excess pressure. The use of heat transfer fluids carries the risk that, in the event of leaks under certain pressure conditions, the refrigerant could enter the heat transfer fluids via the corresponding heat exchangers. This is possible if the heat transfer fluid has a lower pressure than the refrigerant at the point of leakage, which can result in pressure building up in the heat transfer fluid. This particularly affects the warm side of the refrigeration circuit, as the compressor in the refrigeration circuit generates the pressure, which is then present in the condenser heat exchanger. From there, refrigerant can enter the heat transfer fluid under pressure in the event of a leak.This pressure increase in the heat transfer circuit then causes the safety valves in the pressure-tight inner casing to open, which can further result in large quantities of warm heat transfer fluid being introduced into the pressure-tight inner casing in addition to the refrigerant. Depending on the pressure and temperature, flash evaporation can then occur. Water and brine are typically considered as heat transfer fluids.

[0013] This poses the problem that the heat transfer fluids must not enter the sorbent filter, as this would reduce the sorbent filter's separation capacity for the refrigerant. Therefore, gas-liquid separation is required. On the other hand, refrigerant components dissolved in the heat transfer fluid, which have entered the pressure-tight inner casing via safety valves, must not escape as dissolved components in the liquid phase and outgas uncontrollably at an unfavorable location.

[0014] Humidity can also condense in the cold spots within the heat pump housing, and through the adsorbent filter, it can also enter the pressure-tight inner casing. With conventional adsorbents, there is also a risk that the moisture could condense on the adsorbent and impair its adsorption capacity for leaked refrigerant. Condensate can also escape through air separators or other safety valves.

[0015] This is countered by the requirement for reliable condensate drainage, which requires that condensate, which typically occurs during operation, be safely removed from the heat pump casing and the pressure-tight inner casing, while at the same time ensuring that no refrigerant escapes in the event of a leak. The condensate should also not come into contact with the adsorbent.

[0016] According to the conventional state of the art, such condensate drainage takes place via an opening or a hose. Such a condensate drainage system is described, for example, for an air conditioning system in KR 10 2007 0053 835 A. However, no capsule housing is used; instead, the room air is passed directly through the refrigerant-carrying heat exchanger, ignoring the problem of flammable refrigerant.

[0017] Another condensate drainage system for an air conditioning system is described in JP 2012 184 861 A, in which a collecting tank with a connected condensate pump ensures that odors caused by condensate formation are prevented.

[0018] DE 10 2020 100 806 A1 describes an air-to-water heat pump with an evaporator chamber into which the outlet of a safety valve leads. This evaporator chamber also collects any refrigerant leaks. The condensate is pumped to the outside via a condensate pump, and any contaminated air is vented to the outside via a duct.

[0019] The condensate is then either drained into the wastewater or evaporates, and the hydraulic seal is formed by a siphon. These are found in virtually all refrigerators and air conditioning systems. In the event that a flammable refrigerant leak could occur within a sealed heat pump housing, such a simple drainage of the condensate is not permitted.

[0020] Even the use of a conventional siphon is not safe because it can dry out or stick. A U-tube siphon relies on a constant supply of liquid. Water evaporates over time, and gas could then escape. This can be prevented by applying a non-evaporating or very slowly evaporating barrier layer, such as oil, to the liquid's surface. However, in the event of a large amount of liquid being released, as can occur when a pressure relief valve in a heating circuit is triggered, this barrier layer would be washed away, and the system would subsequently no longer function. Adequate gas tightness is difficult to achieve with dry siphons.

[0021] Then, according to the current state of the art, draining the condensate becomes impossible without running the risk of the refrigerant escaping as well, either if it is in gaseous form due to a leak or if it has bubbled into the heating water from a leak in a heat exchanger.

[0022] Specifically, the invention solves the problem by a device for moisture management in the housing of a heat pump or refrigeration system, wherein the heat pump or refrigeration system is intended for installation in an interior of a building and is subject to the relevant safety regulations, and wherein in the housing, a closed, hermetically sealed working fluid circuit is guided, the refrigeration circuit of which is operated with a flammable refrigerant and which comprises at least one compressor, one expansion valve and two heat exchangers which act as an evaporator and a condenser, and wherein the housing is closed but is permeable to air through a gas outlet, and this gas outlet is provided for discharging gaseous substances from the housing via a line to the outside or into a collecting device or into a separating cleaning device, safety valves are provided in the housing or safety valves blow off into the housing, wherein for discharging liquid from the housing, a siphon connected to the housing is provided which has a pressure-operated shut-off device to the interior of the housing.

[0023] In one embodiment, the pressure-operated shut-off device towards the housing is effected by a sliding gate valve, which releases the fluid outlet when pressure is applied. The sliding gate valve has a horizontal slide rail with a fluid seal and a return mechanism. The fluid seal tightly closes the outlet of the housing above against the U-tube section of the siphon below. A pressure force applied from the side pushes the fluid seal to the side along the slide rail. The return mechanism consists of a compression spring that is compressed when the pressure force is applied and, once pressure is no longer applied, moves the fluid seal back to its closed position using the spring force. As long as no pressure is applied, i.e. during pressureless operation, the sliding gate valve seals the siphon.

[0024] In one embodiment, the pressure buildup for the pressure-operated shut-off device is achieved by a safety valve; pressure buildup through an external device such as a compressed air connection or an inert gas cartridge is also possible. In a preferred embodiment, a safety valve in the heating circuit flow is used for pressure buildup, and the pressure line conveys the substances blown off by the safety valve to the siphon.

[0025] In one embodiment, the siphon has a dry-out protection device on the liquid outlet side. This dry-out protection is preferably provided by a float, which normally rests on the liquid surface of the water outlet side of the siphon and is raised when liquid is discharged, opening the liquid outlet.

[0026] In one embodiment, the discharge side of a safety valve in the heating circuit is used to build up pressure, and the discharged liquid is directed via a connection into the siphon's sliding gate valve and introduced into the siphon above the sliding gate valve seal. In practice, this means that when a gas-liquid mixture is discharged, it cannot flow directly into the siphon, but is first directed into the housing, where separation and pressure reduction occur.

[0027] Pressure reduction occurs via the drain from the housing. Once the pressure has equalized with the environment and the safety valve is closed again, the sliding gate is pushed back to its original position, sealing off the siphon from the rest of the housing.

[0028] The invention also encompasses the case where, in a building with multiple floors, separate devices according to the invention are used on each floor. In this case, they are each connected to a common drain via a non-return valve. This prevents leaking refrigerant from a single device from spreading to other floors.

[0029] The invention is illustrated by the figures Fig. 1 bis Fig. 4 This is explained in more detail using schematic diagrams, all of which depict the same heat pump housing with siphon in operation; the same would be the case with a refrigeration system. They show: Fig. 1 the heat pump housing with closed sliding gate in the siphon, Fig. 2 the heat pump housing with open sliding gate in the siphon and draining liquid, Fig. 3 the heat pump housing with open sliding gate in the siphon and pressure reduction, Fig. 4 the heat pump housing with open sliding gate in the siphon and draining liquid.

[0030] The figures are not to scale, but serve only as examples to better illustrate the invention. In practical designs, the siphon and heat pump housing have the dimensions of conventional washing machines and dishwashers. Furthermore, vulnerable equipment can also be separately encapsulated, each of which represents a separate housing within the meaning of the invention. The housing shown can also be part of a variety of integrated installations, such as hot water tanks or air conditioning units. The siphon can also be installed next to the equipment.

[0031] Fig. 1 shows a schematic representation of a housing 1 of a heat pump with the siphon device according to the invention. The housing 1 is shown in a simplified form here and contains the refrigeration circuit 2, in which condensate occasionally occurs and from which refrigerant can escape in the event of a leak. The refrigeration circuit 2 in its simplified representation consists of the compressor 4, the expansion valve 5, the evaporator 6, and the condenser 9. The evaporator 6 is connected to the heat source circuit via the heat source inlet 7 and the heat source return 8.

[0032] Condenser 9 is connected to the heating circuit flow 10 and the heating circuit return 11, with the highest temperature and system pressure in the heating circuit typically being present at the heating circuit flow 10. Therefore, the safety valve 12 is provided here; it could equally well be located within the heat pump housing 1 or within a correspondingly encapsulated housing within the heat pump housing, depending on the desired accessibility. For the sake of simplicity, neither an encapsulated housing nor a possible safety valve for summer operation, in which the heat source becomes a heat sink, are shown here.

[0033] If a leak occurs in the refrigerant circuit 2, gaseous refrigerant 14 escapes into the heat pump housing 1; the same happens when the pressure relief valve 13 downstream of the compressor 4 is triggered. Both cases are extremely rare, but would be very dangerous if the refrigerant is flammable and the mixture is within the ignition limits. In this case, the heat pump housing 1 must be vented as quickly as possible via the gas outlet 3. The gas outlet 3 leads either to the outside or to a collection or separation device, such as an adsorber, which is not shown here. In practice, however, this also means that only a small amount of pressure can build up in the heat pump housing, since the gas outlet is always open and any pressure build-up can only occur to the extent of the flow resistance of the gas outlet 3.

[0034] If a large amount of liquid were to accumulate simultaneously, for example, heating circuit water from the safety valve 12, the accumulating liquid and the air-refrigerant mixture would be difficult to drain separately, and the air-refrigerant mixture could enter the installation room almost unhindered via the housing drain or a conventional siphon. This is prevented by the device according to the invention.

[0035] The fluid flows from the heat pump housing 1 through its drain opening 16 into the siphon inlet 17, where it is normally stopped by the closure body 20. This closure body 20 is part of the sliding gate valve 18 and can be displaced by applying pressure against the return spring 19, thereby clearing the passage for fluid.

[0036] In the normal case, which Fig. 1 As shown, there is always liquid in the siphon U-tube 21, and it is odor-tight even when the slide valve 18 with the closure body 20 is open. The closure body 22, which can be designed as a cone, for example, rests on the rising side of the siphon U-tube 21. This closure body 22 floats on the standing liquid and can be pushed upward toward the siphon outlet 23 when the liquid level rises.

[0037] Above the lateral outlet 25 from the siphon outlet 23 is the closure body volume 24, which accommodates the closure body 22 during the release of the outlet and thus prevents it from being carried along with the draining liquid.

[0038] The sliding gate valve 18 is actuated by pressure application, which in this embodiment occurs from the safety valve 12 via its blow-off connection 27 and the pressure line 26, whereby this pressure line can also be designed in such a way that it carries the liquid that accrues when the safety valve 12 is blown off, and this is then fed directly into the sliding gate valve 18. Alternatively, the pressure build-up can also be achieved by compressed air or by inert gas from a switchable inert gas cartridge, which is not shown here, whereby the latter has the advantage that the heat pump housing is equally inerted if a leak occurs, for example if the safety valve 13 is activated at the same time. If there is no leak, conveying the liquid through the pressure line 26 has the advantage that the accruing liquid does not first have to be passed through the heat pump housing, but goes directly to the siphon.

[0039] Fig. 2 shows the case where the safety valve 12 has responded and liquid, together with gas components, is introduced through the pressure line 26 into the sliding gate valve 18. As a result, the closure body 20 slides sideways against the return spring 19 and clears the way for both the gas components and the liquid from the pressure line 26. The gas components can then escape through the drain opening 16 into the heat pump housing and from there through the gas outlet 3 into the open air, while the liquid flows directly into the siphon U-pipe. The liquid then causes the closure body 22 to be lifted into the closure body volume 24, as described above, and the liquid can flow out via the drain 25 without any gas connection to the installation room or the wastewater being created.

[0040] Fig. 3 shows the phase in which only air is pumped through the pressure line 26, but no more liquid flows in. The liquid seal in the siphon U-tube is then restored, with the height difference between the liquid levels corresponding to the pressure difference on both sides, and the closure body 22 sinking back out of the closure body volume.

[0041] Fig. 4 shows the case where only liquid comes from the safety valve 22 through the pressure line 26. This case is analogous to that in Fig. 2 The same applies to the case described above, with the difference that no gas flow enters the heat pump casing. Here, the static head of the liquid from the safety valve 12 alone is sufficient to generate the pressure to actuate the sliding gate. As soon as the liquid has drained away, the pressure in Fig. 1 shown state. List of reference symbols

[0042] 1 Housing 2 Refrigeration circuit 3 Gas outlet 4 Compressor 5 Expansion valve 6 Evaporator 7 Heat source inlet 8 Heat source return 9 Condenser 10 Heating circuit flow 11 Heating circuit return 12 Heating circuit safety valve 13 Refrigeration circuit safety valve 14 Leakage contamination 15 Housing drain 16 Drain opening 17 Siphon inlet 18 Slide valve 19 Return spring 20 Sealing body 21 Siphon U-tube 22 Sealing body 23 Siphon outlet 24 Sealing body volume 25 Drain 26 Pressure line 27 Blow-off connection

Claims

1. Device for humidity management in the housing (1) of a heat pump or refrigeration system, wherein the heat pump or refrigeration system is intended for installation in the interior of a building and is subject to the relevant safety regulations, wherein - a closed, hermetically sealed working fluid circuit is guided in the housing (1), - the refrigeration circuit (2) of which is operated with a flammable refrigerant and which comprises at least one compressor (4), an expansion valve (5) and two heat exchangers (6, 9) which act as an evaporator (6) and a condenser (9), - and wherein the housing (1) is closed but is permeable to air through a gas outlet (3), and this gas outlet (3) is provided for discharging gaseous substances from the housing (1) via a line to the outside or into a collecting device or into a separating cleaning system, - safety valves (12,13) are provided or safety valves (12) lead into the housing (1) or blow into the lines directly connected to them, , characterized in that - the housing (1) is provided with a siphon (21) connected to the housing for discharging liquid from the housing (1), which siphon has a pressure-operated shut-off device (18, 19, 20) towards the interior of the housing.

2. Device according to claim 1, characterized in that the pressure-operated shut-off device towards the housing is effected by a sliding gate valve (18) which releases the fluid outlet in the event of a pressure application and otherwise closes it tightly.

3. Device according to claim 2, characterized in that the sliding gate valve (18) has a horizontal slide rail with a liquid seal and a return mechanism and a pressure connection (26).

4. Device according to one of claims 1 to 3, characterized in thatthe pressure build-up for the pressure-operated shut-off device is carried out by a safety valve (12) which is connected to the siphon via a pressure line (26).

5. Device according to one of claims 1 to 4, characterized in that the siphon on the liquid outlet side is equipped with a dry-out protection.

6. Device according to claim 5, characterized in that the drying-out protection is preferably effected by a closure body (22) as a float, which is designed in such a way that it normally rests on the liquid surface of the water outlet side of the siphon and is raised in the case of liquid discharge, thereby releasing the siphon outlet (23) laterally.

7. Device according to one of claims 1 to 6, characterized in thatthe blow-off side (27) of a safety valve (12) of the heating circuit is used to build up pressure and the blown-off liquid is fed via a connection (26) into the sliding gate valve (18) of the siphon.

8. Use of a plurality of devices according to one of claims 1 to 7 in a plurality of floors of a building, characterized in that These are each connected to a common drain via a non-return valve.

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