CN100366992C - Low-temperature air-conditioning heat pump system and method for reducing temperature regulation fluctuation by using same - Google Patents

Abstract

A low-temperature air-conditioning heat pump system, including a liquid receiver, a gas-liquid separator, a secondary cooling coil, a four-way valve, an outdoor unit heat exchanger, an outdoor unit electronic expansion valve, and a compressor air supply system, the compressor The gas system includes an EVI solenoid valve, an EVI electronic expansion valve, a compressor with an air supply port, and a liquid reservoir. The liquid reservoir is connected to the EVI solenoid valve and the EVI electronic expansion valve, and the compressor is connected to the EVI solenoid valve. The machine supplementary air system also includes two temperature-sensing packages; the liquid reservoir is connected with the EVI solenoid valve and the EVI electronic expansion valve with metal pipes, the compressor and the EVI solenoid valve are connected with metal pipes, and one temperature-sensing package is placed in the compressor One is placed on the surface of the metal pipe used to connect the EVI solenoid valve, and the other is placed on the surface of the metal pipe used to connect the liquid reservoir to the EVI electronic expansion valve. The invention controls the opening and closing time of the compressor air supply system through two temperature sensing packages, and improves the heating capacity and energy efficiency ratio of the unit under the outdoor low temperature working condition.

Description

Low-temperature air-conditioning heat pump system and method for reducing temperature regulation fluctuation using the system

【Technical field】

The invention relates to the field of air source heat pump air conditioners, in particular to a low temperature air conditioner heat pump system with good heating effect under outdoor low temperature conditions and a method for reducing temperature adjustment fluctuations.

【Background technique】

At present, the ordinary air source heat pump air conditioners sold in the market have serious attenuation of heating capacity under the low temperature outdoor conditions, and even cannot start and run normally. In the cold regions of northern my country, they can only be used in the transition season, and cannot Meet basic heating needs. Therefore, traditional central heating methods are generally still used in cold regions, and these heating methods are mainly coal-fired and gas-fired, which cannot meet the requirements of social development in terms of energy saving, environmental protection, and safety. Some air conditioner manufacturers now provide a heat pump device with an injection circuit, which can efficiently defrost and prevent the decline in heating capacity caused by defrosting operation, such as the publication number JP2001-263882A, the publication date is 2001 On September 26, 2010, the patent document titled heat pump device. However, this document does not introduce the working timing and control method of the injection circuit; at the same time, due to the development of compressor technology, a new capacity adjustment technology mainly used in scroll compressors "Enhanced VapourInjection" (English "Enhanced VapourInjection", Abbreviation "EVI"), through the "load state" and "unload state" time average method to achieve the capacity adjustment of the compressor; because the earliest developer of the American Copeland Corporation, it is called "Digital Scroll^TM (Copeland Digital scroll technology), known as "jet digital scroll compressor" in the industry. Based on the above conditions, the applicant proposes the concept of the present invention.

【Content of invention】

The purpose of the present invention is to provide a low-temperature air-conditioning heat pump system with good heating effect under the condition of outdoor low-temperature operation.

Another object of the present invention is to provide a method for reducing temperature adjustment fluctuations using the above-mentioned low-temperature air-conditioning heat pump system.

To achieve the above object, the present invention adopts the following technical solutions:

A low-temperature air-conditioning heat pump system, including a liquid receiver, a gas-liquid separator, a secondary cooling coil, a four-way valve, an outdoor unit heat exchanger, an outdoor unit electronic expansion valve, and a compressor air supplement system, the compressor supplement The gas system includes an EVI solenoid valve, an EVI electronic expansion valve, a compressor with an air supply port, and a liquid reservoir. The liquid reservoir is connected to the EVI solenoid valve and the EVI electronic expansion valve, and the compressor is connected to the EVI solenoid valve. The air supplement system also includes two temperature-sensing packages; the liquid reservoir is connected with the EVI solenoid valve and the EVI electronic expansion valve with metal pipes, the compressor and the EVI solenoid valve are connected with metal pipes, and one temperature-sensing package is placed in the compressor. One is placed on the surface of the metal pipe used to connect the EVI solenoid valve, and the other is placed on the surface of the metal pipe used to connect the liquid reservoir to the EVI electronic expansion valve.

A method for reducing temperature adjustment fluctuations of an air-conditioning heat pump system includes the first step: separately preparing a compressor with an air supply port, a liquid receiver, a gas-liquid separator, an auxiliary cooling coil, a four-way valve, and an outdoor unit heat exchanger , outdoor unit electronic expansion valve, EVI solenoid valve, EVI electronic expansion valve and two temperature-sensing packages; the second step: put one temperature-sensing package on the surface of the metal pipe used to connect the compressor and the EVI solenoid valve, and the other on the The surface of the metal pipe used to connect the liquid reservoir to the EVI electronic expansion valve; Step 3: Set a target superheat degree in the system; Step 4: Subtract the temperature values measured by the two temperature sensing bulbs to obtain the first temperature difference; step 5: use the subtraction of the first temperature difference and the target superheat to obtain a second temperature difference to control the opening of the EVI electronic expansion valve.

Compared with the prior art, the low-temperature air-conditioning heat pump system of the present invention adopts an air-jet digital scroll compressor and a compressor air supply system. When the outdoor ambient temperature is lower than zero, the compressor air supply system in the unit plays a role, and the EVI solenoid valve is opened. Supplement the saturated refrigerant gas with intermediate pressure to the compressor, realize two-stage compression inside the compressor, and improve the heating capacity and energy efficiency ratio of the unit under outdoor low temperature conditions.

【Description of drawings】

Fig. 1 is a schematic diagram of the internal structure of the low-temperature air-conditioning heat pump system of the present invention;

Fig. 2 is a pressure-enthalpy diagram of the heating operation of the low-temperature air-conditioning heat pump system of the present invention when the EVI solenoid valve is opened.

【Detailed ways】

Please refer to Figure 1, a low-temperature air-conditioning heat pump system 1 includes a liquid receiver 12, a gas-liquid separator 15, a secondary cooling coil 19, a four-way valve 16, an outdoor unit heat exchanger 17 and an outdoor unit electronic expansion valve 18 and a compressor air supply system. The air supply system for the compressor includes an EVI solenoid valve 14, an EVI electronic expansion valve 13, a compressor 9 provided with an air supply port, and a liquid storage device 12. Machine 9 is connected with EVI electromagnetic valve 14.

In order to better implement the present invention, the air supply system for the compressor may also include two temperature sensing packages 20 and 21 . In this embodiment, the temperature sensing package is a thermistor, and the compressor is an air-jet digital scroll compressor. The liquid reservoir 12 is connected with the EVI solenoid valve 14 and the EVI electronic expansion valve 13 by metal pipes, the compressor 9 and the EVI solenoid valve 14 are connected by metal pipes, and the temperature sensing package 20 is placed in the space between the compressor 9 and the EVI solenoid valve 14. On the surface of the metal pipe, the temperature sensing package 21 is placed on the surface of the metal pipe used to connect the liquid reservoir 12 and the EVI electronic expansion valve 13 .

Please refer to FIG. 2 . In the low-temperature air-conditioning heat pump system 1, it is preferable that all components are connected by copper pipes. When the low-temperature air-conditioning heat pump system is in heating operation, the compressor 9 compresses the low-temperature and low-pressure refrigerant gas (state point 1) evaporated from the heat exchanger of the outdoor unit to the state point 2 of the intermediate pressure. The disk is mixed with the intermediate-pressure gas (state point 9) sucked from the air inlet of the compressor to the state point 10, and then continues to be compressed by the compressor into high-temperature and high-pressure gas (state point 3), and the high-temperature and high-pressure refrigerant gas is in the room The machine heat exchanger 22 is cooled and condensed into a high-temperature and high-pressure refrigerant liquid (state point 4), and the high-pressure liquid is throttled by the indoor unit electronic expansion valve 4 and EVI electronic expansion valve 13 to become a gas-liquid mixture of intermediate pressure (state point 5 ) into the liquid storage tank 12, a part of the refrigerant in the liquid storage tank 12 flashes to intermediate pressure refrigerant gas (state point 9) and is inhaled by the gas supply port of the compressor, and another part of the refrigerant in the liquid storage tank 12 is passed through The subcooled liquid with intermediate pressure (state point 7) is throttled to state point 8 by the electronic expansion valve 18 of the outdoor unit, and then enters the outdoor unit heat exchanger 17 to evaporate to state point 1 and is sucked by the suction port of the compressor, completing a heating cycle.

A method for reducing temperature adjustment fluctuations of an air-conditioning heat pump system includes the first step: separately preparing a compressor with an air supply port, a liquid receiver, a gas-liquid separator, an auxiliary cooling coil, a four-way valve, an outdoor unit heat exchanger, Outdoor unit electronic expansion valve, EVI solenoid valve, EVI electronic expansion valve and two temperature-sensing packages; Step 2: Put one temperature-sensing package on the surface of the metal pipe used to connect the compressor and EVI solenoid valve, and the other on the storage The surface of the metal pipe used to connect the liquid tank and the EVI electronic expansion valve; the third step: set a target superheat in the system; the fourth step: subtract the temperature values measured by the two temperature sensing bulbs to obtain the first temperature difference value; the fifth step: using the subtraction of the above-mentioned first temperature difference and the target degree of superheat to obtain the second temperature difference to control the opening degree of the EVI electronic expansion valve.

The present invention introduces the use of a compressor supplementary air system to reduce the attenuation of heating capacity of an air-conditioning heat pump system at low temperature, which should not be considered as a limitation on the claims of the present invention. If those skilled in the art make insubstantial and obvious changes or improvements according to the present invention, they shall all belong to the protection scope of the claims of the present invention.

Claims (5)

1. A low-temperature air-conditioning heat pump system, comprising a liquid accumulator, a gas-liquid separator, an auxiliary cooling coil, a four-way valve, an outdoor unit heat exchanger, an outdoor unit electronic expansion valve and a compressor gas supply system, the compression The machine air supply system includes EVI solenoid valve, EVI electronic expansion valve, compressor with air supply port, and liquid storage. The liquid storage is connected with EVI solenoid valve and EVI electronic expansion valve, and the compressor is connected with EVI solenoid valve. It is characterized in that: the air supply system of the compressor also includes two temperature-sensing packages; the liquid reservoir is connected with the EVI solenoid valve and the EVI electronic expansion valve by metal pipes, and the compressor and the EVI solenoid valve are connected by metal pipes, and the temperature sensing One package is placed on the surface of the metal pipe used to connect the compressor and the EVI solenoid valve, and the other is placed on the surface of the metal pipe used to connect the liquid reservoir to the EVI electronic expansion valve. 2. The low-temperature air-conditioning heat pump system according to claim 1, wherein the compressor is an air-jet digital scroll compressor. 3. A method for reducing temperature adjustment fluctuations in an air-conditioning heat pump system includes the first step: separately preparing a compressor with an air supply port, a liquid receiver, a gas-liquid separator, an auxiliary cooling coil, a four-way valve, and an outdoor unit replacement Heater, outdoor unit electronic expansion valve, EVI solenoid valve, EVI electronic expansion valve and two temperature-sensing packages; the second step: put one temperature-sensing package on the surface of the metal pipe used to connect the compressor and EVI solenoid valve, and the other Place it on the surface of the metal pipe used to connect the liquid reservoir to the EVI electronic expansion valve; Step 3: Set a target superheat in the system; Step 4: Subtract the temperature values measured by the two temperature sensors to obtain the first A temperature difference; the fifth step: use the subtraction of the first temperature difference and the target superheat to obtain a second temperature difference to control the opening of the EVI electronic expansion valve. 4. The method for reducing temperature adjustment fluctuations in an air-conditioning heat pump system according to claim 3, wherein the temperature sensing package is a thermistor. 5. The method for reducing temperature adjustment fluctuations in an air-conditioning heat pump system according to claim 3, wherein the compressor is an air-jet digital scroll compressor.

Images