JPS62125273A - Heat pump device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a heat pump device that performs air conditioning and heating by reversing the flow direction of a refrigerant, and more particularly relates to a heat pump device that performs air conditioning and heating by reversing the flow direction of a refrigerant. Regarding improving heating capacity. Although its use is not particularly limited, it is effective for use as an air conditioner for automobiles having heat exchangers in each of the front and rear seats, for example.

[Conventional technology]

Conventionally, this type of heat pump device is used, for example, in automobiles, for so-called immediate heating after the engine starts until the engine cooling water warms up, or for auxiliary heating when heating capacity is insufficient with engine cooling water alone. This is particularly effective for vehicles with a large interior space despite their small engine displacement, such as single-engine cars equipped with a diesel engine. By the way, the so-called 1
As shown in Fig. 6, the boxcar has two heat exchangers 6, 7 (one for the front seats and one for the rear seats) as indoor heat exchangers.
From now on, for simplicity, F HE (Eront 1leat
Ex-changer), RHE (fLear j
During cooling, the high-temperature, high-pressure gas refrigerant compressed and discharged from the compressor 1 is routed through piping A - four-way valve 3 - distribution vH - condenser 4 -.
Distribution 'IF-Receiver 12-Piping E-Solenoid valve 14.15=
It flows through the expansion valve 8.9 - FHE6 and RWE7 - piping B - four-way valve 3 - piping l - compressor 1 to cool the vehicle interior. Also, during heating, the four-way valve 3 switches the flow path to the compressor 1-
Piping A-Four-way valve 3-Piping B-FHE6 and RWE7-
Piping, D' (check valves 17a, 17b) - receiver 12
- Piping G - Expansion valve 1) - Condenser 4 - Piping H - Four-way valve 3 - Piping ■ - Compressor 1 to heat the vehicle interior.

[Problem that the invention seeks to solve]

By the way, in the above-mentioned conventional heat pump device, during cooling, the expansion valve 8.9
Alternatively, the cooling capacity can be adjusted by adjusting the opening degree of the solenoid valves 14 and 15, but the capacity cannot be adjusted by these means during heating.

Generally speaking, in the above-mentioned 1-box cars, the front seat side is heated by introducing outside air to prevent the window glass from fogging up, while the rear seat side uses internal air circulation, so the front seat side and the rear seat side are heated. This creates a very large temperature difference in the air flowing into the seat-side heat exchanger. Therefore, there was a problem in that there was a significant imbalance in the evaporation of the refrigerant, and effective heating was not performed.

[Means for solving problems]

Therefore, in order to solve the problems of the prior art, the present invention includes at least a compressor, a four-way valve, an indoor heat exchanger, a pressure reducing device, and an outdoor heat exchanger, and the four-way valve controls the refrigerant flow direction. In a heat pump device that performs air conditioning and heating, the indoor heat exchanger is composed of a plurality of indoor heat exchangers, and the refrigerant is distributed and passed through the plurality of indoor heat exchangers in parallel during cooling, and the refrigerant is passed through the plurality of indoor heat exchangers in parallel during heating. It employs a heat pump device that passes refrigerant in series through an inner heat exchanger.

[Effect]

In the above means, since the refrigerant is configured to pass through the plurality of indoor heat exchangers in series during heating, even if there is a temperature difference in the temperature of the air introduced into the plurality of indoor heat exchangers, Since all the refrigerant passes through the indoor heat exchanger in sequence, the temperature of the refrigerant passing through the heat exchanger remains almost constant regardless of the temperature difference of the introduced air, and efficient heating is performed.

〔Example〕

The present invention will be explained in detail below based on embodiments shown in the drawings. FIG. 1 is a system diagram illustrating the configuration of the automobile heat pump device of the present invention, in which 1 is rotationally driven by transmitting the driving force of an engine (not shown) through an electromagnetic clutch 2, and sucks a low-temperature, low-pressure gas phase refrigerant. a compressor that sucks in through a port 1a and discharges high-temperature, high-pressure gas phase refrigerant from a discharge port 1b; 3;
Reference numeral 4 indicates a four-way valve that switches the flow path and reverses the flow direction of the refrigerant by controlling the energization of an electromagnetic coil (not shown) to switch between air conditioning and heating, and 4 indicates a first valve of the present invention which is arranged in parallel with an automobile radiator (not shown). A condenser serving as an outdoor heat exchanger cools and liquefies high IL & pressure gas refrigerant.

6 and 7 are a front seat heat exchanger (FHE) and a rear seat heat exchanger (RWE) that function as an evaporator during cooling and a condenser during heating; although not shown, FHE 6 is for the front seat in front of the driver's seat. The RWE 7 is disposed within the air conditioning casing, and the RWE 7 is disposed within the rear seat air conditioning casing attached to the rear of the rear seat, and the amount of air blown is independently controlled by each blower.

An inside/outside air switching damper is provided in the front air conditioning casing, and inside/outside air is selectively introduced, whereas the rear seat side only has an inside air intake port. 8 and 9 are expansion valves that reduce the pressure and supply liquid refrigerant to the FHE 6 and RHE 7.

Reference numeral 10 denotes a hot water heat exchanger as a second outdoor heat exchanger of the present invention, which uses engine cooling water as a heat source to efficiently evaporate liquid refrigerant during heating, and is installed at an appropriate location such as in the engine room. ing. The hot water heat exchanger 10 is connected to inlet and outlet pipes 10a and 10b of engine cooling water supply pipes. Note that 1) is an expansion valve that reduces the pressure and supplies liquid refrigerant to the hot water heat exchanger 10. Further, 12 is a receiver that performs gas-liquid separation of the condensed refrigerant and stores the liquid phase refrigerant.

Piping A-1 is a refrigerant pipe arranged so that a heat pump cycle is formed by the above-mentioned components, and is equipped with solenoid valves 13, 14, 15, check valves 16° 17.1B, 19.2 as appropriate.
via 0. The functions of each electromagnetic valve and check valve will become clear from the operation of the present invention described later. Here, the pipe C is provided to connect the FHE 6 and the RHE 7 in series during heating in the present invention, and is provided through a check valve 19.

Next, the operation of the heat pump system configured as described above will be explained separately during cooling and heating.

First, during cooling, all of the solenoid valves 13, 14, and 15 are opened, and refrigerant flows in the direction shown by the solid arrow in FIG. 1 to cool the interior of the vehicle. That is, the high-temperature, high-pressure gas refrigerant compressed and discharged by the compressor 1 flows through the pipe A, the four-way valve 3, the pipe H (electromagnetic valve 13), and the condenser 4, and is cooled in the condenser to become a gas-liquid mixed refrigerant. The gas-liquid mixed refrigerant passes through the check valve 16 and is prevented from flowing into the piping by the check valve 17, and all flows into the receiver 12. After the gas-liquid separation, the liquid refrigerant does not flow into the pipe G side but enters the pipe E because the pressure in the pipe G is lower than the pressure in the pipe H across the check valve 20. It is distributed at the branch point J, and the solenoid valve 14,1
5, the pressure is reduced through the expansion valve 8.9, and the FHE6. R
It flows through the HET and evaporates, and the latent heat of vaporization at this time performs cooling.

Note that the refrigerant whose pressure has been reduced by the expansion valve 8 does not flow into the piping C due to the check valve 19, and the refrigerant whose pressure has been reduced by the expansion valve 9 has a low pressure and therefore does not flow into the piping. FHE6. The gas refrigerant vaporized in the RHE 7 joins at the confluence point and returns to the compressor 1 via the four-way valve 3 and the pipe ①.

Next, during heating, all the solenoid valves 13, 14, and 15 are closed, and the refrigerant flows in the direction shown by the broken line arrow in FIG. 1 to perform heating. That is, the high-temperature, high-pressure gas refrigerant compressed by the compressor 1 flows into the pipe through the four-way valve 3, and then flows into the pipe C after being prevented from flowing into the pipe B by the check valve 18. After that, since the solenoid valve 14 is closed, the check valve 19-FH
The refrigerant flows in series from E6 to RHE7, and at this time, the high temperature and high pressure gas phase refrigerant is condensed within the two heat exchangers to perform heating.

Since the electromagnetic valve 15 is closed, the liquid refrigerant that has exited the RHE 7 flows into the pipe 9D, is blocked by the check valve 17 and the check valve 16, and flows into the receiver 12. The liquid refrigerant separated by the receiver 12 flows through the pipe G, the expansion valve 1), and the hot water heat exchanger 10, and is vaporized in this hot water heat exchanger. And check valve 20-
Return to compression IT via piping H - four-way valve 3 - piping ■.

By the way, in the conventional configuration shown in FIG.
If the amount of refrigerant distributed and supplied to the RHE7 is appropriately distributed at the branch point, for example, if the passenger adjusts the air volume of the rear seat air conditioner to reduce it according to his/her preference, the result will be as shown in Figure 2 ( As shown in the schematic diagram showing the gas capacity and liquid capacity of the alO heat exchanger, more refrigerant than necessary flows into RHE7, the superheated gas area increases, and some gas refrigerant cannot be fully condensed and the outlet of RHE7 Even in the case of FHE6, it flows out as saturated steam.
and shows the refrigerant temperature in the refrigerant flow direction of RHE7. This exit state becomes point A on the Mollier diagram shown in FIG. On the other hand, in this receiver cycle, an expansion valve 1) that controls the degree of superheating of the refrigerant at the outlet of the hot water heat exchanger 10, which functions as an evaporator, is kept constant, and an expansion valve 1), which functions as a condenser, and a
HE6. The refrigeration cycle is controlled by a receiver 7 that controls the refrigerant at the outlet of the RHE 7 to a saturated liquid state. That is, the receiver 12 converts the refrigerant that has exited FHE6 and RHE7 into saturated liquid (point 0 on the Mollier diagram) to the expansion valve 1.
), the liquid refrigerant at the outlet of FHE6 is brought to a degree of supercooling by the amount of heat that can condense the gas refrigerant at the outlet of RWE7, and this state corresponds to point B on the Mollier diagram. The state will be as follows. If the total number of heat values of FHE6 and RHE7 is the same as in the optimal state, such an imbalance will not only lead to inefficient operation, but also cause the RHE7 to have a higher temperature superheated steam region compared to an optimally distributed state. In FHE6, the liquid region where the temperature is low and the heat exchange efficiency is poor increases, so the temperature difference between the respective blown airs tends to increase. However, since lowering the inflow air volume of RHEl will lower the heating load as a whole, the condensing pressure will generally rise and the blowout temperature of FHE6 will also rise, but the rise in RHE7 is greater. Therefore, if we control the capacity to lower the blowout temperature of RHE7,
The blowing temperature on the FHE6 side will drop more than necessary.

On the other hand, in the first embodiment, FHE6 and R
Since it is configured so that the refrigerant flows in series with HE7,
As shown in Fig. 4(al), the gas refrigerant is controlled to finish condensing at the outlet of RHE7 on the downstream side.
As shown in bl, the temperature of the refrigerant in the side heat exchanger is almost constant except for the superheated gas area near the inlet of the RHE 6. Therefore, both FHE6 and RHE7 are optimally used.

Furthermore, as is clear from comparing the system diagrams of the embodiment of the present invention in FIG. 1 and the conventional system diagram in FIG. 6, the present invention eliminates the conventional piping D' and check valve 17b, Piping C
and check valves 19 and 18 are added, and although the number of check valves is increased by one, there is no significant addition of parts compared to the conventional model, and there is no significant increase in price. Note that each of the check valves 18 and 19 may be replaced with a solenoid valve, or 18 and 19 may be omitted and a three-way valve may be provided at the branch point M.

Next, a second embodiment of the present invention will be described based on FIG. 5. In this embodiment, the pipe C and check valve 19 of the first embodiment are eliminated, and a pipe branches from between the FHE 6 and the expansion valve 8 and joins between the RHE 7 and the branch point of the pipe B. The second embodiment is the same as the first embodiment except that a solenoid valve 5 is provided on the pipe C'. Note that the check valve 18 is moved to the side opposite to the branch point.

In this embodiment, during heating, the high-temperature, high-pressure gas refrigerant is blocked by the check valve 18 and flows in series from FHE6 to pipe C' (the solenoid valve 5 is closed during heating and cooling) to RHE7. provides the same heating effect as the embodiment. Here, the solenoid valve 5 is installed for the purpose of preventing the refrigerant expanded by the expansion valve 8 during cooling from being sucked directly into the compressor l side, similar to the check valve 19 of the first embodiment. Since the refrigerant flows in the same direction during heating and cooling, it is necessary to use an on-off valve such as a solenoid valve.

Furthermore, the heat pump device of the present invention can of course be applied not only to the one-box car in the above embodiment, but also to ordinary passenger cars, commercial vehicles, etc., and can also be applied to multiple indoor heat exchangers, not just for automobiles. It is also applicable for residential use.

〔Effect of the invention〕

As described above, in the heat pump device of the present invention, since the refrigerant is configured to pass through the plurality of indoor heat exchangers in series during heating, the temperature of the air flowing into the plurality of indoor heat exchangers can be adjusted. It is possible to provide an extremely practical heat pump device that can perform heating efficiently as a whole even when there are differences.

[Brief explanation of drawings]

Fig. 1 is a system diagram showing the configuration of the first embodiment of the heat pump device of the present invention, and Fig. 2 (al, (b), (c) shows the ratio of gas-liquid refrigerant when refrigerant is flowed in parallel. A schematic diagram and a characteristic diagram to explain the refrigerant temperature, Figure 3 is a Mollier diagram to explain the refrigeration work of the refrigeration cycle, and Figures 4 (a) and (b) show the gas-liquid refrigerant when the refrigerant is passed in series. A schematic diagram and a characteristic diagram explaining the refrigerant temperature, FIG. 5 is a system diagram showing the configuration of the second embodiment of the present invention, and FIG. 6 is a system diagram showing the configuration of a conventional heat pump device.・Compressor, 3... Four-way valve, 4... Condenser, 6... Heat exchanger for front seats, 7... Heat exchanger for rear seats,
8,9゜1)...Expansion valve, 10...Hot water heat exchanger.

Claims (2)

[Claims] (1) A heat pump device that includes at least a compressor, a four-way valve, an indoor heat exchanger, a pressure reducing device, and an outdoor heat exchanger, and performs heating and cooling by reversing the flow direction of refrigerant using the four-way valve, The indoor heat exchanger is composed of a plurality of units, and during cooling, the refrigerant is distributed and passed through the plurality of indoor heat exchangers in parallel, and during heating, the refrigerant is passed through the plurality of indoor heat exchangers in series. Features of heat pump equipment. (2) The outdoor heat exchanger includes a first outdoor heat exchanger that liquefies the gas refrigerant by heat exchange with outside air during cooling, and a first outdoor heat exchanger that liquefies the gas refrigerant by exchanging heat with the engine cooling water during heating. 2. The heat pump device according to claim 1, further comprising a second outdoor heat exchanger.