Temperature controller with a user-friendly interface and two-way communication

Digital temperature controller

The subject of the invention is a digital temperature controller for central heating, district heating and air conditioning. It is intended for use in all types of facilities from a small single-family home to apartment blocks and public buildings.

This invention solves four technical problems

Problem 1.

The digital temperature controller should be so easy to use that any normal and literate person, including a non-expert, user-friendly expert, can successfully use it.

Problem 2.

The digital temperature controller should be designed in such a way that no extensive written documentation, instructions, etc. are required at the first installation or later when used.

Problem 3.

The digital temperature controller must allow for cheap, easy and reliable two-way communication for all control valves and pumps it controls, as well as for all physical quantities measured and other parameters.

Problem 4.

The digital temperature controller should also be able to measure the energy consumed so that it can assume the function of a calorimeter.

The known solutions to these problems are as follows.

Problem 1.

Modern digital controllers have many features, programs and schematics built in. The user needs to know what combination of keystrokes will be able to make a certain change. In order to do this, it must examine the package leaflet. The problem is that the crowdfunding instructions for most people are too complex and too complex. Often, instructions are also lost or partially damaged. Most controllers have at least four to five keys, switches or buttons, as well as five to ten different symbols that appear on the screen or printed on the chassis, describing the state of operation and system elements. Often different signal lights are also used. The keys and symbols are not standardized and uniform. Each manufacturer works on their own. Symbols are often similar to other devices. However, the same symbol does not necessarily mean the same thing. The confusion is great. The more options the regulator offers, the less likely it is that the operating result will be positive. Instead of greater energy savings, the opposite is often achieved.

Problem 2.

Procedures for installing new programs on computers are known. When a floppy disk is inserted into the computer, an installation program automatically starts asking the user all the necessary questions. This is not the case with regulators. Each controller has a written instruction manual for installation and use. The installer performs assembly and parameter tuning on the basis of complicated and often ambiguous instructions. The problem is that the instruction may be lost. Especially after a long time, after years of operation, the likelihood of the instructions disappearing or partially destroying is increasing. The more complex and clever the controller is, the less likely it will be to manage after a long time without written instructions. It is often easier to get another new regulator than to train an old one.

Problem 3.

Some existing regulators allow remote control of the position of the control valves and of the circulation pumps. However, additional and relatively expensive devices are needed.

Problem 4.

Calorimeters are used to measure the energy consumed, which are installed as separate units in boiler rooms or thermal substations.

Solutions to the Problems of the Invention

Solution to the problem 1.

1.1 The digital temperature controller automatically talks to the user in his or her spoken language via the display. The user only answers the questions. However, the questions are asked in such a way that after a couple of answers they lead him to the result.

1.2 Four buttons are sufficient to operate the controller. Next to the two cursor keys (forward, backward) are the plus and minus keys. The latter change the parameter value on the screen and also serve as an affirmative and a negative answer to the question asked.

1.3 The use of all graphic symbols is excluded. There are no graphic symbols on the screen or on the controller housing. Only letters, numbers, and some standard characters are used (+, -, ° C,%, arrows)

The advantage of this type of work with the controller is that it can be used by anyone who is literate, without guidance and without expertise. The disadvantage is that it takes a little longer to read a certain piece of information or change a setting. Use the arrow keys to find the appropriate question at the basic level. With the right answer, we move deeper, to a more demanding level, where we can already change certain settings.

Since the settings rarely need to be changed, losing a few minutes seems acceptable. This is the price for a much more important feature, namely that the regulator is always and always understandable and useful for everyone. The advantage is that it serves the pilot's screen at the same time as: room thermometer, outdoor thermometer, clock, calendar, etc. Other information such as power consumption, heating costs, etc. can also be displayed on the screen ...

Solution to the problem 2.

When setting up for the first time, the digital temperature controller tells the expert who connected it which sensors are correctly connected and what temperature they are detecting. The controller allows a specialist to manually move each actuator on the valve (using the + and - keys) to the desired direction, thereby verifying the connection. The controller also allows each pump or user to switch on and off manually (with the help of the + and - buttons), thus verifying the correct connection.

The regulator terminal terminals are multicolored. Each consumer has its own color of terminal blocks, which further reduces the possibility of incorrect connection.

Solution to the problem 3.

The communication between the controller and the control unit is two-way. This means that the control unit shows us the status of all consumers and sensors connected to the controller and other parameters. With the help of the control unit we can also change the status of the consumers and other parameters. In order to avoid communication errors, a communication protocol with verification of the transmitted data is used. The control unit can be in the same building or several kilometers away. In the latter case, a public telephone or other network is used as the medium of communication.

3.1 The lifetime of the pumps is several decades. The greatest risk of damage to the pump occurs when the pump is stationary in the system. Namely, after a long standstill, the pump "sticks" and fails to start automatically. Such "bonding" is caused by calculus, which is deposited on the walls of a stationary pump turbine. To prevent this, the digital temperature controller does not allow the pump to stand idle for a longer period of time, but instead switches it on for a short period of time. This ensures greater reliability of the pump and, at the same time, correct communication with the control unit.

3.2 The operating status of the control valve is undoubtedly one of the most important information of the heating system. Various mechanical particles coming down the pipeline can prevent the quality of operation of the control valve and thus cause more or less damage. Therefore, the actuator of the control valve also contains a sensor that measures the current position of the valve plate. In this way, the position of the control valve can be accurately identified and monitored and a possible defect noted.

Solution to the problem 4.

Calorimeters intended for energy measurement are essential for district heating, in particular. Without them, it is not possible to determine precisely the amount of energy consumed by a particular consumer. The calorimeter needs information about specific temperatures and flow in the system for its operation. The digital temperature controller also needs this information for its operation, and since it also contains permanent memory (EEPROM), the controller can perform the function of a calorimeter. The combined functions of the calorimeter and the controller in the common housing would certainly contribute to the compactness of the thermal sub-installation.

Description of the design solution

Figure 1

The digital temperature controller consists of two parts, the base (1) and the pilot (2). The base may have the following connections: bi-directional communication with control panel (3) by wire, connector for bi-directional communication with control panel by radio (4), connector for two-way communication with a laptop (5), connector for two-way communication with a pilot, connectors for temperature sensors (6) , circulation pump connections (7), motor actuators for control valves (8), connection for one-way communication with the calorimeter (9), and power supply connector (10). The controller database contains the elements necessary for regulation, communication and storage of data. The pilot has a room temperature sensor, buttons (11) and a screen (12) on which the text is displayed. When the pilot is installed next to the controller in the home station, the room sensor must be switched off.

The digital temperature controller is designed in such a way that the use of any symbols except numbers, letters and some standard characters is completely and everywhere excluded. This rule applies to on-screen texts and housing inscriptions.

Installation of a digital temperature controller by an expert installer is as follows. With the help of an image located between the connectors and clearly showing how the sensors and consumers are connected, the installer executes the controller wiring. The connectors, with their variety of colors, indicate and guide the installer and additionally prevent the possibility of wiring failure. The controller module then pushes it into the wired base and turns on the power supply. The display will indicate which sensors are connected and what temperature they are detecting. Also, the installer will be able to manually check the functioning of all consumers to ensure that they are properly wired. In addition, installers are asked some more questions that pop up on screen. These are the questions that concern the installation and setting of the demanding parameters. The installer does not need additional written instructions to perform the installation. All instructions are stored in memory in several languages. The language of communication may change during installation.

In order to make the use of the controller as simple as possible for the average user, the first level of questions on the screen are those matters that the user most needs. In the second level, those who are less often in need. In the third level, there are matters that the ordinary user does not have access to in order not to jeopardize the quality of regulation. Dangerous issues are protected by a special code.

The controller contains a personal program that does not allow the pumps to stand idle for a long time. This ensures maximum life of the circulation pumps. The position of the control valve is measured using a sensor integrated into the valve actuator. This ensures precise control of the position of the control valve. The calorimeter function integrated into the controller does not require any additional interference with the system. The solution is derived programmatically on the basis of a calculation whose parameters are certain temperatures and flow.