JPS61122023A - Heat pump type cooling and heating device for car - Google Patents

Abstract

PURPOSE:To prevent the insufficiency in the amount of coolant by providing two main and sub suction ports in a compressor and connecting a coolant return path that passes through a third heat exchanger to a main suction port and a coolant return path that passes through a first exchanger to a sub suction port. CONSTITUTION:At heating cycle, the main suction port 47 of a compressor 1 is connected to the exit section of a second heat exchanger 5 that is the final component of a coolant circulation system. In addition, the sub suction port 46 of the compressor 1 is connected to the exit section of a capacitor as a first heat exchanger 2 that can anticipate several atmospheric heat absorption functions, interposed in a bypass coolant return path at this cycle. Consequently, even if a leak is generated in a check valve interposed in a coolant circulation system and the coolant is collected gradually in a condenser 2, the coolant is sucked in the sub suction port 46. As a result, there is no insufficiency in the amount of coolant that flows in the coolant circulation system.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a heat pump air conditioning system for a vehicle in which engine cooling water temperature is absorbed into a refrigerant as a heat source for heating.

[Prior Art] Conventionally, a hot water heater type heating system that uses engine cooling hot water as a heat source has been generally used to heat the interior of a vehicle, especially an automobile, but diesel engines with high fuel combustion efficiency and recent high-speed Cars equipped with rotating gasoline engines tend to lack constant heating capacity in cold regions, and even ordinary gasoline engine cars have the inconvenience of being forced to feel cold when starting the engine until the radiator gets wet. Therefore, a new type of heat pump type air conditioning system was developed as a vehicle air conditioner with higher heating capacity and so-called immediate heating performance, in which engine cooling water temperature is absorbed into the refrigerant as a heat source for heating.

FIG. 5 is a system diagram of the heat pump type air-conditioning device that absorbs the temperature of the engine cooling water described above. To briefly explain its operation, first, during the cooling cycle, the compressor 1
The high-pressure, high-temperature gas phase refrigerant compressed by passes through the four-way refrigerant flow switching valve 8 set at the cooling cycle position, follows the flow path shown by the solid arrow in the figure, and is transferred to the condenser 2. It flows in, is cooled by the outside air, becomes liquefied, passes through the check valve 9, and is temporarily stored in the receiver 3. The refrigerant discharged from the receiver 3 is sent to the pressure reducing device 4 due to the existence of the solenoid valve 12 which is closed during this cycle, expands, and is supplied to the evaporator 5 after being atomized. The refrigerant performs cooling work by removing latent heat of vaporization from the refrigerant, returns to a gas phase refrigerant, and is sucked into the compressor 1 via the four-way valve 8 and the check valve 11.

Next, during the heating cycle, the high-pressure, high-temperature gas phase refrigerant discharged from the compressor 1 passes through the four-way valve set at the heating cycle position and follows the flow path indicated by the broken line arrow in the figure.
It flows into the heat exchanger 5, which functions as an evaporator during cooling and as a heater during heating, and the retained heat is taken away by the room air at low temperature, thereby performing heating work and liquefying itself, passing through the check valve 10. After that, it is blocked by the check valve 9 and once flows into the receiver 3. The liquid phase refrigerant discharged from the receiver 3 does not flow to the pressure reducing device 4, which is closed during this cycle, but passes through the solenoid valve 12, which is open during this cycle, and is expanded and atomized by the heating cycle pressure reducing device 6. After that, while passing through a heat exchanger 7 that uses engine cooling water as a heat source, the hot water absorbs the retained heat, vaporizes it again, and is sucked into the compressor 1 for recirculation.

The engine cooling water heat absorption type heat pump air conditioning system with the above configuration has significantly superior heating capacity, especially in extremely cold weather, compared to a normal heat pump air conditioning system that absorbs outside air temperature through the condenser 2. It is clear that it has the following.

[Problems to be Solved by the Invention] The above-mentioned engine-cooled water heat absorption type heat pump type air-conditioning device has a problem in that the check valve 9 and the check valve 11 are closed during the heating cycle.
The presence of the refrigerant prevents the refrigerant from flowing into the condenser 2. The pressure inside the condenser 2, which is exposed to low outside temperatures in winter, is reduced to the saturation pressure at this low temperature, whereas during the heating cycle, the suction pressure of the compressor 1 is as high as 2 to 4 kg/cm2 G. Outside temperature is O℃
Even when the pressure inside the condenser 2 is lower than the suction pressure of the compressor 1, the refrigerant after passing through the heater 5 can easily leak into the condenser 2 if there is a defect in the fluid sealing ability of the check valves 9 and 11. It invades the body, condenses, and gradually accumulates. Once the refrigerant is stored in the condenser 2, it will not return to the refrigerant circulation system unless switching to cooling cycle operation, so if this check valve leakage is left unchecked, the system will eventually enter a refrigerant starvation state. It leads to falling into. However, since the suction pressure of the compressor temporarily decreases when the heat pump is started, it is possible that the refrigerant in the condenser may flow out into the circulation system, but this effect is hardly expected. Therefore, it is necessary to select check valves 9 and 11 that have sufficiently reliable sealing performance, but this is currently difficult to achieve due to both cost and technology. This situation also applies to the four-way valve 8 to some extent.

The present invention provides a heat pump air-conditioning system for vehicles equipped with a novel refrigerant circulation system that does not cause the above-mentioned problem of refrigerant flowing into the 1-denser even if a check valve that does not necessarily have a sufficient sealing function is used. The purpose is to provide.

[Means for Solving the Problems] In order to achieve the above object, the heat pump type air conditioning system for vehicles of the present invention includes a compressor for gas phase refrigerant and a first heat pump that acts as a condenser for pressurized gas phase refrigerant during the cooling cycle. an exchanger, a receiver for liquefied refrigerant, a pressure reducing device for atomizing liquid refrigerant, and a second heat exchanger that functions as an evaporator during a cooling cycle and as a heater during a heating cycle;
In the engine cooling water temperature absorption type heat pump air conditioning system, which is provided downstream of the second heat exchanger and is equipped with a third heat exchanger for absorbing engine cooling water heat, Two suction ports are provided, and a refrigerant return path passing through the third heat exchanger is connected to the main suction port, and the refrigerant is connected to the main suction port via the first heat exchanger in parallel with the third heat exchanger. The configuration includes a bypass refrigerant return path connected to the sub-intake port of the compressor.

[Function] In the vehicle heat pump air conditioning system having the above configuration, during the heating cycle, the main suction port of the compressor is connected to the outlet of the second heat exchanger, which is the final component of the refrigerant circulation system. In addition, the sub-inlet of the compressor is connected to the outlet of the condenser as the first heat exchanger, which can be expected to absorb some outside air heat through the bypass refrigerant return path during this cycle. Therefore, even if a leak occurs in the check valve installed in the refrigerant circulation system and refrigerant gradually accumulates in the condenser, unlike conventional similar devices, the check valve installed in the compressor Since the refrigerant is sucked into the auxiliary suction port, there is no problem of insufficient amount of refrigerant flowing through the refrigerant circulation system.

[Example] The specific configuration of the present invention will be explained below with reference to the accompanying drawings.

FIG. 1 is an operation cycle diagram of a heat pump air conditioning system for a vehicle according to the present invention, in which 1 is a compressor, 60 is a refrigerant discharge port of the compressor 1, 47 is a main refrigerant suction port, 4
6 is a refrigerant sub-intake port, 2 is a first heat exchanger as a condenser, 3 is a receiver, 4 is a liquid phase refrigerant atomization Rr gA
tx unit a, 5 is a second unit that functions as an evaporator during the cooling cycle and as a heater during the heating cycle.
A heat exchanger, 6 a pressure reducing device for the heating cycle, 7 a third heat exchanger for allowing the refrigerant to absorb the engine cooling water temperature, 8 a four-way valve for switching the refrigerant flow path for switching between the cooling cycle and the heating cycle. , 9.10 and 11 are check valves interposed in the refrigerant flow path, 12 is a solenoid valve provided on the upstream side of the third heat exchanger 1, and 13 is a connection between the inlet of the third heat exchanger 7 and the first heat exchanger. A bypass refrigerant return path provided between the heating cycle inlet of the exchanger 2, 14 a pressure reducing device for the first heat exchanger interposed in the bypass refrigerant return path 13, and 15 a sub suction port 4 of the compressor 1.
Refrigerant return path to 6, 16.17.18 is heat sensitive cylinder, and A
1 is a vehicle engine, and 19 and 20 are hot water circulation piping for heating the third heat exchanger 7 with hot water in a water jacket to the engine.

Figures 2 and 3 show the main and sub 2 parts used in the device of the present invention.
3 is a side sectional view showing an example of the structure of a compressor equipped with two suction ports, and a BB sectional view thereof, in which the compressor type is a 10-cylinder swash plate type, and 30 is a cylinder chamber for forming a cylinder chamber. The center housing, 31 and 32 are front and rear housings for forming fluid inlet/outlet boats, respectively, 33 is a swash plate chamber formed in the center of the center housing 30, 34 is a swash plate, and 35 is a swash plate chamber for the swash plate 34. It is a rotating shaft. Numeral 36 indicates five pistons which move back and forth as the swash plate 34 rotates obliquely with respect to the axial direction of the shaft 35, and five pistons are provided so as to surround the shaft 35. The peripheral edge of the swash plate 34 is located within a groove 36a provided in the piston 36, and the swash plate 34
In order to smoothly transmit the movement to the piston 36,
A shoe 37 and a ball 38 are interposed between the two. Reference numerals 39 and 40 denote front and rear cylinder chambers, respectively, which are surrounded by both the front and rear end surfaces of the piston 36 and the cylinder wall surface 41 formed in the center housing 30, and each have five seedlings, so the total capacity of the compressor as a whole is There are 10 solstice. In the compressor used for the purpose of the present invention, only one cylinder chamber 39 among these ten cylinder chambers is provided with a sub suction port in addition to the main suction port, and the remaining cylinder chambers 40 and 9
The two cylinder chambers were configured to have only a main suction port, similar to a normal compressor. A valve plate 42 located on the piston top dead center side of the cylinder chamber 39 is provided with a valve port 44 having a valve body 43 made of an elastic metal plate, which is connected to an auxiliary suction port 46 via a suction port 45. It is becoming more and more. Further, a slit 48 is provided in the cylinder wall 41 near the bottom dead center of the piston, which communicates with the main suction port 47 through the space between the swash plate 33. On the other hand, the cylinder chamber 40 is connected to the main suction port 47 via a suction boat 50 from a valve port 49 provided with a valve body 43 attached to a valve plate 42 . The remaining eight cylinder chambers, like the cylinder chamber 40, communicate only with the main suction port 47. 51 is a discharge port for compressed refrigerant.

52 is the center, front and rear housing 30.3
1 and 32 are through-bolts for joining; 53 is a bolt hole provided in the valve plate 42 that serves both the function of inserting the through-bolt 52 and communicating between the swash plate cavity 33 and the suction boat 50; and 54 is a bolt hole for storing lubricating oil. This is an oil pan for use.

FIG. 4 is a schematic diagram of the compressor illustrating the refrigerant flow path of the compressor shown in FIGS. 2 and 3;
0 is a refrigerant discharge port, 61 is a compressor driving boob, and other symbols are the same as those described above. In this embodiment, only one cylinder of the swash plate type 10-cylinder compressor is provided with a sub-intake port, but if necessary, sub-intake ports may be provided in two or more cylinders.

Next, the operation of the apparatus of the present invention having the above configuration will be explained.

During the heating cycle, the high-pressure, high-temperature refrigerant discharged from the compressor 1 passes through the four-way valve 8 and follows the flow path indicated by the broken line arrow in the figure. 2 heat exchanger 5
The cool air flows into the vehicle and is liquefied by the cold air inside the car, and the cold air gives its retained heat to perform heating work. During this cycle, the pressure reducing device 4 is closed, so it passes through the check valve and the non-return valve It is blocked by the valve 9, flows into the receiver 3, and is temporarily stored. The refrigerant discharged from the receiver 3 passes through the current valve 12 which is opened during the heating cycle, and is reduced in pressure and atomized by a pressure reducing device 6 for atomization, specifically by a thermostatic expansion valve, etc., and is then sent to the engine. A check valve that is interposed in the refrigerant return path from the first heat exchanger 2 after the refrigerant is evaporated while absorbing the heat by being passed through the third heat exchanger 7 that is supplied with the heat of the cooling hot water. 11, the refrigerant does not flow into the refrigerant return path 15 to the auxiliary suction port 46 of the compressor, and reaches the main suction port 47 of the compressor, completing one cycle of refrigerant circulation. When the outside temperature is -20°C, the pressure inside the third heat exchanger 1 is approximately 3 kg/cm2 G
The same pressure is maintained at the main suction port 47 of the compressor 1 as well.

On the other hand, the refrigerant that has followed the bypass refrigerant return path 13 is expanded and cooled to a temperature lower than the outside temperature by passing through the atomization pressure reducing device 14, so that the first heat exchanger 2 is heated even though the outside temperature is low. Although it is somewhat effective, it can perform the function of absorbing outside heat. Since the amount of refrigerant flowing into the first heat exchanger 2 is originally small, the refrigerant pressure is only slightly lower than the saturation pressure at the outside temperature, which is approximately 0.2 to 0.3 kg/c.
The refrigerant discharged from the first heat exchanger at a level of m 2 G returns to the auxiliary suction port 46 of the compressor 1 via the return pipe 15 . The pressure reducing device 14 has the function of controlling the refrigerant supply ω so that the refrigerant turns into superheated steam at the outlet of the first heat exchanger 2. Therefore, if the space to be heated is in a steady state, the first heat exchanger 2 It has the ability to maintain the flow rate of refrigerant in 2 at a constant level and increase or decrease the refrigerant supply ω in response to changes in external conditions. Therefore, if the refrigerant sealing function of the check valves 9 or 11 deteriorates and refrigerant passes through these check valves and flows into the first heat exchanger 2, the amount of refrigerant flowing through the bypass refrigerant return path 13 will decrease. If refrigerant accumulates in the first heat exchanger 2 before heating starts, the refrigerant supply will naturally be stopped until the amount of refrigerant in the heat exchanger 2 falls to an appropriate level. Therefore, it is possible to prevent the occurrence of a refrigerant shortage state in the refrigerant circulation system during the heating cycle due to excessive refrigerant retention in the first heat exchanger 2, and it is possible to prevent the occurrence of a refrigerant shortage state in the refrigerant circulation system during the heating cycle. No countermeasures are required.

Next, with reference to Figure 2, we will explain the mechanism for sucking two systems of gas phase refrigerant, each with a different pressure, from the two main and sub suction ports of =1 refrigerant 1 and sending them out from one common discharge port. explain. When the suction process in which the piston 36 moves from the top dead center position on the right side of the figure toward the bottom dead center begins, 0.2 to 0.3 kg/kg as described above is released from the sub suction port 46.
A relatively small amount of refrigerant from the first heat exchanger 2 at a low pressure level of cm 2 G is sucked into the cylinder chamber 39 via the suction boat 45 and the valve port 44 . When the piston 36 retreats to near the bottom dead center, the slit 48 that was previously blocked by the piston 36 opens into the swash plate chamber 3.
Since the refrigerant is communicated with the main suction port 47 through the third heat exchanger 7, the pressure discharged from the third heat exchanger 7 is 3 kg/cII12G. The low-pressure refrigerant flows in due to the pressure difference between the refrigerant and the low-pressure refrigerant. Then, when the piston 36 moves to the compression process, the mixed refrigerant that flows in from the main and sub-eye inlets is pushed out under pressure to the discharge boat 51, and from the discharge port 60, which is omitted in this figure, to the other main suction port. It is sent out toward the refrigerant circulation system together with the refrigerant pressurized to the same level discharged from the cylinder chamber having only a port via the discharge boat 51. The cylinder chamber 39 remains in communication with the remaining cylinder chambers including the cylinder chamber 40 through the slit 48 until the pressure level within the third heat exchanger 7 is reached just before the compression process begins. After the refrigerant is sucked, the compression process begins, and the amount of refrigerant circulated to the third heat exchanger Pr7 is reduced to approximately half of the cylinder capacity.

In addition, in the above embodiment, even if the bypass refrigerant return path B and the pressure reducing device 14 are not provided, the refrigerant in the first heat exchanger 2 can be sucked by using a compressor that can withstand negative pressure operation. It is.

[Effects of the Invention] The vehicle heat pump air-conditioning device of the present invention having the above-described configuration has the following effects.

In the unlikely event that the check valve, which is responsible for preventing refrigerant from flowing into the cooling condenser during the heating cycle, fails in its sealing function, refrigerant gradually accumulates inside the condenser. Also, the refrigerant outlet side of the condenser is connected to the auxiliary suction port of the compressor, which has a spare auxiliary suction port in addition to the main suction port, so the refrigerant that flows into the condenser does not stay inside and flows into the compressor. This will cause the refrigerant to be inhaled and forcibly returned to the normal refrigerant circulation system, avoiding the economic disadvantage of deliberately adopting a high-quality check valve that is technically difficult to manufacture at this stage and therefore expensive. Although this is a good measure, it is possible to use a check valve of ordinary quality without causing any practical inconvenience.

4. Brief explanation of the figures Figure 1 is an operating cycle diagram of the vehicle heat pump air conditioning system according to the present invention, and Figures 2, 3, and 4 are side cross sections of the compressor used in the pile-wood invention device. FIG. 5 is a schematic diagram of a compressor illustrating a BB sectional view and a refrigerant flow path in FIG.

In the diagram: 1... Compressor 2... First heat exchanger 5
...Second heat exchanger γ...Third heat exchanger 8...
Four-way valve 13...Bypass refrigerant return path 46...Sub suction port 47...Main suction port

Claims (1)

[Scope of Claims] 1) A compressor for a gas phase refrigerant, a first heat exchanger that functions as a condenser for pressurized gas phase refrigerant during a cooling cycle, a receiver for a liquefied refrigerant, and a pressure reducing device for atomizing the liquid phase refrigerant; A second heat exchanger that functions as an evaporator during a cooling cycle and as a heater during a heating cycle, and a third heat exchanger that is provided downstream of the second heat exchanger and is configured to absorb engine cooling water heat. In addition, in the heat pump air-conditioning device of the engine cooling water heat absorption type, the compressor is provided with two main and sub suction ports, a refrigerant return path via the third heat exchanger is connected to the main suction port, and the A heat pump air-conditioning system for a vehicle, characterized in that a bypass refrigerant return path is provided in parallel with a third heat exchanger and connected to a sub-intake port of the compressor via the first heat exchanger.