A self-learning control method for the expansion valve of a heat pump EVI natural fluorine and ground fluorine host

Abstract

The present invention discloses a self-learning control method for the expansion valve of a heat pump (EVI) natural fluorine and difluorine main unit. When the main unit is started, it determines whether the current startup is the first startup or a restart: a) If the current startup is the first startup, the main unit's expansion valve determines its initial opening based on the outdoor ambient temperature and adjusts the initial opening for the restart of the main unit; b) If the current startup is the restart, the main unit's expansion valve is started based on the initial restart opening stored in the main unit and adjusts the initial restart opening for the restart of the main unit. By determining if there is a problem with the initial opening and automatically adjusting the flow rate of the main unit's expansion valve during restart, the present invention can self-discover the previous problem and prevent it from recurring.

Description

Technical Field

[0001] The invention relates to a self-learning control method for an expansion valve of a heat pump EVI natural fluorine and ground fluorine main unit. Background Art

[0002] The use of environmentally friendly refrigerants to heat the floor through capillary radiation is a new technology. This system does not give you the feeling of being scorched by heaters or stoves in winter. It is very comfortable and does not take up any space, thus avoiding the air-conditioning diseases caused by the use of conventional air-conditioning systems.

[0003] The capillary radiation air conditioning system can ensure that the indoor temperature always remains balanced, and is more conducive to people's living, and the living environment is more comfortable. Compared with traditional air conditioning systems, it can provide more uniform heat radiation and contain fresh air without a blowing feeling. In addition, this air conditioning system can avoid any noise disturbing the user's office and rest, and the indoor space is also wider and quieter.

[0004] Since the refrigerant in fluorine floor heating is 80% more than that in conventional units, the initial opening of the expansion valve when the heating main unit is started in winter is generally controlled based on the suction superheat. However, since the temperature sensor reacts relatively slowly when the unit is just started, if the given starting opening is too large, that is, the refrigerant flow of the outdoor heat exchanger is too large, it will cause the compressor return liquid exhaust superheat to be low. If the initial starting opening is too small, it will lead to problems such as too low low pressure on the low-pressure side, too high pressure on the high-pressure side, and too high exhaust pressure, which will eventually cause high-pressure failure or excessive pressure ratio, affecting the reliability of the unit. Summary of the Invention

[0005] In response to the above problems, the present invention provides a self-learning control method for the expansion valve of the heat pump EVI natural fluorine and ground fluorine main unit, which effectively solves the problems pointed out in the background technology.

[0006] The technical solution adopted in the present invention is:

[0007] A self-learning control method for the expansion valve of a heat pump EVI natural fluorine and difluorine host, when the host is started, determines whether the current start is the first start or the restart:

[0008] a) The current startup is the first startup. The expansion valve of the host determines the initial opening according to the outdoor ambient temperature and adjusts the initial opening when the host is restarted;

[0009] b) The current start is restart: the expansion valve of the host is started according to the initial opening degree for restart stored in the host, and the initial opening degree for restart of the host is adjusted;

[0010] The initial opening adjustment when the host is restarted includes the following steps:

[0011] Step 1), after the host runs for a set time t, if the exhaust superheat of the compressor is lower than the set value T1 or a low exhaust superheat fault occurs and the compressor stops, it means that the initial opening of the expansion valve at startup is too large. At this time, the initial opening of the expansion valve for restarting is reduced by a set number of steps k and stored in the host until the initial opening stored in the host is the minimum opening, and the initial opening for restarting is no longer reduced. If the exhaust temperature of the compressor is higher than the set value T2 or a high exhaust temperature fault occurs and the compressor stops, or the high pressure is greater than the set value P, it means that the initial opening of the expansion valve at startup is too small. At this time, the initial opening of the expansion valve for restarting is increased by a set number of steps k and stored in the host until the initial opening stored in the host is the maximum opening, and the initial opening for restarting is no longer increased;

[0012] Step 2) Repeat step 1) to adjust the initial opening of the expansion valve when the host is restarted, which is stored in the host.

[0013] The t is 5 minutes, T1 is 5°C, k is 10 steps, T2 is 95°C, and P is 3.8 MPa.

[0014] The maximum opening of the expansion valve is 480 steps, and the minimum opening is 60 steps.

[0015] The present invention determines the problem of the initial opening and automatically adjusts the flow of the host expansion valve when restarting, so that the problem that occurred last time can be self-shielded to avoid the problem from occurring again.

[0016] The present invention automatically searches for the most appropriate initial opening by the host. Regardless of changes in ambient temperature or the amount of refrigerant stored in the gas-liquid separator at the time, the initial opening can be self-adjusted, thereby reducing problems caused to customers by unit failures. DETAILED DESCRIPTION

[0017] The present invention is further described in detail below through specific examples.

[0018] The present invention discloses a self-learning control method for the expansion valve of a heat pump EVI natural fluorine and fluorine host. When the host is started, it is determined whether the current start is the first start or the restart:

[0019] a) The current startup is the first startup. The expansion valve of the host determines the initial opening according to the outdoor ambient temperature and adjusts the initial opening when the host is restarted:

[0020] Step 1), after the host runs for a set time of 5 minutes, if the exhaust superheat of the compressor is lower than the set value by 5°C or a low exhaust superheat fault occurs and the machine shuts down, it means that the initial opening of the expansion valve at startup is too large. At this time, the initial opening of the expansion valve for restarting is reduced by a set number of steps by 10 steps and stored in the host. When the initial opening stored in the host is the minimum opening of 60 steps, the initial opening for restarting is no longer reduced. If the exhaust temperature of the compressor is higher than the set value of 95°C or a high exhaust temperature fault occurs and the machine shuts down, or the high pressure is greater than the set value of 3.8Mpa, it means that the initial opening of the expansion valve at startup is too small. At this time, the initial opening of the expansion valve for restarting is increased by a set number of steps by 10 steps and stored in the host. When the initial opening stored in the host is the maximum opening of 480 steps, the initial opening for restarting is no longer increased.

[0021] Step 2), repeat step 1), adjust the initial opening of the expansion valve when the host is restarted stored in the host;

[0022] b) The current start is restart: the expansion valve of the host is started according to the initial opening of restart stored in the host, and the initial opening of the host restart is adjusted:

[0023] Step 1), after the host runs for a set time of 5 minutes, if the exhaust superheat of the compressor is lower than the set value by 5°C or a low exhaust superheat fault occurs and the machine shuts down, it means that the initial opening of the expansion valve at startup is too large. At this time, the initial opening of the expansion valve for restarting is reduced by a set number of steps by 10 steps and stored in the host. When the initial opening stored in the host is the minimum opening of 60 steps, the initial opening for restarting is no longer reduced. If the exhaust temperature of the compressor is higher than the set value of 95°C or a high exhaust temperature fault occurs and the machine shuts down, or the high pressure is greater than the set value of 3.8Mpa, it means that the initial opening of the expansion valve at startup is too small. At this time, the initial opening of the expansion valve for restarting is increased by a set number of steps by 10 steps and stored in the host. When the initial opening stored in the host is the maximum opening of 480 steps, the initial opening for restarting is no longer increased.

[0024] Step 2) Repeat step 1) to adjust the initial opening of the expansion valve when the host is restarted, which is stored in the host.

[0025] Finally, it should be noted that the above examples are merely specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments and is subject to numerous variations. All variations that can be directly derived or conceived by a person of ordinary skill in the art from the disclosure of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A self-learning control method for the expansion valve of a heat pump EVI natural fluorine and ground fluorine host, characterized in that: When the host starts, determine whether the current startup is the first startup or the restart: a) The current startup is the first startup. The expansion valve of the host determines the initial opening according to the outdoor ambient temperature and adjusts the initial opening when the host is restarted; b) The current start is restart: the expansion valve of the host is started according to the initial opening degree for restart stored in the host, and the initial opening degree for restart of the host is adjusted; The initial opening adjustment when the host is restarted includes the following steps: Step 1), after the host runs for a set time t, if the exhaust superheat of the compressor is lower than the set value T1 or a low exhaust superheat fault occurs and the compressor stops, it means that the initial opening of the expansion valve at startup is too large. At this time, the initial opening of the expansion valve for restarting is reduced by a set number of steps k and stored in the host until the initial opening stored in the host is the minimum opening, and the initial opening for restarting is no longer reduced. If the exhaust temperature of the compressor is higher than the set value T2 or a high exhaust temperature fault occurs and the compressor stops, or the high pressure is greater than the set value P, it means that the initial opening of the expansion valve at startup is too small. At this time, the initial opening of the expansion valve for restarting is increased by a set number of steps k and stored in the host until the initial opening stored in the host is the maximum opening, and the initial opening for restarting is no longer increased; Step 2) Repeat step 1) to adjust the initial opening of the expansion valve when the host is restarted, which is stored in the host.

2. The self-learning control method for the expansion valve of a heat pump EVI natural fluorine and difluorine host according to claim 1 is characterized in that: The t is 5 minutes, T1 is 5°C, k is 10 steps, T2 is 95°C, and P is 3.8 MPa.

3. The self-learning control method for the expansion valve of a heat pump EVI natural fluorine and difluorine host according to claim 1 is characterized in that: The maximum opening of the expansion valve is 480 steps, and the minimum opening is 60 steps.