JPS60263066A - 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 Field of Industrial Application The present invention relates to an improvement of a heat pump device such as an air-conditioning device.
In particular, the present invention relates to a refrigerant circulation amount control configuration of a refrigeration cycle using a non-azeotropic mixed refrigerant with emphasis on performance during heating operation.

Conventional configurations and their problems In conventional air-conditioning systems, there is a method called a gas injection method to improve performance during heating operation.In this method, a gas-liquid separator placed at an intermediate pressure with a condenser volume of 1 is used. By directly injecting the gas refrigerant separated into the compressor cylinder, the amount of refrigerant circulation is increased and the heating performance is improved. However, with this method, the intermediate pressure must be set high in order to increase the amount of refrigerant injected, but conversely, if the intermediate pressure is set too high, the amount of gas refrigerant generated at the intermediate pressure will decrease. There were limits to what could be achieved. Recently, as another method for improving heating performance, a non-azeotropic refrigerant mixture is used, in which a main component refrigerant such as R22 is filled with a subcomponent refrigerant such as R13B1 having a lower boiling point, to reduce the compressor suction specific volume. Proposals have also been made to increase the amount of refrigerant circulated. However, no concrete proposal has been found regarding a refrigerant circulation amount control configuration for a method that combines these methods.In a method that simply uses a thermostatic expansion valve, the refrigerant in the expansion valve temperature-sensitive cylinder and the refrigeration cycle are Because the pressure characteristics of the non-azeotropic mixed refrigerants inside were different, sufficient control was not possible.

Purpose of the Invention The present invention was invented in view of the above-mentioned conventional problems.
The refrigerant circulation amount control using a non-azeotropic mixed refrigerant is made possible by utilizing the temperature characteristics of the non-azeotropic mixed refrigerant, and the configuration is particularly suitable for gas injection systems that aim to improve heating performance. This is a proposal.

Structure of the Invention The heat pump device according to the present invention is a refrigeration cycle using a non-azeotropic mixed refrigerant. A second temperature sensor is installed between the outlet and just before the intake of the compressor, and an expansion valve is installed that is controlled by the temperature difference between the two temperature sensors.In particular, in the gas injection method, an intermediate pressure gas-liquid separator is installed. The expansion valve is arranged on the upstream side of the valve.

DESCRIPTION OF EMBODIMENTS An embodiment of a heat pump device according to the present invention will be described with reference to FIG. 1, in which it is applied to an air-conditioning device. In Figure 1, 1
is a compressor, 2 is a four-way valve, 3 is an indoor heat exchanger that functions as a condenser during heating, 4 is an outdoor heat exchanger that functions as an evaporator during heating, 5.6 is a check valve, 7 is a capillary tube,
8 is! This is a liquid A separator, and the top of the gas-liquid separator 8 is connected to an injection circuit 10 that directly injects the gas refrigerant to be separated into the cylinder of the compressor 1 via a solenoid valve 9. Reference numeral 11 is a reversible expansion valve installed at the upstream side of the gas-liquid separator 8 during heating, and 12 is a reversible expansion valve located upstream of the gas-liquid separator 8 during heating. A first temperature sensor 13 is provided between the outlet of the outdoor heat exchanger 4, which also functions as an evaporator during heating, and a second temperature sensor provided immediately before the intake of the compressor 1. R13B1 in the refrigeration cycle where the components are connected
A non-azeotropic mixed refrigerant such as /R22 is enclosed.

Now, the mode of operation of such a heat pump device will be explained with reference to FIG. 2, especially during heating operation. In Figure 2,
A is the theoretical temperature distribution in the evaporator when there is no pressure loss in the evaporator and the gas flows out as a saturated gas at the outlet, and in the case of a non-azeotropic refrigerant mixture, the temperature increases as the evaporation process progresses. However, in an actual heat pump device as shown in Fig. 1, pressure loss occurs in the evaporator, so when the amount of refrigerant circulation is small, the temperature rise rate is smaller than A, as shown in B, and at the evaporator outlet. It has the characteristics of a large degree of superheating. In addition, when the amount of refrigerant circulation is large, C
On the contrary, since the temperature reduction effect due to pressure loss is large, the temperature decreases as evaporation progresses, and the degree of superheating is extremely low or almost impossible. Also, the average pressure during these evaporation processes is higher in a mixed refrigerant such as R13R17R22 than in a single R22 refrigerant.

Therefore, as in the configuration of the present invention, the first temperature sensor 12 is provided between the inlet and the outlet of the outdoor heat exchanger 4 which functions as an evaporator during heating, and the second temperature sensor 13 is provided between the inlet and the outlet of the outdoor heat exchanger 4 which functions as an evaporator during heating. The compressor 1 is connected to the outlet of the outdoor heat exchanger 4 which functions as a heat exchanger.
Since the sensor is installed before the intake of refrigerant, it detects a temperature difference that is larger than the actual degree of superheating when the amount of refrigerant circulation is small, and detects a temperature difference that is smaller than the actual degree of superheating when the amount of refrigerant circulation is large. It will be detected. Therefore, the refrigerant circulation amount control of the expansion valve 11 can provide a faster response than simple superheat degree control. Furthermore, these effects can be achieved by using the present invention because when a conventional temperature/pressure expansion valve (not shown) is used, the vapor pressure in the evaporator and the refrigerant pressure in the temperature-sensitive tube (not shown) are different. It is not possible to control the amount of refrigerant circulation as finely as possible.

Furthermore, when applying the main configuration of the present invention to a gas injection type air-conditioning system as shown in FIG.
Since the liquid density of is larger than that of R22 single refrigerant,
It is effective to throttle and control the supercooled liquid at the outlet of the indoor heat exchanger 3, which functions as a condenser, and it is preferable that the expansion valve 11 be placed upstream of the gas-liquid separator 8.

Although the mode of operation during cooling operation was not specifically explained in the explanation of this embodiment, the expansion valve 11 is of a reversible type, and a bypass port (not shown) is provided inside the expansion valve 11. In particular, when using a mixed refrigerant, the suitable throttle opening is much smaller during cooling operation than during heating operation, so by configuring the diameter of the bypass port to suit cooling operation, can also be adequately addressed.

Effects of the Invention The heat pump device according to the present invention specifically proposes a refrigerant circulation rate control configuration for a refrigeration cycle using a non-azeotropic mixed refrigerant, which has not been seen before. Allows for fine-grained control that cannot be achieved with expansion valves.

■ Fast control response.

(2) In a gas injection heating and cooling system, it is particularly suitable for non-azeotropic mixed refrigerants to place an expansion valve upstream of the gas-liquid separator.

It has the following effects.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment in which a heat pump device according to the present invention is applied as an air-conditioning device, and FIG. 2 is a diagram particularly illustrating the mode of operation during heating operation in FIG. 1. , 1...Compressor, 3...Indoor heat exchanger (condenser), 4...Outdoor heat exchanger (evaporator), 8...
・Gas-liquid separator, 1o...injection circuit, 11
...Expansion valve, 12.13...Temperature detector.

Claims (1)

[Claims] A non-azeotropic mixed refrigerant is sealed in a refrigeration cycle in which a compressor, a condenser, an expansion valve, an evaporator, etc. are connected, and a first temperature detector detects when the evaporator is open from the inlet to the outlet; A heat pump device is provided with a second temperature detector that detects the temperature between the chamber outlet and just before suction into the compressor, and the expansion valve controls the refrigerant circulation amount based on the temperature difference between the two temperature detectors.