JPH02103329A - Multi chamber type air conditioner - Google Patents

Abstract

PURPOSE:To prevent useless defrosting and obtain a stabilized defrosting cycle by ending defrosting operation by way of an output signal transmitted from a control device when a condensation temperature of refrigerant is higher than an arbitrary set value during defrosting operation or when a high pressure of refrigerant is higher than an arbitrary set value. CONSTITUTION:At the same time when defrosting operation starts, a condensation temperature of refrigerant is detected by a detector 12 and comparison is made with a preset value. Then, a high pressure on the discharge side of a compressor 1 is detected by 13, and comparison is made with a preset value. When the condensation temperature or the high pressure exceeds the preset value, a control device 14 is arranged to output a defrosting end signal so that an air conditioner may end defrosting operation and return to heating operation. This control makes it possible to end defrosting, thus preventing any potential action of a high pressure breaker designed to protect the compressor induced by a dramatic temperature rise during defrosting operation, and provide a normal and a steady defrosting cycle.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a multi-chamber air conditioner, and particularly to control of condensing temperature and high pressure during defrosting operation.

[Conventional technology]

As an example of an air conditioner, there is one described in Japanese Patent Laid-Open No. 114670/1983. This air conditioner outputs a defrosting signal from the υ control device based on the detection signal of the outside temperature sensor, and at the same time sends a pulse signal to the drive circuit of the electric expansion valve to control the opening degree of the electric expansion valve. The compressor is configured to operate at maximum frequency when the expansion valve is fully open. In an air conditioner with this configuration, by fully opening the electric expansion valve after starting defrosting operation, high-temperature, high-pressure refrigerant can be quickly flowed into the outdoor heat exchanger, increasing the defrosting speed and increasing the defrosting time. It was also supposed to be shorter.

[Problem to be solved by the invention]

In the above conventional technology, even if the box does not adhere to the O-fin of the outdoor heat exchanger, if the initial opening of the electric expansion valve is set large, that is, fully opened, the refrigerant circulation area becomes large and the temperature rises rapidly. There is a problem that the high pressure chain force switch for protecting the compressor is activated due to the rise in high pressure, causing the air conditioner to stop abnormally and become inoperable.

The purpose of the present invention is to use simple control to detect a high pressure rise during defrosting, especially when there is not much frost on the heat exchanger, and to terminate the defrosting operation before it is stopped by the protection device. To provide an air conditioner that can return to heating operation.

[Means to solve the problem]

The above purpose is to detect temperature and pressure using a detector that detects the condensation temperature of the refrigerant after the defrosting operation and a detector that detects the high pressure on the discharge side of the compressor, and input them in advance during the defrosting operation. a control device that is determined according to a program that is set, and when the condensation temperature of the refrigerant is higher than an arbitrary set value during defrosting operation, or when the high pressure of the refrigerant is higher than an arbitrary set value, the control device Remove ff1l through the output signal
This is achieved by terminating the operation.

[Effect]

During defrosting operation, the control device takes in data on the condensation temperature of the refrigerant from the temperature sensor, compares it with the preset temperature, and if the temperature is higher than the set temperature, the control device issues an output signal indicating the end of defrosting and defrosts. terminate. Similarly, data on the high pressure of the refrigerant is taken in from the pressure sensor on the compressor discharge side, and compared with a preset pressure value. If the pressure is higher than the set pressure value, the control device outputs an output signal to indicate the end of defrosting. Finish defrosting. As a result, even if the fins of the unexpected heat exchanger are frost-covered and do not adhere to the 4-hour operation and the high pressure increases with a sudden temperature rise, the high-pressure switch for protecting the compressor will not operate. Since the removal of xl can be completed, normal operation can be continued.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

As shown in Fig. 1, this air conditioner has nine configurations, with four outdoor units connected to one unexpected unit.Outdoor unit A has a compressor 1, a four-way valve z1, A neemulator 8, an unexpected heat exchanger 4, and a receiver 5 provided in the refrigerant liquid side main pipe 6 are provided. In addition, four liquid side branch pipes 10a @ 10b branched from the refrigerant liquid side main pipe 6.
Forward and reverse flow electric expansion valves 9 for llOC and lOd, respectively.
a*9b+9'e9d is provided. And indoor heat exchangers 8) B, C, D, and B each have their own indoor heat exchanger 8.
ae8b*8c+8d is provided, and each device in outdoor unit A and indoor unit) B, C.

A heat pump type refrigeration cycle is constructed by connecting each device in D and E with piping as shown. In addition, the unexpected unit includes a detector 12 that detects the refrigerant condensation temperature in a condensing pipe led from the refrigerant discharge pipe, a detector 18 that detects high pressure during defrosting operation, and a detector 18 that is connected to the detector and detects the detected contents. A control device 14 is provided which performs processing according to a program input in advance and outputs the processed values.

Figure 2 shows the relationship between the defrosting operation and high pressure of the conventional refrigeration cycle, Figure 8 shows the relationship between the defrosting operation of the present invention, the condensation temperature of the refrigerant, and the high pressure, and Figure 4 shows the relationship between the defrosting operation of the conventional refrigeration cycle and the high pressure. Flow of control during operation: FIG. 5 shows the flow of control during defrosting operation according to the present invention.

Next, the four-quarter operation will be explained based on the time chart of FIG. 8 and the control flow of FIG. 5.

At the same time as the removal J1 starts, the condensing temperature of the refrigerant is detected by the detector 12 (Step 19 in Fig. 5), and compared with a preset value, and if it is below the set value, then the high pressure on the discharge side of the compressor is detected by the detector. 18, step 20) in FIG.
Compare with the preset value, and if it is below the set value, then compare the operating value of the high pressure protection device and the high pressure value. Step 15 in Figure 5) If it is below the set value, then defrost time. (time chart C to d in Figure 8) is detected, and the set value T
If it is below the set value, then compare the temperature of the outdoor heat exchanger 4 with the set value (step 17 in Figure 5), and if it is below the set value, return to step 19 and return υ without the same operation. , in the judgment state of step 19 or 20 in FIG.
If the condensing temperature or high pressure is equal to or higher than the set value, the control device 14 outputs an output signal indicating the end of defrosting, and the air conditioner ends the defrosting operation and returns to heating operation. The time chart in Fig. 8 illustrates the movement of the condensing temperature f by 1g1l and the high pressure switch at this time, and shows the pressure switch set value e for finishing the removal of 4 in Fig. 3 or the condensing temperature setting for finishing the removal. When the value gVc is reached, defrosting ends and heating operation returns.

With the above-described control, the removal cycle is completed without operating the high-pressure switch for protecting the pressurizer due to the rapid temperature rise and pressure rise during defrosting, and a normal and stable removal cycle is obtained.

[Effect of Gyomei]

According to the present invention, even if defrosting is started with little frost or ice adhering to the outdoor heat exchanger, the condition can be determined from the condensation temperature or high pressure of the refrigerant. Defrosting can be completed without operating the defrosting system, which has the effect of preventing wasteful defrosting and providing a stable defrosting cycle.

[Brief explanation of drawings]

Fig. 1 is a refrigeration cycle system diagram showing an embodiment of the multi-chamber air conditioner of the present invention, Fig. 2 is a diagram showing the relationship between defrosting operation and high pressure of a conventional refrigeration cycle, and Fig. 8 is a diagram showing the relationship between defrosting operation and high pressure of a conventional refrigeration cycle. FIG. 4 is a flowchart of the control in the conventional defrosting operation, and FIG. 5 is a flowchart of the control in the defrosting operation according to the present invention. l...pressure m machine 2...four-way valve 4...outdoor heat exchanger sa *8b t8c *8d・m internal heat exchanger 9a, 9b @ 9C, 9d...electric expansion valve
12... Condensation temperature detection 6 18... Pressure detector 14... Control device 15-20... Contents of control processing in the present invention. Tomi 1 Zuka 2 Zuho 3 Zukan 5 Zu

Claims (1)

[Claims] Equipped with one outdoor unit consisting of a frequency-controllable compressor, an outdoor heat exchanger, a four-way valve, etc., and multiple indoor units consisting of indoor heat exchangers, etc. via respective connection piping. Continuously detects condensing temperature and high pressure after defrosting operation starts in a multi-chamber air conditioner with a heat pump refrigeration cycle, in which multiple liquid side branch pipes branched from the main liquid side pipe are each equipped with an electric expansion valve. A multi-room air conditioner characterized in that the rapid increase in the condensation temperature or high pressure of the refrigerant is compared with a preset value, and when the temperature exceeds the set value, the defrosting operation is terminated.