JPH0345859A - Cooling/heating device - Google Patents

Abstract

PURPOSE:To prevent decomposition of a refrigerant during heating operation and to prevent lowering of lubricating performance of the drive part of a compressor by providing a heater to heat a compressor, a compressor temperature detecting means to detect the temperatures of the compressor, and a control mechanism to start the compressor when the temperature of the compressor exceeds a set value during the starting of heating after installation. CONSTITUTION:A compressor 3 is provided with a heater 11 to heat a compressor, a temperature detecting means 13 to detect the temperature of the compressor, and a control means 14 to start the compressor and enter pump down operation when it is detected by a temperature detecting means that the temperature of the compressor exceeds a set value are provided. During the starting of heating, a refrigerant residing in the compressor is discharged, and an amount of compressor oil taken out resulting from pump down operation is reduced. Decomposition of a refrigerant and lowering of lubricating performance of the drive part of the compressor due to the local increase of the temperature of a refrigerant heater 7 because of oil can be prevented, and heat stability of a refrigerant and reliability of the compressor can be ensured. An input from a heater to heat the compressor is reduced in a way that, during the starting of heating, the compressor is driven by means of a difference between the temperature of a refrigerant heater 7 and that of the compressor 3 and pump down operation is entered.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to an apparatus for heating and cooling by connecting indoor and outdoor units with refrigerant piping, in particular, heating the refrigerant with a burner or the like and transferring the heat to the indoor unit for heating. Cold Il! It is used for purchasing bouquets.

BACKGROUND OF THE INVENTION Conventionally, as shown in FIG. 5, this type of air conditioning system closes the first solenoid valve 1 and controls the four-way valve 2 to direct the refrigerant gas discharged from the compressor 3 to the indoor heat exchanger 4 at the start of heating operation. The compressor 3 is switched to the outdoor heat exchanger 5. The refrigerant accumulated in the accumulator 6 is pumped down to the indoor heat exchanger 4. After feeding the refrigerant to the refrigerant heater 7 and securing the refrigerant, the compressor 3 is stopped, the refrigerant pump 8 is operated, the refrigerant heater 7 is heated by the burner 9, and the indoor heat exchange fan 10 is started to operate, thereby increasing the indoor heat. The compressor 3, which performs heating by using the exchanger 4 as a condenser, is heated by a compressor heater 11 to maintain a constant temperature and prevent refrigerant from stagnation. During cooling operation, the outdoor heat exchanger 5 is used as a condenser, the indoor heat exchanger 4 is used as an evaporator, the compressor 3 is driven, and the throttle mechanism 12 is used.
Perform the well-known cooling operation (Japanese Patent Application Laid-Open No. 57-101263)
However, in the above-described configuration, when the heating and cooling device is installed and starts heating operation in a short time, the compressor 3 is not sufficiently heated by the compressor heater 11. As the compressor is driven and enters pump-down operation, the refrigerant dissolved in the oil in the compressor 3 rapidly evaporates and is taken out to the indoor heat exchanger 4° refrigerant heater 7 together with the oil. The lubrication performance of the 3 drive parts will deteriorate, causing the compressor 3 to malfunction. Also, if a large amount of oil enters the refrigerant heater 7,
The refrigerant temperature distribution within the refrigerant heater 7 becomes non-uniform, the refrigerant temperature locally increases, and the thermal stability of the refrigerant decreases, which impairs the reliability of the entire device.

The present invention solves these problems and aims to ensure the reliability of the entire device.

Means for Solving the Problems In order to solve the above problems, the air conditioning system of the present invention provides the compressor with a compressor heater and a compressor temperature detection means for detecting the temperature of the compressor. A control mechanism is provided for starting the compressor if the temperature of the compressor is higher than a set temperature by means of temperature detection means.

According to the above-mentioned structure, the present invention uses the compressor heater to maintain the temperature of the compressor without driving the compressor until the temperature of the compressor reaches the set value even if the heating operation starts immediately after installing the air conditioning system. The refrigerant accumulated in the compressor is evaporated by raising the
It is sent to the indoor heat exchanger based on the temperature difference. When the temperature of the compressor rises above the set value, the compressor heater is stopped and the compressor is driven to enter pump down operation. This reduces the amount of compressor oil taken out during pump-down operation, eliminates refrigerant decomposition due to local temperature rise in the refrigerant heater due to oil during heating operation, and eliminates deterioration in lubrication performance of the compressor drive part, improving the thermal stability of the refrigerant. and improves compressor reliability.

Embodiment Hereinafter, one embodiment of the present invention will be described based on the accompanying drawings. Note that the same reference numerals as in FIG. 5 indicate the same members and have the same functions, so a detailed explanation will be omitted and the explanation will focus on the differences.

From FIG. 1, 13 is a temperature sensor installed at the bottom of the compressor 3, and depending on the temperature of the temperature sensor 13, 14 is the first magnetic valve 1.
．． Compressor 3. This is a control mechanism that controls the compressor heater 11. Further, 15 is a second solenoid valve that is opened when heating operation starts, and 16 is a third solenoid valve that is opened when heating operation is started.

Next, the operation of the configuration of this embodiment will be explained based on the control flow shown in FIG.

When heating operation is started after installation of the device, the compressor heater 11 is turned on by the control mechanism 14 to raise the temperature of the compressor 3, evaporate the refrigerant staying in the compression IIIa, and cool the refrigerant through the check valve 17. , discharged to the indoor heat exchanger 4 side.

At the same time, the temperature of the compressor 3 is detected by the temperature detector 13, and it is determined whether the temperature has reached the set temperature. If the temperature has not been reached, continue monitoring the temperature. When the temperature of the compressor 3 reaches the set value, the first solenoid valve 1 is closed, the second solenoid valve 15 is opened, and the compressor heater 11 is turned off. Afterwards, the first electric valve 16 is opened, the compressor 3 is driven for a predetermined period of time, and the outdoor heat exchanger 5. The refrigerant accumulated in the accumulator 6 is pumped down to the indoor heat exchanger 4. The refrigerant is sent to the refrigerant heater 7 to secure the refrigerant. After securing the refrigerant, the compressor 3 is stopped, the refrigerant pump 8 is operated, the refrigerant heater 7 is heated by the burner 9, the refrigerant is heated and evaporated, and the evaporated refrigerant is sent to the indoor heat exchanger 4. In the indoor heat exchanger 4, the indoor air sent by the indoor heat exchange fan IO and the refrigerant exchange heat, and the refrigerant radiates heat and condenses.
Solenoid valve 16. Via the refrigerant pump 8, it enters the refrigerant heater. Heating is performed through this cycle.

As a result, even if heating operation is started immediately after installing the air conditioning system, the compressor 3 will not be driven until the temperature of the compressor 3 exceeds the set value, so oil will not be removed from the compressor 3 during pump-down operation. This eliminates decomposition of the refrigerant and deterioration of the lubricating performance of the drive section of the compressor 3 due to a local temperature rise in the refrigerant heater 7 during heating operation, and improves the thermal stability of the refrigerant and the reliability of the compressor.

Next, another embodiment will be described based on FIGS. 3 and 4.

18 is a temperature sensor provided on the surface of the refrigerant heater 7, and when the temperature difference between the temperature sensor 13 that detects the temperature of the compressor 3 and the temperature sensor 18 on the surface of the refrigerant heater 7 when heating is started is a predetermined value or more. When the temperature of the compressor 3 reaches the temperature of the refrigerant heater 7
When the temperature becomes higher than a predetermined value by a predetermined value or more, the compressor 3 is driven to perform pump-down operation. As a result, the electrical input to the compressor heater 11 when heating is started is small, and the same effects as in the previous embodiment can be obtained.

A similar effect can be obtained in an air-conditioning device or the like that performs heating operation in a short period of time using a refrigerant pressure difference without using the refrigerant pump 8.

Effects of the Invention As described above, according to the heating and cooling apparatus of the present invention, the following effects can be obtained.

(1) A compressor heater is provided in the compressor, a temperature detection means detects the temperature of the compressor, and when the heating is started, the temperature detection means starts the compressor if the temperature of the compressor is higher than the set temperature, By installing a control mechanism that enters pump-down operation, the refrigerant accumulated in the compressor is released when heating is started, and
Reduces the amount of compressor oil carried out due to pump-down operation, prevents refrigerant decomposition due to local temperature rise in the refrigerant heater due to oil, and prevents deterioration of lubrication performance of the compressor drive part, improving the thermal stability of the refrigerant and the reliability of the compressor. Can be secured.

(2) When starting heating, the pressure wIa is driven by the difference between the temperature of the refrigerant heater and the temperature of the compressor, and the input to the compressor heater is reduced by entering pump-down operation,
Moreover, the above effects can be obtained in a short time.

[Brief explanation of drawings]

FIG. 1 is a refrigerant circuit configuration diagram of an air conditioning system according to an embodiment of the present invention, FIG. 2 is a control flowchart of the same device, FIG. 3 is a refrigerant circuit configuration diagram of another embodiment of the invention, and FIG. 4 is the same example. FIG. 5 is a flowchart of an embodiment of the present invention, and FIG. 5 is a diagram showing a refrigerant circuit configuration of a conventional air-conditioning device. 2...Four-way valve, 3...Compressor, 4...
...Indoor heat exchanger, 5...Outdoor heat exchanger,
7... Refrigerant heater, 8... Refrigerant heat transfer means (refrigerant pump), 9... Bars, 11...
...Compressor heater, 13° detection means, 14...
...control mechanism.

Claims (2)

[Claims] (1) During cooling, a refrigerant circuit is composed of a compressor, four-way valve, indoor heat exchanger, outdoor heat exchanger, throttle mechanism, etc., and during heating, a refrigerant heat transfer means, refrigerant heater, burner, indoor heat exchanger, etc. A refrigerant circuit is configured with the main components, and the compressor is equipped with a compressor heater and a compressor temperature detection means for detecting the temperature of the compressor, and when the heating is started, the temperature detection means detects that the temperature of the compressor is higher than the set temperature. A heating and cooling system equipped with a control mechanism that starts the compressor. (2) A heater temperature detection means is provided to detect the temperature of the refrigerant heater, and when heating is started, the compressor is started if the temperature difference between the compressor temperature and the refrigerant heater temperature is a predetermined value or more. A heating and cooling device according to claim (1), which is provided with a mechanism.