JPH01121650A - Injection control device for air conditioner - Google Patents

Abstract

PURPOSE:To provide a comfortable air conditioning and save energy by a method wherein an indoor load condition is detected in response to a condition of outside air temperature and a ratio between an operating time of a compressor and an operating elapse time and then an injection controlling solenoid valve is opened or closed. CONSTITUTION:When a heating operation is started, an outside air temperature is detected for every specified time by a sensor 8 and a value less than a predetermined temperature is discriminated by a comparing means 10, a solenoid valve 7 is opened through an opening or closing means 14 and if it is more than a predetermined temperature, the valve is closed. A time ratio comparing means 13 may discriminate from signals from a compressor operating time sensing means 11 and an operation elapse time sensing means 12 that it requires a heating capability if a time ratio is more than a predetermined value, a solenoid valve 7 is opened. If it is less than a predetermined value, it is judged that a heating capability is not required and the solenoid valve 7 is closed to perform a heating operation. In this way, it is possible to control a capability in correspondence with a load condition at an indoor area which is an object of its normal injection control, save energy and improve a comfortable feeling.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an injection control device for air and cold pump type air conditioners.

Conventional technology.

Conventionally, in air-cooled heat pump type air conditioners.

Injection control is used as a means of controlling compressor capacity.There is a strong market demand for capacity improvement, especially during heating operation, and in response to this, injection control is often used during heating operation.The method is described below. This will be explained with reference to the drawings.

FIG. 3 is a refrigeration system diagram of an air conditioner using an injection-controlled compressor.

In FIG. 3, 1 is a compressor, 2 is a four-way valve, 3 is an indoor heat exchanger, 4 is a pressure reducer, and 6 is an outdoor heat exchanger, which are connected in sequence to form a refrigeration cycle. Also, compressor 1
is equipped with an injection pipe 6 and a solenoid valve 7 for opening and closing communication therebetween. Reference numeral 8 denotes an outside temperature detector that detects the outside temperature outside the room, and the temperature signal detected by this is converted into an electric signal and inputted to the control device 9. This control device 9 includes an injection control setting means 1o that inputs the output from the outside temperature detector 8, and outputs a signal for controlling the injection when the temperature falls below a predetermined set temperature during heating operation. 1
The electromagnetic valve opening/closing means 11 receives the output of the electromagnetic valve 7 and opens and closes the electromagnetic valve 7.

In the refrigeration cycle device having such a configuration, the refrigerant discharged from the compressor 1 is switched by the four-way valve 2 as shown in FIG. 3, as shown in solid lines during cooling operation and as shown in broken lines during heating operation. These operations will be explained below. When the heating operation is started, the outside temperature detected by the outside temperature detector 8 is input to the injection control setting means 10, and compared with the value set from the beginning, and if the outside temperature becomes less than the set value. , outputs a signal for implementing injection control to the electromagnetic valve opening/closing means 11. This output signal causes the solenoid valve opening/closing means 11 to
In order to connect the injection pipe 6, the solenoid valve 7
Outputs a signal to open. This allows the injection to operate when the outside temperature is low, improving heating capacity.

The solenoid valve 7 is closed when there is no output from the injection control setting means 10.

Problems to be Solved by the Invention However, with the above configuration, injection control is performed during heating operation only when the outdoor temperature falls below a certain value, so the heating load on the indoor side is does not take into account changes in In other words, even if the indoor and outdoor temperatures are the same at the start of heating operation, as heating operation continues, the heating load on the indoor side becomes lighter, and the need for injection control disappears, but as the outdoor temperature increases Since the injection control cannot be canceled until the temperature rises, the thermostat starts and stops the compressor more frequently to heat the room with high heating capacity, making it difficult to stabilize the indoor temperature and making it difficult to maintain comfortable air conditioning. In addition to heating the room with unnecessary heating capacity,
This has the disadvantage of consuming unnecessary power. In addition, in order to send the indoor load conditions to the outdoors, the indoor temperature status is performed by data transmission, etc., so indoor and outdoor control must be electronically controlled by a microcomputer, which also has the disadvantage of increasing the cost of the control device. Contains.

In view of the above-mentioned problems, the present invention detects the load conditions on the indoor side using a control device on the outdoor side, thereby making it possible to perform injection control based on a combination of the outdoor temperature conditions and the indoor load conditions. It provides an inexpensive injection control device that enables air conditioning and energy saving, and does not require expensive electronic control such as data transmission.

Means for Solving the Problems In order to solve the above problems, the injection control device of the present invention includes an outside temperature detection means for detecting outside temperature, a temperature comparison means for comparing this with a predetermined set value, and a compression a compressor operation time detection means for detecting machine operation; an operation elapsed time detection time for detecting elapsed time from the start of heating operation; and a time detected by the compressor operation time detection means and a time detected by the operation elapsed time detection means. the temperature comparison means and the time ratio comparison means, and a solenoid valve opening/closing means for controlling the injection by calculating respective output signals of the temperature comparison means and the time ratio comparison means. It is something.

Effect of the Invention With the above-described configuration, the present invention detects the indoor load condition based on the outside temperature condition and the ratio of the compressor operating time to the elapsed operating time in injection control during heating operation, and controls the solenoid valve for injection control. Since the heating capacity is opened and closed, it is possible to judge the indoor load outside the room without receiving indoor load information from the indoor control unit, and to control the heating capacity by injection control according to the indoor load conditions.

Embodiment An embodiment of the present invention will be described with reference to the drawings. 1st
In the figure, the same parts as in FIG. 3 are denoted by the same reference numerals, and detailed explanation will be omitted. Reference numeral 8 denotes an outside temperature detection means for detecting the outside temperature outside the room, and the detected temperature signal is converted into an electrical signal and inputted to the control device 9. The control device 9 inputs the output from the outside temperature detection means 8,
a temperature comparison means 10 for comparing the input with a set value; a compressor operation time detection means 11 for detecting the operation time of the compressor; an elapsed operation time detection means 12 for detecting the operation time during heating operation; time ratio comparison means 13 for inputting the respective outputs of the operation time detection means 11 and the operation elapsed time detection means 12, calculating the ratio of the compressor operation time, and comparing it with a predetermined value set; and the temperature comparison means. 10 and a solenoid valve opening/closing means 14 for inputting the respective outputs of the time ratio comparing means 13 and determining whether to open or close the solenoid valve 7.

In the refrigeration cycle device having such a configuration, the second
The operation will be explained based on the flowchart shown in the figure.

When heating operation is started, the outside air temperature is detected at regular intervals in step 21, and if the outside air temperature detected in step 22 is lower than a predetermined set temperature, step 23 is performed.
Open the solenoid valve 7.

If the outside temperature is above a predetermined set value, the solenoid valve is closed in step 24. In step 26, the heating operation time t is integrated, and in step 26, the compressor operating time t' is integrated, and the ratio of t'/l is calculated at fixed time intervals, and in step 27, t'/l is If it is above the set value, it is assumed that heating capacity is required, and the solenoid valve 7 is opened in step 28.

If t'/t is less than the set value, it is assumed that the heating capacity is unnecessary, and in step 29, the solenoid valve 7 is closed and the flow returns to the heating operation.

As described above, according to this embodiment, it is possible to detect the indoor load condition outside the room by calculating the ratio t'/l between the detection of the outside temperature condition and the operating time of the compressor 1. Therefore, heating capacity control can be performed in accordance with indoor and outdoor temperature conditions without providing expensive control functions such as indoor load condition data transmission, and more comfortable air conditioning can be achieved.

Effects of the Invention As described above, the present invention detects the outside temperature and determines its conditions.
The operation ratio of the compressor is calculated by the elapsed operation time detection means and the compressor operation time detection means and compared with a predetermined set value.The time ratio comparison means opens and closes the injection control solenoid valve by detecting the indoor load condition. By providing a solenoid valve opening/closing means, at the start of heating operation, if the outside temperature is low and high heating capacity is required, the solenoid valve for injection control is opened to supply the necessary capacity to indoor equipment while indoor For example, if the compressor operating time is long and the ratio is more than half of the heating operating time, it can be determined that the indoor load is high, and injection control is performed. If the operating time ratio of the compressor shows a small value, it can be determined that the indoor load is light no matter how low the outdoor temperature is, so the injection control is stopped. Like returning to normal power.

It is possible to control the indoor load conditions directly from indoors without using an expensive electronic control device that uses data transmission, etc., and it is possible to reduce the cost by using only the outdoor control device, and also to control the indoor load conditions, which is the original purpose of injection control. Since it is possible to control the capacity according to the heating capacity, it is extremely effective in practical terms, as it does not lead to wasted power consumption, and improves comfort through energy saving and high heating capacity.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an injection control device showing an embodiment of the present invention, FIG. 2 is a flowchart showing an example of injection control, and FIG. 3 is a block diagram of conventional injection control. 8...External temperature detection means, 10...Temperature comparison means. 11... Compressor operating time detection means, 12...
. . . Operation elapsed time detection means, 13 . . . Time ratio comparison means. 14...Solenoid valve opening/closing means. Name of agent: Patent attorney Toshio Nakao and 1 other person1;
l 13 Figure 2

Claims (1)

[Claims] an outside temperature detection means for detecting the outside temperature; a compressor operation time detection means for detecting the operation time of the compressor; an elapsed operation time detection means for detecting the elapsed time from the start of heating operation of the air conditioner; time ratio comparison means for comparing the ratio of the time detected by the machine operation time detection means and the time detected by the elapsed operation time detection means with a set value, and the temperature detected by the outside temperature detection means and the set value; 1. An injection control device for an air conditioner, comprising: a temperature comparison means for comparing the temperature, and a solenoid valve opening/closing means for controlling injection based on output signals from each of the time ratio comparison means and the temperature comparison means.