JP5553869B2 - Refrigerant circuit - Google Patents

Description

  The present invention relates to a refrigerant circuit for cooling a vehicle and a method of operating an air conditioner.

  In the double-loop air conditioner disclosed in Patent Document 1, heating of the refrigerant is performed in a heat pump or through compression of the refrigerant, and then the refrigerant is stored in a condenser in the internal space module (hereinafter referred to as a heat register). Is called). The heat register heats heat flowing into the internal space. In addition, heat can be extracted from the refrigerant circuit of the motor and directed to the refrigerant through the heat transfer device, or a heating core through which the refrigerant flows in the conventional heating device can flow into the internal space. It is also possible to heat through. In the cooling device, heat removal from the air flowing into the interior is performed by a condenser that functions as an evaporator in this operation. The heat released to the cooling material is then released to the surrounding environment via another condenser.

  The air conditioner disclosed in Patent Document 2 is provided with a refrigerant circuit through which heat during the heat pump process is taken out from outside air. This heat is released to heat the air flowing into the interior space through the condenser under high pressure (see the description of the heat register described below), and this condenser functions as a gas cooler or condenser in the heating unit.

  It is known that refrigerant circuits suitable for both cooling and heat pump operation are provided with high and low pressure regions. Such a refrigerant circuit comprises at least one heat source or heat sink (eg a gas cooler or condenser and / or a glycol heat exchanger), a compressor, an expansion module, and at least a thermal interior space module (evaporator / A condenser = heat register) and a refrigerant storage area.

  In addition, an internal heat exchanger having a high pressure side and a low pressure side is provided, whereby the high pressure side of the internal heat exchanger in the heat pump is placed between the expansion module and the gas cooler. The low pressure side of the internal heat exchanger is arranged on the suction side of the compressor.

  In the case of such a configuration, in view of the state of the current technology, it is disadvantageous because it is impossible to perform heat exchange with the low pressure side portion of the internal heat exchanger in a heat pump operation with a relatively small technical effort. . This is because the internal heat exchanger in the heat pump is also present in the low pressure region of the refrigerant circuit. During the heat pump operation, the internal heat exchanger is in an inactive state.

  In addition, in a heat pump in which an excessive amount of refrigerant is generated due to the charging amount determined by the operation of the air conditioner, the optimum operation of the compressor becomes impossible. This is because suction of the fluid refrigerant into the compressor cannot be excluded.

German Published Application No. 10309779 German Patent No. 10158104

  One of the objects of the present invention is to provide as simple a configuration as possible in order to ensure the active action of the internal heat exchanger in heat pump operation. A further object is to store unnecessary refrigerant correspondingly in various operating situations in cooling and heating operations and to optimally adjust the circulating refrigerant.

  One possibility obtained by guaranteeing the active action of the internal heat exchanger is a reduction in the pressure of the refrigerant downstream of the internal heat exchanger. However, in this case, there is a disadvantage that the refrigerant under high pressure is also supplied to the refrigerant storage area downstream from the internal heat exchanger in the heat pump. However, in this case, as in the heat pump operation, the storage area is too large due to the refrigerant density. Therefore, in this case, sufficient pressure accumulation on the high pressure side cannot be guaranteed.

  According to the invention, the refrigerant circuit includes means for driving the high pressure side of the internal heat exchanger in the heat pump to an intermediate pressure level between the high pressure level and the low pressure level of the refrigerant circuit.

  Due to the pressure escaping from the high pressure side of the inner heat exchanger to the heat source, the pressure level of the two-phase refrigerant whose pressure has been reduced is set higher than the pressure level of the downstream heat source. In extreme cases, this type of medium pressure level region can be increased or decreased, corresponding to high or low pressure levels.

  Due to the specific high heat and constant temperature of the two-phase refrigerant, the internal heat exchanger can be used to positively superheat the refrigerant in the heat pump flowing in the low pressure side portion of the internal heat exchanger. In this way, safe operation of the compressor can be easily ensured, and suction of fluid refrigerant is reliably avoided.

  The configuration and function of the refrigerant circuit can be applied regardless of the refrigerant used. In some cases, differences occur in specific pressure situations for low, medium and high pressure levels.

  In addition, it is possible to execute wiring independently of the drive design of a specific vehicle regardless of a conventional vehicle, a hybrid vehicle, an electric vehicle, or the like. Therefore, it is possible to execute wiring independently from the compressors.

  In a first advantageous embodiment, the means for driving the high pressure part of the internal heat exchanger to a medium pressure level is formed in the shape of a damper. The damper is provided downstream of the heat pump operation for the high pressure side of the internal heat exchanger, and is preferably provided on the rear side of the refrigerant storage region.

  In addition, the damper is set to generate a pressure loss only in the flow direction of the refrigerant in accordance with the narrowing of the cross section of the refrigerant in the heat pump. In the air conditioner, the maximum cross section is possible in the direction opposite to the flow direction. The intermediate pressure level is regulated by an expansion valve in the heat pump and is mitigated by a pressure drop due to the stationary damper after passing through the internal heat exchanger.

  Optionally, means for achieving the intermediate pressure level can also be provided in the form of a hose adjustment of a hose provided between the heat source or heat sink and the expansion valve. In this region, a refrigerant storage region and a high-pressure side part of the internal heat exchanger are also provided. The hose cross-section and hose induction or bending in the hose need to be calculated specifically for each vehicle, which makes it possible to achieve the specified pressure loss for heating operation in heat pump operation, while at the same time significant pressure loss in cooling operation To avoid.

  In particular, the hose cross section is smaller than standard current technology. This is because it makes it possible to reduce the material for the piping hose, as well as the cost and weight. By reducing the cross-section of the hose, a reduction in filling amount can also be achieved, and a necessary amount of refrigerant is also reduced.

  According to the invention, in addition to the controllable expander provided in the flow direction in the heat pump in front of the high pressure side of the internal heat exchanger, at least one controllable expander is further planned. At least one controllable expander is arranged in the direction of flow described above behind the refrigerant storage area on the rear side of the high pressure side of the heat exchanger and in front of the heat source.

  This controllable inflator is initially at a medium pressure level and cannot be lowered to a low pressure level.

  In another advantageous form, in addition to the condenser as a heat source or heat sink in the refrigerant circuit, an additional heat exchanger (especially an external heat exchanger) can be provided as an additional heat source or heat sink, the motor and the refrigerant circuit. It can be used for heat transfer between. This external heat exchanger is in particular formed as a water glycol heat exchanger (also called a cooling device).

  This further heat exchanger can be connected to the refrigerant circuit so that it is essentially in parallel and in series with the condenser.

  In each case, the hose to the condenser and the hose to the further heat exchanger both branch off from the hose extending from the high pressure side of the internal heat exchanger.

  In a particularly advantageous embodiment, these two branches can be combined together in the process via one controllable inflator. First, by controlling the expander for exchanging the switching valve, it is possible to determine whether the flow of the refrigerant flows to one of these two branch portions and the flow state thereof. Secondly, a controllable adjustment of the intermediate pressure level in the internal heat exchanger and the refrigerant storage area is ensured in both branches.

  By setting a controllable expander in the heat pump behind the refrigerant storage area, the pressure level in the refrigerant storage area (and the pressure level in this wiring change in the internal heat exchanger) can be set flexibly. This optimizes the amount of refrigerant that can be used in the refrigerant circuit.

  Furthermore, the present invention relates to a method for operating an air conditioner including a refrigerant circuit as described above. In this way, in addition to a controllable expander provided in front of the high pressure side of the internal heat exchanger in the direction of flow in the heat pump, at least one further controllable expander is provided. This is provided behind the refrigerant storage area and in front of the heat source on the rear side of the high pressure side of the heat exchanger in the flow direction described above.

  According to the present invention, the inflator is controlled such that its operation is defined.

  In particular, in the heat pump, the expander is controlled to operate individually. These particular inflators function individually and any other inflator is fully open.

  In another application, these expanders can all be operated in combination with each other. In this case, these inflators open while interacting to set the desired pressure level.

  Optionally, the inflator can be operated in a specific manner and used alternately for the required cooperative or individual operation.

  Other advantages, properties and applicability of the present invention are shown in the drawings along with the embodiments. In the present specification, claims, and drawings, the reference numerals described in the reference numerals are used.

It is a basic diagram of the refrigerant circuit of the cooling operation by this invention. It is a basic diagram of the refrigerant circuit of the heat pump operation by this invention. 1 shows an advantageous configuration with adjustment of the hose cross section. Fig. 2 shows an advantageous configuration using a controllable expander and series wiring of heat sources (i.e. water (cooling device) and air (condenser)). An advantageous configuration using parallel wiring is shown.

  In the following embodiments, the same components having the same functions are denoted by the same reference numerals.

  FIG. 1 shows a schematic diagram of a refrigerant circuit 10 of a vehicle air conditioner. The refrigerant circuit of this form is suitable for cooling and heat pump operation, but the case of cooling operation is shown in the figure. In this case, the refrigerant flows out of the compressor 12 under high pressure and passes through the condenser / gas cooler 26 and the damper 22 via the three-way valve 14. Reference numeral 14 is preferably a 3- to 2-way valve, but the wiring implementation can also be in the form of two separate controllable shut-off valves. However, the damper is shaped to generate a pressure loss only during heat pump operation. On the other hand, during the cooling operation, the damper hardly generates pressure loss, so that the refrigerant flows in the refrigerant storage region 24 and the high pressure side portion of the internal heat exchanger 20 even at the high pressure level, and the low pressure level only in the main expansion valve 18. It drops to. By opening the shut-off valve 32, the refrigerant seen at the low pressure level passes through the evaporator 34 and then passes through the low pressure side portion of the internal heat exchange 30. Until compressed. According to the current technology, the cooling operation does not change through the damper 22 configured as described above.

  FIG. 1A is a schematic diagram of a refrigerant circuit 10 of the vehicle air conditioner of FIG. In the heat pump operation, the refrigerant passes from the compressor 12 through the three-way valve 14 and then goes to the main expansion valve 18 via the heat register 16. The refrigerant remains at the high pressure level HD until it reaches the main expansion valve 18. The main expansion valve 18 reduces the refrigerant passing through the high pressure side of the internal heat exchanger 20 to the intermediate level pressure MD. In further operation, the damper 22 provided after the refrigerant storage area 24 reduces the refrigerant to the low pressure level ND in the flow direction of the heat pump. At this pressure level, the refrigerant flows in a condenser / gas cooler 26 that functions as an evaporator. Thereafter, the refrigerant flows into the compressor 12 after passing through the low pressure side of the internal heat exchanger 30 due to the shut-off valve 28 in the open state. Here, the refrigerant is compressed again to a high pressure level.

  According to the present invention, the refrigerant flowing through the high pressure side of the internal heat exchanger 20 reaches an intermediate pressure level, and the possibility of heat exchange with the low pressure portion of the exchanger is obtained in the heat pump operation. As a result, there is an advantage that the refrigerant flowing through the low pressure portion of the internal heat exchanger 30 is heated again or heated and then flows into the compressor 12.

  The suction of the fluid refrigerant is avoided with reliability due to overheating of the refrigerant. In this way, safe operation of the compressor 12 is ensured.

  FIG. 2 shows the refrigerant circuit 10 of the vehicle air conditioner in the heat pump operation. This heat pump operation ensures an intermediate pressure level between the main expansion valve 18 and the gas cooler 26 by adjusting the hose cross section 36 in the example of this embodiment. The hose cross section 36 in FIG. 2 is merely schematic. The shape of the hose cross section 36 is a shape that generates a pressure loss in the heat pump operation and does not generate a pressure loss in the cooling operation. This can be achieved based on different states of refrigerant in the two types of operation.

  To ensure this effect, technical hose analysis needs to be calculated separately for each vehicle. In particular, the hose analysis needs to be calculated as a function of hose induction bends or existing bends.

  In another advantageous embodiment as shown in FIG. 3, the refrigerant circuit 10 includes a cooling device 38 (for example of a vehicle motor) for heat exchange with the refrigerant circuit 10 in addition to the condenser / gas cooler 26. ). Additional heat sources can also be obtained by the exhaust system or by various refrigerant circuits of the partial or complete electric vehicle.

  This embodiment envisions further controllable expanders 40 and 42 to ensure a medium pressure level in the high pressure portion of the internal heat exchanger 20 in addition to the main expansion valve 18. In this case, flow guidance can be through the glycol heat exchanger / cooling device 38, the condenser / gas cooler 26, or both. At the controllable expander 40 and 42 pass position, the intermediate pressure level in heat pump operation is reduced to a low pressure, thereby accepting energy in the glycol heat exchanger / cooler 38 and / or the gas cooler 26. Is possible. In this way, it is possible to take advantage of the refrigerant on the high pressure side at the medium pressure level and the refrigerant in the internal heat exchanger 20 for overheating the refrigerant on the suction side of the evaporator 12.

  In addition, the controllable main expansion valve 18 and other expander 40/42 default settings allow adjustment of the pressure level in the refrigerant storage area 24, resulting in efficient heating and safety of the unit and Refrigerant storage is guaranteed at a density that can guarantee both reliable operation.

  The function of the embodiment shown in FIG. 4 essentially corresponds to the function of the embodiment of FIG. In contrast to FIG. 3, a connecting hose is provided. This connection hose connects the flow path through the condenser / gas cooler 26 to the glycol heat exchanger / cooling device 38 in the heat pump. The glycol heat exchanger / cooling device 38 is provided via a shut-off valve 44 on the rear side of the engine in the flow direction. Thus, the possibilities obtained by parallel operation of the condenser / gas cooler 26 and glycol heat exchanger / cooling device 38 and the possibility of series operation are shown in FIG.

DESCRIPTION OF SYMBOLS 10 Refrigerant circuit 12 Compressor 14 3-way valve 16 Heat register 18 Main expander 20 which can be controlled Internal heat exchanger (high pressure)
22 Damper 24 Refrigerant storage area 26 Condenser / gas cooler 28 Shut-off valve 30 Internal heat exchanger (low pressure)
32 Shutoff valve 34 Evaporator 36 Hose cross section 38 Glycol heat exchanger / cooling device 40 Controllable main expander 42 Controllable main expander 44 Shutdown valve ND Low pressure level MD Medium pressure level HD High pressure level

Claims (12)

Refrigerant circuit (10) for cooling and heat pump operation, said refrigerant circuit (10) having high and low pressure regions, wherein the high and low pressure regions are at least one heat source / heat sink (26, 38). And a compressor (12), an expander (18), at least one thermal internal space module (16, 34), and an internal heat exchanger (20, 30), the internal heat exchanger (20 30) comprises a high pressure side (20) and a low pressure side (30), the high pressure side (20) of the internal heat exchanger comprising the expansion module (18) and the heat source (26, 38). The means (22, 36, 40, 42) are provided in the heat pump between and the high pressure of the internal heat exchanger in the heat pump through the means (22, 36, 40, 42). Side (20 There will be operated at intermediate pressure levels (MD), the medium pressure level (MD) is Ri mania the pressure level in the pressure level and the low-pressure region in the high-pressure region (HD) (ND),
The condenser / gas cooler (26) and the heat exchanger (38) are provided as a heat source / heat sink (26, 38), and the heat exchanger (38) is connected in parallel with the gas cooler (26). The refrigerant circuit (10) , wherein the heat exchanger (38) is provided for heat exchange with the motor refrigerant circuit .   The refrigerant according to claim 1, wherein the high-pressure side portion of the internal heat exchanger (20) in heat pump operation is downstream from the stationary damper (22), thereby causing a pressure loss only in the flow direction of the heat pump. Circuit (10).   In the cooling operation, a hose is provided between the heat source / heat sink (26, 38) and the expander (18), and the hose has a particularly smaller cross section than the other hoses. The refrigerant circuit (10) according to claim 1, wherein no significant pressure loss occurs and the intermediate pressure level (MD) is guaranteed in heat pump operation.   The refrigerant circuit (10) according to claim 1, wherein at least one controllable expander (40, 42) is provided between the refrigerant storage area (24) and the heat source / heat sink (26, 38). . The internal heat exchanger the high-pressure side and the gas cooler (20) between the (26), controllable expander (42) refrigerant circuit according to claim 1, characterized in that provided (10) . Furthermore, it provided coolant storage region (24), the coolant storage area (24), according to any one of claims 1 to 5 is arranged within the in-pressure region of the refrigerant circuit (MD) Refrigerant circuit (10). The refrigerant circuit (10) according to any one of claims 1 to 6 , further comprising a shut-off valve configured to preset the operation of the refrigerant circuit in the cooling operation mode. The heat source / sink (26, 38) are water, air, exhaust gas, an electronic appliance, the refrigerant circuit according to any one of claims 1 to 7 works with medium of the heat storage and / or solar thermal / solar energy ( 10). A method for operating an air conditioner comprising a refrigerant circuit according to any one of claims 4 to 8 , wherein the expander (18, 40, 42) is defined in the operation. Feature method. In heat pump operation, the expander can be a single operation separately function in (18,40,42), other optional expander (18,40,42) is according to claim 9, wherein the fully opened Method. 10. The method according to claim 9 , wherein all the inflators (18, 40, 42) can be opened in cooperation with each other. The method according to any one of claims 9 to 11 , wherein the cooperative operation and the individual operation can be alternately used as necessary.

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