JPH049552A - Freezer device - Google Patents

Abstract

PURPOSE:To get a stable operating condition even if a length of an interdevice pipe and a room temperature condition or the like are varied by a method wherein a refrigerant discharging temperature of a compressor and a refrigerant temperature of a condenser are detected and a degree of opening of a valve of a pressure reducing device is controlled so as to accommodate its temperature difference within a predetermined range. CONSTITUTION:A refrigerant discharging temperature is sensed by a temperature sensor 9 of a discharging pipe of a compressor 1 and a refrigerant temperature is detected by a temperature sensor 7 of an outdoor heat exchanger (a condenser) 3, respectively, and concurrently, there are temperature sensors 11 and 10 at suction sides of an indoor device and an outdoor device so as to detect a room temperature and a surrounding air temperature. In this system, a refrigerant discharging temperature of the compressor 1 is defined as D, and a difference between condensing temperatures C1 and C2 detected by temperature sensors 7 and 8 placed at an intermediate part of the condenser 3 is defined as a discharging over- heating degree DSH. That is, during cooling operation, a relation of DSH = D - C2 is attained and during a heating operation, a relation of DSH = D - C2 is attained. In this case, a range of a target DSH is defined in advance and if DSH at the present time is higher than the target DSH, a specified amount of an electrical expansion valve 4 is opened and in turn if the former is lower than the latter, the expansion valve 4 is closed.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a refrigeration system using a pressure reducer such as an electric fat expansion valve whose opening degree can be adjusted.

<Prior art> In an air conditioner having a conventionally used electric fat expansion valve, when controlling the valve, the temperature of each part on the refrigerant circuit is controlled, for example, in Japanese Patent Publication No. 1-36026, the discharge of the compressor is It was common practice to detect temperature with a sensor and control based on that information.

<Problem to be solved by the invention> That is, conventionally, this type of air conditioner has detected the degree of supercooling in the condenser, the degree of superheating in the evaporator, the discharge temperature, etc., and controlled the electric valve by MI. The control system allows stable operation within certain conditions, but often causes hunting outside of those conditions.

For example, if the length of the inter-unit piping connecting the indoor unit and outdoor unit of a separate air conditioner changes, or if there are changes in indoor/outdoor temperature conditions, refrigerant charge, etc.
There was a defect that made it easy to hunt.

In view of the above-mentioned circumstances, it is an object of the present invention to provide a refrigeration system that solves the above-mentioned problems by disposing a temperature sensor between the discharge side of the compressor and the condenser.

<Means for Solving the Problems> The present invention provides an air conditioner that employs a pressure reducer capable of adjusting the opening degree of a valve such as an electric expansion valve. The temperature difference is detected and the valve opening of the pressure reducer is controlled to keep the temperature difference within a predetermined range.

As described in 1., the valve opening of the pressure reducer is controlled to keep the difference between the refrigerant discharge temperature of the compressor and the refrigerant temperature of the condenser within a predetermined range. Even if conditions such as the length of the piping change, stable operation is possible without hunting.

<Example of Real Square Color> Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Figure 1 shows the refrigerant circuit of an air conditioner, and 1 indicates the outdoor unit AO! 1 compressor, a four-way valve 2 is connected to the discharge pipe of the compressor 1, an outdoor heat exchanger 3 serving as a condenser is connected to one side of the west valve 2, and its tip is connected to an indoor unit.
An electric expansion valve 4 (a pressure reducer whose valve opening degree can be adjusted) on the nod B side and an indoor heat exchanger 5 serving as an evaporator are sequentially connected, and
A refrigerant circuit is formed in which the tip of the indoor heat exchanger 5 returns to the compressor via the accumulator 6 via the other side of the four-way valve 2, and a temperature sensor 7 is attached to the outdoor heat exchanger 3. A temperature sensor 8 is attached to the compressed film, and a temperature sensor 9 is attached to the discharge pipe of the compressed film.
Overall, it is an air conditioner that uses an electric expansion valve. 10 is an outdoor temperature sensor, and 11 is an indoor temperature sensor. 12
is the inter-unit piping that connects the outdoor unit A and the indoor unit B, and the length of this piping changes depending on the installation location of both units.9 To explain this effect, for example, during cooling, The high-pressure refrigerant compressed by the compressor 1 is guided through the four-way valve 2 to the outdoor heat exchanger 2 and condensed, and then the refrigerant is evaporated in the indoor heat exchanger, and the room is cooled by the heat exchange. During heating, the refrigerant flows in the opposite direction to the above.

In this case (during cooling and heating), the temperature sensor of the discharge pipe of the compressor 1 detects the temperature of the refrigerant discharged from the compression R1, and the temperature sensor 7 of the outdoor heat exchanger (condenser) 3 detects the temperature of the refrigerant discharged from the condenser. In addition to detecting the respective temperatures, there are also temperature sensors 11 and 10 on the suction sides of the indoor and outdoor units to detect the room temperature and outside temperature.

Here, let the refrigerant discharge temperature of the compressor 1 be D, and the difference between the condensation temperatures C1 and C2 detected by the temperature sensor 78 provided in the middle part of the condenser 3 is the discharge superheat degree L") S H. That is, cooling Time DSH=D(L, heating #DS)l=D-
C2 is 9. Here, determine the range of 1,000 target D S l- (current l) S H or if it is higher than the target DSH, open the electric expansion valve 4 by the specified amount 1 On the contrary, if it is lower, it is There is something to dig into. The regulation V at this time may be a constant value or may be a proportional value of the difference from the standard value. 13 is the controller 7. The refrigerant discharge temperature of the discharge superheat degree (compressor) and the condenser 3.5 A controller that adjusts the opening degree of the electric expansion valve/1 according to the degree of discharge superheat is housed therein.

For example, an example of how to determine this target D S )-4 is shown in FIGS. 2 to 4.

Figures 2 and 3 [4 are the cases where outside temperature and indoor temperature or outside temperature and set temperature are used as parameters, and Figures 1 and 3 show the case where the target D
This is an example in which S H is set to −・constant.

FIG. 5 shows the operation of the present invention) v7-Nayat.

Read the take with each temperature sensor at the start.

Cooling 7 At the start of heating operation, each temperature is detected and the discharge superheat degree D S H = D C + , D S H = r, )
It compares whether C2 is within the target range or not, and controls the opening and opening of the electric expansion valve depending on the temperature.

-<Effects of the Invention> As described above, the refrigeration system of the present invention detects the refrigerant discharge temperature of the compressor and the refrigerant temperature of the condenser, and controls the valve opening of the pressure reducer according to the difference to control the degree of discharge superheat. Since it is maintained at a predetermined value, a stable operating state can be obtained even if the length of the piping between units, the outside air, the room temperature conditions, etc. change.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention. Fig. 1 is a refrigerant circuit diagram of an air conditioner, Fig. 2 is a set temperature diagram showing the relationship between discharge superheat degree and outside air temperature during cooling, and Fig. 3 is a heating FIG. 4 is a target range diagram of the relationship between the discharge superheat degree and the condensing temperature, and FIG. 5 is a flowchart of the same operation. 1... Compressor, 3... Outdoor heat exchanger, 4... Electric l
l! Expansion valve, 5...Indoor heat exchanger, 13...M control device.

Claims (1)

[Claims] 1. In a refrigeration system in which a compressor, a condenser, a pressure reducer whose valve opening degree can be adjusted, and an evaporator are sequentially connected by a refrigerant pipe, the difference between the refrigerant discharge temperature of the compressor and the refrigerant temperature of the condenser is determined. A refrigeration system comprising: a detection means for detecting a detection; and a controller for adjusting a valve opening of the pressure reducer based on a signal from the detection means.