Variable-flow constant-temperature system for primary pump of air conditioner host

Abstract

The utility model provides a variable-flow constant-temperature system for a primary pump of an air conditioner host. The variable-flow constant-temperature system comprises a buffer water tank and the air conditioner host communicated with the buffer water tank through a circulating water supply pipe. The air conditioner host is communicated with the buffer water tank through a circulating water return pipe; a water outlet of the buffer water tank is communicated with a water inlet of the primary circulating pump through a circulating water supply pipe; a water outlet of the primary circulating pump is communicated with a water inlet of the air conditioner host through a circulating water supply pipe; a host water inlet temperature probe T for water inlet is arranged at a water inlet of the air conditioner host; the air conditioning system has the advantages of being capable of saving energy, reducing consumption, running, and being stable, safe and capable of saving energy.

Description

Technical Field

[0001] The utility model relates to a variable flow constant temperature system for a primary pump of an air-conditioning host, and relates to the technical field of heating, ventilation and air conditioning. Background Art

[0002] Water system central air-conditioning system generally adopts secondary circulation system more often. The so-called secondary circulation system is to use buffer water tank or manifold as the link to divide the water system central air-conditioning into two independent circulation systems. That is, the main unit and buffer water tank circulate as an independent circulation system (to produce hot water / cold water), which we call the primary circulation system (this functional circulation pump is called the primary circulation pump); the buffer water tank and fan coil units and other terminals are another circulation system, which is what we often call the air-conditioning pump circulation system (or secondary circulation pump).

[0003] In most systems, since the air-conditioning load is in dynamic change, generally speaking, most secondary pumps (or air-conditioning pumps) use variable flow systems; primary pumps all use fixed frequency and fixed flow systems, and there is no variable frequency and variable flow circulating primary pump system. In order to ensure that problems such as high pressure / low pressure protection do not occur, the 5°C heat exchange temperature difference under extreme working conditions is generally used as the standard for selection, which often leads to the common problem of excessive flow of circulating water pumps. It can neither guarantee the 5°C heat exchange temperature difference under non-extreme working conditions, nor cause the outlet water temperature to fluctuate widely, resulting in problems such as low operating efficiency of the main unit and circulating pump.

[0004] After analysis, if the water pump is too large, the inlet and outlet water temperatures of the air-to-energy heat pump will be about 3.5-3.9°C under low temperature conditions, which is far lower than the design inlet and outlet water temperature difference of 5°C. As a result, the outlet water temperature will be low in low temperature environments, which may not meet heating needs.

[0005] By the same token, if the primary pump is undersized, under ambient conditions above 0°C, the temperature difference between the inlet and outlet water will be too large, and the outlet water temperature will be too high, resulting in low heat pump operating efficiency, high temperature protection shutdown and other problems.

[0006] Assuming the inlet and outlet water temperature difference is 5°C, if the host is detected to have an inlet and outlet water temperature difference that is too small, or is 0, it indicates that the circulating water pump flow is insufficient, and the host executes the insufficient water flow compressor shutdown protection program (or low temperature protection program) to avoid freezing damage to the heat exchanger due to insufficient water flow, and other issues involving the host installation. Utility Model Content

[0007] The technical problem to be solved by the utility model is to provide an air-conditioning host primary pump variable flow constant temperature system with energy-saving and consumption-reducing operation and stable, safe and energy-saving system.

[0008] In order to achieve the above technical problems, the technical solution adopted by the utility model is:

[0009] An air conditioner host primary pump variable flow constant temperature system, comprising a buffer water tank and an air conditioner host connected to the buffer water tank via a circulating water supply pipe;

[0010] The air conditioning host is connected to the buffer water tank through a circulating return pipe;

[0011] The water outlet of the buffer water tank is connected to the water inlet of the primary circulation pump through a circulating water supply pipe;

[0012] The water outlet of the primary circulation pump is connected to the water inlet of the air conditioner host through a circulating water supply pipe;

[0013] The main unit water inlet temperature probe T is set at the water inlet of the air conditioner main unit. 进水 ;

[0014] The main unit water outlet temperature probe T is set at the water outlet of the air conditioner main unit. 出水 .

[0015] Furthermore, the air-conditioning host is a water system air-conditioning host, including a water-cooled chiller, a water (ground) source heat pump, an air-cooling module, an ultra-low temperature air energy heat pump or a centrifugal unit.

[0016] Furthermore, the buffer water tank is a pressure water tank or a non-pressure water tank.

[0017] Furthermore, the host water inlet temperature probe T 进水 , Main engine water outlet temperature probe T 出水 The primary circulation pump is connected to the controller.

[0018] Furthermore, the primary circulation pump is a variable frequency pump.

[0019] The beneficial effects of adopting the above technical solution are:

[0020] The primary pump of the utility model operates in variable working conditions and variable flow rate, and takes the water flow rate of the optimal heat exchange process of the host inlet and outlet water heat exchange temperature difference of about 5°C as the benchmark; by monitoring the heat exchange temperature difference of the host inlet and outlet water, the primary circulation pump can be operated in variable frequency and variable flow rate; when the highest outlet water temperature is maintained under heating conditions, the host will not have high pressure protection; when the lowest outlet water temperature is maintained under cooling conditions, the host will not have low temperature protection; at the same time, it can also avoid the heat exchanger from being damaged by freezing due to insufficient water flow, and other installation problems involving the host.

[0021] The utility model adopts the technical measures of variable working condition and variable flow operation of the primary pump, which can greatly reduce the operating energy consumption of the primary pump, and can ensure the optimal heat exchange process of about 5°C heat exchange temperature difference, improve the heat exchange efficiency, keep the outlet water temperature relatively stable, and is not prone to high and low pressure protection, and avoid problems such as freezing damage of the heat exchanger caused by too small heat exchange temperature difference. It involves the energy-saving and consumption-reducing operation of the primary pump, and has the advantages of system stability, safety, and energy saving. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the central air-conditioning structure of the existing water system;

[0023] Figure 2 It is a schematic diagram of the utility model;

[0024] Among them, 1. Primary circulation pump, 2. Air conditioning host, 3. Buffer water tank, 4-1. Circulating water supply pipe, 4-2. Circulating return pipe, T 进水 : Main engine water inlet temperature probe, T 出水 :Host water outlet temperature probe DETAILED DESCRIPTION

[0025] The present invention will be further described below with reference to the accompanying drawings.

[0026] As attached Figure 1-2 As shown, this embodiment provides an air-conditioning host primary pump variable flow constant temperature system, which includes a buffer water tank 3 and an air-conditioning host 2 connected to the buffer water tank 3 through a circulating water supply pipe 4-1; the air-conditioning host 2 is connected to the buffer water tank 3 through a circulating return water pipe 4-2; the water outlet of the buffer water tank 3 is connected to the water inlet of the primary circulating pump 1 through the circulating water supply pipe 4-1; the water outlet of the primary circulating pump 1 is connected to the water inlet of the air-conditioning host 2 through the circulating water supply pipe 4-1; a host water inlet temperature probe T is provided at the water inlet of the air-conditioning host 2 进水 The air conditioner host 2 is provided with a water outlet temperature probe T at the water outlet. 出水 The air conditioning unit 2 is a water-based air conditioning unit, including water-cooled chillers, water (ground) source heat pumps, air-cooled modules, ultra-low temperature air-energy heat pumps, centrifugal units, and other water-based air conditioning units. The system of the present invention operates based on a temperature difference of ▲T≈5°C between the unit's inlet and outlet water. The primary pump operates in an adaptive variable flow mode. The flow rate is affected by external factors such as the environment, and both the cooling and heating capacities are dynamic. Therefore, the heat exchange circulation flow rate is adjusted based on the unit's inlet and outlet water temperature difference of ▲T≈5°C, thereby achieving energy conservation through variable frequency operation of the primary circulation pump. Water flow rate and pump shaft power are directly proportional. Halving the water flow rate also halves the shaft power. Therefore, after the primary circulation pump's flow rate is adjusted, its operating power also changes accordingly.

[0027] The buffer water tank 3 is a pressure water tank or a non-pressure water tank, and a larger manifold can also be used.

[0028] The host water inlet temperature probe T 进水 , Main engine water outlet temperature probe T 出水 Connected to the controller, the host water inlet temperature probe T 进水 , mainly used to detect the temperature at the water inlet of the air conditioner host, the host water outlet temperature probe T 出水 , mainly used to detect the temperature at the water outlet of the air conditioner host. The primary circulation pump 1 is connected to the controller. The primary circulation pump 1 is a variable frequency pump. The primary circulation pump 1 is used to maintain the heat exchange cycle between the air conditioner host 2 and the buffer water tank 3. The circulating water flow of the primary circulation pump 1 is controlled by the water inlet temperature probe T of the air conditioner host 2. 进水 , Main engine water outlet temperature probe T 出水 The main unit inlet and outlet water temperature difference is ▲T≈5℃; when ▲T≥5℃, it indicates that the water flow is too small. At this time, the circulating water pump frequency is increased, the water flow is increased, and the heat exchange temperature difference is close to the heat exchange water flow of 5℃; conversely, the circulating water pump frequency is reduced, the water flow is reduced, and the heat exchange temperature difference is close to the heat exchange water flow of 5℃. The main unit water inlet temperature probe T 进水 , Main engine water outlet temperature probe T 出水 , controller, and variable frequency pump models can be selected on the market according to actual needs, and can meet the functional requirements of this application. The system settings can also set high-temperature protection and low-temperature protection applicable working conditions according to needs. The utility model adopts the technical measures of variable working conditions and variable flow operation of a single circulation pump, which can greatly reduce the operating energy consumption of the primary pump, and can ensure the optimal heat exchange process of about 5°C heat exchange temperature difference, improve heat exchange efficiency, keep the outlet water temperature relatively stable, and avoid high and low pressure protection. It avoids the problem of heat exchanger freezing damage caused by too small heat exchange temperature difference. It involves the energy-saving and consumption-reducing operation of the primary pump, system stability, safety, energy saving and other advantages.

[0029] The specific heat exchange cycle process is:

[0030] ①. The primary circulation pump 1 starts the circulation, draws circulating water from the buffer water tank 3 through the circulating water supply pipe 4-1, enters the main unit through the water inlet of the air conditioner 2 to absorb heat (or release heat) and complete the heat exchange, then flows through the water outlet of the air conditioner 2, flows through the circulating return pipe 4-2 and returns to the buffer water tank 3, completing the complete water flow circulation and heat exchange process.

[0031] ②, monitor the water inlet temperature T of the air conditioner host 2 at a certain frequency 进水 , main engine water outlet temperature T 出水A simple addition and subtraction indicates that the main unit's inlet and outlet water temperature difference, ▲T, is approximately 5°C. The flow rate is maintained at the current 5°C temperature difference. If the main unit's inlet and outlet water temperature difference, ▲T, is detected to be ≥5°C, indicating insufficient water flow, the circulating water pump frequency is increased, increasing the water flow rate to bring the heat exchange temperature difference closer to the 5°C heat exchange flow rate. Conversely, the circulating water pump frequency is decreased, reducing the water flow rate to bring the heat exchange temperature difference closer to the 5°C efficient heat exchange flow rate. By monitoring and calculating the main unit's inlet and outlet water temperature difference, ▲T is ​​determined to be approximately 5°C. The pump frequency is adjusted, and the flow rate is adaptively adjusted to the appropriate level, ensuring efficient and safe heat exchange.

[0032] High temperature and high pressure protection / low temperature safety protection instructions:

[0033] Due to changes in external factors such as ambient temperature, the condensing temperature (or evaporating temperature) changes, which not only causes the value of the host's inlet and outlet water temperature difference ▲T to change, but also may cause the outlet water temperature to be too high (or too low) under extreme working conditions, and then cause problems such as high temperature and high pressure protection / low temperature safety protection of the host. In order to avoid high temperature, low temperature and other problems under extreme working conditions, set the upper limit of high pressure and high temperature protection (or the lower limit of low temperature antifreeze cycle), and adaptively adjust the flow rate so that the host is in a safe heat exchange state where it is not easy to have high temperature, high pressure and low temperature antifreeze cycle. For example, when the condensing temperature of a certain air-conditioning host 2 is close to the high pressure and high temperature protection critical value of 55℃, high pressure protection and other problems may occur. Although the host inlet and outlet water temperature difference ▲T≈5℃ at this time, in order to avoid problems such as high pressure and high temperature protection, the primary circulation pump 1 must also increase the operating frequency and increase the circulation flow rate so that the outlet temperature T of the air-conditioning host 2 出水 Below the critical value, the host can run safely and stably.

[0034] On the contrary, in order to avoid the low temperature antifreeze protection and other problems such as low water temperature during the heat exchange cycle of the air conditioner host 2, for example, when the evaporation temperature of a certain air conditioner host 2 is close to the low pressure and low temperature antifreeze protection critical value such as 5°C, although the inlet and outlet water temperature difference of the host is ▲T≈5°C, in order to avoid the low pressure and low temperature protection and other problems, the primary circulation pump (frequency conversion) 1 must also increase the operating frequency and increase the circulation flow so that the outlet temperature of the air conditioner host 2 T 出水 Safe operation above the critical value.

[0035] The utility model uses the water flow rate as the benchmark for the optimal heat exchange process when the heat exchange temperature difference between the main unit's inlet and outlet water is about 5°C; by monitoring the heat exchange temperature difference between the main unit's inlet and outlet water, the variable frequency and variable flow operation of the primary circulation pump is realized; when the highest outlet water temperature is maintained under heating conditions, the main unit does not go into high-pressure protection; when the lowest outlet water temperature is maintained under cooling conditions, the main unit does not go into low-temperature protection; at the same time, it can also avoid problems involving the installation of the main unit, such as damage to the heat exchanger due to insufficient water flow, etc.

[0036] The above description of the disclosed embodiments will enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A variable flow constant temperature system for a primary pump of an air conditioner host, characterized in that: It comprises a buffer water tank (3), and an air conditioning main unit (2) connected to the buffer water tank (3) via a circulating water supply pipe (4-1); The air conditioning main unit (2) is connected to the buffer water tank (3) via a circulating water return pipe (4-2); The water outlet of the buffer water tank (3) is connected to the water inlet of the primary circulation pump (1) through the circulating water supply pipe (4-1); The water outlet of the primary circulation pump (1) is connected to the water inlet of the air conditioner main unit (2) through a circulating water supply pipe (4-1); The water inlet of the air-conditioning host (2) is provided with a host water inlet temperature probe T 进水 ; The main unit water outlet temperature probe T is set at the water outlet of the air conditioning main unit (2). 出水 .

2. The variable flow constant temperature system for a primary pump of an air conditioner host according to claim 1, characterized in that: The air-conditioning host (2) is a water system air-conditioning host, including a water-cooled chiller, a water source heat pump, a ground source heat pump, an air-cooling module, an ultra-low temperature air energy heat pump or a centrifugal unit.

3. The variable flow constant temperature system for a primary pump of an air conditioner host according to claim 1, characterized in that: The buffer water tank (3) is a pressure-bearing water tank or a non-pressure-bearing water tank.

4. The variable flow constant temperature system for a primary pump of an air conditioner host according to claim 1, characterized in that: The host water inlet temperature probe T 进水 , Main engine water outlet temperature probe T 出水 The primary circulation pump (1) is connected to the controller.

5. The variable flow constant temperature system for a primary pump of an air conditioner host according to claim 1, characterized in that: The primary circulation pump (1) is a variable frequency pump.

Images