JPH0278861A - Air conditioning device of multi-room type - Google Patents

Abstract

PURPOSE:To attempt to stabilize the operation cycle by calculating the amount of adjustment of the degree of opening in an expansion valve so as to obtain a target degree of superheating on the side of discharging to the expansion valve of an unit in operation and at the same time outputting the adjusting amount of the degree of opening which is reduced by a specified ratio to the expansion valve of an unit not in operation. CONSTITUTION:Temperature Td of the discharged gas and condensation temperature Tc are read in a control device 12 by detectors 11 and 12 everytime a specified time has elapsed. The degree of overheating SH of the coolant on the discharge side at present is calculated by the difference of temperature data. From the deviation between the degree of overheating SH of the coolant on the discharge side at present and a target degree of overheating SH' of the coolant on the discharge side the adjusting amount DELTAP of the degree of opening in an expansion valve is calculated by a PID calculation formula and it is distributed among units in an operation room by the formula as follows: DELTAP1=Q/SIGMAQiXDELTAP (Qi is a cord to represent the capability of each unit in the operation room). Further, for an unit not in operation the degree of expansion valve opening is distributed by the formula below: DELTAPj=Qj/(SIGMAQi+SIGMAQj)XDELTAP (Qj is a cord to represent the capability of each unit not in operation).

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a heat pump type multi-room air conditioner in which a plurality of indoor units are connected to one outdoor unit.
In particular, it relates to surplus refrigerant control when any indoor unit is stopped.

[Conventional technology]

As described in Japanese Patent Publication No. 61-128069, the conventional device is a multi-chamber air #quaternizer VC that is connected to each indoor unit as a surplus refrigerant control means when any indoor unit is at rest. An electric valve is provided on the liquid side branch pipe of the outdoor unit, and the electric valve corresponding to the operating Tomiuchi unit is set to a predetermined opening depending on the number of operating indoor units, and furthermore, each liquid side branch pipe is set to the predetermined opening. The electric valve is corrected so that the refrigerant temperature becomes the average refrigerant temperature of each liquid side branch pipe, and the electric valve corresponding to the pause unit is set to a small opening to prevent the refrigerant from accumulating in the pause unit. When the refrigerant temperature of the liquid-side branch pipe corresponding to the pause unit is lower than the temperature of each liquid-side branch pipe, the electric valve corresponding to the pause unit is corrected to open further to prevent refrigerant from accumulating in the pause unit. I am proposing that.

[Problems that the invention helps solve]

The above conventional technology has the main purpose of removing the refrigerant accumulated in the idle unit, and when it is determined that the refrigerant has accumulated, the electric valve corresponding to the idle unit is opened further to release the refrigerant. Since the control is stepwise and operates independently of the motorized valve on the operating unit side, there is a possibility that the effects of discharge may interfere with the electrically operated valve control on the operating unit side, so sufficient consideration must be given to this point. As a result, there was a problem that even when the load was stable, there was a possibility that the control would be repeated in a hunting manner.

An object of the present invention is to solve the above-mentioned problems, perform refrigerant control to stabilize the operating cycle, and obtain comfortable air conditioning conditions.

[Means to solve the problem]

The above purpose is to be equipped with one outdoor unit consisting of a capacity-controllable compressor, an outdoor heat exchanger, a four-way valve, etc., and multiple indoor units each having an indoor heat exchanger. In a multi-chamber air conditioner in which the main pipe on the liquid side is branched into multiple pipes and an electric expansion valve is provided in each branch pipe on the cough liquid side to form a heat pump type refrigeration cycle,
During heating operation, a discharge gas temperature detector detects the discharge gas temperature of the refrigerant, a condensation temperature detector detects the condensation temperature of the refrigerant, and the degree of superheat on the discharge side of the refrigerant is determined from the temperature data detected by both temperature detectors. and controlling the valve opening degree of the expansion valve corresponding to the indoor unit in operation so that the refrigerant discharge side superheat degree becomes a predetermined value based on the calculation result,
The opening adjustment amount for the electronic expansion valve on the operating unit side is also outputted within a predetermined ratio range to the expansion valve corresponding to the indoor unit that is inactive, and a small amount of refrigerant is also circulated to the inactive unit. Refrigerant control that determines control details for the expansion valve according to a program input in advance so that the opening adjustment for the expansion valve corresponding to the unit is made in accordance with the opening adjustment amount V on the operating unit side. This is achieved by providing a control signal output device that outputs an opening amount to the expansion valve according to the determined control content and drives the expansion valve.

[Effect]

The control device takes in the discharge gas temperature and condensation temperature of the refrigerant from the temperature sensor, determines the degree of superheat on the discharge side of the refrigerant from the difference, and adjusts the electric expansion valve opening degree to achieve the target degree of superheat on the discharge side. It is calculated and output to the electric expansion valve corresponding to the operation unit through the control signal output device. At the same time, an opening adjustment amount is outputted to the electric expansion valve corresponding to the pause unit by a predetermined ratio according to the opening adjustment amount output to the electric expansion valve corresponding to the operation unit, Circulate a small amount of refrigerant to the idle unit.

This prevents the refrigerant from accumulating in the idle unit and causing a shortage of refrigerant during the operation cycle, and also allows the refrigerant targeted to the load to circulate in the operational unit, and outputs an opening adjustment output to the electronic expansion valve corresponding to the idle unit. Since the electronic expansion valves are linked to the operation unit side, it is possible to eliminate mutual interference between the electronic expansion valves on the operation unit side and the rest unit side.

〔Example〕

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

(First Example) As shown in Fig. 1, the air conditioner in this example has 1
It has a configuration in which 8 indoor units are connected to 1 outdoor unit.The outdoor unit has 1 compressor, 2 four-way valves,
Accumulator 8, outdoor heat exchanger 4, and refrigerant liquid side main pipe 5
A receiver 6 is provided. In addition, eight liquid side branch pipes 7m17b branched from the refrigerant liquid side main pipe 5.
Reversible electric expansion valve s a + s b for 17C
+8. c is provided. The indoor unit side is equipped with respective indoor heat exchangers 9a, 9b, and 9c, and by connecting each device in the outdoor unit and each device in the indoor unit with piping as shown in Figure 1, heat pump type refrigeration is possible. constitutes a cycle. Further, the outdoor unit includes a detector 11 for detecting the refrigerant condensation temperature in the condensing pipe 1b led from the refrigerant discharge pipe 1a, and a detector 11 for detecting the refrigerant condensation temperature in the condensing pipe 1b led from the refrigerant discharge pipe 1a. A refrigerant control device 01 that is connected and processes the detected contents according to a program 2 that has been inputted in advance, and a control signal output device that outputs an expansion valve opening adjustment amount to the electric expansion valves 8a+8b+8c by manual cooling of the refrigerant control device 120. 18 are provided.

Fig. 2 shows the control flow of the embodiment, and Fig. 8 shows the control flow of the embodiment.
The figure shows the movement of the opening degree of the electric expansion valve corresponding to the operation unit and stop unit.

The present embodiment will be explained with the above configuration.

During heating operation, when two indoor units with indoor heat exchangers 9m and 9b are operated, refrigerant gas is passed from the compressor 1 through the four-way valve 2 to the gas side main pipe 15 and the gas side branch pipe 14a.
, 14b to the indoor heat exchangers 9a, 9b where it is condensed.
It is sent to the indoor heat exchanger unit via the main liquid side pipe 5 and receiver 6, evaporates into gas, and returns to the compressor 1 via the four-way valve z1 accumulator 8. Here, indoor heat exchanger 9C
In the initial state, the expansion valve 8C corresponding to the pause unit with the opening is maintained at a predetermined minimum opening degree that allows a small amount of refrigerant to flow.

Next, the flow of control for the expansion valve 8a18b18C will be explained.

In this embodiment, the discharge gas temperature Td, the condensation temperature Tc
is read into the control device 12 by the detector 10.11 every predetermined time period (step 16.17 in Fig. 2). From the difference in temperature data, the current discharge side refrigerant superheat degree 8H is determined.
is calculated (step 19). Based on the deviation between the current discharge side refrigerant superheat degree SH and the target discharge side refrigerant superheat degree SH/, the expansion valve opening degree adjustment amount ΔP is calculated using the following PID calculation formula.
Calculate. (Step 20) ΔP=KiX (SH-8H') +KpX (SH-8Hn-1) +KdX((8H-8Hn-1) -(8Hn-1-8Hn-z)) ΔP: Expansion valve opening adjustment amount Ki , Kp, Kd: Various constants for each term SH: Current degree of superheat on the discharge side SH': Target degree of superheat on the discharge side 5Hn-1i Degree of superheat on the discharge side at the time of tempering one time before the present 5Hn-zl Two times before the present After calculating the expansion valve opening adjustment amount ΔP using a formula that is greater than or equal to the degree of superheating on the discharge side during tempering, it is distributed to each operator's indoor unit using the following formula (step 21
).

ΔF + = Q t /ΣQIXΔPΔPi: Opening adjustment distribution amount for each operating indoor unit QiI Code representing the capacity of each operating indoor unit ``ΔPI Linear expansion valve opening adjustment amount for all operating indoor units, and for the rest unit The expansion valve opening is distributed according to the following formula (Step 2i2) ΔPI-Qj/(ΣQl-IQj) Code ΔP: Linear expansion valve opening adjustment amount for all operating indoor units Using the above formula, the opening adjustment amount is distributed to the operating indoor unit and the idle indoor unit.Therefore, in the idle unit, the linear expansion valve opening adjustment amount is Since the degree adjustment amount ΔP is distributed according to the ratio of the capacity code of each idle unit to the total capacity code of the indoor units installed, the capacity of each operating unit to the total capacity code of the operating indoor units. The opening distribution is smaller than that of the operating indoor unit, which distributes the distribution according to the code ratio of In order to maintain the opening at the expansion valve opening 24 corresponding to the operating unit, as shown in FIG.
The movement follows the driver's indoor unit, but the absolute value of the expansion valve opening is kept low. Note that the expansion valve opening degree correction operation is performed at every predetermined sampling time of 1 second, as shown in step 28 in FIG.

By controlling as described above, it becomes possible to control the degree of superheating of the discharge side refrigerant for the entire operation cycle (second embodiment). A configuration in which a pressure sensor is used instead of a temperature sensor will be described as a second embodiment. Here, as for the control flow, in step 18 of FIG. 2, discharge pressure is taken in as data instead of temperature data, and in step 19, When calculating the degree of superheat on the refrigerant discharge side, the condensation temperature is calculated from the pressure and converted, and the degree of superheat on the discharge side is calculated. Further, the condensing temperature is calculated from the discharge pressure using a program stored in advance in the refrigerant control device 1z. Other configurations and control flows are the same as in the first embodiment.

Note that the present invention is not limited to the above-described embodiments; for example, the condensing temperature can be detected directly from the outdoor heat exchanger, and the expansion valve mechanism can be connected to the outdoor unit as in this embodiment. The present invention is applicable not only to cases where an expansion valve mechanism is provided in an indoor unit or in the middle of piping between an indoor unit and an outdoor unit, etc.
Various modifications can be made without changing the gist.

〔Effect of the invention〕

According to the present invention, in a multi-room air conditioner, even if any indoor unit among the plurality of indoor units is stopped, refrigerant will not accumulate in the stopped indoor unit, and the operation cycle will be continued. There is no shortage of refrigerant, the amount of refrigerant circulated to the operating units is ensured, and there is no mutual interference between the electric expansion valves corresponding to the operating units and the idle units, resulting in a stable refrigeration cycle, resulting in comfortable air conditioning. It has the effect of realizing the state.

[Brief explanation of the drawing]

Fig. 1 is a refrigeration cycle system diagram showing the first embodiment of the multi-room air conditioner of the present invention, Fig. 2 is a control flow chart of the first embodiment, and Fig. 8 is an opening of the expansion valve corresponding to the operation and suspension unit. It is a degree change diagram. 1...Compressor 4...Outdoor heat exchanger 8a, 8
b, 8c...Electric expansion valve 9a, 9b, 9c...
・Indoor heat exchanger 12...refrigerant control device 13・
...Control signal output device. Representative Patent Attorney Masaru Ogawa, 1 Tomi 1

Claims (1)

[Claims] 1. Equipped with one outdoor unit consisting of a capacity-controllable compressor, an outdoor heat exchanger, a four-way valve, etc., and multiple indoor units each having an indoor heat exchanger. In a multi-room air conditioner in which a main pipe is branched into multiple pipes and an electric expansion valve is installed in each of the liquid side branch pipes to form a heat pump type refrigeration cycle, the temperature of the discharged gas of the refrigerant is detected during heating operation. A temperature sensor, a condensing temperature sensor that detects the condensation temperature of the refrigerant, and the temperature data detected by both temperature sensors calculate the refrigerant discharge side superheat degree, and based on this calculation result, the refrigerant discharge side superheat degree is calculated. While controlling the valve opening degree of the expansion valve corresponding to the indoor unit that is in operation so that The opening adjustment amount for the expansion valve is reduced by a predetermined ratio and outputted, a small amount of refrigerant is also circulated to the rest unit, and the opening adjustment amount for the expansion valve corresponding to the rest unit is reduced to an amount corresponding to the opening adjustment amount on the operating unit side. a refrigerant control device that determines control content for the expansion valve according to a program input in advance; and a control signal output that outputs an opening amount to the expansion valve and drives the expansion valve according to the determined control content. A multi-room air conditioner characterized by being equipped with a device.